ML073510384
| ML073510384 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 12/20/2007 |
| From: | Wang A NRC/NRR/ADRO/DORL/LPLIV |
| To: | Mitchell T Entergy Operations |
| Wang, A B, NRR/DORL/LPLIV, 415-1445 | |
| References | |
| TAC MD5250 | |
| Download: ML073510384 (9) | |
Text
December 20, 2007 Mr. Timothy G. Mitchell Vice President, Operations Arkansas Nuclear One Entergy Operations, Inc.
1448 S. R. 333 Russellville, AR 72802
SUBJECT:
ARKANSAS NUCLEAR ONE, UNIT 2 - REQUEST FOR ADDITIONAL INFORMATION RE: ANO2-R&R-004, REVISION 1, REQUEST TO USE RISK-INFORMED SAFETY CLASSIFICATION AND TREATMENT FOR REPAIR/REPLACEMENT ACTIVITIES IN CLASS 2 AND 3 MODERATE ENERGY SYSTEMS (TAC NO. MD5250)
Dear Mr. Mitchell:
By letter dated April 17, 2007, as supplemented by letter dated August 6, 2007, Entergy Operations, Inc. (Entergy), submitted its Request for Alternative ANO2-R&R-004, Revision 1, Request to Use Risk-Informed Safety Classification and Treatment for Repair/Replacement Activities in Class 2 and 3 Moderate Energy Systems, at the Arkansas Nuclear One, Unit 2 (ANO-2). The submittal requests authorization to exempt components categorized as low safety significant from the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI, repair and replacement requirements, pursuant to paragraph (a)(3)(i) of Part 50, Section 50.55a of Title 10 of the Code of Federal Regulations. The alternative program is based on ASME Code Case N-752, Risk-Informed Safety Classification and Treatment For Repair/Replacement Activities in Class 2 and 3 Moderate Energy Systems.
The NRC staff has reviewed the request, and has determined that we require additional information to complete our review. A request for additional information is enclosed. This request was discussed with David Bice of your staff on December 12, 2007, and it was agreed that a response would be provided by January 30, 2008.
If you or your staff have any questions concerning the resolution of this matter, please contact me at (301) 415-1445.
Sincerely,
/RA/
Alan B. Wang, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-368
Enclosure:
Request for Additional Information cc w/encl: See next page
December 20, 2007 Mr. Timothy G. Mitchell Vice President, Operations Arkansas Nuclear One Entergy Operations, Inc.
1448 S. R. 333 Russellville, AR 72802
SUBJECT:
ARKANSAS NUCLEAR ONE, UNIT 2 - REQUEST FOR ADDITIONAL INFORMATION RE: ANO2-R&R-004, REVISION 1, REQUEST TO USE RISK-INFORMED SAFETY CLASSIFICATION AND TREATMENT FOR REPAIR/REPLACEMENT ACTIVITIES IN CLASS 2 AND 3 MODERATE ENERGY SYSTEMS (TAC NO. MD5250)
Dear Mr. Mitchell:
By letter dated April 17, 2007, as supplemented by letter dated August 6, 2007, Entergy Operations, Inc. (Entergy), submitted its Request for Alternative ANO2-R&R-004, Revision 1, Request to Use Risk-Informed Safety Classification and Treatment for Repair/Replacement Activities in Class 2 and 3 Moderate Energy Systems, at the Arkansas Nuclear One, Unit 2 (ANO-2). The submittal requests authorization to exempt components categorized as low safety significant from the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI, repair and replacement requirements, pursuant to paragraph (a)(3)(i) of Part 50, Section 50.55a of Title 10 of the Code of Federal Regulations. The alternative program is based on ASME Code Case N-752, Risk-Informed Safety Classification and Treatment For Repair/Replacement Activities in Class 2 and 3 Moderate Energy Systems.
The NRC staff has reviewed the request, and has determined that we require additional information to complete our review. A request for additional information is enclosed. This request was discussed with David Bice of your staff on December 12, 2007, and it was agreed that a response would be provided by January 30, 2008.
If you or your staff have any questions concerning the resolution of this matter, please contact me at (301) 415-1445.
Sincerely,
/RA/
Alan B. Wang, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-368
Enclosure:
Request for Additional Information cc w/encl: See next page DISTRIBUTION:
PUBLIC LPLIV R/F RidsAcrsAcnwMailCenter RidsNrrDorlLpl4 RidsNrrDorlDpr RidsNrrDraApla RidsNrrLAJBurkhardt RidsNrrPMAWang RidsOgcRp RidsRgn4MailCenter SDinsmore, NRR/DRA/APLA DChung, NRR/DRA/APLA ADAMS Accession Number: ML073510384 OFFICE DORL/LPL4/PM DORL/LPL4/LA DRA/APLA/BC DORL/LPL4/BC NAME AWang JBurkhardt MRubin THiltz DATE 12/19/07 12/19/07 12/04/07 12/20/07
OFFICIAL RECORD COPY
REQUEST FOR ADDITIONAL INFORMATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION ARKANSAS NUCLEAR ONE, UNIT 2 ENTERGY OPERATIONS, INC REQUEST FOR ALTERNATIVE ANO2-R&R-004, REVISION 1 DOCKET NO. 50-368 OPERATING LICENSE NO. NPF-6 By letter April 17, 2007 (Agencywide Documents Access and Management System (ADAMS)
Accession No. ML071150108), as supplemented by letter dated August 6, 2007 (ADAMS Accession No. ML072220160), Entergy Operations, Inc. (Entergy, the licensee), submitted its Request for Alternative ANO2-R&R-004, Revision 1, Request to Use Risk-Informed Safety Classification and Treatment for Repair/Replacement Activities in Class 2 and 3 Moderate Energy Systems, at the Arkansas Nuclear One, Unit 2 (ANO-2). The submittal requests authorization to exempt components categorized as low safety significant from the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI, repair and replacement requirements, pursuant to paragraph (a)(3)(i), Part 50, Section 50.55a, of Title 10 of the Code of Federal Regulations, Part 50.55a(a)(3)(i). The alternative program is based on ASME Code Case N-752, Risk-Informed Safety Classification and Treatment For Repair/Replacement Activities in Class 2 and 3 Moderate Energy Systems. The NRC staff has reviewed the request, and has determined that we require the following additional information to complete our review:
- 1.
The example analysis (Example) provided as the enclosure to the August 6, 2007, letter included a number of pages from ANO-2s October 8, 1998, submittal on risk-informed inservice inspection (RI-ISI). Inspection of the October 8, 1998, submittal indicates that a screening process was applied to some piping. Neither this piping nor the screening process are discussed in the Example. Instead, the Example only illustrates the comprehensive categorization methodology described in Enclosure 1 to the April 17, 2007, submittal (Enclosure). This process includes a detailed consequence determination for each segment using the appropriate categorization tables in the Enclosure (e.g., segment CSS-C-01 in the Example). The screening process is apparently applied to some population of piping before, or in lieu of, the detailed analysis. The screening process is not described in the Enclosure or the Example submittals.
Please describe the screening process, including all the guidelines to screen out piping and how these guidelines are appropriate for changing repair and replacement (R&R) activities.
ENCLOSURE
Please describe how the two processes are applied together, beginning with a definition of the initial population of piping and ending with all piping being categorized based on one or more of the processes.
Please identify where the screening process is permitted and/or described in the categorization methodology in the Enclosure.
- 2.
The Example included a categorization of piping in the containment spray system (CSS) performed in support of the RI-ISI program. The CSS was one of many systems evaluated to support ANO-2s RI-ISI program submitted in 1998 and was performed consistent with a draft version of Electric Power Research Institute (EPRI) topical TR-112657 (EPRI Topical). The August 6, 2007, supplemental letter augments the Example with a discussion of 10 conditions (in the form of questions) that are part of the categorization process in the Enclosure but that are not included in the EPRI Topical and therefore not in the Example. No other changes or additional steps were described that would be necessary to convert the RI-ISI categorization into a categorization that satisfies all the guidelines in the Enclosure. There appears to be, however, some differences between categorization described in the Enclosure and the RI-ISI categorization that are not addressed in the submittals.
In the Enclosure, the first paragraph under, III. Requested authorization, concludes by stating that, the process shall be applied on a system basis, including pressure retaining items and their associated supports. The provided Example does not include associated supports and (as noted in RAI) does not include all piping in the system. Please clarify when, and with what guidance documents, piping segments and associated supports will be categorized before changes to the R&R activities are implemented for any given pipe segment.
The Enclosure states that the consequence of each pipe segment failure should be evaluated with and without operator action and that the highest category should be chosen. The EPRI Topical used to perform the categorization in the Example does not require that the highest category be chosen. Please confirm that the analyses done in support of R&R activities (both in the Example and subsequent analyses) will be consistent with the method described in the Enclosure.
Section I-3.0.1 in the Enclosure describes the features that shall be provided if credit is taken for operator actions. The last feature is that operators are trained on the procedures. The EPRI Topical used to perform the categorization in the Example does not require this feature before credit can be taken for operator actions. Please confirm that the analyses done in support of R&R activities (both in the Example and subsequent analyses) will be consistent with the method described in the Enclosure.
Section I-3.2.2 in the Enclosure states that 10 questions shall be answered for each medium and low consequence segment. In contrast, the August 6, 2007, submittal answers each question once for all segments in the system, not for each segment. This may be acceptable
when the same answer is applicable to every segment in the system but this may not always be the case. Please confirm that the questions were considered for each segment in the Example, and that the analysis done in support of R&R activities will be consistent with the method described in the Enclosure.
- 3.
The NRC has endorsed ASME Code Case N-660, Risk-Informed Safety Classification for Use in Risk-Informed Repair/Replacement Activities. The licensee's Enclosure proposes a method similar to Code Case N-660 but with some modifications. Please identify the differences between the proposed method and Code Case N-660, and the basis for acceptability for the differences.
- 4.
Sections I-3.1.2 (e) and (f) in the Enclosure describe how shutdown operations and external events shall be evaluated. The Example did not address shutdown and external events. Please provide an analysis that includes shutdown and external events in the categorization process consistent with the guidance in the Enclosure.
- 5.
Many of the tables referenced in the Example refer to tables in previous documents. Please provide a cross reference relating the tables referenced in the Example to those in the Enclosure.
- 6.
The evaluations in the Example always assumed a large pipe break consistent with the guidance in the EPRI Topical. Code Case N-660 requires the assumption of a large pipe break unless leak-before-break can be justified in accordance with NUREG-1061 or the plant configuration precludes the possibility of a large break. The method proposed in your Enclosure permits assuming a small leak that is determined by analytic evaluations. Please justify the use of a small break instead of a full break and provide illustrative examples of these analytic evaluations.
- 7.
The Enclosure refers to the ASME RA-S-2002, "Standard for Probabilistic Risk Assessment [PRA] for Nuclear Power Plant Applications," up through the RA-Sb-2005 Addenda, as an acceptable method for determining PRA scope, technical adequacy, and peer review requirements.
Is the ANO-2 PRA consistent with the standard up through the RA-Sb-2005 Addenda?
If the ANO-2 PRA has not been reviewed for consistency with the standard up through the RA-Sb-2005 Addenda, when was the last review performed and what guidelines were used for the review?
Please provide all the facts and observations identified during previous reviews of the ANO-2 PRA and describe the resolution of these issues, or why the issues need not be resolved because resolution would have no or limited effect on the categorization.
- 8.
Please discuss the quality of the PRA that was used to support the proposed program and explain why this quality is sufficient to support the proposed changes to R&R activities.
- 9.
ANO-2 has implemented an update process for RI-ISI. Please identify any changes to the risk-informed update process that will be made in order to ensure that issues important to R&R activities will be included in the update.
- 10.
The answers to questions 1, 2, 3, and 6 (on pages 7 and 8 of the Enclosure to the August 6, 2007, submittal) did not provide adequate responses. Please address all parts of each question in your answers.
Arkansas Nuclear One (November 2007) cc:
Senior Vice President Entergy Nuclear Operations P.O. Box 31995 Jackson, MS 39286-1995 Senior Vice President
& Chief Operating Officer Entergy Operations, Inc.
P.O. Box 31995 Jackson, MS 39286-1995 Vice President, Operations Support Entergy Operations, Inc.
P.O. Box 31995 Jackson, MS 39286-1995 Site Vice President Entergy Operations, Inc.
Arkansas Nuclear One 1448 S.R. 333 Russellville, AR 72802 General Manager Plant Operations Entergy Operations, Inc.
Arkansas Nuclear One 1448 SR 333 Russellville, AR 72802 Director, Nuclear Safety & Licensing Entergy Services, Inc.
440 Hamilton Avenue White Plains, NY 10601 Director, Nuclear Safety Assurance Entergy Operations, Inc.
Arkansas Nuclear One 1448 SR 333 Russellville, AR 72802 Senior Manager, Nuclear Safety
& Licensing Entergy Operations, Inc.
1340 Echelon Parkway Jackson, MS 39213-8298 Manager, Licensing Entergy Operations, Inc.
Arkansas Nuclear One 1448 SR 333 Russellville, AR 72802 Section Chief, Division of Health Radiation Control Section Arkansas Department of Health and Human Services 4815 West Markham Street, Slot 30 Little Rock, AR 72205-3867 Section Chief, Division of Health Emergency Management Section Arkansas Department of Health and Human Services 4815 West Markham Street, Slot 30 Little Rock, AR 72205-3867 Pope County Judge Pope County Courthouse 100 W. Main Street Russellville, AR 72801 Senior Resident Inspector U.S. Nuclear Regulatory Commission P.O. Box 310 London, AR 72847 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-806