Defense Nuclear Facilities Safety Board Identifies Potential Safety Hazards In Transuranic Waste Processing At LANL
A crew prepares a waste shipment at LANL for transport to the Waste Isolation Pilot Plant. Courtesy/DOE
By BONNIE J. GORDON
Los Alamos Daily Post
In a letter dated Sept. 24 to Secretary of Energy Dan Brouillette, Defense Nuclear Facilities Safety Board (DNFSB) Acting Chairman Thomas A. Summers updated the Secretary on potential safety hazards in transuranic waste storage, handling and processing across Los Alamos National Laboratory facilities.
The Board has found that safety bases for both National Nuclear Security Administration and Environmental Management facilities at LANL do not consistently or appropriately consider a potential energetic chemical reaction involving transuranic waste.
Transuranic waste (also called TRU waste) is a regulatory classification of waste that applies only in the U.S. This type of waste is called “trans-uranic”, because it contains more than 3700 Bq per gram of elements heavier than uranium (the elements with atomic number higher than 92).
Examples in the letter include:
- Hazard analyses lack systematic evaluations of the chemical compatibility of transuranic waste streams. These analyses are needed to fully identify potential chemical reaction hazards associated with waste constituents.
- Accident analyses are not bounding, assume inappropriate initial conditions, and do not defensibly estimate the quantity of radioactive material that may be released due to an energetic chemical reaction. As such, additional credited safety controls may be necessary to protect workers and the public.
- Some facilities store transuranic waste without any engineered controls beyond the waste container. The radiological release events that occurred at the Waste Isolation Pilot Plant and Idaho National Laboratory have demonstrated the importance of incorporating multiple layers of protection to reduce the consequences of an accident.
These issues are not new, according to the letter, which states, “The concerns mirror those outlined in the Board’s letter dated Jan. 29, 2020, regarding needed revisions to DOE Standard 5506, Preparation of Safety Basis Documents for Transuranic (TRU) Waste Facilities, and highlighted in the Board’s June 20, 2019, public hearing”.
The Board requested in the letter that DOE provide a report within 120 days that describes:
- Whether the hazards associated with the current transuranic waste container population at Los Alamos National Laboratory are consistently and adequately controlled and DOE’s basis for this position; and
- Whether the revision to DOE Standard 5506 will address the broader implications of these concerns, as they are applicable to other DOE sites.
A spokesperson for the National Nuclear Security Administration responded to a request for comment from the Los Alamos Daily Post, saying, “NSA and DOE/EM are aware of the letter and technical report sent to the Secretary of Energy by the Defense Nuclear Facilities Safety Board (DNFSB) on Sept. 24, 2020 regarding transuranic waste storage, handling, and processing. NNSA and DOE/EM are working to provide the DNFSB with their requested information in a timely manner. Maintaining the safety, security, and effectiveness of America’s nuclear deterrent remains paramount to NNSA. The DNFSB plays an important role in ensuring the highest standards of safety at our sites and we look forward to our continued relationship.”
The DNFSB is an independent organization within the executive branch of the United States Government, chartered with the responsibility of providing recommendations and advice to the President and the Secretary of Energy regarding public health and safety issues at Department of Energy defense nuclear facilities. Resident Inspectors produce a Weekly Report that summarizes the pertinent activities and events that occurred during that week at their Defense Nuclear Facility.
Read the full report at https://www.dnfsb.gov/sites/default/files/document/21886/Tech-46%2C%20Potential%20Energetic%20Chemical%20Reaction%20Events%20Involving%20Transuranic%20Waste%20at%20LANL%20%5B2020-100-055%5D.pdf .