Baltimore Gas & Electric Co. v. Natural Resources Defense Council

Under NEPA, the Nuclear Regulatory Commission (defendant) built a table estimating a reactor's yearly environmental impact, assuming waste-storage facilities would not leak, while offsetting that assumption with higher impact estimates elsewhere in the table and requiring supplemental narrative evidence in each licensing proceeding. The Natural Resources Defense Council (NRDC) (plaintiff) challenged the no-leakage assumption as arbitrary and capricious in the D.C. Circuit, which agreed and vacated the rule; the Commission sought Supreme Court review.