The Office of Emergency Management began treating barrels of remediated nitrate in December 2017. Treatment, which began in December, involved removing the UNS waste from drums and mixing it with water and zeolite – an inert material – to render the waste non-reactive. The resulting mixture is in solid form and was repackaged in new drums in accordance with EM Waste Isolation Pilot Plant (WIPP) requirements. The treated nitrate salt drums are being stored at LANL, and will eventually be shipped to WIPP for disposal. The Department of Energy announced Tuesday the completion of remediation of the remaining drums.
Los Alamos lab finishes treating drums of nitrate salt waste

(AP) — Workers at Los Alamos National Laboratory have finished treating more than two dozen drums of waste that contained nitrate salts similar to one that caused a 2014 radiation release at the federal government's underground repository.

The U.S. Energy Department on Tuesday announced the treatment of the 27 drums.

The containers of nitrate salt waste had not previously been treated so over the last three months crews mixed the waste with water and an inert material to neutralize the combustible characteristic of the salts.

In the case of the one container that ruptured in 2014, that waste had been mistakenly mixed with organic cat litter, resulting in a chemical reaction and the radiation release that forced southern New Mexico's Waste Isolation Pilot Plant to close for nearly three years.

Federal officials say the latest treatment effort marks another milestone for Los Alamos.