WIPP’s SSCVS: A breath of fresh air

The SSCVS New Filter Building houses six 1,000-horsepower fans to pull up to 540,000 cubic feet of air per minute through the underground. (Photo: DOE)

Estimated to have cost nearly $500 million, the new facility includes two primary buildings: the Salt Reduction Building, which prefilters salt-laden air coming from the underground repository, and the New Filter Building, which houses six 1,000-horsepower fans and HEPA filtration to further clean the air.

When fully on line, the SSCVS facility will significantly increase air flow through the WIPP underground, allowing the resumption of critical work to be conducted in the repository. Air exiting the underground will pass through a HEPA filtration system made up of 22 filtration units separated into two banks, allowing operators to switch flow for filter changes and other maintenance work.

“This is a big step in getting the SSCVS fully operational and providing additional airflow to the WIPP underground,” said Mark Bollinger, DOE-EM Carlsbad Field Office manager. “This project is important in increasing our workers’ safety while allowing us to continue DOE’s critical environmental cleanup and national security mission.”

WIPP remains the United States’ only deep geological repository for nuclear waste. It’s a system of disposal rooms mined out of an ancient salt bed 2,150 feet underground. It has operated since 1999, accepting TRU waste from DOE cleanup sites across the U.S.

The waste consists of items contaminated with small amounts of plutonium and other human-made radioactive elements. It has been accumulating since the 1940s as part of the nation’s nuclear defense program dating back to the Manhattan Project. So far, the DOE has completed cleanup at 22 sites nationwide.

Since the first acceptance of waste in 1999, WIPP has received more than 14,000 shipments of TRU waste from generator sites throughout the nation. The total number of waste containers emplaced in the WIPP underground is more than 290,000.

Along with a new utility shaft, the SSCVS is one of two major capital projects being conducted at WIPP intended to increase airflow to the underground. WIPP has been operating at a reduced capacity following two underground accidents in 2014—a localized underground fire and a waste drum breach that resulted in radiological contamination of portions of the repository.

The New Filter Building houses 22 HEPA filtration units. (Photo: DOE)

Without the SSCVS, ventilation has remained restricted because air must be filtered after passing through the contaminated portion of the underground, and WIPP has had limited air-filtering capabilities. Because of this restricted ventilation capacity, workers have been limited to conducting mine maintenance operations, mining, or nuclear waste disposal separately. The increased airflow will allow all activities to be conducted simultaneously as needed.

The SSCVS will work in tandem with the new utility shaft, which provides a new entry point for air into the WIPP underground. The 2,150-foot-deep shaft, WIPP’s largest at 26 feet in diameter, will use a large fan on the surface to push air into the underground repository. Three drifts, or passageways, of more than a half mile in length have been cut from the existing mine to the utility shaft area to move air and serve as access to future emplacement panels. After approval of the final DOE-EM review, mining machines will break through in multiple locations underground. At the same time, a final ductwork connection will be made at the exhaust shaft where air exits the underground.

The SSCVS will pull air through the repository, remove salt when required, and send the air through HEPA filtration units before it is released to the environment. The new ventilation system will increase underground airflow from 170,000 cubic feet per minute up to a maximum of 540,000 cubic feet per minute. Ductwork in the WIPP underground is being modified to handle the substantial increase in airflow.

In November 2018, DOE-EM and then WIPP management and operations (M&O) contractor Nuclear Waste Partnership awarded a $135 million contract to Critical Applications Alliance to construct the SSCVS. At the time, the project was projected to be completed by November 2022 at a total project cost of $288 million. In August 2020, however, WIPP terminated its contract with Critical Applications Alliance following cost increases and schedule delays on the project. According to a 2022 report by the Government Accountability Office (GAO-22-105057), the primary root cause of the cost increases and schedule delays was the contractor’s inexperience in managing capital asset projects and its inability to attract and retain qualified staff to WIPP, which is located 26 miles outside Carlsbad, N.M.

The increased ventilation will allow simultaneous mining, ground control, and waste emplacement work to be conducted in the underground. (Photo: DOE)

Following the termination of Critical Applications Alliance’s contract, The Industrial Company was awarded a $163 million contract in 2021 to complete the project. According to a 2024 GAO report (GAO-24-106716), as of April of last year, the total cost of the SSCVS project is $494 million.

Current WIPP M&O contractor Salado Isolation Mining Contractors (SIMCO) began SSCVS commissioning activities last fall after completing construction of the facility in June 2024. Commissioning involved testing each system individually and then the SSCVS as a whole to demonstrate complete functionality. Following the commissioning phase, the SSCVS was turned over to the operations team members so that they could gain proficiency in running the highly efficient system.

“This is a very big day for the WIPP project,” Tammy Hobbes, SIMCO’s vice president and WIPP operations/National TRU Program manager, said in announcing the end of commissioning in March. “I cannot overstate how much I appreciate the partnership between the project and operations team throughout this process. This was truly a team effort.”

Following commissioning, multiple assessments will be conducted to show the SSCVS is fully integrated into other WIPP site systems. This will demonstrate that all primary and backup systems are functional and operating as expected, and that operators are proficient and fully understand the ventilation system.

Finally, DOE-EM will conduct an assessment to authorize SSCVS startup operations. Following approval of that review, team members will connect the SSCVS to the underground ventilation system of the waste repository. SSCVS is expected to be fully operational and on line this year.

Tim Gregoire is editor of Radwaste Solutions and a staff writer for Nuclear News, where he focuses on waste management.