BY MAIRE O’NEILL
The Defense Nuclear Facilities Safety Board is often mentioned in media stories about Los Alamos National Laboratory (LANL) and other Department of Energy (DOE) sites. In fact, weekly reports published by DNFSB onsite inspectors Jonathan Plaue and David Kutowski are often the source of information for reporters on safety incidents or concerns at LANL. Their boss, the Board’s technical director Christopher J. Roscetti spoke last week at a meeting of the Northern New Mexico Citizens Advisory Board, where he gave an overview of the Board’s activities and current concerns related to LANL.
In addition to Plaue and Gutowski, Roscetti supervises more than 60 scientists and engineers who work for the board. He formerly served as the deputy general manager, the associate technical director for nuclear programs and analysis, and the associate technical director for engineering performance.
The DFNSB was established by Congress in the late 80s as an independent agency.
“Although the Department of Energy was responsible for regulating its own activities and conducting government oversight of its contractors operating defense nuclear sites, Congress wanted an independent stand-alone agency to review and advise the Secretary of Energy on safety issues,” Roscetti said. “The core function of the Board is to provide safety recommendations to the Secretary so that the Secretary can determine how to ensure that public health and safety are adequately protected.”
However, the Board doesn’t have oversight of all DOE activities and just focuses on adequate protection and safety measures at defense nuclear facilities, including keeping workers and the public safe during nuclear weapons operations. The Board also oversees remediation of legacy nuclear waste, the design and construction of new defense nuclear facilities, the maintenance and demolition of existing facilities, and reviewing the standards and objectives DOE uses to assure safety and conduct of operations for each of these activities.
“The key part is the placement of resident inspectors at various DOE sites. They witness and provide first-hand accounts of how safety is practiced at the sites,” he said.
Roscetti said for the Board to be most effective in accomplishing its statutory mission, the Board and its staff must have prompt and unfettered access to DOE facilities, personnel and information.
“There will always be an inherent tension between two organizations where one conducts oversight over the other. At the same time, the Board expects a high degree of cooperation between the two federal agencies that have the same safety goals,” he said.
When DOE issued Order 140.1, it established what its expectations for how it expected its interaction with the Board to go, however the Board believes it must be consistent with the roles it was assigned by Congress. Roscetti thanked the NNMCAB for its recommendation that the DOE Order be revised to be more consistent with the statutory rules of the two agencies. The two agencies are now working on a memorandum of understanding to provide a foundation for communication, transparency and information sharing. Roscetti said the joint effort to teach this understanding is consistent with a recent finding from the Government Accountability Office.
“While Congress vested the Board with the substantial power of having safety oversight over another federal agency, the defense nuclear facilities and the information that we oversee all belong to the DOE. The independent safety oversight will always be more efficient and of greater benefit and value to the Secretary when the oversight can be conducted through cooperation rather than through the board issuing subpoenas,” he said.
Roscetti discussed the relationship the Board has with DOE’s Environmental Management Los Alamos Field Office (EM-LA) and legacy waste cleanup contractor N3B. He mentioned some problems early in the year obtaining documents form EM-LA and N3B in a timely manner that were caused by the DOE Order and some “immaturity in recordkeeping practices” at EMLA and N3B. He said currently the relationship with EMLA and N3B is “good and satisfactory” and the Board is receiving documents in a timely manner.
“N3B throughout this process has cooperated with our staff to the extent permitted by EM-LA,” Roscetti said.
He then delved into DNFSB-Tech 46, a report on potential energetic chemical reaction events involving transuranic waste at LANL, which was sent by the Board to the Secretary of Energy in September. The report notes the Board’s concerns about the handling, processing, staging and storing of transuranic waste by LANL in the aftermath of the radiological release events at the Waste Isolation Pilot Plant near Carlsbad in 2014 and at Idaho National Lab in 2018. In the Idaho event, four waste drums underwent over-pressurization, ejecting their radioactive waste at that facility, he said.
Transuranic waste consists of waste that is contaminated with man-made radioactive elements which are heavier than uranium (meaning the elements have higher atomic numbers than uranium on the Periodic Table of the Elements). Because they come after uranium on the periodic table, they are referred to as “transuranic”.
“The Board’s oversight efforts included multiple letters regarding DOE Standard 5506 which relates to developing safety bases for nuclear facilities that handle transuranic waste. Tech 46 also built on the body of work established during the Board’s public hearing in June. It uses LANL as a case study on how the key lessons learned from the release events at WIPP and Idaho have been addressed,” Roscetti said. “The report indicates that DOE needs to incorporate chemical compatibility evaluations into the hazardous analyses of the facility safety bases. These are important because if you don’t understand the hazards you may not have the correct safety controls.”
A chemical compatibility evaluation (CEA) is a systemic evaluation of the chemical characteristics in a waste container used to identify undesirable reactions that could potentially damage a container and release radioactive materials, including things like fires, explosions, forcing the rapid release of gas.
“The results of the CEA inform safety analysts what types of energetic reactions may be possible so that they can decide whether safety controls are needed. The Department already requires CEA for every container received at WIPP. This was a lesson learned from the 2014 release event, however, DOE doesn’t currently require CEAs for containers that reside at generator sites like Los Alamos until the waste is ready to ship. This is a period of time that can take years,” Roscetti said. “Another way to view the situation is that DOE requires the CEA for a container that will be buried about 2,000 feet underground but not for containers sitting on a mesa top at Area G with the community of White Rock only about a mile away.”
Roscetti said safety analyses for LANL facilities are not using technically defensible values for the fraction of radioactive material that can be released from an energetic chemical reaction in waste.
“This value is important because it directly impacts the potential calculated radiological consequences to the public and worker which are then used to identify the need for safety controls to prevent or mitigate such an accident. The Board found that the release fractions being used at LANL were inconsistent across facilities and were significantly lower than what was observed during the WIPP and Idaho release events” he said.
Roscetti said in the aftermath of the WIPP event, DOE calculated that a release fraction of about 20 percent is appropriate for release events similar to what occurred at WIPP. Based on the amount of material around the containers at Idaho, the Board’s assessment is that the release fraction was similarly large, he said.
“At Area G, EM-LA had previously approved N3B’s use of a release factor about 135 lower than the WIPP release factor. Part of the issue is that DOE has yet to issue any guidance on what situations warrant the use of these elevated values,” he said, adding that the Board asked for a response from the Secretary so as to understand the DOE’s perspective as to whether the situation at Los Alamos is safe and whether the revision of 5506 will address the Board concerns.
Opened in 1957, Area G is a site within Technical Area 54 at LANL that contains past radioactive waste disposal areas including some 32 pits, 194 shafts, and four trenches with depths ranging from 10 to 65 feet below the original ground surface. Area G is now dedicated to storing, characterizing, and remediating transuranic and low-level waste to ship it offsite for permanent disposal.
Roscetti said DOE needs to incorporate multiple layers of protection in its operations associated with transuranic waste.
“Area G is a great example. There are thousands of waste containers currently sitting above ground that rely primarily on the waste container to prevent or mitigate the release of radioactive materials. Idaho events taught us that energetic chemical reactions can cause containers to fail and illustrated the importance of incorporating multiple controls even if the controls are not formally credited in the safety bases,” he said.
He noted that over-packing or relocating containers containing a higher risk to locations that afford additional protection are options and that in some cases, N3B has already taken such actions.
A safety basis is the documented analysis required by law that describes the activities to be conducted in a nuclear facility, the associated hazards and the controls necessary to adequately protect the workforce and public.
“The current safety basis for Area G was implemented in 2012 with the expectation that operations were to continue only for a few years. Following the WIPP release event, DOE recognized the need to develop a new safety basis for Area G that complies with the DOE’s modern standard for safety basis development known as Standard 3009-2014. Since then EM-LA has gone through a number of efforts to implement the new version or otherwise improve the safety basis,” said Roscetti. “That’s good news but it’s tempered by the history of attempts to improve the Area G safety bases that includes similar approaches in years past.”
He said the Board thinks now is a good time to address safety challenges before the operational tempo at Area G increases by continuing to “safely and expeditiously eliminate” the above ground transuranic waste inventory by remediating containers and shipping them to WIPP. While EM-LA was successful in resolving the safety risk posed by the remediated nitrate salt waste containers, Roscetti said, they have struggled to restore the waste processing capabilities and the shipping tempo that existed to the cessation of activities at Area G following the 2014 WIPP release event.
“Progress has been impeded by the need for N3B redevelop much of the fundamental administrative infrastructure needed to operate and the COVID epidemic hasn’t helped either. EM-LA and N3B intend to restart several of the needed capabilities in the coming year,” he said.
On the shipping front, Roscetti said last year the DOE prioritized removing newly-generated waste from the National Nuclear Security Administration’s operations at LANL.
“NNSA and Triad were successful in making the most of limited shipping allotments to reduce their accumulation of containers. Looking forward into FY 2021 the Board understands that the DOE desires to better balance shipments between both N3B and Triad, ideally using the pool of certified containers from both contractor to optimize the payloads to WIPP. That goal remains in the future but the board has seen positive steps in that direction,” he said.
Longer term, Roscetti said EM-LA and N3B will contend with the below ground waste inventory containers that likely pose greater risks given their age and uncertainties regarding contents than the waste currently above ground.
“Safely disposing of the below ground containers will require many of the things we’ve already discussed such as resolving the issues regarding safety bases,” he said.
Roscetti also discussed the proposed venting of five flanged tritium waste containers by DOE at Area G. He said the FTWCs are the responsibililty of NNSA and Triad National Security, but that they currently reside at Are G and consequently the venting activity remains within the purview of EM-LA and is likely of interest to the CAB. He noted that Triad is completing various corrective actions from federal readiness reviews at this time,
“The Board is actively overseeing this planned activity. The headquarters staff and resident inspectors at LANL have been following the situation since the initial identification of the issue in 2016 and they will continue to do so until the issue is resolved,” he said. “Both DOE Field Offices and their respective contractors have afforded the Board and staff the required prompt and unfettered access to the information the Board believes is necessary to perform its oversight.”
While the postulated worst case accident consequences of the FTWCs project do not cross the thresholds of nuclear safety concern for the adequate protection of workers or the public, Roscetti said, the safety hazard increases with time and thus must be remediated “as expeditiously as possible”.
Roscetti also noted that the Board is overseeing efforts by EM-LA and N3B to safely demolish Building 257 at TA-21, a former radioactive liquid waste processing facility at the end of DP Road in Los Alamos and its associated industrial waste lines.
“These are legacy facilities that did not get demolished during a previous cleanup. N3B measurements earlier this year indicate that there is a potential for higher residual amounts of radioactive material than were previously understood. As a result they are working through the safety basis process and developing plans to further characterize the structures. The Board’s staff and resident inspectors are also following these efforts,” Roscetti said.