The damage, which allowed rainwater to seep inside, occurred in a structure known as Vault 4, which contains radioactive “saltstone” processed from high-level waste tanks.
Terry Spears, the SRS’ assistant waste disposition manager, said in a July 31 letter to the South Carolina Department of Health & Environmental Control that the large crack in the Vault 4 roof was discovered Feb. 13 and repairs were initiated shortly thereafter.
Issues with rainwater leaking into six of the vault’s cells were corrected by installing membranes and sealants, the letter said, and plans include capping the cells with grout to reduce exposure to workers who would access the roof to apply waterproof coatings.
The incident, although promptly addressed, underscores the importance of radioactive waste cleanup programs and the funding required to keep those efforts intact, said Tom Clements, the Southeastern nuclear campaign coordinator for Friends of the Earth.
“The fact that the vault has degraded so quickly is of concern and may well indicate that there will be medium-term leakage problems,” said Clements, who obtained Spears’ letter from DHEC through a public records request.
SRS officials told South Carolina regulators that the radionuclide leaks, which include cesium, technetium and tritium, are below U.S. Department of Energy regulatory standards.
Rick Kelley, a spokesman for waste contractor Savannah River Remediation, said the Vault 4 disposal unit was completed in 1988 and began receiving its low-level waste mixture in 1990.
“The vaults have been and continue to be inspected on a routine basis during all operations,” he said, adding that the leaks pose no threat to workers, the public or the environment.