Repairs are being made after a tank agitator seal leak and damaged liner paused operations at the Pueblo Chemical Agent-Destruction Pilot Plant (PCAPP).

“A failed seal on one of our 30-day Hydrolysate Storage Tanks and the liner in the secondary containment area surrounding our Brine Concentrator Feed Tanks continue to impact the plant’s ability to process mustard agent,” said Greg Mohrman, site project manager, PCAPP.

During the week of Dec. 12, workers performed a test on one tank, which determined the agitators are not needed to maintain consistency in the feed to the Immobilized Cell Bioreactors. Plant staff will process a permit modification with the state of Colorado to allow the agitators to be removed from all three storage tanks, said Rick Holmes, project manager, Bechtel Pueblo Team.

“The tanks will be sealed with blind flanges because the seals and side mounted agitators present a risk of future failure that is not worth taking,” Holmes said. A blind flange is a plate for covering or closing the end of a pipe.

On Dec. 16, work began on the secondary containment area surrounding the Brine Concentrator Feed Tanks. The liner and coating from the floor and part way up the walls will be removed. A replacement material has not yet been determined.

“While I am not sure the exact material we will apply, the current thinking is to find a material that will be adequate to directly apply over the current floor,” Holmes said. “It will take a few months to complete the work in this area to make it ready for long-term operations.”

Holmes said technicians can resume processing munitions when integrity of the storage tanks is confirmed and a plan for the resumption of biotreatment operations is complete, which he forecasts for early January.

“PCAPP will restart operations when the plant is ready to do so safely,” Mohrman said.