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North Star QRA Update Chlorine and VCM plant (Rafnes)

Report for: Wood

Report no: PRJ11090011 Rev: Final Date: 11 January 2019

Document history

Revision Date Description/changes Changes made by

Draft 30.11.2018 First issue of report Andrea Risan / Ingebjørg Valkvæ / Stian Jensen

Final 11.01.2019 Comments from client Andrea Risan / Ingebjørg Valkvæ incorporated

Executive summary

Lloyds Register (LR) has been engaged by Wood and INOVYN Norge to conduct an update of the quantitative risk assessment (QRA) of the Chlorine and VCM plant at the Rafnes Industrial Site (Grenland, Norway) to accommodate any changes in the risk picture due to the North Star project. The North Star project includes implementation of several modifications to the facility which will increase the total production capacity with around 10 %.

The QRA update is conducted by using the existing risk model of the facility and adding the events potentially caused by the planned modifications. A similar approach as applied in the existing QRA is applied in the risk assessment of the North Star modifications. In that manner the risk level before and after the modification can be compared. The risk acceptance criteria proposed by DSB are applied in the study. Hence, the focus in the study is directed towards major accident events that may cause fatal exposure outside of the boundary of the facility.

The main conclusion of the study is that the North Star project only contributes with a modest risk increase to third parties, and that the main risk drivers remain unchanged after the update. It is still toxic releases of chlorine and HCl that dominates the risk picture, in addition to BLEVE events in the VCM storage area. The calculated risk picture is shown in the below figure.

Report no: PRJ11090011 Rev: Final Page ii Date: 11 January 2019 ©Lloyd’s Register 2019

Glossary/abbreviations

ALARP As Low As Reasonably Practicable

AT The Norwegian Labour Inspection Authority (Arbeidstilsynet). A governmental agency under the Ministry of Labour, focused on occupational safety and health

BLEVE Boiling Liquid Expanding Vapour Explosion

CFD Computational Fluid Dynamics

DSB Norwegian Directorate for civil protection (Direktoratet for Samfunnssikkerhet og Beredskap)

EDC Ethylene DiChloride, 1,2-dichloroethane

ESD Emergency Shut Down

EX Ex-equipment or explosive protected equipment, both electric and mechanical.

FTM Forslag Til Modifikasjoner

Hazardous substances Flammable, reactive, pressurised and explosive substances

HAZID Hazard Identification

Report no: PRJ11090011 Rev: Final Page iii Date: 11 January 2019 ©Lloyd’s Register 2019 HCl Hydrogen Chloride

HTDC High Temperature Direct Chlorination

IR Individual Risk

LFL Lower Flammability Limit

LNF Landbruk-, Natur- og Friluftsområde

LOC Loss Of Containment

OHCL Oxy HydroChlorination

PSD Process Shut Down

QRA Quantitative Risk Analysis

RAC Risk Acceptance Criteria

Safeti Safeti QRA software tool - A user-friendly, industry standard method for carrying out Quantitative Risk Assessments (QRA) of onshore process, chemical and petrochemical facilities. Developed by DNV-GL.

Third party (3rd person) People outside the production plant that may be affected by its activities.

(2nd person: People that are not directly related to the operation of the plant, but benefit from being close to the plant

1st person: People who are directly involved in the operations of the plant, i.e. the employees at the plant)

VCM Vinyl Chloride Monomer

Report no: PRJ11090011 Rev: Final Page iv Date: 11 January 2019 ©Lloyd’s Register 2019 Table of contents Page

1 Introduction 1 1.1 Background 1 1.2 Objective 1 1.3 Scope of work 1 1.4 Presumptions and limitations 1 1.4.1 Presumptions 1 1.4.2 Limitations 1 1.5 Regulations and standards 2 2 Framework 2 2.1 Methodology 2 2.2 Assumptions and input data 4 2.3 Acceptance criteria 4 3 System description 5 3.1 General description 5 3.2 Process description 5 3.2.1 Chlorine – INOVYN scope 5 3.2.2 VCM – Wood scope 6 3.3 North Star project 7 3.3.1 VCM plant modifications 7 3.3.2 Safety measures for the new HTDC module 8 3.3.3 Water curtain in the HTDC module 8 3.3.4 Chlorine plant modifications 9 3.4 Safety measures 9 3.4.1 Pressure monitoring and shutdown 9 3.4.2 Chlorine absorption system 9 3.4.3 Gas detection and emergency shutdown 9 3.4.4 Fire proofing of storage spheres 9 3.4.5 Emergency preparedness 9 4 Selection of hazardous events 9 4.1 Existing QRA 9 4.2 Scenarios for the new HTDC module 11 4.3 Scenarios for the new OHCL reactor 12 4.4 Risk screening of other North Star modifications 12 5 Frequency analysis 14 6 Consequence analysis 15 6.1 Event tree 15 6.2 Fatality criteria 16 6.3 Consequence modelling 16 7 Risk picture and risk evaluation 18 7.1 Total risk picture 18

Report no: PRJ11090011 Rev: Final Page v Date: 11 January 2019 ©Lloyd’s Register 2019 7.2 Risk from the chlorine plant 19 7.3 Risk from the VCM plant 21 7.4 Individual risk at nearest resident 24 8 Uncertainties 26 9 Potential conservatism in the QRA 26 9.1 Release durations and transient effects 26 9.2 Terrain effects 27 9.3 Release modelling 27 9.4 Event frequencies 27 9.5 BLEVE 27 9.6 Flash fire envelope 27 10 Conclusion and recommendations 28 10.1 Recommendations 28 10.2 Conclusions 28 11 References 29

Appendix A – Assumptions and input data Appendix B – Risk screening workshop – VCM plants Appendix C – Risk screening workshop – Chlorine plant

Report no: PRJ11090011 Rev: Final Page vi Date: 11 January 2019 ©Lloyd’s Register 2019 1 Introduction

1.1 Background Lloyd’s Register (LR) has been engaged by Wood and INOVYN Norge to carry out an update of the quantitative risk assessment (QRA) for INOVYN’ s Chlorine and Vinyl Chloride Monomer (VCM) plant at the Rafnes Industrial Site (Rafnes) conducted in 2015 (Ref. /1/). The North Star project introduces several modifications to the Chlorine and VCM plant in order to increase the production capacity of the plant. The modifications include: • Installation of a new High Temperature Direct Chlorination (HTDC) module • Replacing the existing Oxy HydroChlorination (OHCL) reactor with a new one • Several other modifications to process vessels and equipment in the VCM plant to allow for the increased capacity • Installation of a new electrolyser in the chlorine plant • Replacement of the hydrogen compressor, chlorine compressor and chlorine cooler. INOVYN Norge is classified as a so called major accident facility according to “Storulykkeforskriften” (Ref. /9/). Hence, the facility is required by regulations to minimize the risk for major accidents. The QRA can be seen as part of the effort to reach this objective.

1.2 Objective The objective of the QRA update is to investigate the impact of the North Star project on the existing risk picture at INOVYN’s facility at Rafnes. The modifications will be assessed and included in the existing QRA of the facility. Potential risk drivers will be identified, and it will be evaluated if the project introduces significant change in the risk for third parties. The proposed risk acceptance criteria by DSB (Ref. /2/) are applied in the risk assessment.

1.3 Scope of work The scope of work involves using the risk model developed in the existing QRA of INOVYN’s facility at Rafnes as a starting point. The risk model is implemented using the Safeti software. Events introduced by the North Star project will be handled in a similar manner as in the existing QRA by using, e.g., the same event frequency references, fatality criteria and overall assumptions as a basis. The focus in the QRA is to address major accidental events that may influence the extent of risk zones (“hensynssoner” in Norwegian) around the facility.

1.4 Presumptions and limitations 1.4.1 Presumptions The following presumptions apply to the study: 1. Normal operation including regular shut down and maintenance and start up activities are the base of the QRA. 2. If risk reducing measures are disengaged during operation, it is a prerequisite that compensating measures are implemented so that the barrier’s function is kept. If compensating measures are not taken, the QRA is not valid. 1.4.2 Limitations The following limitations apply to the study: 1. Events while ship is at sea or mooring are not included 2. The ships on-board systems (tanks, pumps, piping) are not included

Report no: PRJ11090011 Rev: Final Page 1 Date: 11 January 2019 ©Lloyd’s Register 2019 3. The tunnel with export pipelines to Herøya is not included. A separate risk assessment for the tunnel has been conducted, Ref. /3/ 4. Escalation effects have not been quantified. An escalation is defined as an initial event on the site, e.g. a fire that impairs other equipment containing flammable or toxic material on the same site. Thereby leading to a larger fire or more severe toxic effects. One exception is the inclusion of Boiling Liquid Expanding Vapour Explosion (BLEVE) events in the QRA. A BLEVE can be considered as an escalated event, since a prerequisite for such a scenario to occur is long exposure time to relatively high heat loads, i.e. fire exposure. 5. Domino effects, e.g. events where fire and explosion triggers new release scenarios (or other effects) from equipment in adjacent facilities, have not been calculated specifically. Domino effects are discussed in the risk analysis from 1991 and 1998 (Ref. /4/ and /5/) and in the report "Vurdering av dominoeffekter mellom fabrikkanleggene på Borealis AS, Noretyl AS og Hydro Polymers AS i forbindelse oppdatering av Sikkerhetsrapporten for Hydro Polymers og Noretyl", Ref. /6/.

1.5 Regulations and standards The most central regulations related to health, safety and the environment (HSE) for the onshore chemical process industry which come under the supervisory authority of the DSB and AT are found in the HSE regulations and the working environment regulations. The following relevant regulations apply for INOVYN Norge and set the premise for the current risk assessment: • DSB: "Forskrift om håndtering av brannfarlig, reaksjonsfarlig og trykksatt stoff samt utstyr og anlegg som benyttes ved håndteringen (forskrift om håndtering av farlig stoff) ", FOR-2009-06-08- 602, 8. juni 2009, Ref. /7/. • DSB Temaveileder ”Sikkerheten rundt anlegg som håndterer brannfarlige, reaksjonsfarlige, trykksatte og eksplosjonsfarlige stoffer: Kriterier for akseptabel risiko”, May 2013, Ref. /8/. • Storulykkeforskriften FOR-2005-06-17-672, Council Directive 96/82/EC of 9 December 1996 on the control of major-accident hazards involving dangerous substances, Ref. /9/. Also note, that since the QRA was established, DSB has introduced a new guideline for conducting QRAs, i.e. “Retningslinjer for kvantitative risikovurderinger for anlegg som håndterer farlig stoff” (Ref. /10/). Those new guidelines are not adopted at the present stage.

2 Framework

2.1 Methodology The overall methodology used in the QRA is illustrated in Figure 2.1.

Report no: PRJ11090011 Rev: Final Page 2 Date: 11 January 2019 ©Lloyd’s Register 2019

Figure 2.1 - QRA methodology

The building blocks of the study are briefly discussed below. 1. Risk acceptance criteria The acceptance criteria are used to evaluate the risk and aid in decisions regarding need for risk reducing measures. The acceptance criteria applicable for this project are presented in Chapter 2.3. 2. System definition A presentation of the system included in the scope of the QRA and its limitations are presented in Chapter 3. 3. Hazard identification A hazard identification (HAZID) workshop was performed at Rafnes during the previous QRA update in 2015 and was used to define relevant scenarios for the QRA. A risk screening workshop identifying the possible hazards related to the modifications of the North Star project was performed at Rafnes in October 2018. The results from the risk screening workshop are summarized in Chapter 4 and documented in Appendix B and C. 4. Frequency analysis The frequency analysis is performed to select and define a set of scenarios that represent the risk posed by the Chlorine and VCM plant. The frequency analysis is described in Chapter 5. 5. Consequence analysis The possible consequences from each scenario from the frequency analysis are simulated using the software Safeti. The consequence analysis is described in Chapter 6. 6. QRA results – Risk picture and risk evaluation The risk picture is the result of the frequency analysis and the consequence analysis. The resulting risk picture for the Chlorine and VCM plant is presented in Chapter 7. The risk is evaluated by comparing the resulting risk picture with the applied RAC. 7. Risk-reducing measures Risk-reducing measures are recommended in order to meet the acceptance criteria or to further reduce the risk in line with ALARP. Recommendations are given in Chapter 10.

Report no: PRJ11090011 Rev: Final Page 3 Date: 11 January 2019 ©Lloyd’s Register 2019 2.2 Assumptions and input data All assumptions made in the study are presented in the assumption sheets in Appendix A together with any data used for the study including wind data, population data and vulnerabilities.

2.3 Acceptance criteria This study applies the Risk Acceptance Criteria (RAC) proposed by Norwegian authority DSB (Ref. /8/) in their guidance document regarding RAC for facilities storing and handling hazardous substances. The RAC are based on the individual risk contours calculated for the facility, and defines a number of zones for special consideration. The RAC are presented in Table 2-1 and Figure 2.2. Table 2-1 - Acceptance criteria, defined zones for consideration Zone for Acceptance criteria Provisions for the zone (accepted consideration object and activities in the zone) Inner zone IR is higher than 1E-5 per Primarily within the facility’s property year limits, extension into LNF-areas may be allowed. Intermediate zone IR is in between 1E-5 and Public roads, railway, quays are accepted 1E-6 per year and also industries and offices. No permanent housing is permitted, though some scattered housing may be permissible under certain circumstances Outer zone IR is in between 1E-6 and Housing, public facilities, shops, smaller 1E-7 per year overnight accommodations and other usage for the general public accepted Outside outer zone IR is lower than 1E-7 per Schools, hospitals, shopping centres, year hotels, large venues etc. should be outside the outer zone

Figure 2.2 - Illustration of safety zones around a plant with marked iso-contours that defines the zones (Ref. /8/)

Report no: PRJ11090011 Rev: Final Page 4 Date: 11 January 2019 ©Lloyd’s Register 2019 3 System description

3.1 General description The INOVYN Norge production plant for vinyl chloride monomer, VCM, is located at Rafnes industry facility in Bamble community in Norway. Figure 3.1 show an overview of the Rafnes industrial site and the surrounding areas of the Chlorine and VCM plants. The closest residential area, Herre, is located west of the chlorine plant. The closest house is approximately 400 m from the fence around the chlorine plant. Highway 353 marks the property boundary towards west. The road is at a higher elevation than the plant and there is also a ridge between the plant and the road. There is also a smaller road that goes alongside the plant fence before it connects to the highway again. This road is public, but can be blocked in case of an emergency.

Figure 3.1 – Overview of the Chlorine/VCM plant and the surrounding areas Located southeast on the Rafnes industrial site and neighbouring the VCM plant is Noretyl AS ethylene plant. A polyethylene plant owned by INOVYN Bamble AS lies further to the southeast, at the Rønningen industrial site (not shown in Figure 3.1). This report presents the risk introduced from the North Star project associated with the Chlorine and VCM plant.

3.2 Process description 3.2.1 Chlorine – INOVYN scope There are two almost identical production lines (Chlorine 1 and 2) with membrane electrolysers for production of chlorine. Chlorine is produced on the anode side and hydrogen and caustic soda on cathode side. The moist chlorine gas is cooled, filtered and dried with sulphuric acid before being compressed to approx. 5.5 bar(g) and sent to the VCM plant. The chlorine gas from both line 1 and 2 is delivered in a single 250 mm header.

Report no: PRJ11090011 Rev: Final Page 5 Date: 11 January 2019 ©Lloyd’s Register 2019 The hydrogen gas is cooled, filtered, dried and compressed and sent to the VCM plant and to the neighbouring industry Noretyl to be used as raw material or fuel gas. The caustic soda is concentrated to 50 % using evaporation and then stored. The caustic soda is exported by trucks and shipped by boats to several customers. The chlorine plant is divided into the following areas: • Water purification • Brine • Cell room • Caustic soda • Hydrogen • Lean brine dechlorination • Emergency scrubber/recovery chlorine • Chlorine.

3.2.2 VCM – Wood scope VCM is produced from the intermediate substance Ethylene DiChloride (EDC). EDC is produced in two separate processes in the VCM plant. The first process is by direct chlorination, using ethylene gas from Noretyl and chlorine gas from the chlorine plant. The second is by oxychlorination, using hydrogen chloride, hydrogen gas, ethylene gas and air. The EDC from the direct chlorination and oxychlorination is purified (distilled to remove light and heavy bi products) and intermediately stored before being sent to the cracking furnaces. VCM is produced by cracking EDC to VCM and Hydrogen Chloride (HCl) at a temperature of approx. 500 °C and 20 bar(g) pressure. The gas out of the cracking furnaces still holds a large amount of EDC and a number of steps are needed to separate VCM, HCl and EDC from the raw gas. The EDC is condensed by cooling and HCl stripped off by reducing the pressure. Finally a distillation process removes the last traces of HCl and EDC and by-products from VCM. The pure VCM is stored as liquid in pressurized spherical tanks before being offloaded by ship or pumped through piping under the Frierfjord to INOVYN Norge PVC plant at Herøya. Utility systems include steam and condensate system, cooling water system, waste water treatment, incinerators for vented gases and fuel gas system. The VCM plant is divided into process area, tank farm, control centre, flare and quay. Production, as well as sewage treatment and combustion of bi-products, takes place in the process area. The process area is further divided into a number of plant areas as listed below: • 1100 - Oxychlorination • 1200 - EDC-recovery • 1300 - EDC purification • 1400 - Cracking • 1500 - VCM-purification • 1600 - Direct chlorination • 1700 - HCl-unit • 1800-1900 - Waste water treatment • 1800 - Incinerator • 2700 - EDC/VCM/by-product storage • 3000 - Jetty 2.

Report no: PRJ11090011 Rev: Final Page 6 Date: 11 January 2019 ©Lloyd’s Register 2019 3.3 North Star project The North Star project introduces several modifications to increase the capacity of the Chlorine and VCM plant. The modifications are designed to increase the overall production rate of the plant with around 10 %.

3.3.1 VCM plant modifications The main modifications to the VCM plant are installation of a new HTDC module and an OHCL reactor: • The HTDC module is a new module at INOVYN and will operate in parallel to the existing LTDC module. It is expected to have a footprint of approximately 28 m x 8 m with three levels. The module is relatively congested with process equipment and reactors. A process flow diagram of the new HTDC module located in the VCM plant is shown in Figure 3.2 • The OHCL reactor will replace an existing reactor. The flow throughput and the volume of the reactor will be increased. The existing reactor will be put out of operation and work as a spare reactor. In addition, several minor modifications, or FTMs (“Forslag Til Modifikasjoner”), will be made to allow for the increased production capacity. Details of the scope of these modifications can be found in Appendix B. Figure 3-3 illustrates the locations of the North Star modifications in the VCM plant.

Figure 3.2 – Process flow diagram (PFD) of HTDC module

Report no: PRJ11090011 Rev: Final Page 7 Date: 11 January 2019 ©Lloyd’s Register 2019

Figure 3-3 – VCM plant – Location of FTMs. The yellow box (left) is the location of the new HTDC module, and the orange box (right) is the location of the OHCl reactor

3.3.2 Safety measures for the new HTDC module The North Star modifications include installation of gas detection systems in the new HTDC module. The following gas detection systems will be installed: • EX detectors for explosive gas detection • Chlorine gas detectors (point detectors) • Sniffing detectors for detection of toxic gas releases (low concentrations). Further, there will be replacement of the existing flame arrestor and fire water monitor for the HTDC module. Fire water monitor X1032/12 shall be replaced by a new remotely controlled fire water monitor (X1032/16). Fire water monitor X1032/10 will be moved to ensure better coverage of the HTDC area in addition to the originally covered process areas. 3.3.3 Water curtain in the HTDC module There is a discussion in the North Star project regarding the possible implementation of a water curtain between the HTDC module and the vessels in area 1600. The main purpose of such a water curtain would be to reduce the likelihood of escalation from an accidental event in the HTDC module to the wash tanks in area 1600. In general, water curtains are used to protect personnel from high heat radiation levels during, e.g. escape or other special events such as an ignited flare during a blow down situation. For protection of vessel containing hazardous substances, it is probably more optimal to apply a deluge system. Fire water can then be applied over the tanks to enhance the cooling effect. The HTDC module is already covered be two remotely controlled fire monitors. One of which has a direct line of sight to the abovementioned vessels. This is likely to be sufficient. However, to further quantify the benefit of a deluge system, in addition to fire monitor, one could establish: • The consequence of vessel ruptures. • The probability, or frequency, of fires that may lead to loss of containment of hazardous substances in the 1600 area.

Report no: PRJ11090011 Rev: Final Page 8 Date: 11 January 2019 ©Lloyd’s Register 2019 If INOVYN has a criteria for an unacceptable escalation this can be applied in the decision making, when the consequence and likelihood of vessel rupture (escalation) has been established. If the consequence of a vessel rupture is low, i.e., if it does not significantly increase the severity of the event, a deluge system is unlikely to be in the ALARP range of measures. A similar argument can be made if the frequency of fires that may cause an escalation is low. The above discussion assumes that there is no BLEVE potential in area 1600. The matter should be assessed in more detail if that is not the case. 3.3.4 Chlorine plant modifications The modifications to the chlorine plant are: • Installation of a new electrolyser • Increased capacity of the chlorine compressor, hydrogen compressor and chlorine cooler. Details of the scope of these modifications can be found in Appendix C.

3.4 Safety measures 3.4.1 Pressure monitoring and shutdown The pressure is monitored in the chlorine header and many other places in the process. Detected very low pressures, e.g. in case of a larger leak, lead to automatic shutdown. 3.4.2 Chlorine absorption system In an event of leak or failure in the chlorine plant the production in the cells are stopped and the emergency absorption system is started. The chlorine gas is absorbed in sodium chloride, producing sodium hypochlorite. A low pressure is created with ejectors and the produced chlorine gas is sucked through the absorption system. 3.4.3 Gas detection and emergency shutdown Chlorine gas detectors are located both indoors in the chlorine plant and outdoors in the chlorine and VCM plant. There is no automatic shutdown but an operator will directly suit up in gas protection gear and look for the leak. There is also VCM gas detectors located in the process area and around pumps in the storage area. The detectors are very sensitive and detect at ppm level. No automatic shutdown and procedures are the same as for chlorine. 3.4.4 Fire proofing of storage spheres The VCM storage spheres are fitted with fire detection and deluge in order to minimize risk of escalation and possible BLEVE event in the storage area. 3.4.5 Emergency preparedness At Rafnes and Rønningen there is a common emergency preparedness plan and organisation. Norward is a company providing services within industrial emergency preparedness and they are localized in the fire station at Rafnes. They provide their services to the plants on Rafnes and Rønningen.

4 Selection of hazardous events

This section selects the units or process segments that may cause hazardous events that can influence the risk picture around the facility.

4.1 Existing QRA The events included in the present study are based on evaluations made in the previous QRA update in 2015, Ref. /1/. The general assumptions regarding each subsystem are presented in Table 4.1.

Report no: PRJ11090011 Rev: Final Page 9 Date: 11 January 2019 ©Lloyd’s Register 2019 Table 4.1 – General assumptions regarding scenario selection, ref. /1/ Part of plant Scenarios included in General assumption the QRA Chlorine plant Water purification No scenarios No (or limited) hazardous substances Brine No scenarios No (or limited) hazardous substances

Cell room Cl2 header in the cell Leaks from individual cells and anolyte/ room is considered catolyte solutions are not considered to pose a threat outside the cell room

Leak of H2 is assumed to give fire in the cell room with only local effects. Domino effects

towards Cl2 system is considered negligible Caustic soda No scenarios Leaks of NaOH solution is assumed to give only local effects

Hydrogen H2 header to VCM is Leaks of H2 from compressors etc. are considered assumed to give only local effects.

Domino effects towards Cl2 system is considered negligible

Lean brine No scenarios Small amounts of Cl2, low pressures vacuum- dechlorination 0.2 bar(g) and leaks are assumed to give only local effects. Leaks of anolyte solution is assumed to give only local effects Emergency If pumps P3704, P3706 Pumps are connected to emergency power. scrubber/recovery stops while production Small amounts of Cl2, low pressures vacuum- chlorine trips 0.2 bar(g) and leaks are assumed to give only local effects

Chlorine All leak points of Cl2 Leak of H2SO4 is assumed to give only local gas are considered effects.

No liquid Cl2 at any point assumed VCM plant

1100 Leaks of C2H4 is Leak of EDC (C2H4Cl2) is assumed to give only oxychlorination considered local effects and no scenarios for EDC (incl. Leaks of HCl is reactor V1101/V1106 (OHCL)) are included in considered the calculations

Leaks of H2 is considered

NH3-tank considered 1200 EDC-recovery No scenarios Leak of EDC and by-products are assumed to give only local effects 1300 EDC No scenarios Leak of EDC and by-products are assumed to purification give only local effects

Report no: PRJ11090011 Rev: Final Page 10 Date: 11 January 2019 ©Lloyd’s Register 2019 Part of plant Scenarios included in General assumption the QRA 1400 cracking Fuel gas considered Release from crackers will be above auto No scenarios for ignition and a jet flame with local effects is EDC/VCM/HCl assumed for all releases. according to comments Gaseous release from top system with HCl, VCM and EDC assumed to only give local effects. EDC is the main component in bottom system and refluxes and the same consequences as 100 % EDC (only local effects) are assumed 1500 VCM- All liquid leaks Leaks of EDC are assumed to only give local purification considered (except for effects. liquid in C1502 and Gaseous releases of HCl/VCM/EDC mixtures EDC return) are assumed to give only local effects Gaseous releases of pure HCl are considered

1600 direct Leaks of C2H4 is Leaks of EDC are assumed to only give local chlorination considered effects and no scenarios for EDC (incl. reactors V1601A/B (LTDC) and V1651 Leaks of Cl2 is considered (HTDC)) are included in the calculations 1700 HCl-unit Fuel gas considered Leaks of chlorinated waste, fuel gas, HCl and NaOH solutions are assumed to give only local effects 1800-1900 waste No scenarios No (or limited) hazardous substances water treatment 1800 incinerator Fuel gas considered Pressure in vents etc. is assumed to be ~ atmospheric and leaks are assumed to give only local effects 2700 EDC/VCM/by- VCM storage Leak of EDC and by-products are assumed to product storage considered (liquid give only local effects releases) 3000 Jetty 2 Loading/unloading of The total annual time of operation for VCM VCM considered (liquid loading arms are 115 hour per year releases)

4.2 Scenarios for the new HTDC module All streams downstream the HTDC reactor consists of mainly EDC and some nitrogen. As stated in Table 4.1, leaks of EDC in area 1600 (Direct chlorination) are assumed to only give local effects and no scenarios for EDC are included in the risk evaluation. Neither is Nitrogen a hazardous substance in the context of the QRA. Hence, only leak from the feed lines of ethylene and chlorine, upstream the HTDC reactor (including process tie-ins), are evaluated as additional hazardous events in the update of the risk analysis for the VCM plant.

Report no: PRJ11090011 Rev: Final Page 11 Date: 11 January 2019 ©Lloyd’s Register 2019 4.3 Scenarios for the new OHCL reactor The existing OHCL reactor (V1101) will be replaced by a new reactor (V1106) to allow for increased capacity. As stated in Table 4.1, leaks of EDC in area 1100 (Oxychlorination) are assumed to only give local effects and no scenarios for EDC, including the OHCL reactor V1101/V1106, are included in the calculations. Hence, replacement of the reactor itself does not cause any additional hazardous events. The ethylene and chlorine streams towards the existing OHCL reactor are already included in the risk model, however, process tie-ins to the new reactor will create additional leak potential and are therefore also evaluated in the update of the risk analysis for the VCM plant.

4.4 Risk screening of other North Star modifications A risk screening workshop was held at Rafnes to evaluate the potential risk contribution of each FTM in the context of the QRA. Representatives from Wood, INOVYN and LR were present at the workshop. In addition, two representatives from Bilfinger participated in the site walk through of the chlorine plant. The workshop participants are listed in Table 4.2. Table 4.2 – Participant list for the risk screening workshop Name Company Kjetil Kristoffersen Wood Roger M. Pettersen INOVYN Øystein Palmgren INOVYN Stian Jensen LR Andrea Risan LR Ingebjørg Valkvæ LR

Table 4.3 summarises the FTMs and their relevance to the QRA. A detailed evaluation of the FTMs and their risk contributions is documented in Appendix B and C. Table 4.3 – Summary of risk evaluation of FTMs for the Chlorine and VCM plant FTM Area Scope description Medium Inclusion in No. QRA? VCM plant

FTM 01 1100 Replacement of line 400-RP 1069 to EDC gas No DN500 FTM 02 1100 V1105 modifications HCl gas Yes FTM 03 1100 H1104 replacement HCl gas, Yes condensate and steam FTM 04 1100 Increase oxygen feed to OHCL with Condensate, No new heat exchanger H1151 steam, N2, enriched air and LOX FTM 05 1100 OHCL reactor cooling loop Boiler feed No water FTM 06 1000, 51 New IPS line to Chlorine plant Steam No FTM 07 1300 P1305A/B/S replacement EDC gas No

Report no: PRJ11090011 Rev: Final Page 12 Date: 11 January 2019 ©Lloyd’s Register 2019 FTM Area Scope description Medium Inclusion in No. QRA?

FTM 08 Several Replacement of several control Fuel gas, No valves NaOH, Ethylene, Crude EDC liquid, EDC liquid, EDC/VCM/HCl condensate, VCM liquid

FTM 09 1100 V1102 Modification of demister Steam No FTM 11 1400 Replacement of RP4015, RP4057 EDC gas, No and RP4124 VCM, HCl FTM 12 1400 New P1404S EDC liquid No

FTM 13 1400 New H1405C and new V1407 (new EDC/VCM/HCl No balcony on str. 6) condensate and cooling water

FTM 14 1400 Replacement of H1403 EDC/VCM/HCl No gas FTM 16 2700 Replacement of RP5081 EDC liquid No

FTM 17 1500 Replacement of valves on C1501 EDC/VCM No liquid, EDC/VCM gas, steam, condensate

FTM 18 1500 DBB on C1502 EDC/VCM gas Yes and liquid

FTM 19 1500 New H1541 with access platform EDC/VCM 2- Yes phase

FTM 20 1500 Replacement of H1551 and increase EDC, EDC No diameter on RP5056 and RP5190 liquid FTM 21 1500 Install by-pass of H1512 EDC liquid No

FTM 22 1500 Replacement of H1510 Cooling Yes water, VCM liquid

FTM 23 2700 Existing FTM (M50913-06) EDC No Replacement of P2752 FTM 29 2700,1300 New impeller P1507 EDC No FTM 31 Utility tie-ins Various Yes FTM 32 Process tie-ins Various Yes FTM 33 1800 Vent gas scrubber ANH Nitrogen No FTM 34 1650 Analyser house modifications N/A No

FTM 35 Underground piping H2O No

Report no: PRJ11090011 Rev: Final Page 13 Date: 11 January 2019 ©Lloyd’s Register 2019 FTM Area Scope description Medium Inclusion in No. QRA? FTM 36 1600 Pipe rack HTDC bridge N/A No FTM 37 Fire and gas N/A Yes FTM 38 1600,1800 New flame arrestor for HTDC Nitrogen, No oxygen, ethylene

FTM 39 Fire water New fire water monitor H2O Yes system

FTM 40 1100 Tie-in of new OHCL reactor and HCl, C2H4, Yes required modifications due to EDC, Air preservation of existing reactor FTM 41 New HPN vessel for emergency Nitrogen No purging Chlorine plant

FTM 262 Cell room Installation of new electrolyser Brine, H2, Cl2, Yes NaOH

FTM 361 Chlorine Increased capacity on chlorine cooler Cl2 gas Yes

FTM 366 Chlorine Increased capacity on chlorine Cl2 gas Yes compressor

FTM 421 Hydrogen Increased capacity on hydrogen H2 Yes compressor

5 Frequency analysis

Three leak scenarios (small leak, major leak and rupture) are typically defined for each segment, vessel, specific equipment and transport pipe. Table 5.1 below presents the method to calculate leak frequencies and representative equipment hole sizes for the different parts of the plant. Note that calculated leak frequencies are presented in Appendix A. The different areas where the selected hazardous events are located are presented in Figure 5.1. Table 5.1 – Method for calculating leak frequencies Part of plant Method Reference Chlorine plant – Leak frequencies and representative hole sizes ULF (Ref. /11/) process are calculated using the LRC spreadsheet tool Offshore QRA – segments ULF (Utregning av Lekkasje Frekvenser). Standardised The frequencies are based on Offshore statistics Hydrocarbon Leak Frequencies (Ref. /12/) Chlorine plant – The scenarios and frequencies are calculated HES-HB-002 (Ref. /13/) Vessels and using the Hydro Handbook specific equipment VCM plant – Leak frequencies and representative hole sizes ULF (Ref. /11/) process are calculated using the LRC spreadsheet tool Offshore QRA – segments ULF (Utregning av Lekkasje Frekvenser). Standardised The frequencies are based on Offshore statistics Hydrocarbon Leak Frequencies (Ref. /12/)

Report no: PRJ11090011 Rev: Final Page 14 Date: 11 January 2019 ©Lloyd’s Register 2019 Part of plant Method Reference VCM plant - The scenarios and frequencies are calculated HES-HB-002 (Ref. /13/) Vessels and using the Hydro Handbook. specific Loading arm frequencies are adjusted for equipment estimated annual time of operation Transport piping The scenarios and frequencies are calculated HES-HB-002 (Ref. /13/) using the Hydro Handbook

Figure 5.1 – Illustration of location of hazardous events in QRA

6 Consequence analysis

Consequence modelling and risk calculations are performed using the software Safeti 8.11.

6.1 Event tree The event tree in Figure 6.1 illustrates the different outcomes a release of a hazardous substance may lead to. The outcome is a set of end events such as, e.g., fireball, jet fire or dispersion of toxic gases. Parameters and assumptions for the probability for each branch in the event tree are documented in Appendix A. A BLEVE is an escalated event caused by an initial jet- or pool fire. If a pressurized vessel with liquefied gas is exposed to heat radiation it can lead to a BLEVE event with consequence of both a large fireball and explosion pressure from the expanding vapour. A BLEVE event may occur in the storage area for VCM if the deluge system fails on demand and no other cooling is applied during a severe fire in the area.

Report no: PRJ11090011 Rev: Final Page 15 Date: 11 January 2019 ©Lloyd’s Register 2019 For INOVYN’s facility, the dimensioning events for the risk zones (cf. Figure 2.2) are dispersion of toxic gases (such as chlorine, ammonia and HCl) and fire exposure of VCM storage tanks leading to a BLEVE. This is further detailed in the subsequent section.

Figure 6.1 – Event tree

6.2 Fatality criteria The TNO probit functions are used as fatality criteria. These are inherent in the Safeti software. The process involves several toxic chemicals, where the most severe are listed in Table 6.1. The table offers acute exposure guideline levels (AEGL) for life threatening health effects or death, as proposed by US EPA (https://www.epa.gov/aegl). It can be seen that fairly low concentrations may cause fatal consequences. Table 6.1 – AEGL for airborne chemicals used in INOVYN’s process at Rafnes Chemical AEGL 3 (10 min AEGL 3 (30 min AEGL 3 (60 min exposure limit) [ppm] exposure limit) [ppm] exposure limit) [ppm]

Chlorine (Cl2) 50 28 20 Hydrogen 620 210 100 chloride (HCl)

Ammonia (NH3) 2700 1600 1100

6.3 Consequence modelling Consequences for the outcomes in the event tree are calculated with Safeti. Two examples of consequence computations are given below. The first example addresses a toxic release event and the second example is a consequence computation of a BLEVE event. Figure 6.2 shows downwind distances to different levels of toxic lethality given a rupture of the piping/process equipment on the high pressure side of chlorine compressor #1 for wind conditions 2 m/s wind and Pasquille stability class F. The chlorine gas cloud with concentration corresponding to a toxic lethality of 1 extends approximately 180 m downwind of the rupture location. A toxic lethality of 0.001 may occur up to 1.2 km downwind of the rupture.

Report no: PRJ11090011 Rev: Final Page 16 Date: 11 January 2019 ©Lloyd’s Register 2019 Figure 6.3 shows ellipses of lethality levels for a BLEVE event in the VCM storage area for wind conditions 2 m/s wind and Pasquille stability class F. Note that the consequence of BLEVE event is not sensitive to the wind speed. A lethality of 1 (100 % probability of fatality) occurs in a circle around the BLEVE event with a radius of approximately 400 m. The lethality is reduced to 0.01 in a circle with a radius of approximately 1.1 km.

Figure 6.2 – Toxic lethality footprint for a rupture of the piping/process equipment on the high pressure side of chlorine compressor 1 for wind conditions 2 m/s wind and Pasquille stability class F

Figure 6.3 – Lethality ellipses for a BLEVE fireball event in the VCM storage area for wind conditions 2 m/s wind and Pasquille stability class F

Report no: PRJ11090011 Rev: Final Page 17 Date: 11 January 2019 ©Lloyd’s Register 2019 7 Risk picture and risk evaluation

The results from the QRA are presented as Location Specific Individual Risk (LSIR) contours, or simply risk contours, which allow comparison with the risk zones stipulated by DSB in "Tema 13" (Ref. /8/) as shown in Section 2.3. The definition of LSIR is expressed as the frequency at which an individual may be expected to sustain a given level of harm from the realization of specific hazards. It is usually taken to be the risk of fatality, and normally expressed as risk per year. Individual risk is the risk experienced by a single individual in a given time period and reflects the severity of hazards and the amount of time the individual is exposed. When calculating the risk, it is assumed that an individual is present at a particular location 24 hours per day, and 365 days per year. Vulnerability of humans regarding exposure to toxic releases and from impact of heat loads are used to calculate the lethality from each branch in the event tree. To calculate the individual risk, all the resulting consequences are added for a given point and constitute the combined effect of the frequencies for loss of containment, atmospheric conditions, wind direction, and ignition probability. The resulting risk contours for the facility including the North Star contribution are shown in the subsections below.

7.1 Total risk picture The combined risk contours for the chlorine and VCM plant are shown in Figure 7.1. The black lines represent each contour when the North Star modifications are included. An immediate observation is that the North Star project does not increase the risk for third parties considerably. A few observations can be made when comparing the calculated risk to the RAC: 1. The RAC suggests that only the facility itself should be exposed to a risk of 1E-5 per year, with a possible exception for LNF areas. As seen in the figure, Noretyl’s premises and a part of what is denoted other industry lie within the contour of 1E-05 per year. One could argue that Noretyl and INOVYN is the same company with an integrated production. Then it would probably be acceptable that the 1E-5 per year contour expands into the Noretyl area. It is also noted that a public road is located within the risk contour of 1E-05 per year. DSB’s RAC suggests that public roads should be exposed to a risk below 1E-5 per year 2. Parts of the nearest residential area are located within the contour of 1E-06 per year. Permanent housing should primarily be located in the outer risk zone, but scattered houses may be acceptable under certain circumstances 3. The nearest vulnerable object, a school, is located outside the 1E-07 per year risk contour.

The North Star modifications do not cause any changes to the risk picture with respect to the acceptance criteria.

Report no: PRJ11090011 Rev: Final Page 18 Date: 11 January 2019 ©Lloyd’s Register 2019

Figure 7.1 – Combined risk contours for the VCM and chlorine plant. The black lines represent each contour when the North Star modifications are included. The grey areas in the figure mainly indicate LNF areas

7.2 Risk from the chlorine plant The risk contribution from events in the chlorine plant, including transport piping of chlorine and hydrogen to the VCM plant, is shown in Figure 7.2. The main contributors to the risk from the chlorine plant are leaks from piping/process equipment on the high-pressure side of chlorine compressor 1 and 2 (KLOR1-003 and KLOR2-003). The consequences of these events are larger than for leaks from low-pressure piping/equipment. These segments also have higher leak frequencies than e.g. the chlorine transport pipe to the VCM plant. The contributions from one of the segments are visualized in Figure 7.3. The chlorine plant modifications have been included in the risk model by assuming an overall increased mass flow rate of 10 %. This increase is the cause of the delta risk due to the North Star modifications. However, the delta risk is close to negligible.

Report no: PRJ11090011 Rev: Final Page 19 Date: 11 January 2019 ©Lloyd’s Register 2019

Figure 7.2 – Risk contribution from the chlorine plant

Figure 7.3 – Risk contribution from the segment after the chlorine compressor #1, Klor1-003.

Report no: PRJ11090011 Rev: Final Page 20 Date: 11 January 2019 ©Lloyd’s Register 2019 7.3 Risk from the VCM plant The risk contribution from events in the VCM plant is shown in Figure 7.4. Here, as in the figures above, the black risk contours elucidate the increase in risk due to the North Star project. Again, the North Star contribution is modest. There are several events that contribute to the risk picture of the VCM plant. However, the main contributors to the risk are: • BLEVE in the VCM storage area (the risk contribution is shown in Figure 7.5) • Leaks from the HCl column V1501containing liquid HCl (the risk contribution is shown in Figure 7.6) • Leaks from piping/process equipment with Cl and HCl, e.g.: o The chlorine feed to the LTDC and HTDC modules (1600-Cl-017, 1600-Cl-HTDC). The risk is shown in Figure 7.7. o The HCl feed to C1501 (1500-HCL-011). The risk is shown in Figure 7.8. By comparing the below figures, it can be seen that BLEVE events has the longest reach in terms of exposure of adjacent land areas. As was calculated in the consequence section above (Section 6.3) the analysed BLEVE can cause a fatal exposure up to 1.1 km away from the VCM vessels. Except for BLEVE events, toxic releases dominate the risk picture for the VCM plant. Releases of VCM, ethylene and EDC that ignites and leads to pool-, jet- or flash fires are less critical to the risk for third parties. As an example of events that are not dimensioning for the risk zones, the risk associated with the vessel containing liquid ammonia (NH3), vessel V1012, is shown in Figure 7.9. The main driver of the delta risk is the 10 % increase in overall mass flow rate. The additional feed lines of ethylene and chlorine to the new HTDC module and the additional leak points on existing segments do not contribute significantly to an increase in the overall risk.

Figure 7.4 – Risk contribution from the VCM plant

Report no: PRJ11090011 Rev: Final Page 21 Date: 11 January 2019 ©Lloyd’s Register 2019

Figure 7.5 – Risk contribution from BLEVE events in the VCM storage area

Figure 7.6 – Risk contribution from major releases from the HCl column V1501. Release of liquid HCl

Report no: PRJ11090011 Rev: Final Page 22 Date: 11 January 2019 ©Lloyd’s Register 2019

Figure 7.7 – Risk posed by the chlorine feed to the LTDC and HTDC modules

Figure 7.8 – Risk posed by the HCl feed line to the LTDC and HTDC modules. Release of HCl in liquid phase

Report no: PRJ11090011 Rev: Final Page 23 Date: 11 January 2019 ©Lloyd’s Register 2019

Figure 7.9 – Risk contribution from the liquid ammonia vessel V1012

7.4 Individual risk at nearest resident To further substantiate the discussion above, individual risk due to both the VCM and chlorine plants is measured at two points located at the nearest residential houses as shown in Figure 7.10.

Figure 7.10 – Locations of the nearest residential houses

Report no: PRJ11090011 Rev: Final Page 24 Date: 11 January 2019 ©Lloyd’s Register 2019 The total individual risk at the northernmost of the two locations is 2.88E-06 per year with the North Star project modifications included. The total risk before including the North Star modifications was 2.58E-06. Hence, the North Star modifications cause an increase in the total risk at this point of approximately 12 %. Table 7.1 present the largest contributors to the risk at this point before and after including the North Star modifications. The main risk drivers in this point are the chlorine piping segments. The modifications do not change the main risk drivers. Table 7.1 – Risk contribution at resident location#1 before and after the North Star modifications are included Model name Description Risk Risk contribution contribution before after North North Star Star Chlorine KLOR1-003 Rupture of piping/process equipment on 36 % 35 % RU high-pressure side of chlorine compressor 1 Chlorine KLOR2-003 Rupture of piping/process equipment on 36 % 35 % RU high-pressure side of chlorine compressor 2 Chlorine KLOR1-001 Rupture of piping/process equipment on 6 % 7 % RU chlorine header from cell room 1 Chlorine KLOR1-002 Rupture of piping/process equipment 6 % 6 % RU between chlorine dryer and compressor 1 Chlorine KLOR2-001 Rupture of piping/process equipment on 4 % 4 % RU chlorine header from cell room 2 Chlorine KLOR2-002 Rupture of piping/process equipment 3 % 4 % RU between chlorine dryer and compressor 2

The total individual risk at resident location #2 is 7.09E10-7 per year with the North Star project modifications included. The total risk before including the North Star modifications was 6.87E-07. Hence, the North Star modifications cause an increase in the total risk at this point of approximately 3 %. Table 7.2 present the largest contributors to the risk at nearest resident 2 before and after including the North Star modifications. The main risk driver in this point is a BLEVE event in the VCM storage area. When the mass flow rate in the piping/process equipment segments is increased due to the North Star modifications, the contribution to the total risk from the HCl column (V1501) becomes negligible compared to other segments.

Table 7.2 – Risk contribution at resident location #2 before and after the North Star modifications are included Model name Description Risk Risk contribution contribution before after North North Star Star BLEVE fireball VCM BLEVE in the VCM storage area 70 % 68 % Chlorine KLOR1-003 Rupture of piping/process equipment on 7 % 8 % RU high-pressure side of chlorine compressor 1 Chlorine KLOR2-003 Rupture of piping/process equipment on 7 % 8 % RU high-pressure side of chlorine compressor 2

Report no: PRJ11090011 Rev: Final Page 25 Date: 11 January 2019 ©Lloyd’s Register 2019 Model name Description Risk Risk contribution contribution before after North North Star Star 1500-HCl-011 RU Rupture of HCl feed to C1501 5 % 7 % V1501 RU Rupture of HCl column V1501 4 % ~0 % 1600-Cl-017 RU Rupture of the chlorine feed to the LTDC 2 % 4 % module

8 Uncertainties

When performing a QRA of a complex industry facility, such as the chlorine and VCM plant at Rafnes, a number of uncertainties need to be handled. Three categories of uncertainties are discussed to present the major uncertainties of this study: 1. Uncertainties in parameters and data used as input and modelling assessments, e.g. duration of process leaks. 2. Uncertainties in modelling tools 3. Uncertainties related to hazards that are not included in the QRA – this could be hazards deliberately excluded or hazards that are not identified. There is uncertainty in the use of generic leak scenarios and frequencies. The QRA cannot predict events that will happen in the plant. The uncertainties are controlled by using a large statistical basis for the generic data. The applied modelling tool is a semi-empirical tool, and uses simplified mathematical equations representing experience of natural phenomena. The modelling tool is verified against large scale tests of releases of chemical substances. One example of uncertainty is that topography cannot be specifically modelled. Leaks from EDC and mixtures with EDC as the main medium are excluded due to the assumption that release and possible ignition will only give local effects, i.e. within the plant boundary. A few test releases of EDC have been modelled, albeit not reported, and the gas dispersion distances have been found minimal. There is, however, a significant uncertainty regarding escalation and if a local fire in an EDC release can cause equipment failure and release of e.g. HCl or VCM.

9 Potential conservatism in the QRA

This section addresses potential conservatism embedded in the QRA. Note, however, that there are factors that may not be conservative, such as the exclusion of events with EDC.

9.1 Release durations and transient effects In general, for process leaks the durations are fixed to either 3 min or 10 min depending on the event. Also, the release rate is fixed for the duration of the event. For ruptures and large leaks, this can potentially be conservative. It is typically such events that contribute to the risk contours defining the risk zones. Hence, it could be worthwhile to investigate if transient effects introduce conservatism. In order to do so, additional information (or assessment) is needed regarding process segmentation volumes, flow rates, detection time, initiation of emergency or process shutdown, isolation of segments, time for closing ESD/PSD valves etc.

Report no: PRJ11090011 Rev: Final Page 26 Date: 11 January 2019 ©Lloyd’s Register 2019 9.2 Terrain effects Terrain effects, other than surface roughness, are not captured by the study. The terrain could potentially provide shielding for some adjacent areas for some of the accidental events (see Figure 9-1). Chlorine, for example, is a relatively heavy gas compared to air. Hence, it could be expected to follow the terrain in dispersion scenarios. On the other hand, chlorine is toxic at low concentrations (~50 ppm) and the terrain may not be that influential once the chlorine is diluted in air. Terrain effects can be addressed by, e.g., executing CFD simulations of a selected set of scenarios. In addition, the parameter value for surface roughness applied in the risk model is probably set in a conservative manner.

Figure 9.1 – Risk contours plotted on the terrain around INOVYN’s facility to illustrate the topography in the area

9.3 Release modelling The jet direction follows the wind direction in Safeti. This implies that the probability of jet to face the wind is not included. A jet facing headwind is likely to result in shorter hazard distances. In addition, all releases are modelled as free, i.e., as non-obstructed jets. In reality, some jets will be pointed downwards or into process equipment or other obstacles. This will reduce the momentum of the jet, leading to shorter hazard distances.

9.4 Event frequencies One could consider adapting the event frequencies for the facility, if INOVYN has historic data over accidental events.

9.5 BLEVE A major risk driver for the VCM plant is BLEVE events with the VCM storage tanks; cf. Figure 7.5 in Section 7.3. The BLEVE frequency is based on the fire frequency in the relevant area and a probability of failure on demand of the deluge system (see Appendix A). However, fire water can also be supplied by fire trucks and other means, which has not been credited. Also, the durations of the initial fires may be too short to cause a BLEVE. Hence, the BLEVE event frequency might be conservative, and could be investigated further in subsequent studies.

9.6 Flash fire envelope The main risk drivers are not flash fires. Still, there is some conservatism in the model with respect to how flash fire risks are modelled. The lethality range of a flash fire is linked to the extent of the 50%LFL cloud size. With the new QRA guidelines (Ref. /10/), this would typically be reduced to 100%LFL.

Report no: PRJ11090011 Rev: Final Page 27 Date: 11 January 2019 ©Lloyd’s Register 2019 10 Conclusion and recommendations

10.1 Recommendations It is recommended to address potential conservatism in the risk model in the next revision of the QRA. Section 9 above lists some aspects to investigate in that respect. Following such an update one can look into potential risk reducing measures. For example, avoiding a BLEVE event is obviously important, and if there is a potential to reduce the risk of such an event, this could be addressed in the update. Risk reducing measures regarding toxic releases could also be discussed. One new process module, the HTDC module, is installed as part of the North Star project. A measure to potentially reduce the probability of escalation from an accident in this module has been briefly discussed in this report, i.e. the cooling effect of fire water. If INOVYN is uncomfortable with this assessment, more detail studies can be executed to quantify the escalation potential. For completeness, the recommendations from the existing QRA are included. These are: • It is recommended to further develop and maintain systems and procedures to ensure fast detection and minimisation of duration of a release in case of an accidental scenario involving chlorine gas • Emergency preparedness and quick notification (alarm) to the public to move indoors and close all doors and windows are essential to avoid severe 3rd party injuries, in case of a large toxic release • INOVYN needs to make sure that the risk from the Chlorine and VCM plant are ALARP, As Low As Reasonably Practicable.

10.2 Conclusions Overall, the North Star project does not contribute with a significant risk increase compared to the existing risk picture at INOVYN’s facility at Rafnes. The main risk drivers remain unchanged from the existing QRA. Hence, toxic releases and BLEVE events in the VCM storage area dominate the risk picture and are dimensioning for the risk contours that will define the risk zones around the facility. When comparing the calculated total risk picture for the chlorine and VCM plant at Rafnes against the DSB suggested RAC (Ref. /8/), the following are noted: • Public roads and neighbouring industries are within the 1E-5 per year risk contour • Parts of the neighbouring residential area are within the 1E-6 per year risk contour. However, scattered houses may be permitted within the 1E-6 per year risk curve under certain circumstances. The North Star modifications do not cause any changes to the risk picture with respect to the suggested RAC.

Report no: PRJ11090011 Rev: Final Page 28 Date: 11 January 2019 ©Lloyd’s Register 2019 11 References

/1/ Lloyd’s Register Consulting: "Total risk assessment (QRA) for the Chlorine ad VCM plant – INOVYN Norge AS, Rafnes", Report No. 105797/R1, Rev. Final, 15 September 2015

/2/ DSB: "Forskrift om håndtering av brannfarlig, reaksjonsfarlig og trykksatt stoff samt utstyr og anlegg som benyttes ved håndteringen (forskrift om håndtering av farlig stoff)", FOR-2009-06- 08-602, 8 June 2009.

/3/ Lloyd’s Register Consulting: "Update of risk assessment for the tunnel between Rafnes and Herøya", Report No. 104947/R1, Rev. Final, 16 June 2015

/4/ Hydro Forskningssenter Porsgrunn: "Kvantitativ risikoanalyse – Hydro Rafnes", 91B.DZ8, 15.08.1991.

/5/ Hydro Forskningssenter Porsgrunn: "Oppdatering av kvantitativ risikoanalyse – Petrokjemi Rafnes", 98P_BA8.DOC, 22.01.1998.

/6/ Norsk Hydro: "Vurdering av dominoeffekter mellom fabrikkanleggene på Borealis AS, Noretyl AS og Hydro Polymers AS i forbindelse oppdatering av Sikkerhetsrapporten for Hydro Polymers og Noretyl", Report No. F75578-000, 28.09.2005.

/7/ DSB: "Forskrift om håndtering av brannfarlig, reaksjonsfarlig og trykksatt stoff samt utstyr og anlegg som benyttes ved håndteringen (forskrift om håndtering av farlig stoff)", FOR-2009-06- 08-602, 8 June 2009.

/8/ DSB Temaveileder: "Sikkerheten rundt anlegg som håndterer brannfarlige, reaksjonsfarlige, trykksatte og eksplosjonsfarlige stoffer: Kriterier for akseptabel risiko", May 2013.

/9/ Storulykkeforskriften FOR-2005-06-17-672, Council Directive 96/82/EC of 9 December 1996 on the control of major-accident hazards involving dangerous substances.

/10/ DSB: “Retningslinjer for kvantitative risikovurderinger for anlegg som håndterer farlig stoff”, LR report no. 106535/R1, 2017.

/11/ Lloyd’s Register Consulting: "ULF (Utregning av LekkasjeFrekvenser) ", Version 2015_v1.03

/12/ DNV: "Offshore QRA – Standardised Hydrocarbon Leak Frequencies", Report No./DNV Reg. No. 2008-1768/1241Y35-16 - Rev. 1, 2009-05-19.

/13/ Hydro: "Handbook of Risk Assessment", HES-HB-002, July 2000.

Report no: PRJ11090011 Rev: Final Page 29 Date: 11 January 2019 ©Lloyd’s Register 2019 Appendix A Assumptions and input data

Report no: PRJ11090011/R1 Rev: Final Date: 11 January 2019 ©Lloyd’s Register 2019 Table of contents Page

1 Introduction A1 2 Selection of hazardous events A1 2.1 Scenario selection - general assumptions A1 2.2 Chlorine plant A3 2.2.1 Process piping and equipment A3 2.2.2 Vessels and specific equipment A3 2.3 VCM plant A4 2.3.1 Process piping and equipment A4 2.3.2 Vessels and specific equipment A5 2.4 Transport piping A6 3 Leak scenarios and frequency analysis A6 3.1 Chlorine plant segments A7 3.2 VCM plant segments A9 3.3 Storage and jetty A11 3.4 Transport piping A12 4 Operation and emergency shutdown A12 5 Area conditions A13 5.1 Wind conditions and distribution A13 5.2 Temperature and humidity A14 5.3 Topography and ground surface A14 6 Ignition model A14 6.1 Immediate ignition A15 6.2 Delayed ignition A15 6.2.1 Hydrogen A15 6.2.2 Flares and cracker furnaces A15 6.2.3 Cars A15 6.2.4 Factory areas A15 6.2.5 Ships at berth A15 6.3 Probability of explosion given ignition A16 7 Consequence analysis and risk calculations A16 7.1 Discharge and dispersion A16 7.2 Fire A17 7.2.1 Jet fire A17 7.2.2 Pool fire A17 7.2.3 Fire ball A17 7.2.4 Flash fire A17 7.3 Explosion A17 7.4 Human vulnerability A18 7.5 BLEVE A19 8 References A20

Report no: PRJ11090011/R1 Rev: Final Page Ai Date: 11 January 2019 ©Lloyd’s Register 2019

1 Introduction

The purpose of this appendix is to document all the assumptions made to model all leak scenarios and perform calculations of consequences and risk for the INOVYN Chlorine and VCM plant at Rafnes. This appendix also list the references used for the assumptions and input data.

2 Selection of hazardous events

The theory of QRA is that a selection of representative scenarios will form the basis for calculating the risk picture. The scenario selection is based on HAZID evaluations made in the previous QRA update performed for the Chlorine and VCM plant, Ref. /1/.

2.1 Scenario selection - general assumptions First a few general assumptions are made regarding the different parts of the Chlorine and VCM plant and the chemicals and mixtures in different steps of the production. The general assumptions are based on the overall process flow diagrams of the Chlorine and VCM plant. A summary of the general assumptions are presented in Table 2.1. All parts of the plant are covered. For some parts of the plant there are no scenarios to be assessed due to no or less dangerous chemicals involved in that part of the process. For other parts of the plant there are no scenarios to be assessed due to the fact that the consequence of the scenario will have no effect outside the defined part of the process. The consequence of a given scenario will have a local effect on the equipment or personnel present.

Table 2.1 – General assumptions regarding scenario selection Part of plant Scenarios in the QRA General assumption Chlorine plant Water purification No scenarios No (or limited) hazardous substances Brine No scenarios No (or limited) hazardous substances

Cell room Cl2 header in the cell Leaks from individual cells and anolyte/ room is considered catolyte solutions are not considered to pose a threat outside the cell room.

Leak of H2 is assumed to give fire in the cell room with only local effects. Domino effects

towards Cl2 system is considered negligible Caustic soda No scenarios Leaks of NaOH solution is assumed to give only local effects

Hydrogen H2 header to VCM is Leaks of H2 from compressors etc. are considered assumed to give only local effects.

Domino effects towards Cl2 system is considered negligible

Lean brine No scenarios Small amounts of Cl2, low pressures vacuum- dechlorination 0.2 bar(g) and leaks are assumed to give only local effects. Leaks of anolyte solution is assumed to give only local effects

Report no: PRJ11090011/R1 Rev: Final Page A1 Date: 11 January 2019 ©Lloyd’s Register 2019

Part of plant Scenarios in the QRA General assumption Emergency If pumps P3704, P3706 Pumps are connected to emergency power. scrubber/recovery stops while production Small amounts of Cl2, low pressures vacuum- chlorine trips 0.2 bar(g) and leaks are assumed to give only local effects

Chlorine All leak points of Cl2 Leak of H2SO4 is assumed to give only local gas are considered effects.

No liquid Cl2 at any point assumed VCM plant

1100 Leaks of C2H4 are Leak of EDC (C2H4Cl2) is assumed to give only Oxychlorination considered. local effects and no scenarios for EDC (incl. Leaks of HCl are reactor V1101/V1106 (OHCL)) are included in considered. the calculations

Leaks of H2 are considered.

NH3-tank considered 1200 EDC-recovery No scenarios Leak of EDC and by-products are assumed to give only local effects 1300 EDC No scenarios Leak of EDC and by-products are assumed to purification give only local effects 1400 cracking Fuel gas considered. Release from crackers will be above auto No scenarios for ignition and a jet flame with local effects is EDC/VCM/HCl assumed for all releases. according to comments Gaseous release from top system with HCl, VCM, EDC assumed to only give local effects. EDC are the main component in bottom system and refluxes and the same consequences as 100 % EDC (only local effects) are assumed 1500 VCM- All liquid leaks Leak of EDC is assumed to only give local purification considered (except for effects. liquid in C1502 and Gaseous releases of HCl/VCM/EDC mixtures EDC return). are assumed to give only local effects Gaseous releases of pure HCl are considered

1600 direct Leaks of C2H4 are Leak of EDC is assumed to give only local chlorination considered. effects and no scenarios for EDC (incl. reactors V1601A/B (LTDC) and V1651 Leaks of Cl2 are considered (HTDC)) are included in the calculations 1700 HCl-unit Fuel gas considered Leaks of chlorinated waste, flue gas, HCl and NaOH solutions are assumed to give only local effects 1800-1900 waste No scenarios No (or limited) hazardous substances water treatment 1800 incinerator Fuel gas considered Pressure in vents etc. is assumed to be ~ atmospheric and leaks are assumed to give only local effects

Report no: PRJ11090011/R1 Rev: Final Page A2 Date: 11 January 2019 ©Lloyd’s Register 2019

Part of plant Scenarios in the QRA General assumption 2700 EDC/VCM/By- VCM storage Leak of EDC and by-products are assumed to product Storage considered (liquid give only local effects. releases). Assumptions of likelihood and consequences BLEVE as a result of for the BLEVE event are presented in Chapter pool fire or jet fire 7.5 considered 3000 Jetty 2 Loading/unloading of The total annual time of operation for VCM VCM considered (liquid loading arms are 115 hour per year releases)

2.2 Chlorine plant 2.2.1 Process piping and equipment Table 2.2 present the segments in the Chlorine process area. Parameters are taken from the process description of the chlorine systems 1 and 2.

Table 2.2 – Chlorine process plant segments included in QRA Segment Flow ID Gas/liquid P (barg) T (oC) P&ID Klor1-001 Wet chlorine Gas 0.239 88 06-CL-UDO-C78- 00023 Klor1-002 Dry chlorine Gas 0.205 19 06-CL-UDO-C78- 00024 Klor1-003 Chlorine compressor Gas 5.77 29.5 06-CL-UDO-C78- 00044 Klor2-001 Wet chlorine Gas 0.183 81 6F-28002-3845 Klor2-002 Dry chlorine Gas 0.096 19 6F-28002-3846 Klor2-003 Chlorine compressor Gas 5.77 29.5 6F-28002-3847

2.2.2 Vessels and specific equipment Table 2.5 present all vessels and specific equipment in the Chlorine plant.

Table 2.3 – Vessels and specific equipment Vessel/ Media P (barg) T (oC) P&ID equipment (gas/liquid)

H3650 Cl2 (G) 0.239 88 06-CL-UDO-C78-00023

U3650 Cl2 (G) 0.239 18.5 06-CL-UDO-C78-00023

C3650 Cl2 (G) 0.205 19 06-CL-UDO-C78-00024

U3651 Cl2 (G) 0.205 13.8 06-CL-UDO-C78-00024

K3201 Cl2 (G) 5.77 29.5 06-CL-UDO-C78-00044

T3101 Cl2 (G) 0.183 81 6F-28002-3845

H3104-5 Cl2 (G) 0.183 81 6F-28002-3845

U3113 Cl2 (G) 0.183 19.6 6F-28002-3845

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Vessel/ Media P (barg) T (oC) P&ID equipment (gas/liquid)

C3110 Cl2 (G) 0.096 19.6 6F-28002-3846

U3127 Cl2 (G) 0.096 18.8 6F-28002-3846

K3206 Cl2 (G) 5.77 29.5 6F-28002-3847

2.3 VCM plant 2.3.1 Process piping and equipment Table 2.4 present the segments in the VCM process area. Parameters are taken from mass balance sheets for the existing VCM plant and the new HTDC module. Two new segments, 1100- C2H4-HTDC and 1600-Cl-HTDC, have been introduced as a result of installation of the new HTDC module. Other segments that have been exposed to change due to the North Star modifications are listed below: • 1100- C2H4-002: Change in operating pressure. Additional leak points due to process tie in of new HTDC module (including FTM 32) • 1100-HCl-003: Additional leak points due to tie in of new OHCL reactor • 1500-EDC/VCM-012: Additional leak points due to FTM 19 • 1600-Cl-017: Additional leak points due to process tie in of new HTDC module (including FTM 32).

Table 2.4 – Process segments Segment Flow ID Gas/liquid P (barg) T (oC) P&ID 6F-28001 1100-H2-001 1110 Gas 10 90 11C 1100-C2H4-002 1101, 1102, 1103, Gas 10 (1103) -10 (1103) 11C, 11E, 1104A, 1104 16A, 16B, (including FTM 32 16E and part of HTDC module) 1100-C2H4- 01C* Gas 2 (HTDC) ~0 (HTDC) 16E, 16F HTDC 1100-HCl-003 1107, 1108 Gas 7.4 180 11C, 11E, (including inlet to 11L new OHCL reactor) 11/14/1500-HCl- 1501, 1521, 1106 Gas 11.9 -25 (1501) 11C, 14F, 004 (1501) 15B 1500-HCl-011 C1501 reflux Liquid 17 -25 15A, 15B 1500-EDC/VCM- 1502 (including Liquid 12.8 100 15A, 15C 012 FTM 19) (50% EDC/ 50% VCM)** 1500-VCM-013 C1502 OVDH, Gas 3.7 31 (C1502) 15C, 15D C1504 OVDH (C1502)

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Segment Flow ID Gas/liquid P (barg) T (oC) P&ID 6F-28001 1500-VCM-014 C1502 reflux Liquid 9 (1507) 23 (1507) 15A, 15C, 15D, 15G, 15H 1500-VCM-015 1508, 1509 Liquid 13.2 33.4 (1508) 15G, 15H (1508) 1400-FG-016 Fuel gas system Gas 3 40 14A/B/C (composition: 17B 66vol% Hydrogen 18K, 18L 34 vol% methane) 1600-Cl-017 1602 (including Gas 5.5 90 16A, 16B, FTM 32 and part 16E, 16N of HTDC module) 1600-Cl-HTDC 02C* Gas 2 (HTDC) 20 (HTDC) 16E, 16F 2700-VCM-018 VCM storage and Liquid Sat*** 10 27D/F/FA loading pumps and equipment in the storage area 2700-VCM-019 Liquid from VCM Liquid Sat*** 10 vapour recovery in storage area

* Streams from HTDC module Heat and Mass Balance ** Modelled as 100 % VCM *** Saturation pressure for VCM at 10°C used in consequence calculation

2.3.2 Vessels and specific equipment Table 2.5 present all vessels and specific equipment in VCM plant. Vessels and equipment with mainly EDC content are excluded according to the general assumption. Vessels with no liquid volume in normal operation are excluded.

Table 2.5 – Vessels and specific equipment Vessel/ Media (gas/ Liquid volume (m3) P (barg) T (oC) P&ID equipment liquid) max/operation 6F-28001

V1012 NH3 (L) 3.3/3 11 20 10QA C1501 EDC/VCM (L) 109/15 11/11.4 -24/98 15A (50% EDC/ 50% VCM) V1501 HCl (L) 272/110 10.7 -25 15B V1502 VCM (L) 21.2/10 3.7 38 15D C1504 VCM (L) 28.4/7 4/4.3 41/47 15G H1509 VCM (L) 0.22/0.15 3.3 16 15H 2708A/BC VCM (L) 395/100 Sat* 10 27C/D/E 2709 VCM (L) 5200/3500 Sat* 10 27F 2710 VCM (L) 5200/3500 Sat* 10 27G

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Vessel/ Media (gas/ Liquid volume (m3) P (barg) T (oC) P&ID equipment liquid) max/operation 6F-28001 X3002A/B VCM (L) - Ship pump 10 pressure 4.5

* Saturation pressure for VCM at 10°C used in consequence calculation

2.4 Transport piping Assumptions regarding transport piping defined as separate segments are presented in Table 2.6.

Table 2.6 – Transport piping segments Segment Length Dimension Gas/liquid P (barg) T (oC) P&ID

Cl2 header 400 m 350 mm Gas 5.77 29.5 06-CL-UDO- (replaces Stg14- C78-00026 34003-VCM2-5)

H2 header(s) 150 mm Gas 6.5 15 VCM line from 100 mm Liquid 12.7 25 6F-28001- production to 15H,-27C storage VCM line from 200 mm Liquid Ship 10 storage are to pump jetty pressure 4.5

3 Leak scenarios and frequency analysis

Three leak scenarios, small leakage (SM), medium leakage (ME) and rupture (RU) are defined for each segment, vessel, specific equipment and transport pipe. These are the same definitions for leak scenarios used by Hydro in earlier risk assessments. Table 3.1 below presents the method to calculate leak frequencies and representative hole sizes on equipment for the different parts of the plant.

Table 3.1 – Method for calculating leak frequencies Part of plant Method Reference Chlorine plant – Leak frequencies and representative hole sizes are ULF (Ref. /2/) process calculated using the LR spreadsheet tool ULF Offshore QRA – segments (Utregning av Lekkasje Frekvenser). Standardised The frequencies are based on Offshore statistics Hydrocarbon Leak Frequencies (Ref. /3/) Chlorine plant - The scenarios and frequencies are calculated using HES-HB-002 (Ref. /4/) Vessels and the Hydro Handbook specific equipment

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Part of plant Method Reference VCM plant – Leak frequencies and representative hole sizes are ULF (Ref. /2/) process calculated using the LR spreadsheet tool ULF Offshore QRA – segments (Utregning av Lekkasje Frekvenser). Standardised The frequencies are based on Offshore statistics Hydrocarbon Leak Frequencies (Ref. /3/) VCM plant - The scenarios and frequencies are calculated using HES-HB-002 (Ref. /4/) Vessels and the Hydro Handbook. specific Loading arm frequencies are adjusted for equipment estimated annual time of operation Transport piping The scenarios and frequencies are calculated using HES-HB-002 (Ref. /4/) the Hydro Handbook

Note that even though the following FTMs for the North Star project were found relevant for the update of the QRA, the FTMs are evaluated to not have an impact on the leak frequency picture: VCM plant: FTM 02, FTM 03, FTM 17, FTM 18, FTM 22, FTM 31, FTM 37, FTM 39 and FTM 40 Chlorine plant: FTM 262, FTM 361, FTM 366 and FTM 421

3.1 Chlorine plant segments Leak frequencies for the Chlorine plant segments are presented in Table 3.2. There is no change in leak frequency as a result of the North Star modifications. Hence, the leak frequencies are kept unchanged from the frequencies given in the QRA from 2015, Ref. /1/.

Table 3.2 – Chlorine plant leak scenarios and frequencies Scenario Frequency Reference Process piping and equipment KLOR1-001 SM 8.68E-03 KLOR1-001 ME 2.14E-03 KLOR1-001 RU 3.44E-04 KLOR1-002 SM 8.68E-03 KLOR1-002 ME 2.14E-03 KLOR1-002 RU 3.44E-04 KLOR1-003 SM 8.68E-03 Leak frequency results for the Chlorine plant are KLOR1-003 ME 2.14E-03 implemented with calculations from the chlorine KLOR1-003 RU 3.44E-04 feed stream to the VCM plant, Ref. /1/ (Draft B update) KLOR2-001 SM 8.68E-03 KLOR2-001 ME 2.14E-03 KLOR2-001 RU 3.44E-04 KLOR2-002 SM 8.68E-03 KLOR2-002 ME 2.14E-03 KLOR2-002 RU 3.44E-04 KLOR2-003 SM 8.68E-03

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Scenario Frequency Reference KLOR2-003 ME 2.14E-03 KLOR2-003 RU 3.44E-04 Vessels and specific equipment H3650 RU 2.00E-06 H3650 ME 1.00E-05 H3650 SM 1.00E-03 U3650 RU 2.00E-06 U3650 ME 1.00E-05 U3650 SM 1.00E-03 C3650 RU 2.00E-06 C3650 ME 1.00E-05 C3650 SM 1.00E-03 U3651 RU 2.00E-06 U3651 ME 1.00E-05 U3651 SM 1.00E-03 K3201 SM 6.00E-03 K3201 ME 2.00E-04 K3201 RU 2.00E-05 T3101 RU 2.00E-06 Pressurized vessels according to HES-HB-002 T3101 ME 1.00E-05 (Ref. /4/) T3101 SM 1.00E-03 H3104-5 RU 4.00E-06 H3104-5 ME 2.00E-05 H3104-5 SM 2.00E-03 U3113 RU 2.00E-06 U3113 ME 1.00E-05 U3113 SM 1.00E-03 C3110 RU 2.00E-06 C3110 ME 1.00E-05 C3110 SM 1.00E-03 U3127 RU 2.00E-06 U3127 ME 1.00E-05 U3127 SM 1.00E-03 K3206 SM 6.00E-03 K3206 ME 2.00E-04 K3206 RU 2.00E-05

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3.2 VCM plant segments Leak frequencies for the VCM plant segments have been updated according to the North Star modifications, and are presented in Table 3.3. The total percentage increase in leak frequency for the process piping and equipment is 9 %.

Table 3.3 – VCM plant leak scenarios and frequencies Scenario Frequency Reference Process piping and equipment 1100-H2-001 SM 3.75E-03 1100-H2-001 ME 1.31E-03 1100-C2H4-002 SM 2.63E-02 1100-C2H4-002 ME 7.35E-03 1100- C2H4-002 ME 10 min 8.17E-03 1100- C2H4-002 RU 8.97E-04 1100- C2H4-HTDC SM 1.46E-03 1100- C2H4- HTDC ME 4.44E-04 1100- C2H4- HTDC ME 10 min 4.93E-05 1100- C2H4-002 RU 1.67E-05 1100-HCl-003 SM 1.36E-02 1100-HCl-003 ME 3.68E-03

1100-HCl-003 ME 10 min 4.09E-03 Calculation of leak points on P&ID 1100-HCl-003 RU 3.83E-04 and use of ULF (Ref. /2/) to calculate frequencies and representative hole 11/14/1500-HCl-004 SM 1.65E-02 sizes. 11/14/1500-HCl-004 ME 5.17E-03 Offshore QRA – Standardised Hydrocarbon Leak Frequencies 11/14/1500-HCl-004 ME 10 min 5.74E-04 (Ref. /3/) reference for leak 11/14/1500-HCl-004 RU 1.23E-03 frequencies per equipment type. 1500-HCl-011 SM 1.11E-02 1500-HCl-011 ME 2.50E-03 1500-HCl-011 ME 10 min 2.78E-04 1500-HCl-011 RU 3.67E-04 1500-EDC/VCM-012 SM 1.36E-02 1500-EDC/VCM-012 ME 3.52E-03 1500-EDC/VCM-012 ME 10 min 3.91E-04 1500-EDC/VCM-012 RU 8.48E-04 1500-VCM-013 SM 6.22E-03 1500-VCM-013 ME 1.62E-03 1500-VCM-013 ME 10 min 1.80E-04 1500-VCM-013 RU 1.72E-04

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Scenario Frequency Reference 1500-VCM-014 SM 3.86E-02 1500-VCM-014 ME 9.91E-03 1500-VCM-014 ME 10 min 1.10E-03 1500-VCM-014 RU 1.76E-03 1500-VCM-015 SM 1.58E-02 1500-VCM-015 ME 4.01E-03 1500-VCM-015 ME 10 min 4.45E-03 1500-VCM-015 RU 5.52E-04 1400-FG-016 SM 1.38E-02 1400-FG-016 ME 3.84E-03 1400-FG-016 ME 10 min 4.27E-04 1400-FG-016 RU 3.35E-04 1600-Cl-017 SM 1.44E-02 1600-Cl-017 ME 3.61E-03 1600-Cl-017 ME 10 min 4.01E-04 1600-Cl-017 RU 5.75E-04 1600-Cl-HTDC SM 1.51E-03 1600-Cl- HTDC ME 4.54E-04 1600-Cl- HTDC ME 10 min 5.04E-05 1600-Cl- HTDC RU 1.80E-05 Vessels and specific equipment V1501 RU 2.00E-06 V1501 ME 1.00E-05 V1501 SM 1.00E-03 C1501 RU 2.00E-06 C1501 ME 1.00E-05

C1501 SM 1.00E-03 Pressurized vessels according to HES- V1502 RU 2.00E-06 HB-002 (Ref. /4/) V1502 ME 1.00E-05 V1502 SM 1.00E-03 C1504 RU 2.00E-06 C1504 ME 1.00E-05 C1504 SM 1.00E-03

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3.3 Storage and jetty Leak frequencies for the storage and jetty segments are presented in Table 3.4. There is no change in leak frequency as a result of the North Star modifications.

Table 3.4– Storage and jetty (VCM) leak scenarios and frequencies Scenario Frequency Reference 2708A/B/C RU 6.00E-06 2708A/B/C ME 3.00E-05

2708A/B/C SM 3.00E-03 Pressurized vessels according to HES-HB-002 2709/10 RU 4.00E-06 (Ref. /4/) 2709/10 ME 2.00E-05 2709/10 SM 2.00E-03 X3002A/B RU 3.54E-06 X3002A/B RU 10 min 3.94E-07 Loading arm according to HES-HB-002 X3002A/B ME 3.60E-05 (Ref. /4/) X3002A/B ME 10 min 3.94E-06 X3002A/B SM 3.94E-04 2700-VCM-018a SM 2.98E-02 2700-VCM-018a ME 7.21E-03 2700-VCM-018a ME 10 min 8.01E-04 2700-VCM-018a RU 7.70E-04 2700-VCM-018a RU 10 min 8.56E-05 2700-VCM-018b SM 9.33E-03 Calculation of leak points on P&ID and use of 2700-VCM-018b ME 2.11E-03 ULF (Ref. /2/) to calculate frequencies and representative hole sizes 2700-VCM-018b ME 10 min 2.35E-04 Offshore QRA – Standardised Hydrocarbon 2700-VCM-018b RU 2.20E-04 Leak Frequencies (Ref. /3/) reference for leak frequencies per equipment type 2700-VCM-018b RU 10 min 2.45E-05 2700-VCM-019b SM 1.70E-02 2700-VCM-019b ME 3.82E-03 2700-VCM-019b ME 10 min 4.24E-04 2700-VCM-019b RU 4.02E-04 2700-VCM-019b RU 10 min 4.47E-05

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3.4 Transport piping Leak frequencies for the transport piping segments are presented in Table 3.5. There is no change in leak frequency as a result of the North Star modifications.

Table 3.5 – Transport piping leak scenarios and frequencies Scenario Frequency Reference Cl2 header RU 6.68E-09 /m Cl2 header ME 2.00E-07 /m Cl2 header SM 6.68E-07 /m VCM header RU 2.00E-08 /m VCM header ME 5.40E-07 /m VCM header ME 10 min 6.00E-08 /m VCM header SM 2.00E-06 /m Pipeline (transport) according to HES-HB-002 H2 header RU 2.00E-08 /m (Ref. /4/) H2 header ME 6.00E-07 /m H2 header SM 6.00E-07 /m VCM jetty header RU 6.00E-09 /m VCM jetty header RU 10 min 6.67E-10 /m VCM jetty header ME 1.80E-07 /m VCM jetty header ME 10 min 2.00E-08 /m VCM jetty header SM 6.67E-07 /m

4 Operation and emergency shutdown

Assumptions regarding operation of the Chlorine and VCM plant and time for shut down are summarized in Table 4.1.

Table 4.1 – Operation and ESD assumptions Parameter Assumption/estimate Comment Plant in operation It is assumed the Chlorine and Start and shutdown, maintenance VCM plant is in operation etc. are included in operation 8,760 hours per year VCM loading/ VCM is loaded/unloaded at jetty Used to adjust leak frequencies for unloading frequency 2 approx. 1,152 hours/year loading/ unloading scenarios Total time of ship at Jetty 2 is occupied approx. Used for estimate of probability of berth at jetty 2 3,336 hours/year ignition at Jetty 2 ESD Chlorine plant – Small leaks – 10 min Detector pick up but no automatic Time for shutdown shutdown. (also applies for Major leaks – 3 min Pressure drop and automatic chlorine and shutdown.

hydrogen transport Pressure drop and automatic Ruptures – 3 min piping) shutdown

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Parameter Assumption/estimate Comment

ESD VCM Plant Cl2, Small leaks - 10 min Detector pick up but no automatic

C2H4, VCM – Time shutdown. for shutdown Major leaks – 3 min 90 %, Disturbance trigger automatic shut 10 min 10 % down in 90 % of the cases, in 10 % of the cases manual shutdown after

10 min is assumed. Ruptures – 3 min All ruptures are assumed to lead to a disturbance with automatic shutdown ESD VCM Plant HCl Small leaks – 30 min No HCl detectors Major leaks - 3 min 90 %, 10 Disturbance trigger automatic shut min 10 % down in 90 % of the cases, in 10 % of the cases manual shutdown after 10 min is assumed.

All ruptures are assumed to lead to a Ruptures 3 min disturbance with automatic shutdown ESD VCM storage Small leaks - 10 min Detection at PPM level and all leaks area Major leaks – 3 min 90%, will be detected. For small leaks (also applies for 10 min 10% operator need to go out and check. Major leaks and ruptures are VCM line from Ruptures – 3 min 90%, 10 min assumed to be able to detect on production to 10% storage area) camera and shutdown within 3 min in 90 % of the cases ESD vessels Release of whole liquid content ESD loading/ Small leaks – 3 min 90 %, 10 Loading/unloading is supervised and unloading – Time min 10 % manual shutdown is assumed within for shut down Major leaks – 3 min 90 %, 10 3 min 90 % of the cases. (also applies for min 10 % In 10 % of the cases it is assumed transport piping Ruptures – 3 min 90 %, 10 min that supervisor is compromised and between jetty and 10 % manual shutdown instead takes storage) 10 min

5 Area conditions

5.1 Wind conditions and distribution Three different weather scenarios are assumed to represent the actual weather conditions at Rafnes: • 2 m/s with Pasquille stability class F • 2 m/s with Pasquille stability class D • 6 m/s with Pasquille stability class D. The distribution of wind speed and directions is based on wind data from eKlima.no (Ref. /5/) covering the last 10 years of observations from Porsgrunn - Ås. Figure 5.1 presents the wind rose for the weather station at Porsgrunn - Ås. Statistics for 12 wind sectors of 30° and 4 m/s parts has been used. Wind speeds of 0-4 m/s are represented by 2 m/s wind speed and wind speeds above 4 m/s are represented by 6 m/s.

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Figure 5.1 – Wind rose for Porsgrunn – Ås

For stability class it is assumed that class F is prevailing for 40 % of the time for 0-4 m/s and class D for 60 % of the time for 0-4 m/s and 100% of the time for wind speeds > 4 m/s. Pasquille class distribution is based on stability class data from Porsgrunn - Ås as documented in the 1991 QRA report for Rafnes (Ref. /7/).

5.2 Temperature and humidity Air temperature and ground temperature is set to 10°C and a relative air humidity of 70 % are assumed in all cases (Ref. /7/).

5.3 Topography and ground surface The topography and ground surface is represented by surface roughness parameter of 0.1 representing a surface height of 182.6 mm according to 1991 QRA report for Rafnes (Ref. /7/). The surface roughness parameter is used by Phast Risk to model ground surface turbulence and the impact on gas dispersion (Ref. /6/).

6 Ignition model

The ignition model applies to leak scenarios for flammable substances (H2, C2H4, VCM and Fuel Gas). The assumed ignition model is a combination of the assumptions from the 1991 QRA (Ref. /7/), the risk based explosion load calculations for Noretyl (Ref. /8/) and new assumptions for cracker furnaces, ships at berth and electrical high voltage cable and flares.

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6.1 Immediate ignition

The probability (Pi) of a release of H2 being ignited immediately in the event of the release is assumed to be 0.05 (Ref. /9/)

The probability (Pi) of a release of C2H4 and VCM being ignited immediately in the event of the release is assumed to be (Ref. /9/): • Pi = 1 for release over auto ignition temperature • Pi = 0.007 for releases from a pump • Pi = 0.00015 for all other cases.

6.2 Delayed ignition The delayed ignition model in Phast Risk is based on the formula:

-ωit Pi,t = fi(1-e )

Pi,t = Probability of ignition by source i in the duration of time step t

fi = Operating probability of source i, (i.e. if the ignition source only is present part of the time)

ωi = Effectiveness factor for ignition source i t = Duration of time step. 6.2.1 Hydrogen For all hydrogen releases the ignition probability is adjusted so that total ignition probability always reaches 1. 6.2.2 Flares and cracker furnaces Flares and cracker furnaces are defined as point sources with effectiveness factor = ∞ and operating probability 100 % giving 100 % ignition if a flammable gas cloud reaches the point source. The flare is assumed to be elevated to 70 m above ground. 6.2.3 Cars A car running is assumed to have a 40 % probability of ignition in 60 s (Ref. /10/). The operating probability is dependent on traffic density (number of cars and speed). Numbers from the explosion analysis (Ref. /8/) are used for defining ignition from cars near the INOVYN plant and figures from vegvesen.no (Ref. /11/) is used for FV 353. The traffic density is presented in table. Only total number of cars is used and no detailed analysis of differences between day, night and weekends are assumed.

Table 6.1 – Traffic density around Noretyl Road Number of cars per day Assumed speed Main road Rafnes 226 40 km/ FV 353 3700 70 km/h

6.2.4 Factory areas In accordance with the 1991 QRA ignition areas are defined for the Chlorine plant, VCM plant and Noretyl plant. The ignition probability is assumed to be 75 % in 60 s and the operating probability 20 %. The probability is based on an area of 25 m x 25 m (625 m2). 6.2.5 Ships at berth The probability of a gas cloud being ignited if it spreads to a ship is assumed to be 50 % in 60 s. Only ships at berth at jetty 2 are considered as ignition sources. The operating probability is equal to the discharge and loading times used for leak frequencies.

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6.3 Probability of explosion given ignition The probability of explosion (Pe) given ignition depends on the volume of the flammable part of a gas cloud on ignition and the laminar burning velocity of the flammable material according to Table 6.2 (Ref. /12/).

Table 6.2 – Volume based probability of explosion

Obstructed cloud Pe low flame speed Pe medium flame speed Pe high flame speed volume (< 0.45 m/s) (0.45 m/s - 0.75 m/s) (> 0.75 m/s) H2,C2H4 200 m3 0 0.3 0.6 3,000 m3 0.3 0.6 0.9 6,000 m3 0.6 0.9 1

7 Consequence analysis and risk calculations

7.1 Discharge and dispersion The leak rates and dispersion of gas/vapours from the defined leak scenarios are calculated in SAFETI. The 10 % increase in overall mass flow rate, due to the North Star project, is accounted for by increasing the pressure in process piping and equipment segments by 10 % and the inflow rate for long pipeline segments by 10 %. The leak models used for the study are summarized in Table 7.1.

Table 7.1 – SAFETI models used Scenarios Leak model in SAFETI Comment All small and medium Leak Constant leak rate with full pressure leaks (both liquid and maintained. gas) VCM vessels are modelled with a fixed volume (maximum leak duration is 1 hr). Process piping and equipment and chlorine vessels are modelled as fixed duration leaks according to the emergency shut down philosophy in chapter 4. Ruptures from liquid Leak Constant leak rate with full pressure process equipment maintained: • Fixed duration leaks according to the emergency shut down philosophy in chapter 4. • Maintaining full pressure is regarded conservative • on the other hand the model assumes no back flow from equipment downstream rupture Ruptures from vessels Catastrophic rupture Instantaneous release of full content with liquid

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Scenarios Leak model in SAFETI Comment Ruptures from liquid Line rupture Average leak rate over the duration (3 VCM transport piping min) used. between plant and storage and to jetty Rupture on chlorine feed Long pipeline Average leak rate over the duration to 1600 (1600-Cl-017 RU • Distance to break (3 min) used and 1600-Cl-HTDC RU) 400 m and 200 m respectively* • Inflow of 10.3 kg/s Rupture on chlorine Long pipeline Average leak rate over the duration (3 header • Inflow 10.3 kg/s min) used. • Distance to break 200 m Rupture on hydrogen Line rupture Average leak rate over the duration header (3 min) used Rupture on chlorine Long pipeline Average leak rate over the duration (3 segments • Inflow 4.7 kg/s for min) used. vessels and 5.2 kg/s for piping and equipment (10% increase) • Distance to break 10 m*

* Assumed length of pipelines

7.2 Fire 7.2.1 Jet fire A jet fire occurs if an ongoing continuous release of flammable substance is ignited. The extent of the jet is assumed to be to the stoichiometric concentration of the release. 7.2.2 Pool fire A pool fire occurs if there is a pool of flammable material is present on ignition (the pool needs to be in contact with the ignited flammable vapour). 7.2.3 Fire ball A fire ball occurs on immediate ignition of an instantaneous release (or as a short duration effect of a continuous release) of flammable substance. 7.2.4 Flash fire A flash fire occurs if a flammable gas cloud is ignited. The extent of the gas cloud is assumed to be to half LFL to take into account the nonconformities in the gas cloud. Ignition can also lead to additional explosion effects (see Chapters 6.3 and 7.3)

7.3 Explosion Vapour cloud explosions are modelled in Phast Risk using the TNO – Multi Energy Method (ME). Two categories of explosion are modelled:

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1. Confined vapour cloud explosion 2. Unconfined vapour cloud explosion Confined explosions are assumed to be able to happen in the VCM plant process area where flammables are present and process equipment creates volumes of congestion. Two volumes are defined according to figure. Explosion within these volumes are calculated using ME curve number 5.

7.4 Human vulnerability The assumed vulnerability of humans exposed to fire and explosion are according to Table 7.2. The assumptions is based on an unprotected person located outdoors (Ref. /13/).

Table 7.2 – Human vulnerability on exposure (outdoor vulnerability) Effect Probability of death (P) Flash fire P = 1 within flammable envelope Fire radiation dose (time t in s and heat radiation/ area P = Probit function of Pr q in W/m2) Pr = -36.38 + 2.56·ln(t·q·1.333) Explosion (side on pressure in barg) P = 0 for p < 0.3 barg P = 1 for p > 0.3 barg Chlorine toxic dose (concentration c in ppm and time t P = Probit function of Pr in minutes) Pr = -4.81 + 0.5·ln(t·c^2.75) Hydrogen chloride toxic dose (concentration c in ppm P = Probit function of Pr and time t in minutes) Pr = -15.69 + 1.69·ln(t·c^1.18)

Figure 7.1 – Obstructed regions (congested areas) in the VCM plant For unconfined explosion ME curve number 2 is chosen.

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7.5 BLEVE The BLEVE event can happen in case of jet fire or large pool fire in the storage area and if the deluge system fails on demand. The likelihood of a BLEVE is calculated using the SAFETI risk calculations for jet fire and pool fire outcomes from releases of VCM in the storage area = 8·10-4 (all ignited rupture and medium leak scenarios in storage area contributes). A generic probability of failure on demand for fire proofing is according to CCPS (Ref. /14/) in the order of 10-2 and multiplying that factor to the jet fire and pool fire frequencies sets the frequency of a BLEVE event in the storage area. BLEVE frequency = 8·10-6 A BLEVE scenario is simulated using a fireball and an explosion event in parallel. Vessel volume = 5,000 m3 Stored liquid volume = 3,500 m3 Pressure at time of BLEVE = 1.21 x PSV set point (absolute pressure) (Ref. /10/) = 8.92 bar(g) Liquid fraction on release = 0.73 (calculated using SAFETI for release of VCM at 8.92 bar(g))

Report no: PRJ11090011/R1 Rev: Final Page A19 Date: 11 January 2019 ©Lloyd’s Register 2019

8 References

/1/ Lloyd’s Register Consulting: «Total risk assessment (QRA) for the Chlorine ad VCM plant – INOVYN Norge AS, Rafnes», Report No. 105797/R1, Rev. Final, 15 September 2015

/2/ Lloyd’s Register Consulting: «ULF (Utregning av LekkasjeFrekvenser)», Version 2015_v1.03

/3/ "Offshore QRA – Standardised Hydrocarbon Leak Frequencies", Report No./DNV Reg. No. 2008- 1768/1241Y35-16 - Rev. 1, 2009-05-19.

/4/ "Handbook of Risk Assessment", HES-HB-002, Hydro, July 2000.

/5/ eklima.no, Norwegian Meteorological Institute, 2014-07-02.

/6/ "Unified Dispersion Model (UDM) Theory", DNV Software, June 2011.

/7/ Hydro Forskningssenter Porsgrunn: "Kvantitativ risikoanalyse – Hydro Rafnes", 91B.DZ8, 15.88.1991.

/8/ Scandpower AS: "Risk-based Calculations of (Design) Explosion Loads on manned Buildings – Rafnes", Report No. 80.102.017/R2, 24 September 2009.

/9/ Lloyd’s Register Consulting: “Modelling of ignition sources on land based process facilities operated by Statoil”, Report No. 103381/R1, 24 October 2014.

/10/ RIVM: "Reference Manual Bevi Risk Assessments", Version 3.2, 2009-07-01.

/11/ https://www.vegvesen.no/vegkart/vegkart/, 2014-07-02

/12/ "MPACT Theory", DNV Software, December 2010.

/13/ "Methods for the determination of possible damage", CPR 16E, TNO, 1992.

/14/ “Layer of Protection Analysis”, CCPS Concept Book, CCPS, 2001.

Report no: PRJ11090011/R1 Rev: Final Page A20 Date: 11 January 2019 ©Lloyd’s Register 2019 Appendix B Risk screening workshop - VCM plant

Report no: PRJ11090011 Rev: Final Page B1 Date: 11 January 2019 ©Lloyd’s Register 2019

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Memo

Risk screening workshop - VCM scope

To: Wood Cc:

From: Ingebjørg Valkvæ/Andrea Risan/ Date: 30 November 2018 Stian Jensen/Ane Kristiansen

Project no: PRJ11090011

Table of Contents

1 Introduction ...... 3 2 Process description ...... 4 3 VCM plant modifications ...... 5 3.1 FTM 01 - Replacement of line 400-RP 1069 to DN500...... 6 3.2 FTM 02 - V1105 modifications ...... 6 3.3 FTM 03 - H1104 replacement ...... 6 3.4 FTM 04 – Increase oxygen feed to OHCL with new heat exchanger H1151 ...... 7 3.5 FTM 05 – OHCL reactor cooling loop ...... 8 3.6 FTM 06 – New IPS line to Chlorine plant ...... 8 3.7 FTM 07 - P1305A/S replacement ...... 8 3.8 FTM 08 - Replacement of several control valves ...... 9 3.9 FTM 09 - V1102 Modification of demister ...... 9 3.10 FTM 11 - Replacement of RP4015, RP4057 and RP4124 ...... 10 3.11 FTM 12 - New P1404S ...... 10 3.12 FTM 13 - New H1405C and new V1407 (new balcony on str. 6) ...... 11 3.13 FTM 14 - Replacement of H1403 ...... 11 3.14 FTM 16 – Replacement of RP5081 ...... 12 3.15 FTM 17 – Replacement of valves on C1501 ...... 12 3.16 FTM 18 – DBB on C1502 ...... 12 3.17 FTM 19 – New H1541 with access platform ...... 13 3.18 FTM 20 – Replacement of H1551 and increase diameter on RP5056 and RP5190 ...... 13 3.19 FTM 21 – Install by-pass of H1512 ...... 13 3.20 FTM 22 – Replacement of H1510 ...... 14 3.21 FTM 23 – Existing FTM (M50913-06) Increase capacity of P2752 ...... 14 3.22 FTM 29 – New impeller P1507 (reduce efficiency requirement) ...... 14 3.23 FTM 31 – Utility tie-ins ...... 16

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3.24 FTM 32 – Process tie-ins ...... 16 3.25 FTM 33 – Vent gas scrubber ANH ...... 16 3.26 FTM 34 – Analyser house modifications ...... 17 3.27 FTM 35 – Underground piping ...... 17 3.28 FTM 36 – Pipe rack HTDC bridge ...... 18 3.29 FTM 37 – Fire and gas ...... 18 3.30 FTM 38 – New flame arrestor for HTDC ...... 18 3.31 FTM 39 – New fire water monitor ...... 19 3.32 FTM 40 – Tie-in of new OHCL reactor and required modifications due to preservation of existing reactor ...... 20 3.33 FTM 41 – New HPN vessel for emergency purging ...... 20 4 Summary ...... 21 5 References ...... 23

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1 Introduction

INOVYN operates a vinyl chloride monomer (VCM) and chlorine plant at the Rafnes industrial area, marked in Figure 1.1. At present, the implementation of several modifications to the facility is ongoing as part of the North Star project. Of special interest for the risk analysis work, which LR is contracted to, is: • a new HTDC module and • a new OHCL reactor The HTDC module is a new module at INOVYN. It is expected to have a footprint of approximately 28 m x 8 m with three levels. The module is relatively congested with process equipment and reactors. The OHCL reactor replaces an existing reactor. This will increase both the flow throughput and the volume of the reactor. In addition to the new HTDC module and new OHCL reactor, several minor modifications are planned for the plants. In order to ensure that all risk contributors associated with the project are accounted for in the QRA update, a one-day workshop was held at Rafnes with a scope including up to 40 modifications. In the workshop, Wood and INOVYN presented the various modifications and replacements planned for the VCM plant. The workshop also included a guided tour around the plant. This memo presents the planned minor modifications (FTMs – “Forslag til modifikasjoner”) for the VCM plant with a comment on their potential as risk contributors in the context of the QRA. The QRA focus on the “delta” risk, i.e. increase or decrease in risk potential of implementing the FTM. As an example, if a new valve replaces an existing valve, the delta risk is assessed to be negligible. However, if new valves are installed or if pipes are replaced with larger ones, increasing the volume of hazardous material, the risk potential will increase. The modifications with a considerable delta risk potential will be passed on to the QRA update activity. The selection of modifications to be included in the QRA is based on the information from the Risk screening workshop and general assumptions made in the previous QRA performed for INOVYN Chlorine and VCM plant in 2015 (Ref. /1/)

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Figure 1.1 – Overview of the Rafnes industrial area. The VCM and chlorine plants are highlighted in orange

2 Process description

VCM is produced from the intermediate substance EDC. The EDC is produced in two separate processes in the VCM plant. The first process is by direct chlorination, using ethylene gas from Noretyl and chlorine gas from the chlorine plant. The second is by oxychlorination, using hydrogen chloride, hydrogen gas, ethylene gas and air. The EDC from the direct chlorination and oxychlorination is purified (distilled to remove light and heavy bi products) and intermediately stored before being sent to the cracking furnaces. VCM is produced by cracking EDC to VCM and HCl at a temperature of approx. 500 °C and 20 bar(g) pressure. The gas out of the cracking furnaces still holds a large amount of EDC and a number of steps are needed to separate VCM, HCl and EDC from the raw gas. In a number of steps the EDC is condensated out by cooling and HCl stripped off by reducing the pressure. Finally a distillation process removes the last traces of HCl and EDC and by-products from VCM. The pure VCM is stored as liquid in pressurized spherical tanks before being offloaded by ship or pumped through piping under the Frierfjord to INOVYN Norge PVC plant at Herøya. Utility systems include steam and condensate system, cooling water system, waste water treatment, incinerators for vented gases and fuel gas system. The VCM plant is divided into process area, tank farm, control centre, flare and quay. Production, as well as sewage treatment and combustion of bi-products, takes place in the process area. The process area is further divided into a number of plant areas as listed below: • 1100 - Oxychlorination • 1200 - EDC-recovery • 1300 - EDC purification • 1400 - Cracking • 1500 - VCM-purification • 1600 - Direct chlorination • 1700 - HCl-unit

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• 1800-1900 - Waste water treatment • 1800 - Incinerator • 2700 - EDC/VCM/by-product storage • 3000 - Jetty 2

3 VCM plant modifications

The FTMs for the VCM plant are presented in the following sections. Each FTM is presented with area, medium, description and risk evaluation. Locations of the different FTMs in the VCM plant are shown in Figure 3.1. Note that the following FTMs were voided prior to, or after, the Risk screening workshop and will not be a part of the QRA scope: • FTM 10 • FTM 15 • FTM 24 • FTM 25 • FTM 26 • FTM 27 • FTM 28 • FTM 30

Figure 3.1 - VCM plant - Location of FTMs

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3.1 FTM 01 - Replacement of line 400-RP 1069 to DN500 Area: 1100 Medium: EDC gas Description Line RP1069 connects the overhead of Oxy hot quench column, C-1101, to the crude EDC condensers, H1106 A/B. The linear velocity in this line will be too high following the VCM production increase, and it must be increased to DN500. The material in the line is SAF2507, this shall be kept. Temperature measurement TI1406 and pressure transducer PT1106 are installed on the line; these functions must be maintained in the new line. The outlet nozzle on C-1101 is DN 500, i.e. no modifications to the nozzle. The inlet nozzles on H1106A is DN600, i.e. the existing 400/600 expander must be replaced by a 500/600. Risk evaluation The line replacement reduces the amount of potential leak sources, but increases the mass flow and segment volume due to increased line diameter. However, it is assumed that leaks of EDC will only give local effects, Ref. /2/. Hence, FTM 01 will not be included in the QRA. Inclusion in QRA: No

3.2 FTM 02 - V1105 modifications Area: 1100 Medium: HCl gas Description Acetylene hydrogenation reactor V1105 should be modified to take a higher catalyst loading to allow the increase throughput. An insert is welded to the existing DN250 inlet nozzle in accordance to the recommendations from OxyVinyls and the internal grid is removed to allow increased catalyst inventory. Risk evaluation The modification does not impart any new potential leak sources, but the mass flow will increase. Based on previous evaluations (Ref. /2/) leaks of HCl in area 1100 will be included in the QRA. Inclusion in QRA: Yes

3.3 FTM 03 - H1104 replacement Area: 1100 Medium: HCl gas, condensate and steam Description Existing HCl preheater, H1104, is too small for the increased throughput and must be replaced. HCl outlet pipe, 250-RP1014-A25 shall be increased to DN300 up to NRV1014 Increased diameter on MPS feed nozzle, DN80 feed line expanded to DN100 Minor modifications to steam trap on condensate outlet from H1104.

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Risk evaluation The replacement of H1104 and related modifications will lead to an increased mass flow and increased segment volume. Based on previous evaluations (Ref. /2/) leaks of HCl in area 1100 will be included in the QRA. Inclusion in QRA: Yes

3.4 FTM 04 – Increase oxygen feed to OHCL with new heat exchanger H1151 Area: 1100 Medium: Condensate, steam, N2, enriched air and LOX Description The increased HCl conversion in the oxychlorination section will be covered by increased oxygen enrichment of the air feed. The air compressor does not have any spare capacity. Oxygen will be supplied by the same means as currently, i.e. from evaporation of liquid oxygen (LOX). The LOX will be supplied by AGA, or another supplier, by trucks to the LOX unit outside the plant fence at Rafnes. The oxygen evaporator (E3902) in the LOX unit has sufficient capacity for the increased consumption of oxygen. The scope of the FTM is: • Remove existing oxygen feed line to VCM plant • Install oxygen preheater, H1151, below Structure 2 in the VCM plant. Heating medium is MPS. Heat required: 90 kW • Install a DN80 oxygen line from E3902 to H1151 • Install a DN100 line from H1151 to the air feed line to the oxychlorination reactor • Reroute the condensate return line from H1108 to condensate tank, V1005, to avoid hammering • Connect high pressure N2 purge to the O2 line upfront H1151 • Connect N2 purge to the O2 line upfront H1151 (from 7 barg N2 net) Risk evaluation In this context, neither steam nor LOX can cause major accidents. Hence, FTM 04 will not be analysed in the QRA update. Inclusion in QRA: No

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3.5 FTM 05 – OHCL reactor cooling loop Area: 1100 Medium: Boiler feed water Description Forced circulating steam boiler is used to cool the oxychlorination reactor. The current BFW circulation rate results in about 13% evaporation per pass. To keep the steam quality unchanged the circulation of BFW should be increased by 10%. This is achieved by reducing the pressure drop in the circulation loop and reducing the P1101 impeller diameter from 380 to 360 mm. The last is necessary to reduce the load on the motor. A spectacle blind will be installed between P1101 and BFW header. Blind will be replaced by orifice if required. This is a backup solution if the chosen orifices, 23 mm, is too large. Risk evaluation No (or limited) hazardous substances, hence FTM 05 will not be analysed in the QRA. Inclusion in QRA: No

3.6 FTM 06 – New IPS line to Chlorine plant Area: 1000, 51 Medium: Steam Description Following the HTDC installation there will be a surplus of Intermediate Pressure Steam (IPS) in the VCM plant. This IPS can be utilised in the NaOH concentration unit in Klor 2. A new DN200 pipe must be installed between the VCM plant and Klor 2. The pipe shall be installed on existing pipe racks. A control valve with bypass possibilities and a flow meter is foreseen, but location and control philosophy is not decided. Risk evaluation No (or limited) hazardous substances, hence FTM 06 will not be analysed in the QRA. Inclusion in QRA: No

3.7 FTM 07 - P1305A/S replacement Area: 1300 Medium: EDC gas Description Pumps P1305A and P1305S are old and needs to be repaired to be kept in operation. They will therefore be replaced with identical pumps. The new pumps will be installed on the existing pump skid. A new motor will be installed for pump P1305A, and a recertified pump will be installed for pump P1305S. Risk evaluation The replacement will not impart any new leak sources. In addition, it is assumed that leaks of EDC will only give local effects, Ref. /2/. Hence, FTM 07 will not be analysed in the QRA. Inclusion in QRA: No

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3.8 FTM 08 - Replacement of several control valves Area: Several Medium: Fuel gas, NaOH, Ethylene, Crude EDC liquid, EDC liquid, EDC/VCM/HCl condensate, VCM liquid Description The following control valves needs to be replaced:

DN ID P&ID no Current New LCV202 12A 50 80 FCV313 13D 25 50 FCV450 14E 100 150 FCV518 15D 80 100 PCV114 11C 80 100 FCV148 11G 25 25 PCV053 10SA 150 200 PCV135 11C 200 200

Risk evaluation Number of leak sources and pipe dimension is kept unchanged, only the valve dimension will increase. The impact on the risk contours will be negligible. Hence, FTM 08 will not be evaluated in the QRA. Inclusion in QRA: No

3.9 FTM 09 - V1102 Modification of demister Area: 1100 Medium: Steam Description Oxy steam drum, V1102, has a demister pad at the steam outlet. This demister is too small for the increased steam production following a capacity increase and a bigger demister must be installed. Risk evaluation No (or limited) hazardous substances, hence FTM 06 will not be analysed in the QRA. Inclusion in QRA: No

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3.10 FTM 11 - Replacement of RP4015, RP4057 and RP4124 Area: 1400 Medium: EDC gas, VCM, HCl Description The gas outlet line (RP4124) from H1406 to H1402 A/B is DN250. This gives a too high linear velocity in the line. The line shall be increased to DN350. The outlet nozzle on H1406 is DN250, therefore the spare outlet head must be modified with a larger outlet nozzle. The inlet nozzles on H1402 A/B are DN350 so no modifications are required. The condensate outlet lines from H1402A and H1402B are DN200 up to where they are expanded to DN250 and merged together. The DN200 part of these lines (200-RP4066-BA40 and 200-RP4015-BA40) shall be expanded to DN250. Outlet temperature is controlled by the by-pass lines. These have sufficient capacity. Risk evaluation The replacement will not impart any new leak sources, but the mass flow and the segment volume will increase due to increased dimensions. However, these lines are a part of the top system in the cracking area and release from top system with HCl, VCM, EDC is assumed to only give local effects, Ref. /2/. Hence, FTM 11 will not be analysed in the QRA. Inclusion in QRA: No

3.11 FTM 12 - New P1404S Area: 1400 Medium: EDC liquid Description In case of insufficient condensation in H1401 and H1406, reflux to the quench columns C1401 A/B/C can be supplied by P1404. Currently this is a single pump installation. By installing spare pump, P1404S, and allowing for auto start of the pump from the control room, increasing the size of quench reflux drum V1406 can be avoided. The pump shall be a copy of the existing pump. KSB has supplied a price for this. A new foundation for the spare pump must be constructed. Existing P1404 is on Variabel Speed Drive, but is normally operated at fixed RPM and HIC499 is used for flow control. Existing will be rebuilt to operate with fixed RPM. The new pump will also be operated on fixed RPM. The flow will be manually controlled by HIC499. HIC499 must be moved to allow control of either pump – See red marked P&ID 14107DA for instrument details. Risk evaluation A new spare pump may lead to an increase in potential leak sources. However, leak of EDC is assumed to only give local effects (Ref. /2/) and will not be analysed in the QRA. Inclusion in QRA: No

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3.12 FTM 13 - New H1405C and new V1407 (new balcony on str. 6) Area: 1400 Medium: EDC/VCM/HCl condensate and cooling water Description The capacity of the quench overhead vent condensers H1405 A/B needs to be increased to reduce the load on the reflux on C1501.To allow the increased load a third parallel exchanger, H1405C, should be installed. This will be a copy of the larger condenser, H1405B, and will be installed on a new balcony west of the existing H1405B. Three H1405 in parallel will allow cleaning of the CW side of the heat exchangers while the VCM plant is running at high load. In addition a larger quench vapour separator, V1407, shall be installed to allow better separation of the H1405 A/B/C outlet. The new V1407 shall be installed below H1405 A/B/C on a skirt. RP4055 from V1407 bottom to C1501 shall be increased from DN80 to DN100. For further details on the scope of this modification, please refer to the individual FTM descriptions, Ref. /2/. Risk evaluation Additional equipment will lead to an increased total leak frequency. However, the new heat exchanger and the new separator are a part of the top system in the cracking area and release from top system with HCl, VCM, EDC is assumed to only give local effects, Ref. /2/. Hence, FTM 11 will not be analysed in the QRA. Inclusion in QRA: No

3.13 FTM 14 - Replacement of H1403 Area: 1400 Medium: EDC/VCM/HCl gas Description HCl exchanger H1403 is too small for the increased capacity and must be replaced. The new exchanger will have a larger diameter than the current exchanger. The top flange connections to the exchanger shall be kept as they are, and the exchanger must be expanded downwards. The height of the steel foundation will be reduced. Risk evaluation The replacement will not impart any new potential leak sources and the replacement is assumed to be “one to one”. Segment volume will increase due to increased dimensions. Heat exchanger H1403 is a part of the top system in the cracking area and release from top system with HCl, VCM, EDC is assumed to only give local effects, Ref. /2/. Hence, FTM 11 will not be analysed in the QRA. Inclusion in QRA: No

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3.14 FTM 16 – Replacement of RP5081 Area: 2700 Medium: EDC liquid Description Pipeline RP5081 from X1503 to T2707 is partially in pipe class LC25 and partially in A25.The scope of this FTM is to replace the A25 part with LC25. This is a long DN100 pipeline from the north/south main pipe rack in the VCM plant to the recycle EDC tank, T2707, in the south tank farm. There is no instrumentation on the pipeline. Risk evaluation The change in pipe class will increase the robustness of the pipe and have a benign effect on risk. However, the pipe class is not a parameter in the risk model, and this modification will therefore not be reflected in the QRA. Inclusion in QRA: No

3.15 FTM 17 – Replacement of valves on C1501 Area: 1500 Medium: EDC/VCM liquid, EDC/VCM gas, steam, condensate Description Valves on the inlet and outlet of the reboiler on HCl column, H1501, will be replaced. Risk evaluation Replacing the valves will not introduce additional leak points. The modification will not be considered in the QRA. Inclusion in QRA: No

3.16 FTM 18 – DBB on C1502 Area: 1500 Medium: EDC/VCM gas and liquid Description VCM column, C1502, has two reboilers, H1503 A and B. To avoid stopping the VCM production during reboiler replacement, double block and bleed valves shall be installed on the inlet and outlet of the reboilers. Butterfly valves are preferred. Hand operated valves are accepted. Valves are DN400 and DN900, thus long lead items. Bleed to Slop System (SS). Risk evaluation The DBB valves will introduce additional leak points. The modification will be considered in the QRA. Inclusion in QRA: Yes

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3.17 FTM 19 – New H1541 with access platform Area: 1500 Medium: EDC/VCM 2-phase Description The feed from the HCl column to the VCM column should be cross exchanged with the bottom stream of the VCM column. This will reduce the steam consumption in the VCM column, which is a requirement to reach the 1700 t/d target. A new cross exchanger that cools the bottom outlet of the VCM column by preheating the feed to the column, H1541, shall be installed. The location of the cross exchanger is tight, and a structure that allows installation and removal of the heat exchanger from underneath the main pipe rack is required. Risk evaluation This FTM introduce new leak points of 2-phase EDC/VCM, and increase the segment volume. The FTM will be considered in the QRA. Inclusion in QRA: Yes

3.18 FTM 20 – Replacement of H1551 and increase diameter on RP5056 and RP5190 Area: 1500 Medium: EDC, EDC liquid Description Dry crude EDC exchanger H1551 has too small heat transfer area, too small nozzles and a triangular pitch that makes cleaning very difficult. A new H1551 is designed to increase the heat transfer and avoid tube bundle vibrations. The new H1551 shall be installed in the same physical location as the existing one. In addition this FTM contains the replacement of RP5056 from C1502 to H1551 from DN100 to DN150 and the replacement of RP5190 from downstream LCV517 from DN100 to DN150. Risk evaluation Although the segment volume will increase, EDC leaks are assumed to only give local effects, Ref. /2/, and the modification will not be considered in the QRA. Inclusion in QRA: No

3.19 FTM 21 – Install by-pass of H1512 Area: 1500 Medium: EDC liquid Description A bypass of Dry crude EDC cooler H1512 will allow plant operation with the heat exchanger out for maintenance. Risk evaluation Although the segment volume will increase, EDC leaks are assumed to only give local effects, Ref. /2/, and the modification will not be considered in the QRA. Inclusion in QRA: No

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3.20 FTM 22 – Replacement of H1510 Area: 1500 Medium: Cooling water, VCM liquid Description VCM production cooler H1510 must be replaced as the pressure drop limits the capacity of the VCM stripper bottom pump P1507. Risk evaluation Replacing H1510 does not introduce any new leak points, but the mass flow rate will increase. The modification will therefore be considered in the QRA. Inclusion in QRA: Yes

3.21 FTM 23 – Existing FTM (M50913-06) Increase capacity of P2752 Area: 2700 Medium: EDC Description Increase the capacity of P2752A/S for return EDC. The scope includes electrical modifications on existing pumps. Risk evaluation Although the mass flow rate will increase, EDC leaks are assumed to only cause local effects, Ref. /2/. Inclusion in QRA: No

3.22 FTM 29 – New impeller P1507 (reduce efficiency requirement) Area: 2700 and 1300 Medium: EDC Description For the P-2703 position we need installation of two new and bigger pumps, and one pump in spare. We will also in this FTM add a number of valves to the existing scope in order to separate the content in T2702 and T2703 from each other. • Today the pumps P2703 A/S operate as follows: o P2703A takes full furnace feed from T2702 to V2704 o P2703S takes imported EDC from T2703 to V2704 via the same pipe as P2703A (flow limited by position of manual valve on discharge P2703 S) o Pumps are equipped with check valve in discharge line o Each existing pump P2703 is considered to be able to take 100% of current capacity, but not more (discharge valve fully open)

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• Additional valves to be foreseen to prevent contamination of import/export EDC in T2703 by purified EDC in T2702 (also in case P2703A out of service and switched to position P2703S). See drawing for valve positions: o Valve position 1: Double valve needed to avoid contaminating T2703 with EDC coming from C1302. Zwick-valve is designed to block-> will install it instead of two valves o Valve position 2: double valve needed. In case P2703A is switched to position S, EDC from T2702 can contaminate T2703 when not double blocked. Zwick-valve o Valve position 3: double valve needed. In case P2703A is switched to position S and HTDC is sent to T2703, EDC from T2702 can contaminate T2703 when not double blocked o Valve position 4: Double valve needed. Separation of purified and import/export EDC in normal operation (P2703A from T2702 and P2703S from T2703 to V2704) Zwick-valve o Valve position 5: Is it is today, no change o Valve position 7: In case of normal operation and unloading of vessel to T2703, this position can contaminate T2703. Existing manual valves from Jetty line to T2703 are closed in normal operation double valve required o Valve position 6: In case P2703A is switched to position S and unloading of vessel to T2703, this position can contaminate T2703. Rare scenario double valve not required. No, change from current configuration o In addition, not a numbered valve on the drawing. We will need a extra line from the new HTDC line from HTDC-unit to cracker-feed tank. There is a spare nozzle on top of the cracker-feed tank. This line will need a dip-tube. One valve on top of the tank o Need blinds on two valves near sampling station 27-03 (not on the drawing) o Supply benzene free EDC to HTDC

Risk evaluation EDC leaks are assumed to only give local effects, Ref. /2/. This modification will therefore not be considered in the QRA. Inclusion in QRA: No

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3.23 FTM 31 – Utility tie-ins Area: Medium: Description Utility tie-ins to the new HTDC module. Extent of modifications will be identified in the QRA update. Risk evaluation All tie-ins to the new HTDC module will be considered in connection with installing the new HTDC module. This FTM will be further analysed in the QRA to identify if the utility tie-ins include any hazardous substances. The blowdown system is assumed not to be pressurized. Inclusion in QRA: Yes

3.24 FTM 32 – Process tie-ins Area: Medium: Description Process tie-ins to the new HTDC module. Extent of modifications will be identified in the QRA update. Risk evaluation All tie-ins to the new HTDC module will be considered in connection with installing the new HTDC module. Inclusion in QRA: Yes

3.25 FTM 33 – Vent gas scrubber ANH Area: 1800 Medium: Nitrogen Description The HTDC unit will run at lower pressure than the LTDC, to be able to absorb the vent gas in ANH in case of incinerator S/D a vent gas scrubber system shall be installed on HCl neutralization tank, T1801. A new pump, P1859S, will be installed to allow circulation of caustic in the scrubber in case of electrical black out. Risk evaluation Nitrogen is not considered as a hazardous substance in the context of the QRA. Also, input from Wood shows that the pressure in the vent gas scrubber system will be low, and a leak should not cause any large scale effects. Therefore, this FTM will not be considered in the QRA update. Inclusion in QRA: No

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3.26 FTM 34 – Analyser house modifications Area: 1650 Medium: N/A Description The existing analyser house needs to be extended to accommodate the new HTDC analysers (fig.1). The additional room has a simple metal roof which needs to be replaced by a reinforced concrete roof. Some equipment has to be relocated when opening the wall between the existing and new room. Final location of the new analysers in the new room has to be done based on final sample system and analyser layout. There are five available slots on the walls in the new room. The existing bottle room will be reduced to one small compartment suitable for the required number of bottles. Risk evaluation Only structural changes, not relevant for the QRA. Inclusion in QRA: No

3.27 FTM 35 – Underground piping Area:

Medium: H2O Description Underground piping must be rerouted due to conflict with the foundation of the HTDC module. The following pipes must be rerouted: • 150-RP8315-LC16 • 150-FW0010-LC16 • 200-FW0003-LC16 • 200-FW0001-LC16 • 160-CS1041-ZD10 • 50-CS0025-ZD10 Risk evaluation Non-hazardous substances (drain water, fire water etc.) The modifications will not be included in the QRA. Inclusion in QRA: No

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3.28 FTM 36 – Pipe rack HTDC bridge Area: 1600 Medium: N/A Description New steel pipe rack bridge from battery limit at HTDC module to battery limits at wash area pipe rack. Risk evaluation Only structural changes, not relevant for the QRA. Inclusion in QRA: No

3.29 FTM 37 – Fire and gas Area: New HTDC module Medium: N/A Description Installation of gas detection systems in the new HTDC module: • EX detectors for explosive gas detection • Chlorine gas detectors (point detectors) • Sniffing detectors for detection of toxic gas releases (low concentrations) Risk evaluation Gas detection in the new HTDC module will be considered as a barrier in the QRA. Inclusion in QRA: Yes

3.30 FTM 38 – New flame arrestor for HTDC Area: 1600, 1800 Medium: Nitrogen, oxygen, ethylene Description Replacement of existing flame arrestor and RP6045 from 1600 to incinerator F1821.

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Risk evaluation Input from Wood shows that there is only a small fraction of ethylene in this pipe (9 vol%). Nitrogen and oxygen are not considered in the QRA, so it is assumed that this FTM will have a negligible effect on the risk contours. Therefore, the FTM will not be considered in the QRA update. Inclusion in QRA: No

3.31 FTM 39 – New fire water monitor Area: Fire water system

Medium: H2O Description Monitor X1032/12 shall be replaced by new remotely controlled fire water monitor X1032/16 in TAR 2019. Risk evaluation The fire water monitor will be considered as a barrier/risk reducing measure in the QRA. Inclusion in QRA: Yes

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3.32 FTM 40 – Tie-in of new OHCL reactor and required modifications due to preservation of existing reactor Area: 1100

Medium: HCl, C2H4, EDC, Air Description The following items to be included in the work description of FTM40 - Tie-in of OHCL: • Tie-in of new reactor V1106 • Preservation of existing reactor V1101 • Modify Y-piece of existing reactor or purchase new y-piece • Removable spool on RP1055 to the existing reactor to be included • New ladder from platform on top of existing OHCL reactor • Access to existing ladder from platform on top of OHCL reactor to be closed Risk evaluation Tie-ins of OHCL reactor will be considered in connection with the installation of the new OHCL reactor. Inclusion in QRA: Yes

3.33 FTM 41 – New HPN vessel for emergency purging Area: Medium: Nitrogen Description One new nitrogen tank V1107 shall be installed. Location is north of existing tanks. The tank shall have an access platform at the top, similar to those which are located on existing tanks. These platforms shall be connected with bolts. There is good access for cranes in the particular area. Risk evaluation Nitrogen is not a hazardous substance in the context of the QRA. Inclusion in QRA: No

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4 Summary

Table 4.1 presents a summary of the VCM FTMs and comment on their potential as risk contributors in the context of the QRA update. Out of the 33 FTMs presented in this memo, 11 FTMs/modifications will be analysed further in the update of the QRA. In addition, risk assessment of the new HTDC module and OHCL reactor will be included.

Table 4.1 – Summary of risk evaluation of FTMs FTM Area Scope description Medium Inclusion in No. QRA? FTM 01 1100 Replacement of line 400-RP 1069 to EDC gas No DN500 FTM 02 1100 V1105 modifications HCl gas Yes FTM 03 1100 H1104 replacement HCl gas, Yes condensate and steam FTM 04 1100 Increase oxygen feed to OHCL with Condensate, No new heat exchanger H1151 steam, N2, enriched air and LOX FTM 05 1100 OHCL reactor cooling loop Boiler feed No water FTM 06 1000, 51 New IPS line to Clorine plant Steam No FTM 07 1300 P1305A/B/S replacement EDC gas No FTM 08 Several Replacement of several control Fuel gas, No valves NaOH, Ethylene, Crude EDC liquid, EDC liquid, EDC/VCM/HCl condensate, VCM liquid FTM 09 1100 V1102 Modification of demister Steam No FTM 11 1400 Replacement of RP4015, RP4057 EDC gas, No and RP4124 VCM, HCl FTM 12 1400 New P1404S EDC liquid No FTM 13 1400 New H1405C and new V1407 (new EDC/VCM/HCl No balcony on str. 6) condensate and cooling water

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FTM Area Scope description Medium Inclusion in No. QRA? FTM 14 1400 Replacement of H1403 EDC/VCM/HCl No gas FTM 16 2700 Replacement of RP5081 EDC liquid No FTM 17 1500 Replacement of valves on C1501 EDC/VCM No liquid, EDC/VCM gas, steam, condensate FTM 18 1500 DBB on C1502 EDC/VCM gas Yes and liquid FTM 19 1500 New H1541 with access platform EDC/VCM 2- Yes phase FTM 20 1500 Replacement of H1551 and increase EDC, EDC No diameter on RP5056 and RP5190 liquid FTM 21 1500 Install by-pass of H1512 EDC liquid No FTM 22 1500 Replacement of H1510 Cooling Yes water, VCM liquid FTM 23 2700 Existing FTM (M50913-06) EDC No Replacement of P2752 FTM 29 2700,1300 New impeller P1507 EDC No FTM 31 Utility tie-ins Unknown Yes FTM 32 Process tie-ins Unknown Yes FTM 33 1800 Vent gas scrubber ANH Nitrogen No FTM 34 1650 Analyser house modifications N/A No

FTM 35 Underground piping H2O No FTM 36 1600 Pipe rack HTDC bridge N/A No FTM 37 Fire and gas N/A Yes FTM 38 1600,1800 New flame arrestor for HTDC Nitrogen, No oxygen, ethylene

FTM 39 Fire water New fire water monitor H2O Yes system

FTM 40 1100 Tie-in of new OHCL reactor and HCl, C2H4, Yes required modifications due to EDC, Air preservation of existing reactor FTM 41 New HPN vessel for emergency Nitrogen No purging

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5 References

/1/ Lloyd’s Register Consulting: «Total risk assessment (QRA) for the Chlorine and VCM plant – INOVYN Norge AS, Rafnes”, Report no. 105797/R1, Rev. Final, 15 September 2015

/2/ INEOS Norge AS/Noretyl AS: “Arbeidsbeskrivelse FTM 13”, Doc. No. 10113993-I50477-I- TF-0002, 10113993-I50477-L-TF-0013, 10113993-I50477-N-TF-0013 and 10113993- I50477-R-TF-0013, Rev. 01

Memo: Risk screening workshop - VCM scope Page 23 of 23 Date: 30 November 2018 ©Lloyd’s Register 2018 Appendix C Risk screening workshop - Chlorine plant

Report no: PRJ11090011 Rev: Final Page C1 Date: 11 January 2019 ©Lloyd’s Register 2019

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Memo

Risk screening workshop - Chlorine plant

To: Inovyn Cc:

From: Ingebjørg Valkvæ/Andrea Risan/ Date: 30 November 2018 Stian Jensen/Ane Kristiansen

Project no: PRJ11091548

Table of Contents

1 Introduction ...... 2 2 Process description ...... 3 3 Chlorine plant modifications ...... 3 3.1 FTM 262 - Installation of new electrolyser ...... 3 3.2 FTM 361 - Increased capacity on chlorine cooler ...... 4 3.3 FTM 366 - Increased capacity on chlorine compressor ...... 4 3.4 FTM 421 - Increased capacity on hydrogen compressor ...... 4 4 Summary ...... 5 5 References ...... 5

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1 Introduction

INOVYN operates a vinyl chloride monomer (VCM) and chlorine plant at the Rafnes industrial area, marked in Figure 1.1. At present, the chlorine plant is upgraded to higher production rates as part of the North Star project. LR is contracted by Inovyn to investigate the impact on the risk picture as a result of this upgrade. In addition to the new HTDC module and new OHCL reactor, several minor modifications are planned for the plants. In order to ensure that all risk contributors associated with the project are accounted for in the QRA update, a one-day workshop was held at Rafnes with a scope including up to 40 modifications. In the workshop, Wood and INOVYN presented the various modifications and replacements planned for the chlorine and VCM plants. The workshop also included a guided tour around the plants. This memo presents the planned modifications (FTMs – “Forslag til modifikasjoner”) for the chlorine plant with a comment on their potential as risk contributors in the context of the QRA. The QRA focus on the “delta” risk, i.e. increase or decrease in risk potential of implementing the FTM. As an example, if a new valve replaces an existing valve, the delta risk is assessed to be negligible. However, if new valves are installed or if pipes are replaced with larger ones, increasing the volume of hazardous material, the risk potential will increase. The modifications with a considerable delta risk potential will be passed on to the QRA update activity. The selection of modifications to be included in the QRA is based on the information from the Risk screening workshop and general assumptions made in the previous QRA performed for INOVYN Chlorine and VCM plant in 2015 (Ref. /1/)

Figure 1.1 – Overview of the Rafnes industrial area. The VCM and chlorine plants are highlighted in orange

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2 Process description

Chlorine is produced in two almost identical plants, Chlorine 1 and 2, with membrane electrolysers. Chlorine is produced on the anode side and hydrogen and caustic soda on the cathode side. The moist chlorine gas is cooled, filtered and dried with sulphuric acid before being compressed to approx. 5.5 bar(g) and sent to the VCM plant. The Chlorine gas from both plant 1 and 2 is delivered in a single 250 mm header. The Hydrogen gas is cooled, filtered, dried and compressed and sent to the VCM plant and to the neighbouring industry Noretyl to be used as raw material or fuel gas. The caustic soda is concentrated to 50 % using evaporation and then stored. The caustic soda is exported by trucks and shipped by boats to several customers. The chlorine plant is divided into the following areas: • Water purification • Brine • Cell room • Caustic soda • Hydrogen • Lean brine dechlorination • Emergency scrubber/recovery chlorine • Chlorine

3 Chlorine plant modifications

3.1 FTM 262 - Installation of new electrolyser Area: Cell room

Medium: Brine, H2, Cl2, NaOH Description Installation of a new electrolyser in the existing cell room for Klor 1. Process design and material delivery is part of tkUCE's contract. Follow-up of technical conditions and delivery as such are carried out in the modification. Risk evaluation Leaks from individual cells are not considered to pose a threat outside the cell room, Ref. /1/. The new electrolyser will however result in increased mass flow rate in the chlorine header, and will therefore be included in the QRA. Inclusion in QRA: Yes

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3.2 FTM 361 - Increased capacity on chlorine cooler Area: Chlorine

Medium: Cl2 gas Description The capacity of existing chlorine cooler is too low and must be replaced. Process and mechanical design as well as material / equipment delivery are part of tkUCE's contract. Follow-up of technical conditions and delivery as such are carried out in the modification. Potential solution: Replacement of existing cooler with new cooler with sufficient capacity Risk evaluation Replacing the chlorine cooler will increase the segment volume and will therefore be included in the QRA. Inclusion in QRA: Yes

3.3 FTM 366 - Increased capacity on chlorine compressor Area: Chlorine

Medium: Cl2 gas Description The capacity of existing chlorine compressor is not sufficient to handle increased production and thus capacity must be increased. Modification work on the compressor is performed in TAR2019. The modification follows up on contract, preparation work, and work carried out on site. The K3201 is a single-handed 3-speed radial turbo compressor manufactured by Demag (Siemens AG). Risk evaluation Revamping the chlorine compressor will increase the segment volume and will therefore be included in the QRA. Inclusion in QRA: Yes

3.4 FTM 421 - Increased capacity on hydrogen compressor Area: Hydrogen

Medium: H2 Description The capacity of existing hydrogen compressor is insufficient and the capacity must thus be increased. There are two current alternatives: • New compressor train in parallel with existing (most likely not this option) • Replacement of existing compressor train Risk evaluation Leaks of hydrogen from compressors are assumed to give only local effects. However, replacing the hydrogen compressor will increase the mass flow rate in the hydrogen header, and will therefore be included in the QRA. Inclusion in QRA: Yes

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4 Summary

Table 4.1 presents a summary of the chlorine plant FTMs and comment on their potential as risk contributors in the context of the QRA update. All 4 FTMs presented in this memo will be analysed further in the update of the QRA.

Table 4.1 – Summary of risk evaluation of FTMs FTM Area Scope description Medium Inclusion in No. QRA?

FTM 262 Cell room Installation of new electrolyser Brine, H2, Cl2, Yes NaOH

FTM 361 Chlorine Increased capacity on chlorine cooler Cl2 gas Yes

FTM 366 Chlorine Increased capacity on chlorine Cl2 gas Yes compressor

FTM 421 Hydrogen Increased capacity on hydrogen H2 Yes compressor

5 References

/1/ Lloyd’s Register Consulting: «Total risk assessment (QRA) for the Chlorine and VCM plant – INOVYN Norge AS, Rafnes”, Report no. 105797/R1, Rev. Final, 15 September 2015

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