CNRO-2004-00003, Request for Alternative RBS-PT-001 - Proposed Alternative to ASME Section Xl Visual Examination Requirements

Request for Alternative RBS-PT-001 - Proposed Alternative to ASME Section Xl Visual Examination Requirements

ML041550858
Person / Time
Site:	River Bend
Issue date:	05/26/2004
From:	Burford F Entergy Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CNRO-2004-00003, RBS-PT-001
Download: ML041550858 (10)

Text

t Entergy Operations, Inc.

- Entergy 1340 Echelon Parkway Jackson. Mississippi 39213-8298 Tel 601-368-5758 F. G. Burford Acting Director Nuclear Safety & Licensing CNRO-2004-00003 May 26, 2004 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001

SUBJECT:

Request for Alternative RBS-PT-001 -

Proposed Alternative to ASME Section Xl Visual Examination Requirements River Bend Station Docket No. 50-458 License No. NPF-47

Dear Sir or Madam:

Pursuant to 10 CFR 50.55a(a)(3)(ii), Entergy Operations, Inc. (Entergy) requests relief from and proposes an alternative to the requirements of ASME Section Xl pertaining to pressure testing for River Bend Station (RBS). Performing Section Xi-required system leakage tests on these Class 2 systems is a burden without a compensating increase in the level of quality and safety. Testing in accordance with ASME Code Case N-522 would provide an acceptable level of quality and safety; however, these Class 2 systems do not meet the conditions required to apply this Code Case. Therefore, relief is required. Relief Request RBS-PT-001 is provided in Enclosure 1.

The NRC staff approved a similar request for Nine Mile Point Nuclear Station, Unit 2 (TAC. No. MA2151) in a letter dated February 29, 2000.

Entergy requests that the NRC staff grant RBS-PT-001 on or before May 28, 2005.

This letter contains two commitments as documented in Enclosure 2.

ALA-

CNRO-2004-00003 Page 2 of 2 Should you have any questions regarding these requests, please contact Guy Davant at (601) 368-5756.

Very truly yours, FGB/GHD/ghd

Enclosures:

1. Request for Alternative RBS-PT-001

2. Licensee-identified Commitments cc: Mr. W. A. Eaton (ECH)

Mr. P. D. Hinnenkamp (RBS)

Dr. Bruce S. Mallett U. S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011 NRC Senior Resident Inspector P. 0. Box 1050 St. Francisville, LA 70775 U.S. Nuclear Regulatory Commission Attn: Mr. Michael K. Webb MS 0-7D1 Washington, DC 20555-0001

ENCLOSURE 1 CNRO-2004-00003 REQUEST FOR ALTERNATIVE RBS-PT-OO1

ENTERGY OPERATIONS, INC.

REQUEST FOR ALTERNATIVE RBS-PT-001 I. COMPONENTS Components/Numbers: Hydrogen Analyzer (CMS) Loops A and B piping, and sampling system (SSR) piping connected to CMS Loop B1 ASME Code Class: 2

References:

1. ASME Section Xl 1992 Edition, 1993 Addenda, Table IWC-2500-1

2. ASME Section Xl 1992 Edition, IWA-5211 and IWA-5240 Examination Category: C-H Item Numbers: C7.30, C7.70

Description:

Performance of system leakage test as required by Table IWC-2500-1 Unit / Inspection River Bend Station - Second (2nd) 10-year interval Interval Applicability:

II. CODE REQUIREMENT(S)

ASME Section XI, Table IWC-2500-1, Examination Category C-H, Items C7.30 and C7.70 require the subject piping to be VT-2 visually examined during a system leakage test each inspection period. IWA-5211 requires that the VT-2 visual examination be performed while the component being tested is maintained at normal operating pressure.

Ill. REQUESTED ALTERNATIVE Pursuant to 10 CFR 50.55a(a)(3)(ii), Entergy Operations, Inc. (Entergy) proposes an alternative to the system leakage test with a VT-2 visual examination as required by ASME Section Xl Table IWC-2500-1 as discussed below.

The integrity of the subject piping will be verified and monitored by performing leakage rate testing in accordance with the River Bend Station Leakage Reduction and Monitoring Program and the Appendix J Program. The system leakage rate test will be performed on the supply and return pneumatic tubing/piping and the hydrogen analyzer components; specifically, from two manual isolation valves (one each in the supply and return pneumatic lines for the analyzer) located within containment to the pneumatic tubing, analyzer, isolation valves, and piping located outside containment (see Figures 1 and 2). System piping will be pressurized to > 8 psi and held for 15 minutes. The leakage rate will then be measured and compared to the acceptance criterion, which for 1 Figures 1 and 2 depict the configuration of the CMS hydrogen analyzer piping loops and SSR sampling station and piping.

Page 1 of 5

the subject piping is < 2,000 sccm per loop as established in the Leakage Reduction and Monitoring Program.

A local leak-rate test will be performed for the four (4) SSR containment isolation valves in accordance with 10 CFR 50 Appendix J. The CMS and SSR piping leak rate will be measured as part of the containment leak rate during the integrated leak-rate test, which is performed in accordance with the Appendix J Program.

IV. BASIS FOR ALTERNATIVE The subject CMS hydrogen analyzers and piping and SSR piping are designed to sample the containment and drywell atmospheres for the presence of hydrogen during post-LOCA conditions (the analyzers are placed in STANDBY mode during normal plant operation). A sample pump internal to the hydrogen analyzer draws an air sample from the containment or drywell atmosphere, which is then processed through an internal hydrogen sensor. Once analyzed, the sample is returned to the drywell atmosphere.

These functions are performed using a closed loop system with a portion of the system (pneumatic tubing and hydrogen analyzer) located outside containment and a portion located inside containment. The system includes approximately 700 feet of piping, of which about 350 feet are heat traced and insulated.

Performing the Code-required system leakage test with a VT-2 visual examination entails removing the insulation and heat tracing and applying leak detection fluid for every system pressure test. Once testing is complete, the fluid is removed and the heat tracing and insulation are reinstalled. The activities associated with these examinations would result in plant life exposure to personnel of approximately 29 man-Rem. Disposing of the fluid, the wipes used in fluid removal, and any damaged insulation and heat tracing is a significant radwaste impact.

This piping has two safety functions: (1) supports the ability of the CMS hydrogen analyzers to accurately detect the amount of hydrogen contained within the containment/drywell atmosphere; and (2) serves as a portion of the containment boundary.

The first safety function will not be affected by the presence of a leak that is less than the acceptance criteria of the leakage reduction program in any portion of the pneumatic supply or return system during post-LOCA operation. This is based on post-LOCA containment pressure being greater than the atmospheric pressure in the area of the plant where the pneumatic lines and analyzer are located (outside containment in the Auxiliary Building Elevation 141-foot area). With containment pressure being greater than that of the auxiliary building during post-LOCA operation, leakage would be outward so as not to affect the concentration of hydrogen being delivered to the hydrogen analyzer. The sample lines inboard of the manual isolation valves are not inside the test boundary. One of the sample valves is maintained open to containment atmosphere during system operation in accordance with procedure; therefore, there is no differential pressure between the inside and outside of the piping. Any leak in this portion of the system would merely change the location of the sample and have no effect on this safety function.

The second safety function, which is passive, is ensured via Appendix J testing. This testing is the appropriate mechanism to ensure the containment boundary function is maintained.

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As discussed in Section 1II,CMS and SSR system integrity will be verified by performing system leakage rate testing to Appendix J requirements and the Leakage Reduction Program in lieu of ASME Section Xl examinations. This is similar to the IWA-5244(a) requirements that allow the owner to establish acceptable leakage rate criteria for buried piping that can be isolable by means of valves. Although the subject piping is not buried, more than 50% of it is covered with heat trace and insulation.

V. CONCLUSION 10 CFR 50.55a(a)(3) states:

"Proposed alternatives to the requirements of (c), (d), (e), (f), (g), and (h) of this section or portions thereof may be used when authorized by the Director of the Office of Nuclear Reactor Regulation. The applicant shall demonstrate that:

(i) The proposed alternatives would provide an acceptable level of quality and safety, or (ii) Compliance with the specified requirements of this section would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety."

Based on the burden of radwaste disposal, resources commitment, ALARA exposures and performing the system leakage rate testing as discussed in Section IV, the Code-required VT-2 visual examination does not provide a compensating increase in the level of safety or quality. Therefore, Entergy requests authorization to perform the requested alternative to the Code requirement pursuant to 10 CFR 50.55a(a)(3)(ii).

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Auxiliary Building Containment Drywell

~SeNote LI I A II Leak Test I I Boundary

,- -- _ _- 1 - -- - -A.*- --

Return LEGEND Leak Test Boundary Manual Valve Power Valve (SOV)

NOTE t',J Check Valve One sample valve is maintained open during

-- - Heat Traced Piping system operation.

FIGURE 1 CMS Loop A Page 4 of 5

Auxiliary Building Containment Drywell fl! l f I A

I l Leak Test Boundary

-- -- II4 -4 I1 I Supply CIV l

Return CIV Leak Test LEGEND Boundary

>< Manual Valve I

Power Valve (SO\)

CIV l NOTE t'- Check Valve One sample valve is - - - Heat Traced Piping maintained open during system operation. CIV Containment Isolation Valve FIGURE 2 CMS Loop B Page 5 of 5

ENCLOSURE 2 CNRO-2004-00003 LICENSEE-IDENTIFIED COMMITMENTS to CNRO-2004-00003 Page 1 of 1 LICENSEE-IDENTIFIED COMMITMENTS TYPE (C eck one) SCHEDULED ONE-TIME CONTINUING COMPLETION COMMITMENT ACTION COMPLIANCE DATE

1. The integrity of the subject piping will be verified and monitored by performing leakage rate testing in accordance with the River Bend Station Leakage Reduction and Monitoring Program and the Appendix J Program. The system leakage rate test will be performed on the supply and return pneumatic tubing/piping and the hydrogen analyzer components; specifically, from two manual isolation valves (one each in the supply and return pneumatic lines for the analyzer) located within containment to the pneumatic tubing, analyzer, isolation valves, and piping located outside containment (see Figures 1 and 2). System piping will be pressurized to > 8 psi and held for 15 minutes. The leakage rate will then be measured and compared to the acceptance criterion, which for the subject piping is

< 2,000 sccm per loop as established in the Leakage Reduction and Monitoring Program.

2. A local leak-rate test will be performed for v the four (4) SSR containment isolation valves in accordance with 10 CFR 50 Appendix J. The CMS and SSR piping leak rate will be measured as part of the containment leak rate during the integrated leak-rate test, which is performed in accordance with the Appendix J Program.