ML20111B263

Application for Amend to License NPF-29,placing Containment Purge Valves W/Resilient Seals on Performance Based Leakage Testing Frequency

ML20111B263
Person / Time
Site:	Grand Gulf
Issue date:	05/08/1996
From:	Hutchinson C ENTERGY OPERATIONS, INC.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20111B265	List: ML20111B263 ML20111B270
References
GNRO-96-00051, GNRO-96-51, NUDOCS 9605140302
Download: ML20111B263 (14)

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! L-- Ent:rgy Oper tlins,Inc.

• ~l ENTERGY e o a - 7s6 Pyr G bsut MS 39E0 Tel 601437 2800 C. R. Hutchinson vu newra Opra'R(6 Cf3r.1 C$.;ff Psf hw $WM May 8, 1996 U.S. Nuclear Regulatory Commission Mail Station P1-37 Washington, D.C. 20555 Attention: Document Control Desk

Subject:

Grand Gulf Nuclear Station Docket No. 50-416 License No. NPF-29 Purge Valve Testing Proposed Amendment to the Operating License (PCOL-96/07)

GNRO-96/00051 Gentlemen:

Entergy Operations, Inc. is submitting by this letter a proposed amendment to the Grand Gulf Nuclear Station (GGNS) Operating License to put containment purge valves with resilient seals on a performance based teakage testing frequency. Currently these valves are tested every 184 days and once within 92 days after opening a valve. The proposed change would test these valves in accordance with our Appendix J testing program. The proposed change affects Operating License Surveillance Requirement (SR) 3.6.1.3.5.

During initial licensing of GGNS there was little available data on the reliability of large containment isolation valves with resilient seals. As a consequence, we agreed to more frequent testing of these valves than for other containment isolation valves. Since that time the valves have been routinely tested on an augmented testing frequency with no indication of seal degradation. We therefore believe that the augmented testing requirement imposes an undue burden without a commensurate safety benefit.

We also believe that GGNS is in a unique position to be able to implement this change.

We have demonstrated our understanding of the containment leakage factors important to safety through your approval of an Appendix J exemption implementing a performance-based testing program prior to rulemaking.

The cost savings over the assumed life of the plant are expected to be on the order of

$588,000. This savings meets the criteria for consideration under the Cost Beneficial Licensing Actions program. We request that this revision be approved by August 1,1996.

9605140302 96050s PDR '

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t May 8, 1996 i GNRO-96/00051 Page 2 of 3 i

Attachment 1 is the oath and affirmation required by 10 CFR 50.30. Attachment 2

provides justification for the change and contains the no significant hazards t considerations. Attachment 3 contains actualleakage data for the containment purge i supply & exhaust isolation valves. Attachment 4 is a copy of the marked-up GGNS

. Operating License.

Yours truly, /g 1 -,

( CRH/WBB/ams attachments: 1. Affirmation per 10 CFR 50.30 1 2. Justification for Removal of Leakage Rate Testing of Containment

! Purge Supply & Exhaust isolation Valves from Plant Specific Technical Specification

3. Actual Leakage Data for Containment Purge Supply & Exhaust isolation Valves

4. Marked-up Psges To The GGNS Operating License cc: Mr. J. Tedrow (w/a)

Mr. R. B. McGehee (w/a)

Mr. N. S. Reynolds (w/a)

. Mr. H. L. Thomas (w/o)

Mr. J. W. Yelverton (w/o)

Mr. L. J. Callan (w/a)

Regional Administrator U.S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011 Mr. J. N. Donohew, Project Manager (w/a) l Office of Nuclear Reactor Regulation 4

U.S. Nuclear Regulatory Commission Mail Stop 13H3 Washington, D.C. 20555

Dr. Alton B. Cobb (w/a)

State Health Officer State Board of Health P.O. Box 1700 Jackson, Mississippi 39205

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! Attachment 1 To GNRO-96/00051 1

Amrmation per 10 CFR 50.30 4

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BEFORE THE UNITED STATES NUCLEAR REGULATORY COMMISSION LICENSE NO. NPF-29

' DOCKET NO.' 50-416 IN THE MATTER OF MISSISSIPPI POWER & LIGHT COMPANY and SYSTEM ENERGY RESOURCES, INC.

and SOUTH MISSISSIPPI ELECTRIC POWER ASSOCIATION and ENTERGY OPERATIONS, INC.

AFFIRMATION 1, C. R. Hutchinson, being duly swom, state that I am Vice President, Operations GGNS of Entergy Operations, Inc.; that on behalf of Entergy Operations, Inc., System Energy Resources, Inc., and South Mississippi Electric Power Association I am authorized by Entergy Operations, Inc. to sign and file with the Nuclear Regulatory Commission, this application for amendment of the Operating License of the Grand Gulf Nuclear Station; that I signed this application as Vice President, Operations GGNS of Entergy Operations, Inc.; and that the statements made and the tienJfeetf erein are true and correct to the best of my knowledge, Informatio ar b fl' .

W .

C. R. Hutchinson f.

STATE OF MISSISSIPPI COUNTY OF CLAIBORNE SUBSCRIBED AND SWORN TO before me, a NoJgry Public, in and for the County and State above named, this ## day of Mau .1996.

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. y, My commission expires:

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Attachment 2 To GNRO-96/00051 4

J Justification for Removal of Leakage Rate Testing of Containment Purge l Supply & Exhaurt isolation Valves from Plant Specific Technical Specification i

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. A. Aff:cted Technic:1 Specificati:ns

- The following Technical Specification Surveillance Requirement (SR) in affected by the proposed change.-

SR 3.6.1.3.5 The proposed Technical Specification change and the associated Technical Specification Bases changes to be implemented following NRC approval of the

- proposed change are detailed in Attachment 4.

- B. Background As a result of numerous reports of unsatisfactory performance of resilient seats in butterfly-type isolation valves due to seal deterioration (see IE Circular 77-11), the

NRC imposed augmented leakage testing requirements (i.e., beyond the minimum

. Appendix J leak rate requirements) for containment purge / vent line isolation valves that utilize resilient seal materials. These requirements were typically imposed as technical specification surveillance requirements during initiallicensing of new plants. Because of this, the actual testing requirements differ on a plant specific basis. While the Staff may have acted in a prudent manner in imposing additional testing until seal degradation rates were determined, we believe it is reasonable to retum to the Appendix J testing requirements, since it has been demonstrated that seal degradation does not occur at an accelerated rate.

The NRC has approved similar changes in testing frequencies at the Vogtle Electric Generating Plant. The safety evaluation proffered by the Office of Nuclear Reactor Regulation for the Vogtle Plant further indicates the Staff's intentions with respect to containment purge valves with resilient seals. In the evaluation the Staff states the

"(o)perating experience has shown that for well maintained butterfly valves with resilient seals, used at suitable environmental and operating conditions, the 24-month Appendix J leakage rate test interval is sufficiently frequent. Accordingly, the Staff will approve a reduced leakage testing frequency if supported by plant-specific data (i.e., history of test results)." This indicates that the augmented testing program was designed to determine if performance of these valves degraded over time and if increased testing frequencies would be necessary on a permanent basis.

C. Current Technical Specification Requirements SR 3.6.1.3.5 of the GGNS Technical Specifications requires performance of leakage rate testing for primary containment purge valves witn resilient seals every 184 days and once within 92 days after opening the valves.

D. Proposed Technical Specification Change This change would change the frequency of SR 3.6.1.3.5 to be in accordance with the Appendix J Testing Program.

- E. Justification l

! ' The containment purge system has a high volume purge (HVP) with 20-inch supply and exhaust valves and a low volume purge (LVP) with 6-inch supply and exhaust valves. Each of these penetrations has two valves in series to provide the redundancy necessary for containment isolation capability. Operation of the purge

, . syst:m has been entlyzed during power operation end tha valvrs cra quIlifitd for use in all operational conditions. The valves are normally maintained closed during '

. Modes 1,2, and 3 to ensure leak tightness. During power operation, the use of the HVP is restricted to containment pressure control; ALARA and air quality considerations for personnel entry due to high explosive gas concentration, low oxygen concentration, high airbome particulate activity, high gaseous radioactivity, smoke or fumes; or for surveillance or special testing on the purge system that requires the isolation valve (s) to be open. In cold shutdown or refueling operating modes, the continuous use of the 20-inch purge system is unrestricted. The use of LVP is unrestricted in all modes of operation. Wdh the exception of the containment isolation function, the system has no safety-related function.

The improved Standard Technical Specifications (STS) specify a leakage testing frequency for these valves of 184 days and within 92 days after opening the valves.

These requirements apply to all sizes of containment purge valves with resilient seals (even though early problems associated with resilient seals were apparently limited to specific valves of 36" or 42" diameters from specific vendors), except for wives installed in lines that are isolated by blind flanges during power operation.

Given that the problems with resilient seats have not been shown to be generic in nature and since GGNS can produce the plant specific data (i.e., histories of test results) to demonstrate that our valves are not subject to excess degradation, we believe that allowing testing frequencies to revert to those of Appendix J is appropriate and consistent with current NRC policy.

GGNS has compiled over 14 years of historical data that clearly shows there has never been a problem with leakage through containment purge supply or exhaust isolation valves. The attached data (Attachment 3) clearly indicates that extensive testing has not only never identified any propensity for leakage, but that leakage through these valves has never even approached the leakage limits. Even a cursory review of this data indicates that Appendix J testing intervals would be sufficient and appropriate. -

We believe that the NRC's Appendix J rulemaking, which allows performance based leakage rate testing, clearly demonstrates the Staff's understanding that component failure probabilities are not a function of testing. Rather, test results can only be used as a check on the reasonableness of the testing frequency. In this case, the current testing frequencies are not reasonable, as demonstrated by the GGNS data.

The new rule (Option B) presents a reasonable methodology for determining testing frequencies that is based not only on performance, but also on other relevant factors, such as operating conditions, component application, system function, and risk insights. Under the new rule, the licensee determines what a safe interval is, within the limitations specified by the NRC. We feel that allowing these valves to be controlled by the rules of Appendix J is consistent with the philosophies developed by the Staff as a result of the effort to develop a performance based testing program and that there is no substantiated basis for the continuation of the augmented testing requirements.

F. Savings Acsociated with the Requested Change The following is an estimate of the cost savings associated with changing the test intervals for these valves. There are four containment purge penetrations with two e redundant isolation valves in sach penetration. The valves in each individual penetration are tested as a set, and therefore the cost analysis is based on cost per penetration. The analysis assumes four tests per year (every 92 days), because the w

v:lv2s cra required t3 be ex!rcised cv:ry 92 dIys und:r the Pump cnd Velva ,

inservice Testing Program. Because of good past performance, the analysis assumes no trouble-shooting for excess leakage. The analysis is based on a $40.00 per hour rate for all labor and an assumed thirty year plant life.

Position Activity Man Hours Cost Per Per Penet. Test (Man Hours X

$40.00)

Planner Plan WO Package 1 40 Engineer Develop data package, test pressure .

calculations, allowable leakage etc. 1 40 Maint. Schedule testing Coordinator 0.5 20

Scheduler Schedule test on weekly schedule 0.25 10 l

Health Physics Ftaview work orders and monitor open &

closing test valves. 1 40 Operations (2) Alion system for testing 6 240 Shift Supv. Sign on & review test results 0.5 20 Mechanic (2) Set-up test equipment & perform test 16 640 Operators (3) Restore system 6 240 Maint. Supv. Review test results & sign package ready 0.5 20 for retest.

Engineer Review test results & log leakage into CTMT  !

totals 1 40 t Sury. Coor. Review test & update computer tracking 0.25 program 10 Work Close Out. Review & scan data 1 40 Total Alllabor 35 $1400 Current Plan Costs t

Total hours per test (35) X total penetrations (4) = 140 hours0.00162 days <br />0.0389 hours <br />2.314815e-4 weeks <br />5.327e-5 months <br /> per test of all penetrations.

l Total hours (140) X tests per year (4) = 560 hours0.00648 days <br />0.156 hours <br />9.259259e-4 weeks <br />2.1308e-4 months <br /> per year Total hours per year (560) X years (30) = 16,800 hours0.00926 days <br />0.222 hours <br />0.00132 weeks <br />3.044e-4 months <br /> Total hours (16,800) X labor rate ($40/hr.) = $672,000 Proposed Plan Costs Total hours per test (35) X average number of tests per year (2) = 70 hours8.101852e-4 days <br />0.0194 hours <br />1.157407e-4 weeks <br />2.6635e-5 months <br /> per year Total hours per year (70) X years (30) = 2,100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> Total hours (2,100) X labor rate ($40/hr.) = $84,000 Total Savings Current Plan $672,000 Proposed Plan -884.000 Savings $588,000 Even more savings will accrue if the valves are good performers, under Option B of 10 CFR 50, Appendix J, since penetrations could be tested at intervals of up to five years.

G. No Significant Hazards Consideration in accordance with 10 CFR 50.92, Entergy Operations, Inc. has evaluated the proposed change to the Operating License of GGNS and has determined that the operation of the facility in accordance with the proposed amendment would not

. involve any significant hazards considerations. In accordance with 10 CFR 50.91(a),

Entergy Operations, Inc. is providing the following analysis of the proposed 1 amendment against the three standards of 10 CFR 50.92(c):

1) The proposed chance does not sianificantiv increase the probability or i conseauences of an accident oreviousiv evaluated. j l

This change deletes the augmented testing requirement for these containment isolation valves and allows the surveillance intervals to be set in  !

accordance with the Appendix J testing program. This change does not affect the system function or design. The purge valves are not an initiator of .

any previously analyzed accident. Leakage rates do not affect the probability 1 of the occurrence of any accident. Operating history has demonstrated that these valves do not degrade and cause leakage as previously anticipated.

Because these valves have been demonstrated to be reliable, these valves can be expected to perform the containment isolation function as assumed in the accident analyses. Therefore, there is no significant increase in the consequences of any previously evaluated accident.

2) The proposed chanae would not create the possibility of a new or different kind of accident from any accident oreviously evaluated.

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Extending the test intervals has no influence on, nor does it contribute in any l way to, the possibility of a new or different kind of accident or malfunction l from those previously analyzed. No change has been made to the design,

! function or method of performing leakage testing. Leakage acceptance l criteria have not changed. No new accident modes are created by extending l- the testing intervals. No safety-related equipment or safety functions are

altered as a result of this change.

3) The proposed chanae does not involve a slanificant reduction in a marain of safety l

! The only margin of safety that has the potential of being impacted by the proposed changes involves the offsite dose consequences of postulated accidents which are directly related to the containment leakage rate. The proposed change does not alter the method of performing the tests nor does

it change the leakage acceptance criteria. Sufficient data has been collected to demonstrate that the resilient seals do not degrade at an accelerated rate.

Because of this demonstrated reliability, this change will provide sufficient surveillance to determine an increase in the unfiltered leakage prior to the

leakage exceeding that assumed in the accident analysis. Therefore, the proposed change does not result in a significant reduction in a margin of safety.

Based on the above evaluation, Entergy Operation, Inc. has concluded that operation in 4

accordance with the proposed amendment involves no significant hazards considerations.

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Attachment 3 to GNRO-96/00051 LLRT Leakage Data for Containment Purge Supply & Exhaust isolation Valves i

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i LLRT Data for Co"alnment Purge isolation Valves (all test leakage rates are in standard cubic centimeters per minute)

Date : E61F009 & 10TE61F056 & 57l M41F011 & 121 M41F034 & 351 leakage limit 6/5/81 40 1435 6/23/81 12 1435 11/6/81 350 1435 12/1/81 110 60 1435 j 12/14/81 30 1435 l 9/1/82 165 50 1435 11/1/82 70 20 1435 1 7 2/6/82 140 40 1435 3/21/83 100 1435 3/23/83 150 1435 6/7/83 300 1435 l 6/9/83 0 100 1435 9/6/83 200 1435 12/6/83 0 76 1435 12/7/83 40 1435 2/27/84 400 200 1435 2/28/84 130 1435 5/21/84 100 300 200 1435 5/22/84 100 1435 8/18/84 10 50 0 1435 10/11/84 140 1435 11/5/84 250 300 1435 11/8/84 150 1435 1/24/85 0 1435 1/25/85 0 0 1435 2/15/85 60 1435 4/22/85 33.37 1435 1 4/23/85 146.68 1435 4/26/85 48.98 1435 7/15/85 0 1435 7/16/85 48.9 1435 l

- 7/17/85 0 1435 l 10/10/85 0 98.15 49.08 1435 l 1/10/86 199 0 99 1435 1/13/86 49 1435 4/2/86 0 1435 4/3/86 68.32 _

0 1435 4/4/86 0 1435 5/1/86 0 1435 6/23/86 0 1435 .

6/24/86 28.856 0 1435 6/25/86 0 1435 9/11/86 19.8 0 148.9 1435 9/12/86 39.7 1435 11/12/86 0 0 1435 11/13/86 0 0 1435 I

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. l LLRT Data for Containment Purge isolation Valves (all test leakage rates are in standard cubic centirneters per minute)

Date E61F009 & 10 E61F056 & 57 M41F011 & 12 M41F034 & 35 leakage limit l 12/6/86 39.924 1435 2/3/87 0 0 1435 2/5/87 39.478584 0 1435 4/23/87 0 0 1435 4/24/87 0 0 1435 7/14/87 0 0 1435 7/16/87 0 0 1435 10/6/87 0 0 1435 10/8/87 0 0 1435 12/16/87 0 0 0 1435 12/16/87 60.2 1435 3/12/88 0 0 1435 3/13/88 0 0 1435 6/8/88 0 0 1435 6/9/88 0 0 1435 9/16/88 0 1435 9/27/88 0 0 1435 12/13/88 0 1435 12/21/88 0 0 1435 3/13/89 0 0 1435 ,

3/14/89 0 0 1435 3/23/89 0 1435 3/26/89 0 30 1435 6/13/89 0 0 1435 <

6/14/89 0 0 1435 6/28/89 0 1435 6/30/89 0 1435 9/11/89 0 1435 9/12/89 0 1435 9/29/89 0 0 1435 12/8/89 44 1435 12/12/89 0 1435 1/8/90 60 0 1435 1/16/90 0 1435 3/8/90 0 1435 3/9/90 0 1435 4/4/90 0 1435 4/5/90 0 1435 6/5/90 0 1435 6/6/90 0 1435 6/26/90 0 1435 6/27/90 0 1435 9/4/90 0 1435 9/11/90 0 1435 9/20/90 0 0 1435 2/26/91 0 1435 Page 2 of 4 i

- LLRT Data for Containment Purge Isolation Valves (all test leakage rates are in standard cubic centimeters per minute)

Date l E61F009 & 10 E61F056 & 57 M41F011 & 12 M41F034 & 35 : leakage limit 2/27/91 0 1435 3/5/91 0 1435 3/6/91 0 1435 5/28/91 0 1435 5/29/91 0 1435 6/4/91 0 1435 6/5/91 0 1435 7/23/91 0 1435 8/22/91 0 1435 8/23/91 0 1435 8/29/91 0 1435 8/30/91 0 1435 11/25/91 0 0 1435 11/26/91 0 0 1435 2/19/92 0 1435 2/20/92 0 1435 2/26/92 0 1435 2/27/92 56 1435 4/1/92 40 1435 4/2/92 0 1435 4/7/92 0 7 1435 7/1/92 0 1435 7/;U92 0 1435 7/7/92 0 0 1435 9/29/92 0 1435 10/6/92 0 0 1435 10/19/92 0 1435 12/29/92 0 1435 1/5/93 0 0 1435 1/18/93 0 1435 3/30/93 0 1435 4/5/93 16 1435 4/6/93 39.627 1435 4/15/93 0 1435 6/29/93 0 1435 7/1/93 0 1435 7/6/93 0 1435 7/12/93 0 1435 10/1/93 0 0 2116 10/12/93 0 0 2116 11/8/93 0 2116 11/15/93 0 2116 12/27/93 37 2116 1/10/94 10 20 2116 2/7/94 0 0 2116 4/5/94 0 2116 Page 3 of 4

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LLRT Data for Containment Purge isolation Valves (all test leakage rates are in standard cubic centimeters per minute)

Date E61F009 & 10 [E61F056 & 57] M41F011 & 12 l M41F034 & 35 l leakage limit 4/12/94 0 2116 l 4/13/94 0 2116 )

5/11/94 0 2116 7/12/94 0 2116 7/13/94 0 2116 4 7/23/94 0 2116 I 8/4/94 0 .2116 10/3/94 0 2116 1 10/11/94 0 0 2116 11/8/94 2.5 2116 1/4/95 32.5 2116 1/10/95 0 2116 l 1/11/95 0 2116 I 3/21/95 0 2116 l 3/22/95 0 2116 3/23/95 0 2116 5/9/95 0 2116

~ 5/9/35 0 2116 5/1b/95 40 2116 5/22/95 20 2116 6/1/95 0 2116 8/7/95 0 2116 8/8/95 0 2116 8/16/95 0 2116 9/1/95 0 2116 11/7/95 0 2116 11/8/95 0 2116 11/15/95 0 2116 11/30/95 0 2116 2/7/96 0 0 2116 2/14/96 0 2116 I

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