Salem Unit 1 Nuclear Generating Station- Tritium Investigation and Remediation Project
Groundwater monitoring activities have been ongoing since the discovery of tritium contamination in groundwater in 2002. The source of the tritium-contaminated water was leakage from the spent fuel pool. The pathway to the onsite environment from the original leak source was from the spent fuel pool into the 6-inch seismic gap via a construction joint then into the onsite environment. In 2003, PSEG Nuclear undertook a voluntary remediation of the contaminated groundwater in the shallow aquifer. Forty-one (41) groundwater monitoring wells were installed. Prior to the initiation of remediation, the tritium concentration exceeded the New Jersey Groundwater Quality Standard (20,000 pCi/L) in fourteen (14) monitoring wells. As of the fourth quarter of 2023 only four wells, located in the immediate vicinity of the leak, exhibited tritium concentrations in excess of 20,000 pCi/L. The highest groundwater concentration detected pre-groundwater recovery was 15,000,000 pCi/L in Well AC in the immediate vicinity of the leak. Recent highest groundwater concentration in Well AC was 25, 800 pCi/L in December of 2023.
Tritium was discovered in a deeper aquifer (Vincentown); the maximum groundwater concentration was 13,100 pCi/L. Under direction of the BNE, in 2003, PSEG implemented an enhanced monitoring program to include the deeper aquifer and installation of several more monitoring wells to help better define the direction of groundwater flow in the deeper formation. Groundwater extraction was selected as the remedial strategy in 2005 and continues with the capacity to pump from several wells.
The results of the groundwater monitoring activities have demonstrated that off-site groundwater, including drinking water sources, have not been impacted by these leaks, and that ongoing remedial activities have successfully reduced the level of tritium contamination in on-site groundwater. Additional information can be found at NRC ADAMS system.