ICP External

RPT-1659 Formal Cause Analysis for the ARP V (WMF-1617) Drum Event at the RWMC October 2018 RPT-1659 Formal Cause Analysis for the ARP V (WMF-1617) Drum Event at the RWMC October 2018 Idaho Cleanup Project Core Idaho Falls, Idaho 83402 Formal Cause Analysis for the ARP V (WMF-1617) Drum Event at the RWMC RPT-1659 October 2018 Prepared by: Leader Date TFE, Root Cause Analysis Team f!1-1~ I I Ron Guymon Date Root Cause Analysis Team o 9 /z 8 /z&>/B fomciements~~ Date Root Cause Analysis Team ~ t Le~if~zt Date Fluor Idaho Cause Analysist Peer Review Concurred by: Richard Swanson PMI-Inc. Root 7ause Specialist /o/ I I:J-olt lli!!JJ£J Date Fluor Idaho ARP V Event Team Leader cub.. ~ el.£c.:t~-w_: ~-t...-, Mike Coyle Date TFE, Nuclear Safety Culture Specialist Approved by: 10( I II 8 Fred P. Hughes Date ICP Core Program Manager M~~G= ~' \ 30\~ M~C~~ L D~e TFE, Nuclear Safely Culture Specialist ABSTRACT This report documents a formal cause analysis conducted of a thermal event and subsequent energetic release of radioactive material from four 55-gal drums that occurred in the Accelerated Retrieval Project V facility (WMF-1617) on April 11, 2018. No workers were in the facility at the time of the event, and no release to the environment was detected. The ARP V facility is part of the Radioactive Waste Management Complex at the Idaho National Laboratory Site. iii iv EXECUTIVE SUMMARY At approximately 2235 Mountain Daylight Time (MDT) on April 11, 2018, there was an incident in the Accelerated Retrieval Project (ARP) V facility, WMF-1617, at the Radioactive Waste Management Complex (RWMC) at Idaho National Laboratory (INL) Site. This incident resulted in a thermal event and subsequent energetic release of radioactive material from four 55-gal drums to a work area normally accessible to facility workers. There were no workers in the facility at the time. There was no detected release to the environment. The retrieval enclosures in ARP V (WMF-1617) are large tension membrane buildings erected over specified exhumation areas to limit the spread of contamination and provide protection from the weather. They are actively ventilated with high efficiency particulate air (HEPA) filtration systems. The INL Fire Department responded to the site following receipt of fire alarms and initially entered the facility through the vestibule in turnout gear. Upon entry, the first firefighter smelled smoke, backed out of the facility, and had the entry team don self-contained breathing apparatuses. The firefighters then re-entered the facility into the airlock area where drums that had been repackaged that afternoon were staged to be removed the next day. On initial entry, one drum was observed with a lid off; no flames were observed, but smoke was emanating from the top of the drum. The external temperature of the drum was measured to be 190 degrees Fahrenheit and increasing, using a thermal imaging camera. The firefighters attempted unsuccessfully to extinguish the hot spots in the affected drum, moved the drum away from the array of staged drums, and exited the facility at 0005 on April 12, 2018. A loud noise was heard at 0024, indicative of additional drum breaching. Personnel in the area later stated there was so much dust and debris in the air that they could not see through the window. At this time, personnel were evacuated to 100m per emergency response guidelines. All three firefighters were taken to the Central Facilities Area (CFA) for decontamination at the Site decontamination facility where they were successfully decontaminated and transported to the Radiological and Environmental Sciences Laboratory (RESL) in town for precautionary lung counts. Another loud noise was reported at 0328 by personnel in the vicinity of ARP V indicative of an escalating event. During initial reentry on April 19, 2018, it was discovered that a total of four drums had undergone exothermic reactions with their lids and contents being ejected. On April 16, 2018, Fred Hughes, Fluor Idaho Project Manager, directed the establishment of an event investigation team led by Gene Balsmeier. Mr. Balsmeier established teams to address causal analysis, technical investigation, and reentry/facility recovery planning and execution. The letter from Mr. Hughes directed development of a comprehensive corrective action plan following the investigation and cause analysis of the event to address root, direct, and contributing causes to prevent recurrence. The Root Cause Team was also chartered to provide recommendations for a corrective action plan addressing the identified root causes. PROBLEM STATEMENT At approximately 2235 on April 11, 2018, the Accelerated Retrieval Project (ARP) V facility, WMF-1617, experienced an overpressure event on a repackaged sludge drum. Additionally, three other drums experienced similar over pressurizations during the night. v This causal analysis report is supported by available results from the Technical Team’s analysis of samples taken from the event drums, selected unreacted drums and locations, and sampling of expelled material in the airlock area. Data gained from the sample results will be used in the technical analysis to confirm that drum containing depleted uranium was processed which was ultimately packaged into four daughter drums that exothermically reacted approximately 8 hours later. When all sample results have been obtained and analyzed, the Technical Team will prepare an addendum to this final report that will provide a detailed analysis of the materials, chemicals, and mechanics of the exothermic event. At that time, the Root Cause Team will revise the Cause Analysis if necessary, based on the additional information. The most recent data from indicates that two previously unidentified mechanisms possibly led to the event: 1. Oxidation of a nonroaster oxide depleted uranium metal over a period of approximately eight hours (heat source that initiated secondary reactions) 2. Generation of methane from secondary chemical reactions from beryllium carbide with a smaller possible contribution from uranium carbide reactions Neither of these mechanisms was captured in existing Acceptable Knowledge documents and neither was anticipated. A literature review of uranium oxidation experiments indicate that uranium oxidation could occur over an extended period of time. A review of previous methane issues revealed that, in 2015, a population of drums was identified that contained high methane levels that precluded shipment to WIPP. A team was brought in from LANL to identify the source of methane but was unsuccessful (LA-UR-15-26657). These drums have been isolated and remain onsite. The Technical Team is conducting tests to verify this hypothesis and to confirm the mechanisms listed above. The Root Cause Team was chartered to determine the cause of the drum excursion, identify organizational and process weaknesses, analyze potential gaps in hazard controls, and develop recommendations regarding correcting the identified causes. The Root Cause Team performed a detailed analysis of the drum over pressurization event. The Root Cause Team used the information and approaches described in DOE O 225.1B “Accident Investigations”; MCP-190, “Event Investigation and Occurrence Reporting”; and MCP-598, “Corrective Action System.” The analysis was performed in a manner consistent with the requirements of STD-1113, “Cause Analysis and Corrective Action Development.” A comprehensive event and causal factor (E&CF) chart was developed that presents the time sequence for the series of tasks and/or actions that were taken surrounding conditions leading to the project event. The results are displayed in a format that graphically relates event conditions and behaviors to the subsequent causal factors. Summaries are presented in Appendixes N and O. Additionally, the Root Cause Team performed barrier analysis (Appendix D), developed a comparative timeline/change analysis (Appendix C), and performed a safety culture evaluation of the inappropriate actions identified by the Root Cause Team during their analysis of the event timeline which started in 2009 and ended April 12, 2018. The analysis covers a timespan up to the actual event on April 11, 2018 that includes receipt of waste from Rocky Flats, burial, retrieval, storage, and development of the process used to treat the waste. Multiple prime contractors were involved and many of the decisions and actions predate the current contractor. The E&CF chart delineates transition to Fluor Idaho on June 1, 2016. vi Discussion of Direct, Root, and Contributing Causes Overall, the Root Cause Team identified two root causes and eight contributing causes. The Root Cause Team also provided recommended actions to address the root causes and contributing causes. Direct Cause (DC)—the immediate events or conditions that caused the accident. Based on available sample results, the Root Cause Team identified the direct cause of this event. DC—Based on available sample results, the Root Cause Team identified the direct cause of this event as the breach of four transuranic (TRU) waste containers in the ARP V building resulting from the mixing of waste containing reactive uranium from Container #10595963 with additional parent drum material in the repackaging process. The uranium initiated an exothermic reaction that ultimately led to an over pressurization and subsequent expulsion of material from four containers. The initiating mechanism (heat source), based on sample results, was oxidation of the uranium metal which then supported secondary chemical reactions. The breaches resulted in airborne radioactivity escaping to a filtered, uncontaminated area normally occupied by workers. The direct cause will be revised as necessary when additional sample results are available and upon analysis by the Technical Team. Root Causes (RC)—causal factors that, if corrected, would prevent recurrence of the same or similar accidents. The Root Cause Team Identified Two Root Causes for this Event. The root causes will be reviewed and revised (if necessary) when additional input is provided by the Technical Team.

Load more