The U.S. Nuclear Regulatory Commission (NRC) has prepared this Environmental Assessment (EA) to evduate environmental issues associated with the renewal of licenses issued by NRC for facilities operated by Nuclear Metals, Inc. (NMI) in Concord, Massachusetts. By renewing the licenses, NRC proposes to allow the continuation of ongoing operations involving radioactive materials at NMI's facilities. This EA focuses on the potential impacts related to air emissions at NMI during normal (incident-free) operations and accidental releases. Findings indicate that there are only two areas of potential concern. First, modeling results for sulfur dioxide (SO,) emissions from the boilers during normal operations indicate that the potential exists for exceeding the short-term National Ambient Air Quality Standards (NAAQS). NMI is prepared to undertake mitigative action to prevent potential exceedances of the short-term SO, NAAQS, and the Massachusetts Department of Environmental Protection is prepared to resolve the issue via a permit/approval change or through a Consent Order. Second, in the unlikely event of a severe fire, predicted sulfuric acid (H,S04) concentrations based on conservative (upper bound) modeling exceed the Emergency Response Planning Guideline (EWG) levels. NMI has committed to NRC to give a briefing for local emergency response officials regarding the potential for an accidental H2S04 release.iii NU REGICR-6528