A new large-scale ventilation system, also known as the Safety Significant Confinement Ventilation System (SSCVS) is being commissioned at the US Department of Energy’s (DOE’s) Waste Isolation Pilot Plant (WIPP). When completed and online, the SSCVS facility will significantly increase airflow to the WIPP underground areas. WIPP is the only US deep geological salt repository for defence-related transuranic (TRU) waste. Workers have begun testing the first set of electrical cables that will supply power to SSCVS mechanical equipment, such as motors, fans and massive air filtration units.

“This achievement is the culmination of many people’s efforts to support the engineering, procurement and construction of WIPP’s SSCVS project,” said Ralph Musick, Capital Asset Projects manager for Salado Isolation Mining Contractors, WIPP’s management and operations contractor. “Initiating commissioning is a careful, step-by-step process to eventually integrate the SSCVS into daily WIPP operations.”

As facility construction nears completion, key systems are individually turned over to commissioning for methodical testing to ensure each component and system can be energized and functions as designed. When system testing has been completed, integrated testing is performed to assure that all components of the facility work together properly. When testing has been completed, the facility will be handed over to trained WIPP operations personnel to bring the new facility online.

The SSCVS works in tandem with a new air utility shaft, also under construction at WIPP. The shaft sends additional air into the 2,150-foot-deep WIPP underground repository, and the SSCVS pulls air through the repository, removes salt and filters the air before it’s released to the environment. When fully online, the new ventilation will increase underground airflow from 170,000 cubic feet per minute (cfm) up to 540,000 cfm. Increased airflow will allow for simultaneous underground waste emplacement, mining and bolting activities. Bolting controls the movement of salt rock – known as salt creep – in the WIPP underground.

A 125-foot-tall environmental exhaust stack towers over the New Filter Building, one of two buildings that make up the Safety Significant Confinement Ventilation System at the Waste Isolation Pilot Plant. The system serves as an added safety defense in the unlikely event of a radiological incident in the WIPP underground by directing airflow from the underground facility to a series of high-efficiency particulate air (HEPA) filtration units.

“The SSCVS will enhance the quantity, and quality, of air flow for our workforce in the WIPP underground mine,” said Michael Gerle, Environmental Regulatory Compliance director for DOE Office of Environmental Management’s Carlsbad Field Office. “Additionally, the new infrastructure will ensure our operations remain safe for the environment and the public.” The SSCVS project includes two primary buildings, the Salt Reduction Building and the New Filter Building. The former pre-filters salt-laden air coming from the WIPP underground, while the latter has fans and HEPA filtration to further remove contaminants from the exhaust air.

The $100m air intake shaft is part of an almost $500m rebuild of the plant’s ventilation system and will also provide access to the west end of the mine where nuclear waste is disposed of via burial, according to the Carlsbad Current-Argus. The entire project is scheduled to be complete by 2026. Two new panels are being built at the west end to hold nuclear waste. These are needed to replace space lost after a 2014 incident contaminated parts of the underground.

The incident occurred when an incorrectly-packaged drum of waste shipped from Los Alamos National Laboratory in northern New Mexico ruptured due to a chemical reaction. The resulting radiation release contaminated parts of the WIPP underground and led to a three-year shutdown of the facility’s primary operations. The site reopened and began accepting waste again in 2017, with some areas of the underground remaining restricted and requiring workers to wear breathing apparatuses when entering. Following the incident, WIPP’s airflow was restricted to about 170,000 cfm. Several other incidents have been reported since, according to the Carlsbad Current-Argus citing reports from the federal Defense Nuclear Facilities Safety Board.

Image: The 125-foot-tall environmental exhaust stack at the New Filter Building (courtesy of DOE EM)