One of several photos sent to the New Mexico Environment Department by N3B Los Alamos showing snow on the floor in a dome structure used to store transuranic waste at TA-54 of the Los Alamos National Laboratory.
BY MAIRE O’NEILL
Legacy waste cleanup contractor N3B Los Alamos has responded to a January 25 request from the New Mexico Environment Department for information on damage to Domes 229 and 230 in Technical Area 54 of Los Alamos National Laboratory caused by heavy snowfall in early January.
N3B notes in the letter that “at no time was there any damage to the environment or human health” in connection with the damaged domes which are used to store containers of transuranic waste.
The damage was noted during routine weekly inspections January 7 and consisted of a broken cross member and brackets and some torn dome fabric in Dome 229 as well as broken and bent brackets and torn dome fabric in Dome 230. The N3B letter states that the snow collected in sump collection areas of each dome and that no waste containers were impacted.
After the damage was discovered, a structural evaluation was conducted by engineering staff and the area was isolated. All other domes were inspected for damage. N3B provided NMED with photos showing the distance between the snow and the closest waste containers as 25 feet in Dome 229 and 15 feet in Dome 230.
The letter states that reskinning of the domes had been planned for this year. Repairs and reskinning for Dome 230 is scheduled to begin this month and Dome 229 will be reskinned in June. Meanwhile, the containers have been covered with fire-retardant plastic to protect them until the domes are repaired and/or reskinned.
Currently, N3B says the containers in the domes hold “free liquids”. Dome 229 uses secondary containment pallets which did not show any accumulation of liquid resulting from the heavy snowfall. Dome 230 is a permitted secondary containment unit and the sump was impacted by snow accumulation. The secondary containment system maintained sufficient capacity to prevent overflow and retained sufficient capacity to retain 10 percent of the waste volume within the dome.
Because the damage to the domes was located over the sumps, only access to the sumps has been restricted. Waste management areas are not affected by the safety restrictions imposed after the damage was discovered so personnel continue to have sufficient access to perform inspections as required by the Hazardous Waste Permit, the N3B letter states.