RESEARCH REPORT VTT-R-03998-15 SAFIR2014 Annual Report 2014 Authors: Jari Hämäläinen & Vesa Suolanen Confidentiality: Public Preface The mission of the National Nuclear Power Plant Safety Research Programme 2011-2014 (SAFIR2014), derived from the stipulations of the Finnish Nuclear Energy Act, is as follows: The objective of the SAFIR2014 research programme is to develop and maintain experimental research capability, as well as the safety assessment methods and nuclear safety expertise of Finnish nuclear power plants, in order that, should new matters related to nuclear safety arise, their significance can be assessed without delay. The planning period 2011-2014 for the national research programme on nuclear power plant safety involved licensing processes for power plants that are in use or under construction, as well as overall safety evaluations related to licence terms. The construction works of the Olkiluoto 3 plant unit were proceeding, and the construction licence application of Hanhikivi 1 plant unit was to be left for evaluation. These processes are reflected in many ways on national safety research. Research on nuclear safety requires profound training and commitment. The research programme serves as an important environment providing long-term activity that is especially important now when the research community is facing a change of generation. During the planning period and in the following years, many of the experts who have taken part in construction and use of the currently operating plants are retiring. The licensing processes and the possibility of recruiting new personnel for safety-related research projects give an opportunity for experts from different generations to work together, facilitating knowledge transfer to the younger generation. The SAFIR2014 research programme was divided into eight research areas: 1) Man, Organisation and Society, 2) Automation and Control Room, 3) Fuel Research and Reactor Analysis, 4) Thermal Hydraulics, 5) Severe Accidents, 6) Structural Safety of Reactor Circuits, 7) Construction Safety, and 8) Probabilistic Risk Analysis (PRA). Furthermore, projects could be focused on developing of the research infrastructure. Research projects of the programme are chosen on the basis of annual call for proposals. In 2014 the realised volume of the SAFIR2014 programme was 10.2 M€ and 70 person years. Main funding organisations in 2014 were State Waste Management Fund VYR with 5.7 M€ and VTT with 2.7 M€. Research was carried out in 45 projects. This report was prepared by the programme director in co-operation with the project co- ordinator and the managers and staff of the individual research projects. Espoo 31.8.2015 Authors RESEARCH REPORT VTT-R-03998-15 3 (164) Contents Preface ................................................................................................................................... 2 Contents ................................................................................................................................. 3 1. Introduction ....................................................................................................................... 5 2. Main results of the research projects in 2014 .................................................................... 7 2.1 Man, organisation and society ................................................................................ 11 2.1.1 Managing safety culture throughout the lifecycle of nuclear plants (MANSCU) 11 2.1.2 Sustainable and future oriented expertise (SAFEX2014) ............................ 12 2.1.3 Signalled and silenced aspects of nuclear safety (SISIANS) ....................... 14 2.2 Automation and control room .................................................................................. 21 2.2.1 Coverage and rationality of the software I&C safety assurance (CORSICA)21 2.2.2 Human-automation collaboration in incident and accident situations (HACAS) 24 2.2.3 Safety evaluation and reliability analysis of nuclear automation (SARANA) 26 2.2.4 Safety requirements specification and management in nuclear power plants (SAREMAN)................................................................................................ 29 2.2.5 Identification of fault situations propagating between different systems and disciplines (IFAPROBE) .............................................................................. 34 2.3 Fuel research and reactor analysis ......................................................................... 38 2.3.1 Criticality safety and transport methods in reactor analysis (CRISTAL) ....... 38 2.3.2 Three-dimensional reactor analyses (KOURA) ........................................... 41 2.3.3 Development of a Finnish Monte Carlo reactor physics code (KÄÄRME) .... 45 2.3.4 Neutronics, nuclear fuel and burnup (NEPAL)............................................. 47 2.3.5 Extensive fuel modelling (PALAMA) ............................................................ 51 2.4 Thermal hydraulics ................................................................................................. 54 2.4.1 Enhancement of safety evaluation tools (ESA) ........................................... 54 2.4.2 Experimental studies on containment phenomena (EXCOP) ...................... 58 2.4.3 OpenFOAM CFD-solver for nuclear safety related flow simulations (NuFOAM) 63 2.4.4 Numerical modelling of condensation pool (NUMPOOL) ............................. 67 2.4.5 PWR PACTEL experiments (PAX) .............................................................. 70 2.4.6 Modelling of steam generators of nuclear power plants (SGEN) ................. 72 2.4.7 Uncertainty Evaluation for Best Estimate Analyses (UBEA) ........................ 76 2.4.8 Thermal hydraulics and fuel integrity in spent fuel dry cask interim storage facility (SPEFU) .......................................................................................... 78 2.5 Severe accidents .................................................................................................... 83 2.5.1 Core debris coolability (COOLOCE-E) ........................................................ 83 2.5.2 Chemistry of fission products (FISKES) ...................................................... 85 2.5.3 Thermal hydraulics of severe accidents (TERMOSAN) ............................... 88 2.5.4 Transport and chemistry of fission products (TRAFI) .................................. 92 2.5.5 Reactor vessel failures, vapour explosions and spent fuel pool accidents (VESPA) ..................................................................................................... 94 RESEARCH REPORT VTT-R-03998-15 4 (164) 2.5.6 Passive Containment Cooling System tests (PCCS) ................................... 98 2.6 Structural safety of reactor circuits ........................................................................ 102 2.6.1 Environmental influence on cracking susceptibility and ageing of nuclear materials (ENVIS) ..................................................................................... 102 2.6.2 Fracture assessment of reactor circuit (FAR) ............................................ 105 2.6.3 Monitoring of the structural integrity of materials and components in reactor circuit (MAKOMON) .................................................................................. 110 2.6.4 RI-ISI analyses and inspection reliability of piping systems (RAIPSYS) .... 113 2.6.5 Advanced surveillance-techniques and embrittlement modelling (SURVIVE)115 2.6.6 Water chemistry and plant operating reliability (WAPA) ............................ 118 2.6.7 Fatigue affected by residual stresses, environment and thermal fluctuations (FRESH) ................................................................................................... 121 2.6.8 Heavy fouling and corrosion risks in the cooling water systems of NPPs and methods for their mitigation (RICO) ........................................................... 124 2.7 Construction safety ............................................................................................... 128 2.7.1 Impact 2014 (IMPACT2014) ..................................................................... 128 2.7.2 Aging management of concrete structures in nuclear power plants (MANAGE) 130 2.7.3 Structural mechanics analysis of soft and hard impacts (SMASH) ............ 131 2.7.4 Seismic safety of nuclear power plants – targets for research and education (SESA)...................................................................................................... 134 2.8 Probabilistic risk analysis (PRA) ........................................................................... 138 2.8.1 Extreme weather and nuclear power plants (EXWE)................................. 138 2.8.2 Risk assessment of large fire loads (LARGO) ........................................... 141 2.8.3 PRA development and application (PRADA) ............................................. 144 2.8.4 FinPSA knowledge transfer (FINPSA-TRANSFER) .................................. 148 2.9 Development of research infrastructure ................................................................ 151 2.9.1 Enhancement of Lappeenranta instrumentation of nuclear safety experiments (ELAINE) .................................................................................................. 151 2.9.2 Renewal of hot cell infrastructure (REHOT) .............................................. 153 3. Financial and statistical information .............................................................................