The prime contractor for the Waste Isolation Pilot Plant (WIPP) near Carlsbad, N.M., this week played down concerns raised by an internal Energy Department watchdog regarding the transuranic waste storage site’s interim ventilation system (IVS) — a crucial upgrade required to resume waste storage at the underground facility.
On March 16, DOE’s Office of Enterprise Assessments (EA) issued a report challenging whether the interim ventilation system Nuclear Waste Partnership is installing at WIPP can achieve the airflow rate required to reopen the mine to shipments of plutonium-contaminated waste from across the DOE complex if operated in conjunction with another ventilation system.
At issue, the DOE watchdog said, is whether an inactive fan that is part of another planned ventilation upgrade known as the supplemental ventilation system (SVS) would interfere with IVS operations. According to EA, Nuclear Waste Partnership failed to validate and verify documentation for software models the company uses to simulate underground air currents.
“Extrapolated data from this model indicate that the IVS without the SVS operational could sufficiently ventilate the waste face for limited waste emplacement operations. However, during IVS operation, the installed nonfunctional SVS fan provides a significant flow resistance that NWP has not evaluated, resulting in airflow quantities and pathways that differs from the current configuration model,” EA wrote in its report.
A Nuclear Waste Partnership spokesperson did not deny the EA finding, but pointed out the company has plenty of real-life airflow measurements to guide it.
“Air flow in the WIPP underground is verified by taking actual air flow measurements. Validation of the air flow model, which has been used to evaluate the current configuration of the underground, is ongoing,” the spokesperson said by email Thursday. “NWP will continue to use extremely conservative measures to evaluate air flow and ensure the safety and protection of our workforce.”
The IVS, already installed and slated to come online in April, will increase underground air circulation at WIPP to just over 110,000 cubic feet a minute from the current 60,000 cubic feet per minute.
“Electrical and mechanical field work on the IVS was completed in early March,” the Nuclear Waste Partnership spokesperson said. “Component level testing is ongoing. During the last week of March, calibration of the remaining instrumentation and final programming of the fan control logic is scheduled.”
SVS, which the Nuclear Waste Partnership spokesman said will come online by June 30, 2017, will up underground airflow at WIPP to about 180,000 cubic feet a minute. DOE has said it does not need to start up the supplemental ventilation system to resume waste storage by December, but that it would be needed to resume mining the underground.
IVS and SVS are only stopgap measures to ensure DOE can safely store waste and mine out more space at WIPP, and even with both systems active, DOE can do only one of those things at a time.
IVS and SVS are only stopgap measures to ensure DOE can safely store waste and mine out more space at WIPP, and even with both systems active, DOE can do only one of those things at a time, Sean Dunagan, DOE’s senior WIPP recovery manager, said earlier this month at the Waste Management Conference in Phoenix.
A permanent ventilation upgrade that will free the agency to expand the mine while also placing waste shipments and performing routine maintenance that requires the use of diesel-fueled equipment will cost between $270 million and $400 million, and not be ready until 2021 at the earliest, Dunagan said at the conference.
