ML093060173

E-mail, Request for Additional Information, Request for Alternative ANO1-ISI-014, to Implement a Risk-Informed Inservice Inspection Program Based on ASME Code Case N-716

ML093060173
Person / Time
Site:	Arkansas Nuclear
Issue date:	11/02/2009
From:	Kalyanam N Plant Licensing Branch IV
To:	Clark R Entergy Operations
Kalyanam N, NRR/DORL/LPL4, 415-1480
References
TAC ME1488
Download: ML093060173 (3)

Text

From: Kalyanam, Kaly Sent: Monday, November 02, 2009 9:42 AM To: CLARK, ROBERT W Cc: BICE, DAVID B

Subject:

RAI for AN)1-ISI-014, Implementation of RI ISI Program based on CC N-716 (TAC No. ME1488)

Dave/Bob, By letter dated June 11, 2009, Entergy requested authorization to implement a risk-informed Inservice Inspection (RI ISI) program based on the American Society of Mechanical Engineers (ASME) Code Case N-716, as documented in the Request for Alternative ANO1-ISI-014, for Arkansas Nuclear One, Unit 1 (ANO-1).

The NRC staff has reviewed the June 11, 2009, request and has determined that we require additional information to complete our review. A request for additional information appears below.

This request was discussed with Robert Clark of your staff on November 2, 2009, and it was agreed that a response would be provided by the second week of December, 2009.

Thanks Kaly OFFICE OF NUCLEAR REACTOR REGULATION REQUEST FOR ADDITIONAL INFORMATION REQUEST FOR RELIEF ANO1-ISI-014 TO IMPLEMENT RISK-INFORMED INSERVICE INSPECTION (RI ISI) PROGRAM BASED ON CODE CASE N-716 ARKANSAS NUCLEAR ONE, UNIT 1 (ANO-1)

ENTERGY OPERATIONS, INC.

DOCKET NO.: 50-313

1. Appendix 1 of the submittal states that a gap analysis was held in June 2007. The submittal also states that an industry peer review of the ANO-1 Probabilistic Safety Assessment (PSA) was conducted in 2002.

A. Identify the guidance document(s) used for the gap analysis and the peer review (e.g., NEI 00-01).

B. Update Table 2 and the unresolved facts and observations Facts and Observations (F&Os) in Appendix 1 to include a description of the supporting requirement for each corresponding F&O number.

C. Identify the results of the 2002 peer review and explain how unresolved F&Os affect this relief request.

2. The submittal states that the ANO-1 internal flooding analysis (IFA) was significantly upgraded to meet Regulatory Guide (RG) 1.200, Revision 1, in 2008, and a gap analysis was conducted in June 2007. In accordance with the guidance endorsed by RG 1.200, a focused-scope peer review should have been performed for a model upgrade. Please summarize the results of the focused-scope peer review conducted on the ANO-1 internal flooding Probabilistic Risk Analyses (PRA) after the 2008 internal flooding upgrade to the American Society of Mechanical Engineers (ASME) PRA Standard RA-Sb-2005 or latest standard and how the peer review findings have been addressed for this application.

3. The supporting requirement IF-C3 in ASME PRA Standard RA-Sb-2005 identifies the failure mechanisms that shall be evaluated to determine the susceptibility of each safety-related structure, system, and component (SSC) in a flood area to flood-induced failures. Capability Category III identifies failure by submergence and spray as requiring detailed analysis and includes jet impingement, pipe whip, and humidity, condensation, and temperature concerns. As endorsed in RG 1.200, Capability Category II would require all SSC failures induced by a pipe break to be considered. Please demonstrate that all SSC failures that are induced by a pipe break are adequately addressed in your analysis.

4. Supporting requirements, IF-C6 and IF-C8, permits screening out of flood areas based on, in part, the success of human actions to isolate and terminate the flood. The endorsed Risk-Informed Inservice Inspection (RI-ISI) methods require determination of the flood scenario with and without human intervention, which corresponds to the Capability Category III (i.e., scenarios are not screened out based on human actions).

Therefore, a Category III analysis is consistent with the expected RI-ISI analyses. To provide confidence that scenarios that might exceed the quantitative core damage frequency (CDF) and large early release frequency (LERF) guidelines are identified, please describe how credit is given to human actions and identify if the current application analyses meet Capability Category III for these supporting requirements.

5. Supporting requirement IF-D5a addresses the development of flood initiating (pipe rupture) frequencies for use during the scenario development. RI-ISI is premised on inspecting locations with the highest risk, driven mostly by failure frequency. The plant-specific information collected and used should include experience related to degradation mechanisms that could indicate increased likelihood of pipe failure at particular locations. Please describe how plant-specific operating experience was used to identify experience related to degradation mechanisms and how this experience was incorporated into the development of pipe failure frequencies.

6. It is not clear if new examination locations were identified. If so, using an upper-bound estimate for new locations would overestimate the risk decrease and therefore be not conservative. Please demonstrate that this non-conservative approach, if corrected in

the evaluation of your proposed RI-ISI program, would not cause the delta risk guidelines to be exceeded.

E-mail Properties Mail Envelope Properties ()

Subject:

RAI for AN)1-ISI-014, Implementation of RI ISI Program based on CC N-716 (TAC No. ME1488)

Sent Date: 11/2/2009 9:39:05 AM Received Date: 11/2/2009 9:42:00 AM From: Kalyanam, Kaly Created By: Kaly.Kalyanam@nrc.gov Recipients:

RCLARK@entergy.com (CLARK, ROBERT W)

Tracking Status: None DBICE@entergy.com (BICE, DAVID B)

Tracking Status: None Post Office:

Files Size Date & Time MESSAGE 17599 11/2/2009 Options Expiration Date:

Priority: olImportanceNormal ReplyRequested: False Return Notification: False Sensitivity: olNormal Recipients received: