Staff Reports
WC Monitor
11/13/2015
The Department of Energy is always looking for new ways to save money in its liquid waste work, said Jim Folk, the acting assistant manager for the waste disposition project at the Savannah River Site (SRS). One way to accomplish that could include restructuring the way SRS is closing its waste storage tanks. Part of the ongoing discussions with SRS officials is whether it would be more efficient and cost-effective to clean more than one tank at a time before going back and grouting two or three of them in a group. The current method involves cleaning the tanks and grouting them ony-by-one. Folk spoke about the issue last week during a meeting on the closure module for Tank 12 at SRS. The meetings are a requirement before the closure of each tank and are hosted by the South Carolina Department of Health and Environmental Control (SCDHEC).
The closure of Tank 12 is in the public comment phase and is expected to meet a renegotiated deadline for completion by May 31, 2016. Tank 12 will be closed by ridding it of the radioactive waste and grouting it just like the seven other tanks Savannah River Remediation (SRR) has closed at the South Carolina site since taking over the liquid waste contract in 2009. The waste undergoes a vitrification process, which converts it into a nonradioactive glass form, making it suitable for interim storage at SRS until a permanent repository is found.
Tank 12 is one of 29 tanks in the SRS H Tank Farm. In all likelihood, grouting tanks in groups won’t happen in the farm because those containers need to be grouted "as quickly as possible," Folk said. Many of the tanks are either fully or partially submerged in the water table, which makes for a larger pollution risk. Some of the tanks have developed small hairline cracks that allowed leakage of small volumes of salt solution into secondary collection pans underneath, according to SRR. The cracks were induced by high nitrate concentration in the waste solutions and residual stresses near weld sites. Waste levels within those tanks have been lowered below known leak sites.
Still, the conversation of grouping tanks for grouting is ongoing for other tanks, primarily the 22 tanks in F Tank Farm. "F Tank Farm, for instance, is not as close to the water table so that may be more of an option over there. You can clean a tank and then wait for another tank or two to be cleaned as well before grouting," Folk said.
Officials also raised the issue in March during the closure module meeting for Tank 16, which SRR operationally closed in September. SCDHEC federal facilities liaison Shelly Wilson the agency has thought about the matter, but that deadlines and other factors have to be considered first. Former SRS Deputy Manager Ernie Chaput said at the meeting he favors removing the waste and moving on to another tank rather than spending additional time on closing the tanks. "On a bang-for-buck basis, there’s more value in removing waste than closing tanks. And that would free money up to help remove additional waste from tanks," Chaput said.
Finding additional funds for waste removal and tank closures will be another ongoing discussion moving forward. The Department of Energy and SCDHEC extended the deadline for the Tank 12 closure, which was originally scheduled for Sept. 30 of this year. Under current agreements, every tank closure after the May closure is scheduled to miss its deadline. SRS Watch Director Tom Clements said the missed deadline calls for a significant amount of work that will have be done at the negotiating table. "From an administrative perspective, there’s a lot of work that has to be done to rework agreement and address the delays," Clements said.
SCDHEC has already backed off on imposing fines for missed milestones on construction and operation of the SRS Salt Waste Processing Facility. The state agency is in talks with DOE on renegotiating schedule and work expectations and has agreed to wait until at least Dec. 18 before attempting to levy what could be more than $150 million in fines for missed milestones.
