Workers install filtration systems to the RNS drums.
The RNS waste is stored in drums like the ones pictured here.
A HEPA filtration system was installed on the lids of the RNS drums.
LOS ALAMOS, N.M. – EM’s Los Alamos Field Office and contractor Los Alamos National Security, LLC (LANS) recently completed installation of high efficiency particulate air (HEPA) filtration systems to remediated nitrate salt (RNS) drums.
The HEPA filters will eliminate pressure buildup within the drums, which are located at Los Alamos National Laboratory (LANL). In the unlikely event a filter becomes clogged, a pressure relief disc will operate to release pressure.
“Ensuring RNS drums are in the safest possible configuration is our top priority. We are confident that this additional layer of defense for RNS drums will prevent a radiological release similar to what occurred at the Waste Isolation Pilot Plant (WIPP),” said Doug Hintze, manager of the Los Alamos Field Office.
The procedure for adding the filters was completed in carefully planned stages, the last of which involved installing the devices to the lids of the RNS drums over the course of several days.
After the radiological event on Feb. 14, 2014 at WIPP, DOE scientists from several national laboratories conducted extensive experiments and modeling studies to determine what caused the RNS drum to breach. These investigations revealed an incompatible mixture of nitrate salts and an organic absorbent created conditions that resulted in an exothermic reaction that led to a drum breach and radiological release.
As part of this research, two additional parameters were determined to be critical to control an unwanted reaction: temperature and pressure. The information gained from scientific experiments and associated research have helped DOE and LANS develop robust measures for safe storage of the RNS drums located at LANL.
Since the WIPP event, comprehensive measures have been employed to ensure the RNS drums remain at a safe temperature. Additionally, in the summer of 2015, LANS installed a supplemental cooling system in the climate-controlled structure where the RNS drums are stored. The temperature of the RNS drums are monitored and inspections are conducted daily.
A plan for the treatment of the RNS drums is being developed. After the drums are treated, they will be ready for shipment offsite.