This Memorandum can be accessed at:

http://www.nrc.gov/NRC/Y2K/Audit/NRST0199.html

Read the whole memo - it's interesting - but here is the section on shutdown criteria:

"In order to provide a more clearly defined decision rationale for addressing unresolved Y2K issues with individual licensees, the staff is working with OGC to develop criteria on which to base shutdown of a plant. The staff's initial thinking is to divide the plant systems into three categories depending on their function and establish criteria for actions to be taken including plant shutdown based on the impact of the unresolved Y2K concerns on the plant license and its compliance with NRC regulations. This criteria will be provided to the Commission, as appropriate, in the Spring 1999."

"With the approval of the Commission, the staff released the Draft NRC Y2K contingency plan (COMSECY-98-036) to the public. The staff is obtaining comments on the document from stakeholders including NEI and FEMA in order to finalize the plan in the first quarter of 1999. A key issue on which the staff expects input is the question of evoking the provisions of 10 CFR 50.54 (x) versus the need to develop a policy on enforcement discretion for those unanticipated situations where a Y2K problem creates a condition outside the plant license yet shutdown of the plant, in order to maintain license compliance, may not be the desirable action in view of the recognized need for continued plant operation to ensure grid stability on January 1, 2000. The staff will address these options in the final NRC contingency plan."

-- Anonymous, March 08, 1999