DEFENSE NUCLEAR FACILITIES SAFETY BOARD

February 23, 2024

TO: Katherine R. Herrera, Acting Technical Director

FROM: D. Gutowski, Resident Inspector

SUBJECT: Los Alamos Activity Report for the Week Ending February 23, 2024

Staff Activity: On Tuesday, a staff team held a remote interaction with personnel from both the 

NNSA Field and Project Management Offices to discuss federal review and approval of limited 

procurement and construction activities requests. This is part of a staff review that also includes 

capital asset projects at other NNSA sites.

Plutonium Facility–Readiness: A federal team commenced a readiness assessment to evaluate 

the aqueous nitrate process in the Plutonium Facility (see 1/26/2024 report). This process has 

been shut down since 2013 and is the last major processing operation in the facility that has not 

resumed since the 2013 director’s pause. A vigorous readiness assessment for the aqueous 

nitrate process is particularly important as the nature of aqueous processes presents criticality 

safety challenges that operations with primarily solid materials do not. This week, the team 

observed simulated field demonstrations of the ion exchange and calcination processes. They 

also performed numerous personnel interviews. The assessment will continue next week with 

additional field demonstrations and interviews.

Legacy Facilities: On Tuesday, the Environmental Management field office and headquarters 

conditionally approved the new hazard category 2 safety basis for 21-257 and the industrial 

waste lines in Technical Area 21 (see 12/22/2023 report). The one condition of approval was to 

ensure that the first annual update of the safety basis include a description of any industrial waste 

lines remaining east of 21-257. In August 2020, N3B declared a potential inadequacy of the 

safety analysis following sampling results that indicated that these facilities, which were being 

prepared for decontamination and decommissioning as radiological facilities, may have enough 

material at risk present to be nuclear facilities that need coverage by a documented safety 

analysis. The newly approved safety basis authorizes non-destructive assay, sampling, debris 

removal, surveillance, and maintenance. Further decontamination and decommissioning 

activities will be covered under a new safety basis to be developed based on sampling data 

obtained under this safety basis.

Area G–Criticality Safety: On Tuesday, N3B management paused corrugated metal pipe size 

reduction activities following a question as to whether use of water in a sprayer bottle was 

evaluated in the nuclear criticality safety evaluation. The criticality safety evaluation for this 

process evaluates a fully flooded condition, but there is no specific analysis of use of a spray 

bottle. The water spray is used to help control airborne radioactive contamination generated 

during the cutting process. Management released the pause on Thursday following an initial 

assessment from criticality safety personnel stating that use of water spray was acceptable. 

Longer term, criticality safety personnel are revising the criticality safety evaluation to include 

contamination control methods using water and proposed future usage of water with fixative. 

Criticality safety personnel will also perform the annual fissile material operations review of this 

process early.