A system used for liquid waste cleanup at the Energy Department’s Savannah River Site (SRS) has sprung a leak and, if it cannot be repaired, will take years to replace, according to weekly site reports from the Defense Nuclear Facilities Safety Board (DNFSB).
SRS prime liquid cleanup contractor Savannah River Remediation discovered the leak in the 3H Evaporator on Feb. 17, a company spokesperson said on Tuesday. That means the site is down to one working evaporator, called 2H, at the H-Area Tank Farm, a roughly 400-acre complex that houses 29 tanks that are constantly filling up with waste generated by the nearby H-Canyon chemical separation facility.
Evaporators are crucial to removing much of that waste from the tanks, and losing 3H means DOE has only about three years to come up with a workaround before H-Canyon waste clogs up the tank farm and grinds reprocessing work at H-Canyon to a halt, according to multiple reports posted on the DNFSB website.
“We have suspended the operations of 3H pending a review of how the vessel can be either repaired, or the parts replaced,” the SRR spokesperson said. “All those things are under review. At this time we don’t have a set time. It’s still early in the process.”
A DOE spokesperson did not reply to requests for comment on the situation this week.
According to DNFSB reports from Feb. 19 to March 4, replacing the leaky 3H Evaporator pot with a new pot “is expected to take a few years.”
Whatever happens, it will apparently not be possible to operate the leaky evaporator as-is.
After Savannah River Site personnel discovered the leak, they attempted to pin down its precise location by filling the evaporator pot with water to see how long it would leak. According to the March 4 report, enough water leaked out that engineers decided “trying to operate the evaporator at a level below the leak is not feasible.”
SRR estimated the 3H Evaporator has leaked 3,000 gallons of distilled salt waste from its evaporator pot, the chamber where briny liquid waste from H-Canyon is boiled down to so-called salt cakes that take up less space in the tank farm. Initial radiation measurements after Feb. 17 clocked in at 126 rem per hour about 10 feet off the evaporator cell floor, a DNFSB report said.
However, the SRR spokesperson said that does not amount to “increased radiological emissions or levels in the building that houses the evaporator,” and stressed “there is no risk to either people or the environment.”
Among other operations, H-Canyon turns highly enriched uranium into low-enriched uranium that can eventually be used by commercial nuclear power plants. Formerly used to recover weapon-grade material for the U.S. nuclear arsenal, H-Canyon is now critical to downblending highly enriched uranium that comes to the Savannah River Site from countries such as Belgium, Canada, and Germany.
H-Canyon generates both highly radioactive sludge and the less radioactive brine solution the evaporators boil into salt cakes. Compared with the sludge, the liquid waste treated by the evaporators can be removed from tanks relatively quickly to make room for more waste.
