ML070920450

Issuance of License Amendment 152 Leakage Rate Testing Containment Purge Valves

ML070920450
Person / Time
Site:	River Bend
Issue date:	05/03/2007
From:	Bhalchandra Vaidya NRC/NRR/ADRO/DORL/LPLIV
To:	Venable J Entergy Operations
Vaidya B, NRR/DORL/LP4, 415-3308
Shared Package
ML070920443	List: ML070920450 ML070920458
References
Download: ML070920450 (14)

Text

May 3, 2007 Mr. Joseph E. Venable Vice President of Operations Entergy Operations, Inc.

River Bend Station 5485 US Highway 61N St. Francisville, LA 70775

SUBJECT:

RIVER BEND STATION, UNIT 1 - ISSUANCE OF AMENDMENT RE:

LEAKAGE RATE TESTING OF CONTAINMENT PURGE VALVES (TAC NO. MD3025)

Dear Mr. Venable:

The Commission has issued the enclosed Amendment No. 152 to Facility Operating License No. NPF-47 for the River Bend Station, Unit 1 (RBS). The amendment consists of changes to the Technical Specifications (TSs) in response to your application dated September 19, 2006, as supplemented by letter dated February 28, 2007.

The amendment revises RBSs TS Surveillance Requirement (SR) 3.6.1.3.5 to change the currently specified test frequency for leak testing containment purge supply and exhaust isolation valves with resilient seal materials to test these valves in accordance with RBS's TS 5.5.13, Primary Containment Leakage Rate Testing Program. RBS's Primary Containment Leakage Rate Testing Program is implemented in accordance with the Title 10 of the Code of Federal Regulations, Part 50 (10 CFR 50), Appendix J, Option B, and Regulatory Guide (RG) 1.163, "Performance-Based Containment Leak Test Program," dated September 1995.

RG 1.163 allows a nominal test interval of 30 months for containment purge and vent valves, with consideration given to operating experience and safety significance. However, please note that although the longer testing interval allowed in RG 1.163 may be adequate in general application for the RBS containment purge supply and exhaust isolation valves, RBS is responsible for ensuring that the degradation of leak tightness of the valves does not adversely affect the primary containment operability. Any adverse trends of individual valve performance or condition may warrant closer monitoring on a shorter leakage rate testing interval than the nominal or base interval of 30 months for containment purge and vent valves allowed by RG 1.163, in conjunction with 10 CFR 50, Appendix J, Option B.

J. E. Venable A copy of our related Safety Evaluation is enclosed. The Notice of Issuance will be included in the Commission's next biweekly Federal Register notice.

Sincerely,

/RA/

Bhalchandra Vaidya, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-458

Enclosures:

1. Amendment No. 152 to NPF-47

2. Safety Evaluation cc w/encls: See next page

Pkg ML070920443 (Amendment/License ML070920450, TS Pgs ML070920458)

(*) No substantial changes made in SE Input Memorandum OFFICE NRR/LPL4/PM NRR/LPL4/LA NRR/SCVB/BC (*)

OGC NRR/LPL4/BC NAME BVaidya JBurkhardt RDennig BKlukan THiltz DATE 4/25/07 4/25/07 3/26/07 5/2/07 5/3/07

November 2006 River Bend Station cc:

Manager, Licensing Entergy Operations, Inc.

River Bend Station 5485 US Highway 61N St. Francisville, LA 70775 Director, Nuclear Safety & Licensing Entergy Operations, Inc.

1340 Echelon Parkway Jackson, MS 39213-8298 Louisiana Department of Environmental Quality Radiological Emergency Planning and Response Division P.O. Box 4312 Baton Rouge, LA 70821-4312 Louisiana Department of Environmental Quality Office of Environmental Compliance P.O. Box 4312 Baton Rouge, LA 70821-4312 Senior Resident Inspector P.O. Box 1050 St. Francisville, LA 70775 President of West Feliciana Police Jury P.O. Box 1921 St. Francisville, LA 70775 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064 Ms. H. Anne Plettinger 3456 Villa Rose Drive Baton Rouge, LA 70806 Executive Vice President and Chief Operating Officer Entergy Operations, Inc.

P.O. Box 31995 Jackson, MS 39286-1995 General Manager Plant Operations Entergy Operations, Inc.

River Bend Station 5485 US Highway 61N St. Francisville, LA 70775 Director, Nuclear Safety Assurance Entergy Operations, Inc.

River Bend Station 5485 US Highway 61N St. Francisville, LA 70775 Vice President, Operations Support Entergy Operations, Inc.

P.O. Box 31995 Jackson, MS 39286-1995 Mr. Jim Calloway Public Utility Commission of Texas 1701 N. Congress Avenue Austin, TX 78711-3326 Attorney General State of Louisiana P.O. Box 94095 Baton Rouge, LA 70804-9095 Brian Almon Public Utility Commission William B. Travis Building P.O. Box 13326 1701 North Congress Avenue Austin, Texas 78701-3326 Richard Penrod, Senior Environmental Scientist/State Liaison Officer Office of Environmental Services Northwestern State University Russsell Hall, Room 201 Natchitoches, LA 71497

ENTERGY GULF STATES, INC. **

AND ENTERGY OPERATIONS, INC.*

DOCKET NO. 50-458 RIVER BEND STATION, UNIT 1 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 152 License No. NPF-47 1.

The Nuclear Regulatory Commission (the Commission) has found that:

A.

The application for amendment by Entergy Gulf States, Inc.* (the licensee) dated September 19, 2006, as supplemented by letter dated February 28, 2007, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commission's rules and regulations set forth in 10 CFR Chapter I; B.

The facility will operate in conformity with the application, as amended, the provisions of the Act, and the rules and regulations of the Commission; C.

There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commission's regulations; D.

The issuance of this license amendment will not be inimical to the common defense and security or to the health and safety of the public; and Entergy Operations, Inc. is authorized to act as agent for Entergy Gulf States, Inc., and has exclusive responsibility and control over the physical construction, operation and maintenance of the facility.

Entergy Gulf States, Inc., has merged with a wholly-owned subsidiary of Entergy Corporation. Entergy Gulf States, Inc., was the surviving company in the merger.

E.

The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.

2.

Accordingly, the license is amended by changes to the Technical Specifications and Paragraph 2.C.(2) of Facility Operating License No. NPF-47 as indicated in the attachment to this license amendment.

3.

The license amendment is effective as of its date of issuance and shall be implemented within 60 days from the date of issuance.

FOR THE NUCLEAR REGULATORY COMMISSION

/RA/

Thomas G. Hiltz, Chief Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

Attachment:

Changes to Facility Operating License No. NPF-47 and Technical Specifications Date of Issuance: May 3, 2007

ATTACHMENT TO LICENSE AMENDMENT NO. 152 FACILITY OPERATING LICENSE NO. NPF-47 DOCKET NO. 50-458 Replace the following pages of the Facility Operating License No. NPF-47 and Appendix A Technical Specifications with the attached revised pages. The revised pages are identified by Amendment number and contain marginal lines indicating the areas of change.

Remove Insert 3

3 Remove Insert 3.6-17 3.6-17 (3)

EOI, pursuant to the Act and 10 CFR Part 70, to receive, possess and to use at any time special nuclear material as reactor fuel, in accordance with the limitations for storage and amounts required for reactor operation, as described in the Final Safety Analysis Report, as supplemented and amended; (4)

EOI, pursuant to the Act and 10 CFR Parts 30, 40 and 70, to receive, possess, and use at any time any byproduct, source and special nuclear material as sealed neutron sources for reactor startup, sealed sources for reactor instrumentation and radiation monitoring equipment calibration, and as fission detectors in amounts as required; (5)

EOI, pursuant to the Act and 10 CFR Parts 30, 40 and 70, to receive, possess, and use in amounts as required any byproduct, source or special nuclear material without restriction to chemical or physical form, for sample analysis or instrument calibration or associated with radioactive apparatus or components; and (6)

EOI, pursuant to the Act and 10 CFR Parts 30, 40 and 70, to possess, but not separate, such byproduct and special nuclear materials as may be produced by the operation of the facility.

C.

This license shall be deemed to contain and is subject to the conditions specified in the Commission's regulations set forth in 10 CFR Chapter 1 and is subject to all applicable provisions of the Act and to the rules, regulations and orders of the Commission now or hereafter in effect; and is subject to the additional conditions specified or incorporated below:

(1)

Maximum Power Level EOI is authorized to operate the facility at reactor core power levels not in excess of 3091 megawatts thermal (100% rated power) in accordance with the conditions specified herein. The items identified in Attachment 1 to this license shall be completed as specified. Attachment 1 is hereby incorporated into this license.

(2)

Technical Specifications and Environmental Protection Plan The Technical Specifications contained in Appendix A, as revised through Amendment No. 152 and the l

Environmental Protection Plan contained in Appendix B, are hereby incorporated in the license. EOI shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.

Amendment No. 152

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 152 TO FACILITY OPERATING LICENSE NO. NPF-47 ENTERGY OPERATIONS, INC.

RIVER BEND STATION, UNIT 1 DOCKET NO. 50-458

1.0 INTRODUCTION

By application dated September 19, 2006 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML062680173), as supplemented by letter dated February 28, 2007 (ADAMS Accession No. ML070650311), Entergy Operations, Inc. (the licensee),

requested changes to the Technical Specifications (TSs) for the River Bend Station, Unit 1 (RBS). The supplement dated February 28, 2007, provided additional information that clarified the application, did not expand the scope of the application as originally noticed, and did not change the staff's original proposed no significant hazards consideration determination as published in the Federal Register on October 24, 2006 (71 FR 62310).

The proposed changes would revise RBSs TS Surveillance Requirement (SR) 3.6.1.3.5 to replace the currently specified test frequency for leak testing containment purge supply and exhaust isolation valves with resilient seal materials from every 184 days and once within 92 days after opening the valve, with a frequency established in accordance with TS 5.5.13, Primary Containment Leakage Rate Testing Program.

RBS's Primary Containment Leakage Rate Testing Program is implemented in accordance with the Title 10 of the Code of Federal Regulations (10 CFR), Part 50, Appendix J, Option B, and Regulatory Guide (RG) 1.163, "Performance-Based Containment Leak Test Program," dated September 1995. RG 1.163 allows a nominal test interval of 30 months for containment purge and vent valves, with consideration given to operating experience and safety significance.

The NRC staff has granted similar requests from Catawba (ADAMS Accession No. ML051730234) and Grand Gulf Nuclear Station, Amendment No. 128, Dated October 18, 1996 (ADAMS Accession No. ML021490101). The NRC staff has granted these TS changes on the basis of good valve performance demonstrated by plant-specific historical leakage rate testing results, showing that their primary containment purge and vent valves have had consistently good leakage performance and are thus unlikely to experience enough degradation to jeopardize containment operability during the longer test interval permitted by 10 CFR 50, Appendix J, Option B, and RG 1.163.

2.0 REGULATORY EVALUATION

RBS's Containment Purge System is designed to either continuously purge the containment when required or recirculate air during periods of testing. The associated containment isolation valves are 36-inch Posi-seal air-operated butterfly valves. The seal rings are TEFZEL or URETHANE and are inspected and/or repaired or replaced if the valve leakage rate becomes excessive rather than be replaced on a calendar period basis. The Containment Purge System is described in RBSs Updated Safety Analysis Report, Section 9.4.6.5.3.

The regulations in 10 CFR, General Design Criteria (GDC) 54, 55, 56, and 57 of Appendix A, "General Design Criteria for Nuclear Power Plants," require that design of piping systems penetrating primary reactor containment be provided with isolation capabilities that reflect the importance to safety of isolating these piping systems.

Prior to 1995, the regulations in 10 CFR Part 50, Appendix J, "Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors," required that the containment isolation valves, including containment purge and vent valves, be subjected to local leakage rate tests at every refueling outage, but not to exceed about 3 years for Type A testing and 2 years for Type B and C testing. Compliance with 10 CFR, Part 50, Appendix J, provided assurance that the leakage rate of the containment, including those systems and components which penetrate the containment, does not exceed the allowable leakage rate specified in the TS. The allowable leakage rate was determined so that the leakage rate assumed in the safety analyses is not exceeded. The regulations in 10 CFR, Part 50, Appendix J, did not contain any special requirements for containment purge and vent valves.

However, in the 1970s, operating experience had shown that containment purge and vent valves with resilient seals were more susceptible than other containment isolation valves to degradation caused by environmental factors (such as temperature extremes and changes in humidity and barometric pressure) and mechanical factors (such as wear and tear and hardening of resilient seals due to aging and exposure to radiation). This degradation not only could cause high and rapidly increasing leakage rates, but the radiological consequences of such leaks were more significant than for other valves because of the typically large diameters of the containment purge and vent valves and the direct connection they provided between the primary containment atmosphere and the environment outside primary containment.

For this reason, the U.S. Nuclear Regulatory Commission (NRC) staff determined that containment purge and vent valves were, as a class, a special problem in terms of leakage rate.

The NRC established Generic Issue B-20, "Containment Leakage Due to Seal Deterioration" to study the problem and propose a regulatory resolution. As part of the resolution of Generic Issue B-20 (also known as Multi-Plant Action MPA-B020), the NRC staff required increased frequency of local leakage rate testing of containment purge and vent valves, over and above the frequency required by Appendix J (additional background may be found in IE Circular 77-11, "Leakage of Containment Isolation Valves with Resilient Seals," issued September 6, 1977). The purpose was to limit the length of time during which the valves might be inoperable due to excessive leakage and thereby make it more likely that a licensee would catch and correct advancing degradation before it could challenge primary containment operability.

Although there was some variation, a typical test frequency was every 6 months for "passive" valves (those not opened during plant operation), and every 3 months for "active" valves (those opened during plant operation). However, the NRC staff implemented the increased testing frequencies through individual plant TS without changing the requirements in 10 CFR 50, Appendix J. The current requirements in RBS's TS, where the test interval is 184 days for the valves that have not been opened and 92 days for valves that have been opened, reflect the test frequencies mentioned above.

Subsequent to the problems observed in the 1970s, the nuclear industry made considerable strides in correcting the deficiencies of containment purge and vent valves with resilient seals.

Improved seal materials, quality control, and modifications of equipment and environmental conditions have largely corrected valve deficiencies in many plants. After careful evaluation of the progress made by the nuclear industry, in 1995, the NRC revised Appendix J to add a performance-based option for testing, called Option B, whereas the original requirements are called Option A. The NRC staff also issued RG 1.163, which identified a method acceptable to the NRC staff for implementing Option B. RG 1.163 stated that with four exceptions (described in RG 1.163), Nuclear Energy Institute (NEI) guidance document NEI 94-01, Rev. 0, "Industry Guideline for Implementing Performance-Based Option of 10 CFR Part 50, Appendix J," dated July 26, 1995, provided methods acceptable to the NRC staff for complying with Option B. By Amendment No. 84, dated December 19, 1995 (ADAMS Accession No. ML021610670), RBS adopted Option B for Type A, B, and C testing in its TS, which requires compliance with the provisions of RG 1.163. RG 1.163 guidance provides for the following:

an extension in the Type A (integrated leakage rate) test interval to 10 years based upon two consecutive successful tests.

Type B tests (local leakage rate tests of containment penetrations whose design incorporates resilient seals, gaskets, or sealant compounds, piping penetrations fitted with expansion bellows, and electrical penetrations) may be extended up to a maximum interval of 120 months based in part on satisfactory leakage test history.

Type C tests (local leakage rate tests of containment isolation valves) may have intervals extended to 60 months based in part on satisfactory leakage test history.

However, despite the fact that it would be acceptable for most other containment isolation valves to have test intervals of up to 60 months for Type C testing, the NRC staff, in RG 1.163, did not endorse this extended interval for containment purge and vent valves. RG 1.163 endorsed the test interval for containment purge and vent valves from 24 months (10 CFR 50, Appendix J requirement) to 30 months. This determination took into consideration the past poor operating experience and the safety significance of the large diameter and direct connection between the containment atmosphere and the outside environment.

3.0 TECHNICAL EVALUATION

3.1 Valve Cycling, Aging, Degradation, and Wear The containment isolation valves are leak tested in combination by pressurizing between the isolation valves in the supply and exhaust line penetrations. The valves are normally closed during Modes 1, 2, and 3 to ensure leak tightness. The valves must be closed per TS SR 3.6.1.3.1 when not being used for pressure control, ALARA (as low as reasonable achievable), or air quality considerations for personnel entry, or for surveillances or special testing on the purge system that require the valves to be open. During normal plant operation, the purge valves are typically cycled once per 12-hour shift for containment pressure control or about 180 open and close cycles per calendar quarter. The purge valve leakage test results are combined with the other Type B and Type C leakage test results for evaluation of the associated primary containment leakage rate acceptance criterion. The requested change in leakage test interval does not affect the requirements in TS 3.6.1.3, Primary Containment Isolation Valves (PCIVs), Action D, because there are no current TS required leakage limits specific to the primary containment purge valves. The proposed TS change only affects the purge valve leakage rate test interval and does not affect the design or operation of the valves.

Therefore, the isolation capability is maintained in accordance with the GDC requirements.

3.2 Evaluation of Valve Test Results and Reasonable Expectation of Operability In its application, as supplemented, the licensee provided information on purge valve leakage test results and combined Type B and Type C test leakage totals since 1996. This information encompassed approximately 45 tests of the purge valve pairs.

Based on the review of the licensee-provided data, the NRC staff finds that the performance of containment purge and vent valves has been consistent and within the acceptance criterion (use of combined limits for Type B and Type C tests), because the licensee-provided data indicated the following:

Only one of the two pairs of purge valves had their resilient seals replaced since 1996. This data also showed that the combined Type B and Type C total typically ranged from 7 percent to 17 percent of the acceptance criterion value and that the purge valve leakage contribution was less than 30 percent of the combined total.

The test data did not show any resilient seal accelerated degradation due to aging or wear that would warrant continued augmented testing at the current TS interval as there was no strong trend of increasing leakage even after 10 years of seal service.

The trending of the purge valve leakage rate test results showed no potential for impacting the overall leakage limit prior to the next test, even if performed at the RG 1.163-allowed interval rather than the TS augmented interval.

The provided purge valve leakage test history indicates that the TS-required augmented leakage test interval makes a negligible contribution to maintaining containment operability.

Additionally, for evaluation of operability, the applicable licensee procedure, Entergy Nuclear Management Manual, EN-OP-104, Revision 2, Operability Determinations, requires use of the following methodology, which may result in actions leading to, but not limited to, closer monitoring on a shorter leak rate testing interval than that allowed by RG 1.163:

Reasonable Expectation (of Operability) (REO): The discovery of a degraded or nonconforming condition may call the operability of one or more [Structures, Systems, and Components] (SSCs) into question. A subsequent determination of operability should be based on the licensee's "reasonable expectation," from the evidence collected, that the SSCs are operable and that the operability determination will support the expectation. Reasonable expectation does not mean absolute assurance that the SSCs are operable. The SSCs may be considered operable when there is evidence that the possibility of failure of an SSC has increased, but not to the point of eroding confidence in the reasonable expectation that the SSC remains operable. The supporting basis for the reasonable expectation of SSC operability should provide a high degree of confidence that the SSC remains operable. It should be noted that the standard of "reasonable expectation" is a high standard, and there is no such thing as an indeterminate state of operability; an SSC is either operable or inoperable.

The above-referenced methodology is the same as that described in the NRC-approved Regulatory Issue Summary 2005-20, Revision to Guidance Formerly Contained in NRC Generic Letter 91-18, Information to Licensees Regarding Two NRC Inspection Manual Sections on Resolution of Degraded and Nonconforming Conditions and on Operability.

Therefore, the NRC staff finds that the licensee's methodology for determining valve operability is acceptable.

3.3 Conclusion - Technical Evaluation Based on the licensee's submissions and above discussion, the NRC staff has determined that RBS does not have resilient seal purge valve issues. Therefore, the NRC staff finds the licensee's request to revise TS SR 3.6.1.3.5 to require the test frequency to be in accordance with the Primary Containment Leakage Rate Testing Program, in accordance with 10 CFR, Part 50, Appendix J, Option B, and the guidance in RG 1.163, acceptable, which allow a nominal test interval of 30 months for containment purge and vent valves, with consideration given to operating experience and safety significance.

4.0 STATE CONSULTATION

In accordance with the Commission's regulations, the Louisiana State official was notified of the proposed issuance of the amendment. The State official had no comments.

5.0 ENVIRONMENTAL CONSIDERATION

The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration, and there has been no public comment on such finding published October 24, 2006 (71 FR 62310). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b),

no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.

6.0 CONCLUSION

The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

Principal Contributor: J. Bettle, SCVB Date: May 3, 2007