This standard provides the criteria for the format and content for safety analysis reports ~SARs! for research reactors. Purpose Research reactors require safety analysis and documentation showing that they are safe to operate for their allowed envelope of operation and in combination with experiments that may be placed in or around them. This standard identifies specific information and analyses for inclusion in the SAR and establishes a uniform format for the SAR. Adherence to this standard will ensure completeness of the information and maximize its usefulness to research reactor staffs@ support personnel@ and oversight groups for current and future information needs. Sufficient detail is incorporated so that a preparer can understand the desired composition@ and the technical elements@ of the SAR. Because of the special nature and diversity of research reactors@ which ref lect design features and operational characteristics chosen to allow the pursuit of unique missions@ no general standard can be applied to research reactors without thoughtful interpretation. Therefore@ the applicability of any criterion specified in this standard might range from total to nil@ depending on the research reactor.