Resolution of Generic Safety Issues: Item B-37: Chemical Discharges to Receiving Waters ( NUREG-0933, Main Report with Supplements 1–34 )
In accordance with our licensing responsibilities under NEPA, we assess the impact of discharges of chemicals to surface waters. The objective of this assessment is to afford a weighing of impacts of the proposed action and a comparison of alternative actions rather than to provide absolute protection to surface waters. In accordance with Section 511 of FWPCA, effluent limitations are set by EPA and not by NRC under NEPA. However, in accordance with the Second Memorandum of Understanding between EPA and NRC, NRC has the lead in the conduct of the environmental impact assessment for nuclear stations and must assess the limits placed on discharges under the FWPCA. NRC must continue to determine and consider the impact of discharges in its licensing decisions.
The NRC assessment typically considers ambient water quality and addresses the needs of specifically identified users of the impacted waterbody. The assessments usually have not resulted in a quantitative determination of impact but have rather involved a subjective determination of acceptability based on a comparison of projected water quality to published criteria for protection of water users. Such criteria are not always formulated to assure the absence of impact and there are substances discharged for which criteria do not exist. Furthermore, the absolute determination of acceptability does not afford a quantitative comparison of alternative actions. This task will provide additional insight into impact of chemical discharges and provide procedures for quantifying the magnitude of any such impacts. This improvement in NRC procedures for impact assessment will provide a clearer division between NRC responsibilities under NEPA and EPA responsibilities under the FWPCA.
There are three specific water quality effects which have been questioned more frequently recently and which will be studied initially. These are: (1) environmental significance of condenser tube copper in cooling water discharges; (2) impact of increased total dissolved solids in receiving waters; and (3) significance of chlorinated organic compounds produced during condenser chlorination. This item is documented in NUREG-0471.3