A major waste treatment facility at the Department of Energy’s Savannah River Site in South Carolina was placed in deliberate operations last month following multiple safety-related incidents in recent months.
The Defense Waste Processing Facility (DWPF) entered into deliberate operations – a reduced work phase in which personnel pay extra attention to detail and planning when conducting work — on June 20, according to a June 23 site report from the Defense Nuclear Facilities Safety Board (DNFSB). The move followed three technical safety requirement violations and a contamination incident.
“DO will be utilized to provide temporary compensatory measures to address the recent trend of poor [technical safety requirement] administration, and will apply to all work performed on safety class (SC), safety significant (SS) and all SC/SS supporting equipment,” the DNFSB said in the newly released report, indicating that deliberate operations also applied to Saltstone work at the Savannah River Site.
It was not immediately clear whether the operations status was still in place as of this week.
Cold War-era liquid radioactive waste stored at SRS is converted into a glass form at DWPF for interim storage on site until a long-term federal repository is built. The plant has suspended waste processing operations while it waits for a new melter, limiting the impact of any slowdown associated with deliberate operations.
“There were no injuries to workers and no impact to the facilities or the environment,’ an Energy Department spokesperson said by email Tuesday. “The facilities remain in a safe state. The incidents are being investigated to determine corrective actions as appropriate.”
All told, SRS houses more than 30 million gallons of waste in over 40 underground tanks. About 90 percent of that material is salt waste and the rest is sludge.
The DWPF is operated by Savannah River Remediation (SRR), the site’s liquid waste management prime. The contractor is a partnership of AECOM, Bechtel National, CH2M, and BWX Technologies.
The facility experienced several incidents in recent months, according to DNFSB reports.
In one instance, SRR committed a safety violation by failing to establish a “specific administrative control” intended to prevent accidents and other mishaps, the board stated in a May 26 report. Before transferring radioactive waste between buildings or facilities at SRS, work that could rupture the transfer line, or pipeline, must cease. But a lapse in communication caused a control room operator to believe that a review for “in-progress excavations had been performed prior to transferring the contents” of a collection tank to a waste tank, according to the report. “In addition, workers present in an excavation over the transfer line were not notified of the transfer,” the DNFSB said. “SRR determined that sufficient soil coverage remained to prevent any radiological consequences to the workers.”
Savannah River Remediation subsequently placed DWPF waste transfers on administrative hold. “SRR will revise the procedures to strengthen pre-transfer requirements, notably to require that operators performing walk downs in accordance with the SAC must print their own name in the procedure and sign the step off as complete,” the DNFSB said.
The board reported on June 9 that workers with Savannah River Nuclear Solutions (SRNS), the site’s management and operations contractor, were taking samples of radioactively contaminated oil near the Defense Waste Processing Facility when two workers were contaminated. The contractor usually uses a pump to obtain samples. But due to issues with the pump, they detached the tube from the pump and attempted to use the tube to collect samples. The tube slipped out of a worker’s hand and flung contaminated oil at a worker’s clothing and lanyard, and another worker’s shoe.
“During a fact finding meeting, DWPF personnel and the SRNS environmental sampling group identified multiple issues associated with the planning and execution of this activity,” the DNFSB report states. “The work instructions were not reviewed by Radiological Protection (RP) personnel, which led to this activity being incorrectly performed.” The report states that personnel began an analysis to identify corrective actions.
Two other incidents occurred last month at DWPF. Both involved limiting conditions for operation (LCO) – the lowest functional capability or performance level of equipment required for safe operation. In one incident, workers failed to enter a LCO while removing indicators that measure the flow of a nitrogen tank. In the other, workers failed to enter into LCO status while troubleshooting a ventilation issue at DWPF.
In 2015, Savannah River Nuclear Solutions paused all operations not related to safety and security following a series of safety incidents, one involving incorrect storage of a plutonium sample. Within two months, SRNS-operated facilities exited the pause and began deliberate operations. Full operations did not resume until spring 2016.
