Proof of Principle Testing For Inerting a 9978 Containment Vessel

The 9978 SARP Letter Amendment, S-SARA-G-00020, Rev. 2, specifies that when acontainment vessel is loaded with content, the oxygen concentration in the containmentvessel must be low enough to prevent a flammable gas mixture from developing in thevessel.From November 8 through 18, 2016, the SRNL High Pressure Lab in Building 723-Aperformed a Proof of Principle Test for inerting a 9978 containment vessel by:• loading contents into containment vessel inside a glove bag• evacuating the glove bag to remove all of the air• backfilling the glove bag with pure nitrogen gas to atmospheric pressure• installing the lid on the containment vessel and torqueing it closed to 50 foot pounds• removing the containment vessel from the glove bagThe described process was simple to perform and it gave consistent results. The inertingtakes half an hour to an hour to perform with two evacuate/backfill cycles.A team of Argonne National Laboratory and Savannah River National Laboratory usedthis process to inert six containment vessels and load them into 9978 shipping packages ina single day without any problems.The team placed an Entis MX4, which is small battery-powered oxygen meter, in the mouthof the containment vessel to ensure the oxygen level was acceptable in real time. The meterhas a very linear, accurate response from 0 to 21% oxygen concentration. The Proof ofPrinciple Testing demonstrated that simply following a set of procedure steps would notensure the inerting will be acceptable (e.g. small leak in the glove bag may result in anunacceptable inerting).