ML20198N385
| ML20198N385 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 10/28/1997 |
| From: | Hagan J ENTERGY OPERATIONS, INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20198N391 | List: |
| References | |
| GNRO-97-00103, GNRO-97-103, NUDOCS 9711040112 | |
| Download: ML20198N385 (11) | |
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9 Entergy operations. loc. ;
= En.tergy ggy f ax Ul1437 2705 Joseph J. Hagen October 28, 1997 $*/,if" a ,o one a=,
U.S. Nuclear Regulatory Commission Mail Station P137 Washington, D.C. 20555 Attention: Document Control Desk
Subject:
Grand Gulf Nuclear Station Docket No. 50-416 License No. NPF-29 Proposed Amendment to the Operating License (PCOL-97/04)
Adoption of Option 8 of 10 CFR 50, Appendix J GNRO 97/00103 Gentlemen:
By letter dated August 13,1993, as supplemented by letters dated April 15, May 11, June 24, and July 20,1994 and April 18,1995, Entergy Operations, Inc., (EOI) applied for an exemption to the requirements of 10 CFR 50, Appendix J. This exemption permitted the selection of containment leakage rate testing intervals for components on the basis of performance. The Staff agreed to review our proposal in support of proposed rulemaking that would revise Appendix J, to allow licensees the option of a performance-based approach to containment leak rate testing. The exemption was granted on April 26,1995 and remains in effect until startup following Refueling Outage 9 (currently scheduled for the spring of 1998).
10 CFR 50 Appendix J, now allows licensees to adopt Option B (performance based testing requirements) by submitting an implementation plan and requesting a revision to the Technical Specifications (TS). EOI is therefore submitting by this letter a proposed amendment to the Grand Gulf Nuclear Station (GGNS) Operating License to adopt 10 CFR 50, Appendix J, Option B. This amendment would revise the TSs to implement Option B and will reference the Safety Evaluation issued by The Office of Nuclear Reactor Regulation for GGNS's Appendix J exemption as the implementing document for our performance-based leakage testing program. hgh Although our current program meets the requirements of Option B of Appendix J, the I j ,
program was developed prior to industry guidance for performance-based testing and was, f therefore, based on our approved excmption rathn than the guidance. As a result, an '
extensive revision to our program would be requir. i to implement a new program based on l- industry guidance. We believe that this would sen,e no useful purpose and would result in significant effort on our part and on the part of the Staff, without a compensating increase in
- safety. The Staff has previously completed an extensive review of our program and found it 7
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GNRO g7/00103 Page 2 of 3 acceptable. Thereforeiwe believe that continuing with our current program is the most
. economical and logical approach for complying with Option B of Appendix J.
Attachment 1 is the oath and affirmation required by 10 CFR 50.30. Attachment 2 provides ;
a description of the proposed changes and associated justificatiot acluding a basis for No
. Significant Hazards Consideration. Attachment 3 is a copy of the marked-up GGNS Operating License Following NRC approval of this request, EOl will revise the GGNS TS Bases, in accordance with the TS Bases Control Program. Attachment 4 is a mark up of the Bases changes and are provided for Information only. Approval of these proposed TS changes is requested by March 1,1998 in order to adopt these changes prior to Refueling >
Outage g. If you have any questions or require additionalinformantion, please contact Bill Brice at 601-437-6556, Yours truly, i
JJH/WBB/
- attachments: 1. Affirmation per 10 CFR 50,30
- 2. Justification for Adoption of Option,B of 10 CFR 50, Appendix J, and Basis for No Significant Hazards Consideration l 3. Mark up of Affected Technical Specifications
- 4. Mark-up of Affected Technical Specification Bases j cc: (See Next Page)
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GNRO-g7/00103 1 Page 3 of 3 i cc: Ms. J. L. Dixon Herrity, GGNS Senior 3esident (w/a)
Mr. L. J. Smith (Wise Carter) (w/a)
Mr. N. S. Reynolds (w/a)
Mr. H. L. Thomas (w/o) ,
Mr. E. W. Merschoff (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/2)
Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mall Stop 13H3 Washington, D.C. 20555 Dr. E. F. Thompson (wla)
State Health Officer i State Board of Health P.O. Box 1700 Jackson, Mississippi 39205
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, GNRO 97/00103
- Attachment 1 GGNS PCOL 97-04 Affirmation per 10 CFR 50.30 l
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l GNRO 97/00103 + !
=, BEFORE THE i l
- UN11ED STATES NUCLEAR REOULATORY COMMISSION l
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LICENSE NO. NPF.29 DOCKET NO. 50-416 ;
l IN Tile MATIER OF l ENTER 0Y MISSISSIPPI 1
and !
SYSTEM ENEROY RESOURCES,INC, l 1
and. .
SOUTil MISSISSIPPI ELECTRIC POWER ASSOCIA110N l!
and I i
ENTER 0Y OPERATIONS,INC.
s AFFIRMATION ,
I, J. J. liagan, being duly swern, state that I am Vice Prnident Operations GONS 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; that I signed this application as Vice President, - !
Operations GONS of Entergy Operations, Inc.; and that the statements made and the matters set forth therein are trse and correct to the i best of my knowledge, information and belief.
v J.J.llng / ) 1 STATE OF MISSISSIPPI COUNTY OF CLAIBORNE SullSCRiflED AND SWORN TO before me, a Notary Public, in and for the County and State above named, this [ day of d'Tv/er l ,'1997.
Notary 14tific l
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s My comnsalon expired June 5,1998 - _
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, ONRO 97/00103 Attachment 2 l GGNS PCOL 97-04 ,
~ Just$ cation 'or Adoption of Option 8 of 10 CFR 50 Appendix J, and Basis for No Signmcant Hazards Consideration ,
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, Attact. ment 2 of GNRO47/00103 Pageiof$
A. AFFECTED TECHNICAL SPECIFICATIONS The following Technical Specifications (TS) and their associated bases are affected by the proposed change:
SR 3.6.1.1.1 SR 3.6.1.2.1 SR 3.6.1.3.5 SR 3.6.1.3.8
. SR 3.6.1.3.9 5.5 and associed portion of the Table Of Contents
> The Basis for SR 3.0.2 is Mso to be revised to delete the reference to Appendix J, since it will no longer qualify as an example of when SR 3.0.2 does not apply. Since Technical Specification Bases are controlled under the 10 CFR 50.59 program, the mark-up of the Bases Sections are provided for information only.
B. DESCRIPTION OF CHANGES These surveillances are being revised to allow testing frequencies to be controlled by the 10 CFR 50, Appendix J, testing program. The notes that disallow the use of SR 3.0.2 for these surveillance frequencies are being deleted.
C, BACKGROUND On April 26,1995, the NRC issued to GGNS an exemption from certain requirements of 10 CFR Part 50, Appendix J. This exemption permitted the selection of containment leakage rate testing intervals for components on the basis of performance. The exemption was based on a letter dated August 13, 1993, and supplements dated April 15, May 11, June 24, and July 20,1994, and April 18,1995. This exemption remains in effect until startup following Refueling Outage 9.
3 During this time frame the NRC was considering rulemaking to revise Appendix J, to allow licensees the option of a performance based approach to containment leak rate testing. The Staff agreed to review
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our proposal in support of the rulemaking and, in fact, it became part of the basis for the new rule. This proposal did not include testing methods, but only allowed changes to the testing intervals based on previous component performance. Plant specific data as well as plant specific risk analyses were presented in support of the requested changes. The Staff used this information along with the technical information for the on-going rulemaking, including NUREG-1493 " Performance-Based Containment Leak-Test Program", dated Decumber 1994, to review our request. The staff concluded that tne proposal was acceptable and we developed our performance based program on that basis.
At the time the exemption was granted, we expected to adopt the new rule when it became effective with little or no effort. The limited duration of our current exemption was based solely on the expectation that adoption of the new rule would be easily. accomplished by on appropriate license amendment. This tumed out not to be the case.
. Attachment 3 Cf GNRO-97/00103 Page 2 of $
Because the rule was developed based in part on our exemption it was, as we expected, consistent with our proposal. NEl developed industry guidance later, after our program had been developed and implemented for some time. While fundamentally consistent with the NEl approach on a technical basis, our program differed significantly from NEl in the details of implementation. Therefore, adoption of Option B using NEl's guidance would result in a major program revision for us, significant review time for the NRC, and would produce little or no safety benefit.
D. SPECIFIC POSITIONS AND CLARIFICATIONS Because our program was developed prior to NEl's guidance document, there are several differences in our program and the guidance. Generally, our program agrees in principle with the guidance document; however, certain points may warrant special consideration. These positions reflect our current practice and do not represent a change to our program or are proposed changes to our current program to reflect NEl positions as endorsed by NRC regulatory guidance. They are presented here to clarify our current position and to identify chJnges we propose to make to be consistent with current regulatory positions. All of these positions have been previously discussed with the NRC staff.
- Surveillance Requirement Applicability statement 3.0.2 of the GGNS TSs allows a 25% extension of the interval specified in the Frequency to facilitate surveillance scheduling and consideration of plant operating conditions that may not be suitable for conducting the surveillance. Under Option A of Appendix J, this extension could not be applied because the regulation specified the maximum interval. Under Option B, the citensions can be applied and our TSs will be revised to recognize this.
. NEl guidance allows alternative testing or analysis in lieu of as-found tests when maintenance is performed. NRC Regulatory Guide (RG) 1.163 does not endorse this substitution on the grounds that as-found tests provide clear and objective evidence of performance of isolation components.
We agree with the Staff's position but would like to add further clarification. It is our current practice to use Valve Operation Test and Evaluation System (VOTES) testing in lieu of an LLRT for maintenance that does not affect leak-tightness (i.e., maintenance that affects only the valve actuator). VOTES testing is not used to determine leakage performance of isolation components or to establish or maintain extended test intervals. An LLRT would only be performed if the VOTES test detected a degraded thrust value. Thrust values below allowables could cause seat leakage to become a concern and an LLRT would then become necessary.
. Neither our current program, nor NEl guidance, requires an LLF.T in the following cases:
- 1. Primary containment boundaries that do not constitute potential primary containment atmospheric pathways during and following a Design Basis Accident (DBA)
- 2. Boundaries sealed with a qualified seal system; or,
- 3. Test connection vents and drrJns between primary containment isolation valves which are one inch or less in size, administratively secured closed and consist of a double barrier.
. NEl guidance allows test intervals for Type B and C testing to range from 30 months up to a maximum of 120 months. The regulatory position documented in RG 1.163 endorses the Type B interval ranges, but limits Type C testing to a maximum of 60 months. While we believe that available data supports 120 month intervals for Type B and C testing, we are currently restricted to 60 month maximums for both Type B and C testing intervals. We therefore, propose to adopt the NEl position of 120 month maximum intervals fer Type B testing as endersed by the NRC RG.
Although Type C testing will remain at a maximum of 60 months, we would encourage the Staff to
4 Attachment 2 of CiNRO-97/00103 Page 3 of 5 consider endorsement of the 120 month intervals for Type C testing and may request such a change in the near future.
e in our original exemption request, it was stated that, following maintenance on or modification of a component that could affect the component's leak tightness, a Type B or C test would be performed, it was also stated that if the post work Type B or C test leakage rate for extended interval components is not greater than 5% of the Type B or C test leakage rate performed prior to maintenance or modification, and other applicable retests (such as tests required for motor operated valve testing) are acceptable, re-establishment of component performance will not be required and the component will remain on its current test interval. If the post-work Type B or C tect leakage rate for extended interval components was greater than 5% of the Type B or C test leakage rate performed prior to maintenance or modification, os other applicable retests were unacceptable, re-establishment of component performance wauld be required and the test interval would be adjusted to a two-year interval. The test interval could then be extended once satisfactory performance was re-established in accordance with the requirements of the leak rate testing program.
The NEl guidance does not require a change 'n test frequency for Type B or C penetrations that have been repaired or modified if the As-found and As left test results are both less than the component's allowable Administrative Limit. In the Safety Evaluation done by the Office of Nuclear Reacto Regulation in Pupport of the exemption, it was stated that'(t)here appears to be no special significance to the 5% criterion, but the staff considers it to be acceptably conservative." We have therefore modified, r.s allowed by 10 CFR 50.59, the local leak rate testing program to be consistent with the industry ruidance. A change in the test frequency is no longer required by the program, if the As found anJ As left Type B or C test results are both less than a component's allowable administrative limit. The NEl guidance is sufficiently conservative and has been found acceptable by the NRC for implementation of performance based containment leakage testing programs. This change removed unr.ecessary conservatism from the testing program and allowed consistency with current industry practice.
E. JUSTIFICATION The NRC has already reviewed the information provided in support of our exemption request. Only the selection of test intervals changed as a result of the exemption. There was no change in test methods, acceptance criteria or allowable leakage limits. The exemption is predicated on the assumption that all other aspects of Appendix J testing that are not explicitly addressed in the exemption request are conducted in accordance with Appendix J. The Safety Ev :ustion performed for the exemption l concluded that:
The Grand Gulf licensee presented the staff with an innovative proposal for using the previous performance of structures, systems and components covered by Appendix J as a basis for determining future test intervals. In addition, the licensee has presented discussions of the factors which affect the risk of containment leakage and how these factors will be controlled as a result of the proposed changes.
The GGNS exemption request provided the industry and the NRC with a template for implementation of a performance-based testing program and went a long way towards making Qe expedited rulemaking ,
which followed possille. The NRC, in the exemption, found that: '
The licensee's proposal was detailed and well thought-out and thoroughly considered the effect on safety of the proposed changes. Reviewing this exemption request wac l beneficial to the staff's Appendix J rulemaking effort. Granting the exemption will assist l the staff in assessing the process of implementing a performance-based containment )
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, f Attachmer.: 2_cf GNRO-97/00103 P:ge 4 of 5 ~
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leakage rate testing rule which, in turn, is of a clear b'enefit to the public. The staff considers any decrease in safety to be very small. This was config,6d by the risk studies l
[ discussed in Section 3 of the safety eva!uation on this exemption request.
We believe that the justification for this proposal has already been presented in large part in our earlier submittels and therefore is not reiterated here. Specific positions and clarifications listed above are either consistent with guidance found acceptable to the NRC as established by Regulatory Guide 1.163, )
"Pe.formance Based Containment Leak-Test Program" or as justified specifically above. Any changes 1
. requested in this submittal are fundamentally consistent with current NRC positions as stated in RG-1.163. ,
F. BASIS FOR NO SleNIFICANT HAZARDS CONSIDERATION ;
LEOl has evaluated the no significant hazards consideraticas in regard to this request for'a license amendment. In accordance with 10 CFR 50.91(a), EOl is providing' the analysis of the proposed amendment against the three standards in 10 CFR 50.g2(c) below.
- 11. The proposed _ change does not significantly increase the probability or consequences of an
- accident previously evaluated.-
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Two initiating events were identified which could be affected~by the proposed changes. An interfacing n system LOCA could be caused by significant leakage of both normally closed isolation valves in systems with high pressure / low pressure interfaces. Interfacing system LOCAs were considered for the LPCI, LPCS, HPCS, and RCIC systems. Because the frequency for testing of these valves will not be changed under this proposal, there is no increase in the probability or consequences of an accident.
. The second event evaluated was a LOCA outside containment. In this case the probability for failure of
. the MSIVs and the feedwater isolation valves were calculated and combined with the frequency of a pipe _
break outside containment and the conditional probability of core melt given a LOCA. The ircrease in core damage frequency is extremely small and therefore does not significantly increase the probability of any previously evaluated accidant. Further, because the testing frequency for MSIVs and feedwater.
isolation valves are not being changed, the LOCA outside of containment events can be discounted.
- Failure of, or leakage through a containment barrier can however, increase the consequences of those accidents previously evaluated. Because the leakage probability for two valves in series to fail is very small and because all lines isolated by a single containment isolation valve always have a water seal and cannot act as a release pathway unless the integrity of the connected system is compromised, there is no significant increase in the consequences of any previously evaluated accident.
= Containment bypass can also increase the consequences of evaluated accidents. Accident sequences 4
involving containment bypass have been shown to be relatively insignificant by the GGNS IPE. The -
potential for bypass was analyzed. The analysis showc,d that the probabilities for bypass were dominated -
. by failure to close scenarios. Many programs are in place at GGNS to monitor containment component performence and to ensure that proper maintenance and repairs are made during the service life of the
- containment. Other routine surveillances are performed periodically to ensure that the valves will close on demand. In fact, all valves that are required to close for containment isolation and that are not maintained closed at all times during power operations are stroke tested quarterly or at a' minimum, during each ,
refueling outage in accordance with ASME section XI, subsection IWV.
1 The proposed change wou" 4 eate the possibility of a new or different kind of accident from -
any accident previously evaluated.
Attachment 3 of GNRO-97/00103 Page 5 of 5 This request involves the reduction in the local leak rate and the integrated leak rate testing frequencies.
Extending the test frequencies has no influence on, nor does it contribute in any way to, the possibility of a new or different kind of accident or malfunction from those previously analyzed. The method of performing the test is not changed. No new accident modes are created by extending the testing intervals. No safety-related equipment or safety functions are altered as a result of this change.
- 3. The proposed change d0es not involve a significant reduction in a margin of safety.
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 containment leakage rate.
The containment isolation system is designed to limit leakage to L. which is defined by the GGNS TSs to be 0.437 percent by weight of the containment air per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> at 11.5 psig (P.). The limitation on containment leakage rate is designed to ensure that total leakage volume will not exceed the value assumed in the accident analyses at the peak accident pressure (11.5 psig, P,).
To provide additional conservatism, the measured overall integrated leakage rate is further limited to less than or equal to 0.751 during performance of the periodic integrated leakage rate test and to less than or eqaal to 0.60 l for type B and C leakage rate tests. This is done to account for the possible degradation of the containment leakage barriers between tests. This acceptance criteria ensures that an acceptable margin of safety is being maintained and will not be altered by the proposed changes. The preservation of this margin will continue to provide for potential degradation of the leakage barriers between tests.
No change in the method of tet. ting is being pposed. The tests will continue to be done at full pressure (P,) or greater. The test pressure for primary containment isolation valves 'a.il continue to be applied in the same direction as would be required for the valve to perform its safety function (unless a different direction can be shown to be equivalent or conservative). Primary containment penetrations which require Type B leakage rate tests will be perfonned in the same manner as before. The type A test will continue to be performed at full pressure (P.). Other programs are in place to ensure that proper maintenance and repairs are performed during the service life of the primary containment and systems and components penetrating the primary containment.
No change in the owners allowable leakage rate is being proposed. These conservative leakage rates
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ensure that if every penetration were at it's maximum allowable leakage rate, the total containment leakage would still be below 0.601. The effect of multiple penetration barrier;. is not considered which provides further conservatism.
The assessment of risk analysis for the proposed changes concluded that the overall risk impact of the changes are neutral and essentially negligible. Any containment isolation barrier allowed to be tested at less frequent intervals will have demonstrated enhanced performance which minimizes the potential for increased leakage, The assessment further shows that there is reasonable assurance that an acceptable level of performance for the containment isolation function can be maintained. The overall risk impact for the proposed changes are small enough to be almost indeterminate. No change to the leakage rate specified in the TSs is being proposed.
Based on the above evaluation, operation in accordance with the proposed amendment involves no significant hazards considerations.
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