U.S. Department of Energy set to restart last remaining U.S. reprocessing plant

Tom Clements

The U.S. Department of Energy (DOE) has announced that it will soon restart the last remaining reprocessing plant in the United States to reprocess research reactor spent fuel. DOE claims that renewed operation of a reprocessing plant at the Savannah River Site is part of a non-proliferation effort but the economic impact to the site of the program may be of higher priority.

The aging government-owned plant that DOE seeks to restart, called the H-Canyon, is located at the DOE's 800-square kilometer Savannah River Site in South Carolina. It has been operated in the past to reprocess aluminum-clad research reactor and medical isotope reactor spent fuel containing highly enriched uranium (HEU).

According to a news release dated 15 April 2015 and issued by both DOE and Savannah River Nuclear Solutions, the contracting company that operates the facility, the required environmental documentation has been completed and the aim with restart is to "process up to 1,000 bundles of Material Test Reactor (MTR) spent nuclear fuel and 200 cores of High Flux Isotope Reactor fuel." The now-demolished MTR was located in Idaho and the High Flux Isotope Reactor (HFIR) is still operating at DOE's Oak Ridge National Laboratory in Tennessee. The separated HEU would be downblended to low-enriched uranium and be fabricated for use in reactors operated by the Tennessee Valley Authority (TVA), a utility owned by the federal government.

H-Canyon was constructed in the early 1950s and commissioned in 1955. It was a key part of the U.S. nuclear weapons complex, separating HEU from fuel removed from the five now-closed defense reactors at SRS. SRS is also the site of another now-closed reprocessing plant, the F-Canyon, which was primarily used to separate 36 metric tons of weapon-grade plutonium. Due to its operation over six decades, the H-Canyon has developed safety problems, most recently with degraded condition of the exhaust system in case of a seismic event. In addition, proper implementation of operating procedures has been a concern, as indicated by the failure to follow specified critically safety controls in an incident in February 2015 that caused operations to be halted.

According to comments by SRS officials at public meetings near SRS, H-Canyon employs about 800 people and has a base-line annual budget of about $150 million. Highlighting the importance of the new reprocessing campaign, SRS stated in its April 15 news release that "the spent fuel processing campaign is the current major mission for H Canyon." Overall employment is around 11,000 at SRS, where DOE and CB&I AREVA MOX Services are struggling to build a plutonium fuel (MOX) plant (see "Two new reports raise fundamental questions on Savannah River MOX plant").

Both SRS and the Idaho National Laboratory (INL) receive foreign and domestic research reactor spent fuel, with SRS preferring to receive aluminum-clad fuel and stainless-steel clad fuel and TRIGA fuel primarily going to INL. According to a January 2015 Global Threat Reduction Initiative list of research reactor spent fuel imports, SRS has in recent years received spent fuel from Italy, Germany, Mexico, Canada and South Africa.

SRS currently stores about 30 MT of spent fuel in the cooling pool (basin) of the old L-Reactor, which began receiving spent fuel in 1997, comprising about 1% in weight and 30% in volume of all the DOE-owned spent fuel. INL has about 275 MT, including spent submarine fuel, all destined to be placed in dry storage.

Hanford, in the state of Washington, is repackaging the 2,130 MT of DOE spent fuel stored at the site. Both Hanford and INL operated reprocessing plants but those facilities are now permanently closed, leaving the H-Canyon as the last operational facility in the DOE complex. The only commercial reprocessing plant in the U.S. was located at West Valley, New York and operated from 1966-1972. Under U.S. law, the intact spent fuel or high-level nuclear waste streams associated with its reprocessing must go to a geologic repository.

It is unclear why DOE has not developed a uniform policy of dry storage for all its spent fuel but the short-term positive funding impact on SRS for continued operation of H-Canyon is believed to be a primary reason for this.

An SRS official revealed to the SRS Citizens Advisory Board, a federal advisory panel on clean-up, in a January 2015 presentation that a "limited quantity" of SRS spent fuel would need reprocessing in order to free space in the L-Reactor basin for receipt of research reactor spent fuel from foreign and domestic reactors until 2020. The official goal for most of the remaining fuel is to place it in an "interim dry storage facility" but there are indications that SRS hopes to receive spent fuel beyond the stated date and is reluctant to actively pursue a dry cask facility.

While SRS is seeking to reprocess all of the aluminum-clad spent fuel at the site, DOE headquarters in Washington, DC has balked at approving such reprocessing due to costs and concerns about the international non-proliferation message sent by continued operation of a facility based on the PUREX process. As Savannah River National Laboratory concluded in 2011 that "fuel can be stored in L Basin, meeting general safety functions for fuel storage, for an additional 50 years and possibly beyond," there is ample time for dry cask storage to be deployed.

While missions are dwindling for H-Canyon and its eventual closure is within sight, SRS has sought new work for the facility. One project that will be paid for by the DOE's National Nuclear Security Administration is the processing of impure plutonium in the HB-Line, which sits atop H-Canyon, into plutonium oxide "feedstock" for the MOX plant now under construction at the site. The HB-Line is currently closed due to an incident earlier this year and DOE and the contractor are developing a "recovery plan" to restart the facility.

As the fate of the MOX project is up in the air and the future operation of H-Canyon will be limited at best, the focus at SRS should stay on closure of 51 tanks containing about 150 million liters of high-level nuclear waste remaining from production of nuclear weapons materials.