ML093000370
| ML093000370 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 10/22/2009 |
| From: | John Hughey Plant Licensing Branch 1 |
| To: | Stewart G Exelon Corp |
| Hughey J, NRR/DORL, 301-415-3204 | |
| Shared Package | |
| ML093000407 | List: |
| References | |
| TAC ME1284, TAC ME1285 | |
| Download: ML093000370 (2) | |
Text
DRAFT REQUEST FOR ADDITIONAL INFORMATION RELATED TO AN AMENDMENT TO ADOPT TECHNICAL SPECIFICATIONS TASK FORCE TRAVELER TSTF-425 TO RELOCATE SPECIFIC SURVEILLANCE FREQUENCIES TO A LICENSEE CONTROLLED PROGRAM PEACH BOTTOM ATOMIC POWER STATION - UNITS 2 AND 3 DOCKET NO. 50-277 AND 50-278 By letter to the Nuclear Regulatory Commission (NRC) dated August 31, 2009 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML092470153), Exelon Generation Company, LLC, (Exelon) submitted a license amendment request (LAR) for Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3. The LAR seeks to revise the PBAPS Units 2 and 3 Technical Specifications (TSs) to adopt approved Technical Specification Task Force (TSTF) Traveler 425, Revision 3, Relocate Surveillance Frequencies to Licensee Control
- Risk-Informed Technical Specification Task Force Initiative 5b.
The NRC staff has reviewed Exelons submittal and determined that additional information, as described below, is needed to complete the review.
Table 2-1 of Attachment 2 of Reference 1 identifies specific unresolved gaps of the Peach Bottom Atomic Power Station (PBAPS) probabilistic risk assessment (PRA) internal events model to meeting the American Society of Mechanical Engineers (ASME) PRA standard Capability Category II supporting requirements. In the column labeled Importance to Application, the licensee asserts, for some specific supporting requirements which are not met at Capability Category II, that:
i)
Capability Category I is acceptable for surveillance test interval assessments; or ii) The gap has no or minimal impact on surveillance test exceptions.
Section 2.1 of Attachment 2 of the August 31, 2009, submittal states that implementation of the Surveillance Frequency Control Program at PBAPS will follow the guidance provided in Nuclear Energy Institute (NEI) 04-10, Risk-Informed Technical Specifications Initiative 5b, Risk-Informed Method for Control of Surveillance Frequencies, Revision 1. However, asserting that Capability Category I is acceptable for this application is inconsistent with the guidance provided in NEI 04-10, Revision 1. NEI 04-10, Revision 1, does not endorse adherence to Capability Category I. Rather, Capability Category II is applied as the standard and any identified deficiencies to those requirements are assessed further in sensitivity studies to determine any impacts to proposed decreases to surveillance frequencies. This position was accepted by the staff in its safety evaluation of NEI 04-10 Revision 1 (ADAMS Accession No. ML072570267).
Therefore, notwithstanding the assertions in Table 2-1 regarding Capability Category I, each supporting requirement not meeting Capability Category II must be further evaluated by sensitivity studies when applying the internal events PRA model for this application.
With regard to item ii above, the gaps cannot be merely dispositioned a priori, since this would also conflict with the methodology presented in NEI 04-10, Revision 1.
RAI-01: The licensee is requested to confirm that the PBAPS plant program for control of surveillance frequencies includes a
requirement to assess all open gaps to ASME Capability Category II of the standard via sensitivity studies for each application of the NEI 04-10, Revision 1, methodology, and does not rely solely upon any a priori assessment of the relevance of the supporting requirement.