WC Monitor
8/7/2015
Saltstone Operations Resume
The Savannah River Site’s Saltstone facilities resumed operation in June after a suspension forced when elevated levels of mercury were detected in tank waste salt streams, according to a Defense Nuclear Facilities Safety Board report released this week.
“Following DOE’s approval of the Evaluation of the Safety of the Situation for Hg hazards, [liquid waste contractor Savannah River Remediation] resumed processing in late June,” the DNFCB site representatives reported. “With the exception of a couple runs in the winter, SRR had not operated Saltstone in fiscal year 2015.”
Roughly 280,000 gallons of decontaminated salt solution from Tank 50 had been processed as of July 9, and operations have generally been steady, the official said.
Lower-activity waste from tank farms at SRS is sent to Saltstone, where it is combined with grout and disposed of in large repositories at Savannah River Site. Savannah River Remediation (SRR) said in May it suspended processing following the finding of elevated levels of mercury. Analyses of samples found trace amounts of monomethyl mercury, an organic mercury compound, which SRR said suggested the compound “exists in higher than anticipated concentrations throughout the waste streams.” The company said at the time additional analysis was anticipated to determine the cause of the mercury finding and any potential responses.
No workers had been exposed to the mercury, permit limits were not breached, and the temporary halt in operations had not been expected to affect the timeline for tank closures at Savannah River.
