05000456/FIN-2008003-03
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Finding | |
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| Title | AFW Tunnel Hatches Margins of Safety |
| Description | The inspectors reviewed Operability Evaluation 07-007, Revision 2. This operability evaluation was performed because the licensee identified that the design analysis for evaluation of the AFW tunnel flood seal covers did not include the effects of a high energy line break in the main steam isolation valve tunnels. Following this review, the inspectors questioned why a dynamic load factor as a result of the impulse pressure following a high energy line break had not been considered in an analytic calculation perform to support the operability evaluation. The licensee documented the inspectors concerns in IR 783849. Additionally, following a review of a subsequent revision of this operability evaluation, the inspectors questioned the licensees conclusion that the operability of the AFW hatches continued to be supported despite analytical results showing a factor of safety for the concrete expansion anchors supporting the hatches of less than 2.0, which is contrary to the guidance provided in NRC Bulletin 79-02, Pipe Support Base Plate Designs Using Concrete Expansion Anchors. Additionally, the inspectors noted that the operability evaluation did not address Section C.13 of NRC Technical Guidance 9900, Operability Determinations & Functionality Assessment for Resolution of Degraded or Nonconforming Conditions Adverse to Quality or Safety. Specifically, Section C.13 stated that if a structure was degraded, the licensee should assess the structures capability of performing its specified function. As long as the identified degradation did not result in exceeding acceptance limits specified in applicable design codes and standards referenced in the design basis documents, the affected structure was either operable or functional. At the close of the inspection period temporary modifications had been implemented at both units that restored the margin of safety to greater than 2.0. Pending additional follow-up by the inspectors for the timeliness of corrective actions, extent of condition, corrective actions and past operability, this item will remain open. (URI 005000456/2008003-03;05000457/2008003-03) Included in the NRC review will be the licensees\' evaluations of structural degradations to determine their technical adequacy and conformance to licensing and regulatory requirements |
| Site: | Braidwood  |
|---|---|
| Report | IR 05000456/2008003 Section 1R15 |
| Date counted | Jun 30, 2008 (2008Q2) |
| Type: | URI: |
| cornerstone | No Cornerstone |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.15 |
| Inspectors (proximate) | B Dickson A Garmoem Kunowskim Mitchell M Perry N Feliz R Jones R Skokowski S Ray T Bilik V Meghani A Garmoe B Bartlett B Dickson B Metro C Zoia D Betancourt D Hills G Roach J Bozga J Gilliam J Roman M Holmberg |
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Finding - Braidwood - IR 05000456/2008003 | |||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Braidwood) @ 2008Q2
Self-Identified List (Braidwood)
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