DEFENSE NUCLEAR FACILITIES SAFETY BOARD

February 2, 2024

TO: Katherine R. Herrera, Acting Technical Director

FROM: D. Gutowski, Resident Inspector

SUBJECT: Los Alamos Activity Report for the Week Ending February 2, 2024

Staff Activity: M. Sautman was on site to evaluate resident inspector performance.

Plutonium Facility–Safety Basis: Last week, an NNSA facility representative questioned whether 

damage ratios were being appropriately applied when SAVY containers for nuclear material have 

hermetically sealed caps over their vents. These caps can be used to keep an inert environment in the 

container to protect the contents. SAVY containers have been tested in the uncapped configuration to 

provide a 1% damage ratio in specified fire and drop accident scenarios. However, the capped 

configuration has not been tested, and thus no damage ratio can be applied to a capped container. In 

many situations, these capped containers are being improperly credited with a damage ratio. Facility 

personnel entered the limiting condition for operations pertaining to container configuration in the 

room this was discovered in. Following resolution there, an extent of condition review found 

additional problems in other rooms leading to limiting condition for operations entries. All containers 

with caps are currently being evaluated to determine how they have been listed in the software that 

tracks nuclear material. In the long term, Triad is planning to implement software changes to ensure 

these types of containers are tracked properly and are not credited with damage ratios. Existing plans 

to test SAVY containers in the capped configuration to see if a damage ratio can be applied are on hold 

pending resource availability. 

Waste Characterization, Reduction, and Repackaging Facility (WCRRF): Workers performing 

HEPA filter changes for the confinement ventilation system in WCRRF discovered that they were 

using the wrong model of filter. The new filters were not fitting properly into the housings, and after 

using more force than expected on several installs, the workers noted the discrepancy. Engineering 

personnel are evaluating whether the filter housings were damaged by the process of forcing in the 

incorrect filter model. The confinement ventilation system is credited as a safety-significant system in 

the current hazard category 2 safety basis, but is not required to be operational in cold standby mode, 

which is the current facility condition. The safety basis currently in development for the upcoming 

transition to hazard category 3 operation does not credit this system. 

Area G–Operations: On Wednesday, the resident inspector and visiting staff member observed 

corrugated metal pipe size reduction activities in the Dome 375 Permacon. While performing rounds 

within the Permacon, a worker identified that one of the portable HEPA filter units was not

operational. An examination of the power supply discovered a tripped breaker and thermal damage to 

a power cord. The work team appropriately paused work and made notifications. 

Federal Oversight: Two individuals from the NNSA project management office went through final 

senior technical safety manager qualifications this week. Personnel from the NNSA field office acted 

as the qualifying officials. The field office has recently started developing alternative approaches to 

the traditional formal oral board approach for final qualifications. These involve a combination of 

discussion and field walkdown with more emphasis on the candidates volunteering knowledge rather 

than answering specific questions. The resident inspector and visiting staff member provided feedback 

on improving this approach.