DEFENSE NUCLEAR FACILITIES SAFETY BOARD

February 16, 2024

TO: Katherine R. Herrera, Acting Technical Director

FROM: D. Gutowski, Resident Inspector

SUBJECT: Los Alamos Activity Report for the Week Ending February 16, 2024

Staff Activity: M. Bradisse was on site providing resident inspector support. E. McCullough 

was on site for familiarization with transuranic waste activities to support her role as the Board’s 

cognizant engineer for the Waste Isolation Pilot Plant. This included visits to Area G, the RANT 

Shipping Facility, and the Plutonium Facility.

Plutonium Facility–Radiological Control: Last Wednesday, two workers were cleaning out 

containers used for ball-milled heat source plutonium. The process involves emptying the bulk 

contents into a catch pan and then using a wire brush to scrub out the remaining material from 

the inside. The first worker entered the gloves to demonstrate an action (without manipulating 

actual objects in the box) and then exited the gloves. That worker then performed a routine glove 

examination to check for damage and surveyed their hands for contamination on a nearby 

monitor. The second worker then entered the gloves and performed cleaning actions. When 

finished, they also performed the routine glove examination, did not note any issues, and 

exited. This time, however, the worker alarmed the hand monitor at the glovebox and called for 

radiological control personnel. The worker had contamination on the personal protective 

equipment on both hands and forearms but was successfully decontaminated. There was no skin 

contamination. Radiological control personnel later determined that the breach was due to 

cracking on the tip of the right thumb, which was the hand the employee used to hold the wire 

brush during cleaning. The glove will be sent for forensic analysis to help determine the cause of 

the breach. Photographs of the glove breach shared at the fact-finding meeting showed

significant blackening, embrittlement, and some visible cracking, despite the glove being 

installed last November and having not been used for work until last week. 

Plutonium Facility–Safety Basis: On Monday, the NNSA field office transmitted a letter to 

Triad that did not approve the revised safety basis addendum supporting receipt and repackaging 

of large quantities of heat source plutonium (see 10/6/2023 report). The field office provided a 

set of comments on the addendum and requested that Triad resubmit the addendum within 30 

calendar days to address these comments. One key comment from NNSA stated that Triad 

should refine its safety analysis to better demonstrate the efficacy of its safety control strategy 

for glovebox fires.

Area G–Emergency Response: Last Friday, a worker in Dome 375 at Area G smelled and then 

saw smoke coming from an electrical outlet. They immediately notified the operations center 

who called the fire department and the Emergency Operations Support Center. The worker used 

a dry chemical extinguisher on the outlet before evacuating with other personnel to the assembly 

area. The fire department confirmed that there were no active heat sources. The cause of the 

event was a single circuit with two space heaters plugged in. The breaker did trip. N3B 

personnel are performing an extent of condition on space heater usage in domes. Heaters are 

used in winter to protect fire protection systems from freezing and to provide warming stations 

for workers.