Saltstone Operations Shut Down After Elevated Mercury Levels Found
WC Monitor
5/29/2015
Operations at Savannah River’s Saltstone facilities remain shut down after the site’s liquid waste contractor, Savannah River Remediation, found elevated mercury levels in tank waste salt streams. Saltstone receives lower activity waste from Savannah River’s tank farms, mixing it with grout and disposing of it on-site in large vaults. The mercury in the liquid waste stems from site canyon operations in the past, according to SRR. “Earlier this year, higher than expected levels of mercury were detected in the tank waste salt streams,” SRR said in a statement. “While no disposal permit limits have been exceeded, mercury levels were higher than internal safety controls allow, resulting in SRR initiating a system-wide evaluation of mercury in February. Samples taken, analyzed by the Savannah River National Laboratory and an independent chemical laboratory, showed unexpected trace levels of an organic mercury compound, monomethyl mercury. Based on that analysis, SRR is conservatively assuming the monomethyl mercury exists in higher than anticipated concentrations throughout the waste streams while further analysis is conducted to determine the cause and to identify any additional measures that may need to be instituted.”
While monomethyl mercury could be a worker hazard if it comes in contact with skin, no workers have been exposed and additional worker protections are in place, according to SRR. “While standard personnel protection clothing worn in radiological areas provides an adequate level of protection, workers are now required to wear nitrile gloves for added protection,” SRR said. “Based on work practices and results from prior medical testing of SRR employees, there is no indication of mercury exposure. However, voluntary medical testing is being offered to workers.”
The suspension of operations at Saltstone is not expected to impact tank closure schedules. The next two tanks in line have largely been emptied, and the ARP/MCU waste processing systems can continue running if needed, placing waste destined for Saltstone into a large feed tank. Additionally, the ARP/MCU and Defense Waste Processing Facility are currently in maintenance outages. For Saltstone, SRR has submitted safety basis documentation proposing resumption of operations. “This documentation is currently under review,” SRR said. “A schedule for resumption of operations will be established following the DOE review. SRR is using this outage time to continue tie-ins and other work at Saltstone to prepare for the future operation of the Salt Waste Processing Facility.”
SRNS Completes Dismantlement of Radioactive Waste Storage Facility
WC Monitor
5/29/2015
M&O contractor Savannah River Nuclear Solutions announced this week that it has completed dismantling a transuranic waste storage facility known as Pad 16, the first of 15 structures that will undergo D&D now that the bulk of Savannah River’s transuranic waste has been shipped to the Waste Isolation Pilot Plant. The building was dismantled with several unique methods to save money, including using a salvaged railroad boxcar as a waste disposal container and using contaminated wooden pallets for securing the material in the boxcar. The boxcar and its contents will be disposed of on-site as low-level waste and the facility’s flooring will be sealed with a layer of concrete and covered with clay and dirt. “I really appreciate how we’ve come together as a team, dedicated to doing things smarter, safer and better while finding ways to cut costs,” Solid Waste Operations Manager Don Turno said in a statement. “We’re not just working with our feet and hands, but our heads as well through use of our expertise in project management strategy.”
