by Bob Meyer

Palo Verde request a T.S. change to remove the term, "CORE ALTERATION ." Palo Verde staff stated that with the exception of suspending movement of irradiated fuel assemblies, there are no design basis accidents or transients that are initiated by, or mitigation affected by, suspension of CORE ALTERATIONS. Removing CORE ALTERATIONS from applicability of TS 3.3.8, Containment Purge Isolation Actuation Signal (CPIAS) and TS 3.9.3, Containment Penetrations, is justified. The TS Required Actions that currently require suspension of CORE ALTERATIONS also require suspension of movement of irradiated fuel. For these TSs, suspension of CORE ALTERATIONS provides no safety benefit [emphasis added] and the removal of the suspension of CORE ALTERATIONS is justified.

The NRC is requesting additional information based on the following.

NUREG-0800, "Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants: LWR Edition," (SRP) Section 15.7.4, "Radiological Consequences of Fuel Handling Accidents," states:

The purpose of the review is to evaluate the adequacy of system design features and plant procedures provided for the mitigation of the radiological consequences of accidents that involve damage to spent fuel. Such accidents include the dropping of a single fuel assembly and handling tool or of a heavy object onto other spent fuel assemblies [emphasis added].

Previously, suspension of CORE ALTERATIONS would preclude not only the movement of fuel, but would also preclude the movement of SOLlrces and reactivity control components. Dropped fuel sources or reactivity control components could break or they could damage a fuel assembly. Per SRP 15.7.4, these scenarios are to be considered. Although the amount of damage to fuel assemblies due to a dropped radioactive source or components would likely be less than for a dropped assembly, the overall dose to the public and operators might be greater because with the proposed change certain mitigating systems are no longer required to be operable. Please clarify how the suspension of CORE ALTERATIONS would provide "no safety benefit."

Based on the SRP summarized above, please state whether a dropped source or component (or any other item allowed to be moved by CORE ALTERATIONS) can damage a fuel assembly or break and create a radioactive source term. If so, please provide the analysis that shows that the dose consequences of these scenarios are less limiting than the current fuel handling accident. Provide the assumptions, inputs and results of these analyses.