Tritium Detected Downgradient of BLIP
The Brookhaven LINAC Isotope Producer (BLIP) has been in opertion since 1972. Radionuclides produced at BLIP are processed for pharmaceutical and medical imaging applications. BLIP uses a beam of protons delivered from the LINAC to irradiate materials encased in small, disk-like targets. From inside the BLIP building the targets are lowered to the bottom of a 30-foot underground target shaft. During target irradiation, several radionuclides are produced in the target shaft cooling water and a small zone of soil shielding located immediately outside of the target shaft becomes radioactive from neutrons produced during the process. Several radionuclides are created in the soil; only tritium and sodium-22 can be carried from the activated soils into groundwater if they are exposed to rainwater infiltration.
In 1998, improvements were made to storm water management at BLIP after tritium was deteched in the groundwater downgradient at concentrations that exceeded drinking water standards. Sodium-22 was also detected. An investigation determined that the tritium and sodium were being carried from the activated soils surrounding the BLIP target into the groundwater. In an effort to prevent rainwater infiltration into the activated soils, the building's roof drains were redirected, paved areas were resealed, and an extensive gunite cap was installed on three sides of the building.
In May-June 2000, BNL injected colloidal silica grout into the activated soils. The grout reduced the permeability of the soils thus reducing the potential for rainwater to carry radionuclides out of them. Additional monitoring wells were also installed to improve surveillance of the tritium plume.
Documents / Links