ML20151U324
| ML20151U324 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 09/01/1998 |
| From: | Merschoff E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Cottle W HOUSTON LIGHTING & POWER CO. |
| References | |
| NUDOCS 9809100358 | |
| Download: ML20151U324 (6) | |
Text
O t h" "8 %g . UNITED STATES
/p % NUCLEAR REGULATORY COMMISSION e REGION IV
- 8 g
6 611 RYAN PLAZA drive, SUITE 400 I
$ AR LINGTON, TEXAS 76011-8064 N, 9..... f4 SEP - l 1998 William T. Cottle, President and j Chief Executive Officer ^
STP Nuclear Operating Company P.O. Box 289 Wadsworth, Texas 77483
SUBJECT:
NOTICE OF ENFORCEMENT DISCRETION FOR STP NUCLEAR OPERATING COMPANY REGARDING SOUTH TEXAS PROJECT, UNIT 1, NOED NO. 98-4-008
Dear Mr. Cottle:
By letter dated August 28,1998, you requested that the Nuclear Regulatory Commission (NRC) exercise discretion not to enforce compliance with the actions required in the South Texas Project Technical Specification Surveillance Requirement 4.0.5 as it applies to testing requirements for nine containment isolation check valves in Unit 1. The letter documented information that was faxed to the NRC (enclosed) and previously discussed with the NRC on August 27,1998, starting at 4:30 p.m. (CDT). You stated that due to the missed surveillances on these valves, these valves were determined to be inoperable and the action requirements of Technical Specification 3.6.3 for containment isolation valves was entered for each valve at 6:30 p.m. (CDT) on August 26,1998. If the valves were not returned to' operable status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, the specific action statements would result in shutdown for Unit 1. You requested ,
that a Notice of Enforcement Discretion (NOED) be issued pursuant to the NRC's policy regarding exercise of discretion for an operating facility, set out in Section Vll.c, of the " General Statement of Policy and Procedures for NRC Enforcement Actions"(Enforcement Policy),
NUREG-1600. The requested duration of the discretion that would allow the valves to meet the requirements of Technical Specification 4.0.5 is 14 days, which provides adequate time to plan /
and perform the testing in a safe, orderly manner.
D'uring a review of the Inservice Test Plan, you determined that these nine containment i isolation valves had not been tested in the required position for performing a specific safety i function (closed) within the required testing periodicity of the Section XI ASME Code. These I valves have met Section XI ASME Code requirements for testing in the open direction, and have been historically tested in the closed direction by performance of local leak rate testing required by Appendix J of 10 CFR Part 50. STP Nuclear Operating Company received a license amendment to the Technical Specifications on August 13,1996, for allowing I performance-based containment leak testing per Aopendix J, Option B of 10 CFR Part 50. l Leak rate per'ormance testing allowed extension a local leak rate test frequency to i periodicities beyond each refueling cycle, and th. tr- ency of the appropriate plant i surveillances for leak rate testing was extended ft affected valves. However, an alternate !
test method to test the valves in the closed directio , was not developed to meet the Section XI ASME Code test frequency requirements. When the change was made to implement l l
9809100358 980901 PDR ADOCK 05000498 P PDR j
C STP Nuclear Operating Company Appendix J, Option B of 10 CFR Part 50, which allowed extension of local leak rate testing
. periodicities, the change process did not adequately evaluate the impact of Section XI ASME Code testing requirements. l You stated that the purpose of containment isolation valves ensures that the containment atmosphere will be isolated from the outside environment in the event of a release of
~
radioactive material to the containment atmosphere or pressurization of the containment. The valves for which discretion is being requested tested satisfactorily in the closed position in accordance with ASME Code requirements the last time the test was performed.
Performance-based local leak rate testing results have demonstrated the leak tightnese of these valves such that leak rate testing periodicities have been extended beyond the periodicity of a normal refueling cycle. In addition, maintenance history has demonstrated reliable performance of these valves (you provided a summary table of recent localleak rate test results). Also, you stated that the potential failure of these valves to close has no impact on core damage frequency and the impact of these valves, assuming complete failure, from a large early release standpoint is minimal. Based on the above, you concluded that in the event l containment isolation is necessary, the subject valves will have a high probability of performing their intended safety function and the safety significance of the proposed action is extremely l small.
I NRC inspection Manual, Part 9900, " Operations - Notices of Enforcement Discretion,"
Section B, item 1, states:
For an operating plant, the NOED is intended to (a) avoid undesirable transients as a result of forcing compliance with the license condition and, thus, minimize the potential safety consequences and operaticnal risks or (b) eliminate testing, inspection, or system realignment that is inappropriate for the particular plant conditions.
In evaluating the operational readiness of the nine check valves, the staff examined Appendix J leak rate test data provided by STP Nuclear Operating Company from the previous three refueling outages. All valves were previously leak rate tested in accordance with Appendix J in May of 1996, during the previous Unit I refueling outage and passed their acceptance criteria by a significant margin. Historical data from the prior two tests did not reveal any leak rate test failures and also did not indicate that any of the valves were trending such that they would fail their leak rate test if the Appendix J testing was deferred.
The deferred testing of the nine valves in question will result in a test interval that, while greater than the current Code requirements, is within the guidance provided in Generic Letter 89-04,
" Guidance on Developing Acceptable Inservice Test Programs." As a result, a shutdown of South Texas Project, Unit 1, to perform the required testing on these nine valves would constitute an unnecessary operational risk. The criteria of NRC Inspection Manual, Part 9900, Section B, item 1, are met. Therefore, the staff finds that the proposed extension is acceptable.
On the basis of the staff's evaluation, the NRC staff concluded that an NOED is warranted because we are clearly satisfied that this action involves minimal or no safety impact and has no adverse radiological impact on public health and safety. Therefore, it is our intention to exercise discretion not to enforce compliance with Technical Specification 4.0.5 as it relates to Technical Specification 3.6.3 for a maximum of 14 days to provide adequate time to plan and
. . . - . . . - - . . . - . - . . . . - - . ~ . . . .
STP Nuclear Operating Company perform the testing in a safe, orderly manner. This discretion is allowed to be used one time for the applicable Technical Specification discussed above. This letter documents our telephone conversation on August 27,1998, at 5:30 p.m. (CDT) when we orally issued this notice of enforcement discretion.
1 Sincerely, 1 Ellis W. Me choff Regional A inistrator
Enclosure:
STP Nuclear Operating Company's letter dated August 28,1998 Docket Nos.: 50-498 50-499 License Nos.: NPF-76 l NPF-80 l l i
!. cc:
Lawrence E. Martin, Vice President Nuclear Assurance & Licensing STP Nuclear Operating Company P.O. Box 289 Wadsworth, Texas 77483 A. Ramirez/C. M. Canady City of Austin Electric Utility Department 721 Barton Springs Road Austin, Texas 78704 -
Mr. M. T. Hardt/Mr. W. C. Gunst City Public Service Board P.O. Box 1771
. San Antonio, Texas 78296 D. G. Tees /R. L. Balcom
- Houston Lighting & Power Company P.O.~ Box 1700 Houston, Texas 77251 1
2
- - - . . - - . - - ~ . . .. . - - - . - - . . ~ ... - _-
o STP Nuclear Operating Company -4 '
Jon C. Wood Matthews & Branscomb One Alamo Center 106 S. St. Mary's Street, Suite '00 San Antonio, Texas 78205 36;.t.'
Jack R. Newman, Esq.
Morgan, Lewis & Bockius 1800 M. Street, N.W. I Washington, D.C. 20036-5869 Mr. G. E. Vaughn/Mr. C. A. Johnson
. Central Power & Light Company P.O. Box 289 Mail Code: N5012 Wadsworth, Texas 77483 INPO Records Center 700 Galleria Parkway .
Atlanta, Georgia -30339-5957 Bureau of Radiation Control State of Texas 1100 West 49th Street Austin, Texas 78756 Mr. Jim Calloway
-Texas Public Utility Commission William B.Travis Building 1701 North Congress Avenue P.O. Box 13326 Austin, Texas 78701-3326 John Howard, Director Environmental and Natural Resources Policy !
Office of the Governor P.O. Box 12428 Austin, Texas 78711 Judge, Matagorda County i Matagorda County Courthouse l 1700 Seventh Street Bay City, Texas 77414 I l
. . _ _ _ _.-- _ .__.._ _ ._ ._ _. . ~ _ . - _ - _ - _ . . _ _ _ _ , _ . .
.STP Nuclear Operating Company bcc to DME (IE51) bec distrib. by RIV:
H. Thompson, DEDR E. Merschoff, Regional Administrator B. Boger, Acting Associate Director for Projects, NRR B. Sheron, Acting Associate Director for Technical Review,11RR J. Lieberman, Director, Office of Enforcement
. W. Bateman, Project Director _ . .
Public Document Room and Local Public Document Room Technical Assistant, DRP - 1/II/Ill/IV, NRR Electronic copy (Wordperfect file) tc E-mail address: NOED Electronic copy (Wordperfect file) to BBS Operator, E-mail address: TGD Resident inspector Division Director, DRP DRS-PSB Branch Chief (DRP/A) l Project Engineer (DRP/A)
,. Branch Chief (DRP/TSS)
L R. Bachmann, OGC (MS: 15-B-18) ,
- RIV File -
MIS System -
i t
DOCUMENT NAME: R:\_NOED\STP8-4-008
- To receive copy of document, Indicate in box: "c" = cope without enclosures "E" = Copy with enct ures "N" = No copy
, C:DRP/A M , NRR/PD D:DRP A) , RA ef JITapia 7)(htd WHBateman A TPGwynn fTY' EVdbrschoff 8$/98 M i 8/ 9 98 Ab 4// /98 M /98 U '
' OFFICIAL RECORD COPY I
4
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STP Nuclear Operating Company bec to DMB (IE51) bec distrib. by RIV:
H. Thompson, DEDR E. Merschoff, Regional Administrator B. Boger, Acting Associate Director for Projects, NRR B. Sheron, Acting Associate Director for Technical Review, NRR J. Lieberman, Director, Office of Enforcemeni W. Bateman, Project Director Public Document Room and Local Public Document Room Technical Assistant, DRP - 1/ll/ill/IV, NRR Electronic copy (Wordperfect file) to E-mail address: NOED i Electronic copy (Wordperfect file) to BBS Operator, E-mail address: TGD Resident inspector Division Director, DRP DRS-PSB Branch Chief (DRP/A)
Project Engineer (DRP/A)
Branch Chief (DRP/TSS)
R. Bachmann, OGC (MS: 15-B-18)
RIV File MIS System DOCUMENT NAME: R:\_NOED\STP8-4-008 To receive copy of doc,.; ment, Indicate in box: "C" = Copy without enclosures "E" = Copy with encI ures "N" = No copy C:DRP/A ,q , NRR/PD D:DRPl /d , RA d JITapia 7)(_J/p(d WHBateman a TPGwynn f7Y' EW%rschoff 8/9/98 ( M d 8/Sf98 W%o 4/ / /98 M_/98 V '
' OFFICIAL RECORD COPY 090034
, - . . - a
g f0G-29-1998 15:52 NUCLEAR LICENSING 512 972 8298 P.02/03 ENCLOSURE me n n-
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August 28,1998 NOC-AEMI F.h _W G20.02 G21.62 10CFR50.36 STI: 30702558 U. S. Nacher Regulatory Commission Annaaeian: l>mant Control Desk Washsateon, DC 20555 South Texas Pmject Unit 1 Docket No.: STN 50-498 Raouest for NRC Region IV Enforcement Disemtion from Technical Specification 4.0.5 as It Applies to Surveillance Reauirements for Containment Isolation Check Valves.
Reference:
Request for NRR Enforcement Discretion dated August 28,1998, from G. L Parkey to NRC Document Control Desk (ST-NOC-AE-000278)
STP Nucinar Operatmg Company (STPNOC) requests enforcement disemtion from the pmvisions of T-4=ien1 Specification 4.0.5 as it applies to inservice testing requirements of Section XI of the ASME Boiler and Pressure Vessel Code for containment isolation valves. Unit 1 contMmnent isolation valves listed j in Amnekument 2 of this request have not been tested in the closed direction within the Section XI Code !
survedlance frequency requirements. Specifically, STPNOC requests discretion from the requirement to apply Technical Specification Surveillance Requirement 4.0.5 for 14 days to allow on-line testing of the sutgect valves.
j I
'Inis sequent applies to the scope of valves that can be tested with the unit at power. The referenced request to NRR addresses the valves which cannot be tested at power and widch requh an exigent Technical {
M'-- t-i change. Attachments 3,4, and 5 provide the technical supporung information for both the NRR and Regional requests for enfortement discretion.
The amaneA=wi information is provided pursuant to the Nuclear Regulatory Commission guidance for requests for enforcement ducretion. If you should have any questions concerning this matter please contact either S. M. Head at (512) 972-7136 or me at (512) 972-7800.
I G. L Parke-Plant Manager, '
Unit i KTT/
Amadunards: 1. Information in Support of Requested Enfoteement Discretion
- 2. Containment Isolation Valves for which discretion is being requested !
- 3. Safety Function of Valves
- 4. Recent Local Leak Rate Test Results
- 5. Risk Perspective on Containment Isolation Check Valves
===,.c.ume=.mc
M 1998 .15:53 tOCLEAR LICEtGit4G 512 972 498 P.03/03 NOC-AE-000281 i-File No.: G20.02 G21.02 Page2
- Ellis W. Merschoff Jon C. Wood
- Regional Adrninharator, Region IV Matthews & Branscomb U. S. Nuclear Regulatory Commission One Alamo Center
- 611 Ryan Plaza Drive, Suite 400 106 S. St. Mary's Street, Suite 700 i Artingeon,TX 76011-8064 San Antonio,TX 78205-3692 i 'nnomas W. Alexion Institute of NuclearPower
! Projaa Manager, Mail Code 13H3 Operations -Reconis Center U. S. Nuclear Regulatory Commission 700 Galleria Parkway ii Washington, DC 20555-0001 Atlanta, GA 30339-5957
- Casesihas F. O'Keefe Richard A. Ratliff i Sr. Residsetlaspector I Bureau of Radiation Control c/o U. S. Nucinar Regulatory Commission Texas Department of Health
, P. O. Box 910 1100 West 49th Street
- Bay Oty,TX 77404 0910 Austin, TX 78756-3189 i
i J. R. Newman, Bsquire D.G. Tees /R. L. Balcom
[!- Messen,Imis & Bockius Houston Lighting & Power Co.
1800 M. Street, N.W.
P. O. Box 1700
- Washiageon, DC 20036-5869 Houston,TX 77251 i
) M. T. Hardt/W. C. Gunst CentralPower and Light Company i City Public Service A'ITN: G. B. Vaughn/C. A. Johnson
! P. O. Box 1771
' P. O. Box 289, MallCode: N5012 San Antonio,TX 78296 Wadsworth,TX 77483
' A. RassiserJC.M. Canady U.S. Nuclear Regulatory Commission City of Austin Attention: Document Control Desk Blacetic Utility Department Washington, DC 20555 0001 721 Boston Synags Road Austin,TX 78704 TOTAL P.03
.c AUG-28-1998 14:48 NUCLEM LICENSIti; 512 972 8298 P.02/28 Attachment 1 NOC-AE-000281 Page 1 of 8 1
Information in Support of Requested Enforcement Discretion
-1) h Technical Specification or other license conditions that will be affected.
Tehnumi Spcification 4.0.5 requires that inservice testing of ASME Code Class 1,2, and 3 valves shall be performed in accontiance with Section XI of the ASME Boiler and Pressure Vessel Code and applicable Addenda as requhed by 10 CFR Part 50, Section 50.55a(g), except where specific written relief has been granted by the Commission pursuant to 10 CFR Part 50, Section 50.55a(g)(6)(i). STPNOC has established relief to test
- the a5ected valves at a periodicity of each cold shutdown of sufficient duration or refueling outage.
The OPERABIIIIY of the containment isolation valves ensures that the containment atmosphere will be isolated from the outside environment in the event of a release of radioactive material to the containment atmosphere or pressurization of the containment and is consistent with the requirements of General Design Criteria 54 through 57 of Appendix A l to 10 CFR Part 50.
l The valves shown in Awhment 2 to this request have been declared inoperable as a result I of the failure to perform the required surveillances in accordance with Technical l Specification 4.0.5. This has resulted in entry into the action associated with Technical Sp=:' =:on 3.6.3 (Containment Isolation Valves). Conditions associated with the specific peastrations affected will result in the initiation of the shutdown of the STP Unit I at the end of the 24-hour allowed outage time associated with the action statements.
- 2) - h edra===d-~ se-di== the al*==*iao. Inchidi== root e-- the need for
' a +-:-_ - ' "'- "T- -f-:- of any revant ht=*c-ia t e.,t..
Dunng a review of the Inservice Test Plan, it was detemuned that specific containment isolation check valves (shown in Attachment 2) had not been tested in the required position for Afvrining a specific safety function (closed) within the required testing periodici:y of i
the Section XI ASME Code. The safety functions of these valves is indicated in Attachment 3. Relief from the ASME Code requirements to extend the test frequency to coki shutdowns of sufficient duration or a refueling outage had previously been established for the check valves.
l
. RUG-28-1998 14:48 NUCLEAR LICEH51HG 512 972 8298 P 03/28 a Attachment 1 NOC-AFA00281 Page 2 of 8 The valves have met Section XI ASME Code requirements for testing in the open dinction.
These valves have been histodcally tested in the closed direction by performance oflocal leak rate testing mquired by Appendix J of 10CFR50. Note that the leak rates are acceptance criteria for the Appendix J test only; however, the test also adequately damna*ates valve closure. STPNOC received a license amendment to Technical Specifications in August,1996 for allowing performance-based containment leak testing per Appaadix J, Option B of 10CFR50. Leak inte performance allowed extension of the local leak rate test frequency to periodicities beyond each refueling cycle. The frequency of the appropriate plant surveillances for leak rate testing was extended for the affected valves.
However, an altemate test method to test the valves in the shut ducction was not developed to meet the Section XI ASME Code test frequency requirements. As a result, these check ,
valves would only be tested in the shut dimetion when the local leak rate test was l performed.
'Ibe cause is inadequate change management. When the change was made to implement j Apaaadir J, Option B of 10CFR50 which allowed extension oflocal leak rate testing periodicities, the change process did not adequately evaluate the impact on Section XI ASME Code testing mquirements, j A thorough review has been performed and it has been confirmed that this particular request l for discretion is limited to the valves shown in Attachment 2. Since these valves were determined to be inoperable becau:e of the missed surveillance, the ACTION requirements .l of Technical Specification 3.6.3 for contamment isolation valves was entered for each valve j at 1830 hours0.0212 days <br />0.508 hours <br />0.00303 weeks <br />6.96315e-4 months <br /> on August 26,1995. If the valves are not returned to operable status within T hours, the specifk action statement will result in shutdown of the unit.
Prompt action is requested to approve the enforcement discretion to allow the discretion from Technical Specification 4.0.5 for 14 days, which will provide adequate time to test the subject valves. This will allow the station to exit the requirernents of Technical Specification 3.6.3. STPNOC is not aware of any other relevant historical events.
- 3) The safety bads ic- Be_reauest, incin,Ha< an evaluation of the safety aioni&- an<1 massadal3mnaeaname== of the proposed course of action.
7 The purpose of the containment isolation valves ensures that the conrninment atmosphere will be isolated from the outside environment in the event of a release of radioactive maaerial to the containment atmosphere or pressurization of the containment. The valves for which discretion is being requested tested satisfactorily in the closed position in accordance with ASME Code requirements the last time the test was performed.
i l-IMW9MmeCWmftC4po281 DOC L .. - .- .- - .
.. - . . - . -~ . . . . - . . . - ... - . . - _.- - . - - ..- - _ - - - - - - . .
! , .AUG-28-1998 *4:49 1 NJCL 9 R LICENSING 512 972 8298 P.04/28-
, Attachment 1 c NOC-AE-000281 l Page 3 of 8 l
Performance-based local leak rate testing results have demonstrated the leak tightness of these valves such that leak rate testing periodicities have been extended beyond the periodicity of a normal refueling cycle. Maintenance history has demonstrated reliable
. performance of these valves. A summary of recent local leak rate test results is included in Attachment 4.-
As noted above, the subject valves have exhibited a history of satisfactory operation.
Based on their performance history, it is believed that the current PSA modeling of the failure rates for these valves is still accurate. Irrespective of the failure rate modeling, the current STP PSA model indicates that the potential failure of these valves to close has no impact on core damage fzequency. In addition, the impact of these valves [ assuming complete failure] from a Large Early Release standpoint is minima Details of the PSA m~t-ha aspects for the subject valves is included in Attehment 5. I i l l Based on the above, it is evident that in the event that containment isolation is necessary, i the subject valves will have a high probability of performing their intended safety function. Therefore, STPNOC believes that safety significance and potential ;
l consequences of the pmposed plan of action is extremely small. !
i
- 4) ' Ins basis for the conchwinn that the enforcement discretion is not a aa**ahl daMunant_toJlhe mublic bealth and safety and that neither an unreviewed safety nor a sianNicant *=-- -d w - ---f-== is inw,hu Deter =d==&= of No Um= viewed Safety Question
- 1. Does the change involve an increase in the probability of occurrence or the consequences of an accident or malfkmcrian of equiamant important to safety previously evaluated in the Safety Analysis Report?
No.
'Ibe proposed change would relieve the requirement to apply Surveillance 4.0.5 to the subject check valves. SpecificaEy, STPNOC would not have to perform the ASME Section XI exercise of the valves. Neither the valves nor the systems of which they are a part are accident initiators. The proposed change is a deferral of a surveillance test interval which has no potential effect on accident initiation.
'Iherefore, there is no increase in the probability of occurrence of an accident
- previously evaluated in the Safety Analysis Report.
j Previous testing of the valves has demonstrated that they are capable of performing
, their design function. Therefore, the systems of which they are a part would be semeannec woncseassDoc l
, , - - . . _ ~ . ~ . - - . - . - - - ~.- - _-- -. -. ..~.-.- ---....-.-
AUG-28-1998 14:49 IOCLERR LICENSING 512 972 8298 P.05/28
. Attachment 1 t NOC-AE-000281
! Page4 of 8 expected to perform accident mitigation and safe shutdown functions as designed.
There is no effect on safety analysis assumptions from the pmposed discretion.
Cm=atly, there is no increase in the eme=ws of an accident or equipment '
malfunction previously evaluated in the Safety Analysis Report.
~
There is no increase in the pmbability of malfunction of equipment important to safety previously evaluated in the Safety Analysis Report because past leak testing of the subject check valves has shown the valves to be able to close and seal as
> required. The extended surveillance test intervalinvolves no challenge to the function of the valves.
- 2. Does the change create the possibility of an =reldant or malfn=edan of a different type than any evaluated prwlously evaluated in the Safety Analysis Raport?
No.
The effecc of the proposed change is to extend the surveillance test interval. This extension has no effect on the way the subject systems are operated, nor does it affect the configuration of the station. It does not introduce the potential for any new failure modes. Therefore, the change does not involve a possibility of an accident or malfunction of a different type than any evaluated pmvlously in the Safety Analysis Report.
- 3. Does this change involve a reduction in the margin of safety as dermed in the basis for any Tachulemi Specification?
No.
The effect of the proposed change is to extend the surveillance test interval. This extension will not affect a margin of safety for any Technical Specificadon because there is no change in the design functions or performance of any of the subject systems. All design margins remain unchanged fmm the existing design basis.
. Based on the above evaluation, no Unreviewed Safety Question exists.
mwmenewanceamnoc
. -- .~. . . -. = . . . . . . . . . . - ~ ~ - - . . . - - . - . - - . . - -- - . .
l:. AUG-28-1998 14:50 - tAJCLEAR L1CEtGIt43 512 972 8298 P.06/28
. Awh=t 1 NOC-AFA00281 Page 5 of 8 Deterndnation of No Signi5 cant Hazard Considerations South Texas Project has considered the criteria for assessing the potential of creating an unreviewed safety question or a significant hazanis consideration with the exercising of i enforcernent discretion. In evaluating if discretion in enforcernent constitutes a significant hazard the criteria of 10CFR50.92(c) is discussed below:
- 1. Does the change involve a significant increase in the probability or u consequence of an accident previously evaluaied?
L No. ,
This question is addressed in the response to Quesdon 1 of the Unreviewed Safety l Question Evaluation above.
l
- 2. Does the change create the possibility of a new or different kind of accident frein any accident previously evaknatsd?
1 No.
This question is addressed in the response to Question 2 of the Unreviewed Safety Question Evaluation above.
- 3. Does this change involve a significant reduction in a snargin of safety?
No.
l This question is addressed in the response to Question 3 of the Unreviewed Safety Question Evaluation above.
Based on the above evaluation, no Significant Hazard exists.
Since there is no Unreviewed Safety Question or Significant Hazard associated with the mW surveillance, there is no potential detritnent to the public health and safety as a result of this request.
e 5
e4*wesecwsmc4emsinoc l
y
, AUG-28-1998 14:50 NJCLEAR LICERSIN3 512 972 8298 P.07/28 Attaclunent 1 NOC-AE-000281 Page 6 of 8
- 5) Iba basis for the concl=h that the enforcement discretion will not involve adverse l conseensaces to the environment.
i The South Texas Project has reviewed the proposed Enforcement Discretion request and the i Nuclear Regulatory Commission Final Environmental Assessment for the South Texas Pmject Units 1 and 2 and has concluded that pursuant to 10CFR51, there are no significant radiological or non-radiological impacts associated with the proposed Enforcement )
Discretion request.
'Ihis proposed Enforcement Discretion has been evaluated against the criteria for and identification of licensing and regulatory actions requiring envuonmental assessment in accordance with 10CPR51.21. It has been detennined that the proposed changes meet the cnteria for categorical exclusion as pmvided for under 10CFR51.22(c)(9). "Ibe following is a discussion of how the proposed Enforcement Discretion meets the criteria for categorical l exclusion.
l l_ 10CPR51.22(cX9): Although the proposed change involves one-time changes to testing l frequency requirements of specific containment isolation valves; (i) the proposed change involves no Significant Hazards Consideration (refer to the No Significant Hazards Consideration section of this Enfortement Dtscretion Request),
(ii) there is no significant change in the types or signi6 cant increase in the amounts of any efDuent that may be released offsite since the proposed changes do not affect the l- generation of any radioactive effluent nor do they affect any of the permitted release paths, and l
L (iii) there is no signi6 cant increase in individual or cumulative occupational radiation exposum.
Accordingly, the proposed change meets the eligibility criteria for categorical exclusion set forth in 10CFR51.22(c)(9). Based on the aforementioned and pursuant to 10CFR51.22(b),
no environmental assessment or environmental impact statement need be yrcysted.
- 6) Aav nroonsed compensatory actions.
'Ibe specific valves in which discretion is being requested were not tested in the closed direction within the periodicity requirements of the Section XI ASME Code. These valves did test natisfactorily the last time they were tested and demonstrated satisfactory leak tightness. Maintenance history has demonstrated reliable performance of these valves. It
- is the position of STPNOC that these valves will perform their intended safety function of
- contaimnent isolation. Therefore, no compensatory actions are considered necessary.
L wmquenc wetsc eNastpoc
RUG-28-1998 14:51 NUCLEAR LICENS1NG 512 972 8298 P.08/28
. Attachment 1 NOC-AEA)00281 Page 7 of 8
- 7) . m '- - _ a'= for the duratian of the enfa. - =2 =---;:an.
De duration of the request is 14 days. Fourteen (14) days is twice the allowed outage time of Component Cooling Water and provides adequate time to plan and perform the testing in a safe, orderly manner.
This duration is consistent with the position that the valves aze fully capable of performmg their design function so that there is little or no safety significance fmm the missed surveillmare and the fact that the subject check valves are themselves not risk-tigninc*nt en-pnaents.
- 8) A^' ^
N r - - ' has t== ar-:-rcM by the P'--* Cs ::a== RQw Commenhe De South Texas Project Plant Operations Review Committaa has reviewed the proposed Enfoscament Discretion request and concurs with the content of this request.
F -- '
- 9) - af"r- the A "M's N-st'ce of Rafw-i- ==: 1".h-_- ah Critariosi for the
. - 7 m g,a . - St="-i in S= '=- B is C ^' '
This request for enforcement discretion is consistent with B.I.a.. The applicable Notice of Enforranent Discretion criteria for the subject request is to avoid undesirable transients as a result of onmali=aca with the license condition. Should discretion not be approved, the station will be required to shutdown in accordance with the action requirements of Speci6 cation 3.6.3. Performing the testing on the subject valves is fully expected to da=== trade that they will close as required. Shutting the plant down would serve no purpose and is of no value to public safety.
- 10) - 2 1AnanneA-- '- *ReuubM No follow-up amend =aat is required for testing these check valves.
- 11) ^ " =+ m'x
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P ^ Far a= Nde of W *J sTd=t9' DL SE='*- d - we==ld not have C:wM=d the
" -E Runnest
%e proposed Improved Technical Specifications for the South Texas Project have been subestsed; however, review and implementation activity has been deferred until 2001. For this e-lMaa, the Improved Technical Specifications have similar requirements to the South Texas Pmject current Technical Specifications.
STPNOC is not aware of any line item improvements that would have provided relief fmm the condition.
t g
stiwreemacemncdN38120C
R0-28-1998 14:51 NUCLEAR LICENSit0 512 972 8298 P.09/28 Attaciunent 1 j NOC-AE-000281 Page 8 of 8 4
Asur other infed = the NRC stand **== necesary before maktan a decich to
- 6 ,._-_ =: agg Cnaaldanng the assessment performed in Items 3,4, and 9, STPNOC believes the caforcement disention is consistent with protectir.g the public health and safety.
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, f0G-28-1973 14:52 tCCLERR LICEtGING 512 972 8298 P.10/28 l l
Attachment 2 NOC-AE-000281 1 Page1of1 Containment Isolation Valves for ,
which Discretion is being Requested IInid CC 0058, CC-0138 and CC-0198 -
Component Cooling Water to Reactor Containment Fan Cooler Inside Containment Isolation Check Valves CC-0013, CC-0123 and CC-0183 -
Component Cooling Water Supply Inside Reactor Containment Check Valves CV-0158 -
Chemical & Volume Control System Low Pmssure Ixtdown Inside Reactor Containment Isolation Check Valve DW-0502 -
Inside Containment Demmeralized Water to the Reactor Contalument Building Check Valve SI-0058 -
Inside Containment Accumulator Common Nitrogen Supply Check Valve l
1 1
mwoummenasceoutmac k
i
- - . . . - - . - . - . ~ . ~ . . - -- . .
. AUG-28-1953 14:52 NUCLEAR LICEt61tG 512 972 8298 P.11/28 Attachment 3 j NOC-AE.000281 Page 1 of 12 SAFETY FUNCTION OF VALVES
_CC-13,123,183 i l (Penetration No. M33,35,37)
- TPNS NO,
2R201(2)T CC0013 DESCRIITON: (ICIV) TRAIN A CCW TO RHR, j CHECK VALVE SAFETY FUNCTION AND BASES:
i
- 1. Open to provide flow path for CCW through RHR pump 1(2)A seal cooler and RHR 1(2)A heat exchanger (4906 gpm required per DBD Table T-7, Minimum or Maximum Safeguar l l
1 2. Close and leak tight (CAT A) in accordance with UFSAR commitment (Section 6.2.6.3 and Pipue 6.2.4-1, Sheet 35) to provide containment integrity.
, REQUEED TESTS:
a
- 1. Exercise open to meet Safety Function 1.
, 2. Exercise close to meet Safety Function 2.
- 3.
Laak test in accordance with 10 CFR 50 Appendix J to meet Safety Function 2.
TPNS N O.: 2R201(2)T C00123 DESCRFDON: (ICIV) TRAIN B CCW, SUPPLY TO i
RHR CHECK VALVE SAFETYFUNCTION AND BASES:
- 1. Open to provide flow path for CCW through RHR pump 1(2)B seal cooler and RHR 1(2)B heat exchanger (4906 gpm required per DBD Table T-7, Minimum or Maximum Safeguanis).
- 2. Close and leak tight (CAT A) in accordance with UFSAR commitment (Section 6.2.6.3 and Pipse 6.2.4-1, Sheet 37) to provide containment integrity.
RBQURED TESTS:
- 1. E-W open to meet Safety hetion 1.
- 2. Exercise close to meet Safety Function 2.
- 3. Laek test in accordance with 10 CFR 50 Appendix J to meet Safety hetion 2.
- wame - soc
~ . . . . - - - -- - ' ' ' ~ -~ ~' ^^^ ~~
ru3-29-1998 14:53 NUCLERR LICENSING 512 972 8298 P.12/28 Attachment 3 NOC-AE-000281 Page 2 of 12 l
'I?NS NO.: 2R201(2)T CC0183 DESCRIPTION: (ICIV) TRAIN C CCW SUPPLY TO l RHR, CHECK VALVE SAFETY FUNCTION AND BASES:
! exchanger (4906 gpm required per DBD Table T-7, Minimum or Maximum Safegu
- 2. (han and leak tight (CAT A) in accordance with UFSAR commitment (Section 6.2.63 Figure 6.2.4-1, Sheet 39) to pmvide containwat integrity.
RBQURED'IESTS:
- 1. Ewase open to meet Safety Function 1.
- 2. Esandse close to meet Safety Function 2.
I I
- 3. IAsk test in accordance with 10 CFR 50 Appendix J to meet Safety Function 2.
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.. . - . . . . . . . _ . . . ~ . - . ~ ~ . - . - . - - _ . - . ~.- - .. ,..- - ...-. ,.
O AUG-28-1998 14:53 tECLEAR L1CENS1NG 512 972 8298 P.13/28 I
- - Attachment 3 1 i NOC-AE-000281 i Page 3 of12 CC-58.138,198 l
(Penetration No, M25,27,24) l l 'ITNS NO.: 2R201(2)TCC0058 DESCRIPTION: (ICIV) TRAIN A CCW TO RCFCS, l
CHECK VALVE SAPETY FUNCTION AND BASES:
1
- 1. Open to provide cooling water to the Reactor Containment Fan Coolers (RCFC) in the event of l
a Safety Ia'=*an signal or loss of Offsite Power (LOOP) (3600 gpm per DBD Table T-7, '
Safety Injection, Mininwm or Mafi mum Safeguards, or Recirculation).
i I
- 2. Name and leak tight (CAT A) in accordance with UFSAR commitment (Section 6.2.6.3 and Pione 6.2.4-1, Sheet 26) to provide contamment integrity.
j RBQUDtBD1ESTS:
- 1. Exarcise open to meet Safety Function 1.
l
- 2. Exercise close to meet Safety Function 2.
- 3. Imk test in twsdesce with 10 CFR 50 Appendix J to meet Safety Function 2.
TPNS NO.: 2R201(2)T C00138 DESCRIPTION: (ICIV)TRAINB CCW SUPPLYTO RCFCS, CHECK VALVE l SAFETY FUNCTION AND BASES:
j
- 1. Open to provide cooling water to the Reactor '#'tninment Fan Coolers (RCFC)in the event of i
a Safety injection signal or I.oss of Offsite Power (LOOP) (3600 gpm per DBD Table T-7, i-Safety law Mmimum or Maximum Safeguards, or Recirculation).
- 2. Close and leak tight (CAT A) in accordance with UFSAR commitment (Section 6.2.6.3 and Pipne 6.2.4-1, Sheet 28) to provide containtre.nt integrity. -
RBQURED1ESTS:
L Exercise open to meet Safety Function 1.
- 2. Exarcise close to meet Safety Function 2.
- 3. Iaak test in accordance with 10 CFR 50 Appendix J to meet Safety Function 2.
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m _ . - . _ __ . . _ _ . _ .
AUG--28-1999 14'53 tOCLEFR LICENSING 512 972 8298 P.14/28 i i
- Attachment 3 l NOC-AE-000281 Page 4 of12
'I?NS NO.: 2R201(2)T CC0198 DESCRIPHON: (ICIV) TRAIN C CCW SUPPLY TO RCFCS, CHECK VALVE SAPETY FUNCTION AND BASES:
- 1. Open to provide cooling water to the Reactor Containment Fan Coolers (RCFC) in the ev a Safety Injection signal or Loss of Offsite Power (LOOP) (3600 gpm per DBD Table T-7 Safety Injection, Minimum or Maximum Safeguards, or Recirculation).
- 2. C30se and leak tight (CAT A) in accordance with UFSAR commitment (Section 6.2.6.3 and Figure 6.2.4-1, Sheet 25) to pmvide containment integrity.
REQUREDTESTS:
- 1. Exercise open to meet Safety Function 1.
- 2. Exaecise close to meet Safety Function 2.
- 3. Leek nest in accordance with 10 CFR 50 Appendix J to meet Safety Punction 2.
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, . . - - . . . _ . ~ . . . . . . . .. - . . . ... -
fCG-28-1998 14:53 tOCLEAR L1CEtG1t4G '
Attachment 3 l- NOC-AB4)00281 Page 5 of12
_CC-319 (Penetration No. M39) l
'I?NS NO.: 2R201(2)T CC0319 DESCRFrION: (ICIV) CCW SUPPLY TO RCPS, CHECKVALVE SAFETY FUNCTION ANT BASES:
- 1. Close and leak tight (CAT A) to provide containment integrity.
REQUIRED TESTS:
- 1. Exarcise close to meet Safety Function 1.
- 2. IAak test in accordance with 10 CFR 50 Appendix J to meet Safety Function 1.
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,. AUG-28-1998 14:54 NUCLEHR LICENSIiG 512 972 8298 P.16/28 l l i
l- Attachment 3 l NOC-AE-000281 l
Page 6 of 12 CV-26 (Penetration No. M48) 1TNS NO.: 2R171(2)X _CV002fi DESCRIPTION: (ICIV) CHARGING LINE, INSIDE i
THE RCB CHECK VALVE SAFETY FUNCTION AND BASES:
l .
- 1. Close and leak tight (CAT A) to maintain contamment integrity. l 2.
Open to provide 30 gpm for RCS boron and water inventory (charging) control for safe shundown per Technical Requirements Manual 4.1.2.2 d or Technical Specification 4.1.1.
REQURED'IESTS:
i 1. Exacine close to meet Safety Function 1.
l l
- 2. Exercise open to meet Safety Function 2.
i l 3. Imk test in accordance with 10 CFR 50 Appendix J to meet Safety Function 1.
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. . AUG-28-1998 14:54 ti) CLEAR LICENSING 512 972 0298 P.17/28 Attachment 3 NOC-AF<000281 Page 7 of12 CV-34A. B. C, D (Penetration No. M51A,51B,52C,52D)
- TPNS NO.
- 2R171(2)T CV0034A DESCRIPTION: (ICIV)SEALINJECTIONTO
! SAFETY PUNCTION AND BASES:
- 1. Close and leak tight (CAT A) to maintain containment integrity.
- 2. Close to provide isolation in the event of a seal line mpture.
- 3. Open to pmvide 8 gpm of altemate RCS boration for safe shutdown (CVC DBD 3.2.2.14).
l REQUREDIESTS:
- 1. Exercise close to meet Safety Functions I and 2.
l 2. Exarcise open to meet Safety Function 3.
- 3. Imk test in accordance with 10 CFR 50 Appendix J to meet Safety Function 1.
- 'I?NS NO.
- 2R171(2)T CV00348 l DESCRIFFION: (ICIV)SEALINJECTION TO RCP B, CHECK VALVE SANTY PUNCI1ON AND BASES:
- 1. Close and leak tight (CAT A) to maintain containtnent integrity.
- 2. Close to provide isolation in the event of a seal line mpture.
- 3. Open to provide 8 gpm of altemate RCS boration for safe shutdown (CVC DBD 3.2.2.14).
REQURED1TsSTS:
- 1. Exarcise close to meet Safety Functions 1 and 2.
- 2. Excrase open to meet Safety Function 3.
- 3. 1.mak test in accordance with 10 CFR 50 Appendix J to meet Safety Function 1.
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ggJG-28-1998 14:54 tAJCLEfR L iCENS!NG 512 972 8298 P.18/28 L
- l
- Attachment 3 .
NOC-AE-000281 Page 8 of 12 TPNS NO.: 2R171(2)T CV0034C DESCRIPTION: (ICIV) SEALINJECTION TO '
RCP C, CHECK VALVE SAFETY FUNCrlON AND BASES:
i
- 1. Close and leak tight (CAT A) to maintain containment integrity. '
- 2. Close to povide isolation in the event of a seal line rupture.
l
- 3. Open to provide 8 gpm of alternate RCS boration for safe shutdown (CVC DBD 3.2.2.14 REQURED'IESTS:
L Exarcise close to meet Safety Ractions 1 and 2. '
- 2. Exercise open to meet Safety Punction 3.
- 3. Laak test in accordance with 10 CFR 50 Appendix J to meet Safety Raction I.
'1?NS NO.: 2R171(2)T CVORMD DESCRIPTION: (ICV)SEALINJECrlONTO RCP D, CHECK VALVE SAFETY PUNCTION AND BASES:
- 1. Close and leak tight (CAT A) to maintain containment lategrity.
- 2. Close to povide isolation in the event of a sealline rupture.
- 3. Opsa to povide 8 gpm of alternate RCS boration for safe shutdown (CVC DBD 3.2.2.14).
RBQURED'IESTS:
- 1. Exercise close to meet Safety Punctions 1 and 2.
- 2. Exaecise open to meet Safety Punction 3.
- 3. lAsk tASt in accordance with 10 CFR 50 Appendix J to meet Safety Punction 1.
i
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AUG-28-1998 14:55 NUCLEAR L1CENSItG 512 972 8298 P.19/28 Attachment 3 NOC-AE-000281 Page 9 of12 CV-158 (Penetration No. M53) 1?NS NO.: 2R171(2)X CV0158 DESCRIPTION: (ICIV) RC FILTERS OUT TO RHR TRAIN A, CHECK VALVE SAFETY FUNCTION AND BASES:
- 1. 1.mak tight (CAT A) to Inaintain containment integrity RfiQtHREDTESTS:
- 1. Imk *est in accordance with 10 CFR 50 Appendix J to Incet Safety Punction 1.
DW-502 (Penetration No. M61)
TPNS NO.: 2S191(2)T DW9902 DESCRIPTION: (ICIV) DEMINERAITSD WATER TO THE RCB, CHECK VALVE SAFETYFUNCTION AND BASES:
1.
Raamain close.to maintain containment integrity.
RBQURED TESTS:
1.
Imk test in accordance with 10 CFR 50 Appendix J to nm4, Safety Function 1 2
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, AUG-28-1998 14:55 tUCLEAR LICENSitG 512 (572 8298 P.20/28 Attaciunent 3 NOC-AE-000281 Page 10 of 12 FP-0943 (Penetration No.M77)
TPNS NO.: 2Q271(2)T FPQM3 DESCRIPTION: (ICIV) FIRE PROTECTION TO THE RCB. CHECK VALVE SAFETYFUNCTION AND BASES:
- 1. Close to maintain containment integrity.
REQURED TESTS:
l
- 1. Exercise close to satisfy Safety 1%nction 1.
- 2. 14ak test in accordance with 10 CFR 50 Appendix J to satisfy Safety Function 1.
IA-0541 (Penetration No. M58)
TPNS NO.: 2Q111(2)TIA0541 DESCRIPTION: (ICIV) INSTRUMENT AIR TO THE RCB, CHECK VALVE SAFETY PUNCT10N AND BASES:
- 1. Close to rnalatain contain=nt integrity.
RBQURED TESTS:
- 1. Exascine close to meet Safety Punction 1.
- 2. IAnk test in accordance with 10 CFR 50 Appendix J to meet Safety Function 1.
4
- - noe
o AUG-28-1993 14:55 tUCLEAR LICENSING 512 972 8298 P.21/28 a
Attachment 3 NOC-ABOX)281 Page 11 of 12 RC-0046 (Penetradon No. M45)
WNS NO.: 2R141(2)X RC0045 DESCRIIrHON: (ICIV) RMW SUPPLY TO THE PRT, CHECK VALVE SAFETY FUNCTION AND BASES:
- 1. Close and leak tight (CAT A) to provide containment integrity.
REQURED'ESTS:
- 1. Enescise close to meet Safety Function 1.
- 2. Imak test in accordance with 10 CFR 50 Appendix J to meet Safety Function 1.
SA-0505 (Penetradon No.M57)
T?NS NO.: 2Q101(2)T SA0505 DESCRIPTION: (ICIV) SERVICE AIR ISOLATION TO THE RCB, CHECK VLV SAFETY FUNCHON AND BASES:
'1. Close to maintain containment integtity.
REQURED TESTS:
- 1. Ieek test in accordance with 10 CFR 50 Appendix J to meet Safety Function 1.
'K N mTCesengtDOC
E 1998 14:56 tdJCLEAR L1CENSItG . 512 972 8298 P.22/28
- Anachment 3 NOC-APA00281 Page 12 of12 SI-0058 (Penetration No. M68A) 1?NS NO.: 2N121(2)T$19Q$$ DESCRIPTION: (ICIV) ACCUMULATOR COMMON NITROGEN SUPPLY CHECK SAPETY FUNCTION AND BASES:
- 1. Close and leak tight (CAT A) to maintain containment integrity.
REQURED'I15STS:
- 1. Exercise close to meet Safety Function 1.
- 2. Laak test in accordance with 10 CFR 50 Appendix J to meet Safety Function 1.
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^~
t E -a -1998 d ' " ~ ^ $ N $ N ~ ~ ~" ~ ~ ~ ~~~ N 9 d e39e Attachment 4
. NOC-AE-000281 Page 1 of 2 l
Recent Local Leak Rate Test Results i
. The ability of these valves to act as a containment isolation boundary is demonstrated by the 1 CPR 50 Appendix J Program. The valve stroke exercise as identified in IWV-3522 is to id valve degradation. A review of historical valve performance was performed for the past 3 local leakage tests in both units. The results of these tests are as follows:
FENE# VALVE # VALVE TYit'E DATE LEAK RATE GUIDELINE (SCCM) VALUE(SCCM)
UNIT 1 VALVES I M24 CC0198 ICIV 11/08 S 3 6 7644 M24 CC0198 ICIV 03/1565 33 7644 M24 CC0198 ICIV 09/2466 20 7644 _ !
M25 CC0058 ICIV 10/23/92 4102 7644 M25 CC0058 ICIV 09/16/93 35 7644 M25 CC0058 ICIV 03/15/95 300 7644 M25 COOO58 ICIV 12/02M6 3503 7644 M27 CC0138 ICIV 10/07/93 9 7644 :
M27 CC0138 ICIV 03/2065 1010 7644 M27 CC0138 ICIV 08/19/96 11 7644 M33 CC0013 ICIV 09/12/93 279 8736 M33 CC0013 ICIV 03/12/95 407 8736
- M33 CC0013 ICIV 12/03/96 820 8736 M35 CCD123 - ICIV 10/04/93 6 8736 M35 CC0123 ICIV 03/20/95 12 8736 M35 CC0123 ICIV 08/19/96 22 8736 __
M37 CC0183 ICIV 11/09/93 1486 8736 M37 CC0183 ICIV 03/16/95 199 8736 M37 CC0183 ICIV 09/23/96 114 8736 M39 CC0319 ICIV 09/27/93 7 6552 M39 CC0319 ICIV 03/16/95 20 6552
- M39 CCO319 ICIV 05/26/96 85 6552 M48 CV0026 ICIV 10/18/93 1473 2184 M48 CV0026 ICIV- 03/17/95 1472 2184 M48 - CV0026 ICIV 05/27/96 802 2184 amme m mesmimac
\_
- . =_ ~ - - . . - . -
, RUG-28-1998 14:56 NUCLEAR LICEtGING 512 972 8298 P.24/28 At*=chment 4
,.. NOC-AE-000281 Page 2 of 2 i
e l
PENE# VALVE # VALVE TYPE DATE LEAK RATE GUIDELINE (SCCM) VALUE(SCCM)
UNIT 1 VALVES (Continued)
$. [ M51 A CV0034A ICIV
' 09/24/93 258 1092 M51A CV0034A ICIV 03/18/95 27 1092
___ M51A CV0034A ICIV 05/23/96 162 1092
, M51B CV0034B ICIV 09/2463 i- 21 1092
- M51B CV0034B ICIV 03/18 S 5 0 1092
, M518 CV0034B ICIV 05/23 S 6
. 0 1092 M52C CV0034C ICIV i-1W1163 6 1092 M52C CV0034C IC1V 03/1865 30 1092 M52C CV0034C ICIV 05/2466 0 1092 -
M52D CV0034D ICIV 10/04S 3 1 0 1092
- _ M52D CV0034D ICIV 03/18S 5 1- 5 1092 MS2D CV0034D ICIV 05/24 S 6 1 0 1092 M53 CV0158 ICIV 09/2463 11 2184 M53 CV0158 ICIV 03/1865
~
14 2184 M53 CV0158 ICIV 05/27/96; __ 13 2184 i
j M58 IA0541 ICIV 09/12 S 3 43 1092 M58 IA0541 ICIV 03/21/95 i 229 1092 M58 IA0541 ICIV 05/1986 31 1092 M61 DWO502 ICIV 09/22/93 25 1092 M61 DWO502 ICIV 03/2165 30 1092 M61 DWO502 ICIV 05/27/96 8 1092 M68A SI0058 ICIV 08/24/93 13 546 M6tA S10058 ICIV 03/1365 16 546 M6SA SI0058 ICIV 05/20 S 6 49 546 M77 FP0943 ICIV 12/16/93 3333(*) 3276 M77 FP0943 ICIV 03/18/95 162 3276 M77 FP0943 ICIV 05/23/96 1024 3276 __
- Test performed without slipblind installed on the boundary valves istWWESAC-WMIDOC i
.]
, p.UG-28-1998 14:57 tOCLEAR LICEtGit{i 512 972 8298 P.25/28 Attachment 5 NOC-AE-000281 Page1of4 Risk Perspective on Containment Isolation Check Valves
' lie enahinment isolation function is designed to limit the leakage of radioactive materials through lines penetrating the reactor containment building (RCB) so that the site boundary dose guidelines specified in 10CFR100 are not exceeded following a loss-of<oolant accident (LOCA) or other design basis accident. Upon receipt of the appropriate signals, isolation of the RCB is accomplished by automatic isolation of all non-essential fluid systems, which penetrate the RCB.
Le plant-specific Probabilistic Risk Assessment (PRA) analyzes containment isolation for minigating releases to the environment. He index ofinterest is the Large, Early Release Frequency (LERF). This measures the frequency of an event that will exceed 10CFR100 in a abort peri9d of time. This function is documented in the STPEGS Pivbabilistic Safety Assessneent Containtnent Isolation Function Package.
Faihme of coniament penetrations less than 3" in diameter does not contribute to LERF in the Saudi Texas Project PRA. The containment ' solation functions discussed below have little risk impact on I.ERF at the South Texas Project. A PRA risk ranking sensitivity study demonstrates the now risk hnportance for the containwnt isolation function. Failure of the containment imaheiam function does not affect core damage frequency. Note: The Phase A Containment laalanian signal is initiated by the safety injection and automatically isolates all nonessential process lines which penetrate Containment. The Phase B Containment Isolation signalis inimissed by the Containwat HI-3 pressure signal and initiates closure of the rermining process lines. Process lines do not include ESP lines.
The foBowing describes how each of the valves in this submittal are inodeled in the plant-speciSc PRA:
14Y-etMA/B/C/D (IRC) Reactor Coolant Pump (RCP) Seal Injection Line Check Valves he check valves provide a second barrier to normally open motor operated valves (MOVs)
MOV033A, B, C and D. RCP seal injection is isolated upon receipt of a Phase A Containment laaladan signal concurrent with a charging header low-pressure signal. Since continued seal u
~ section to the RCPs is highly desirable in order to prevent an RCP seal LOCA, the isolation valves are permitted to remain open as long as seal injection is actually occurring (i.e., the
_ charging system is providing seal injecthn). The seal injection lines are less than 3" in diameter and therefore do not contribute to LERF.
j 14C4008,2-CC-0058,1-CC 0138,1-CC 0198,2-CC-0198 CCW to RCFC's ICIV Check Vahes and 1-CC-0013,2-CC 0013,1 CC-0123,1-CC-0183, and 2 CC-0183 RHR heat enchanger CCW Supply IRC Check Valves Comaammed CCW supply to the reactor contamment fan coolers (RCFCs) is required to provide long4erm containment heat removal in the South Texas Project PRA. CC-0058,0138, and 0198 a.manecamamemnoc i
i
, RUG-28-t933 14:57 NUCLEAR LICENSING 512 972 8298 P.26/28 Attaohmaat 5 NOC-AE-000281
.Page 2 of 4 (Mimwd CCW supply to the reactor containment fan coolers (RCFCs) is required to provide long tenn enneminment heat removalin the South Texas Project PRA. CC-0058,0138, and 0198 am required to open and remain open for success of this function. Because CCW to the RCFCs I is a closed system inside containment, and the PRA function requires the valves remain open, these check valves are not included in the analysis of the containment isolation function. nose lines are not autornark ally isolated. l l
CCW flow to the residual heat removal (RHR) heat exchangers is required for long-term decay heat reasoval after a design basis initiating event CCW-0013,0123 and 0183 are required to open and renamin open to provide this function. In the unlikely event of a tube rupture in one of the RHR heat exchangers, radioactive materials would be entrained in the CCW system. He operator in the control room would be made aware of this condition by the CCW radiation snoshor. Additional indications of this condition would be given by the CCW flow indications, tas high and low flow alarms, surge tank level indications, and tank high level alarms. The inalmeinn valves in this system are hig=it o be operated remote-manually from the control roomt he CX'W supply IRC check valves are included in the analysis of an Interfacing Systems LOCA.
In the event of an interfacing systems LOCA, th TtHR heat exchanger tubes could fail resulting in a sensese path through the CCW lines. The CCW supply line contains one MOV and the CCW supply check valve; the CCW return line contains two MOVs. Operator action is required to -
cloes the MOVs in the CCW supply and return lines. An analysis of the change in interfacing syssemos LOCA frequency was made by assuming that all three CCW check valves fail to close on desmond. %e contribution to LERF from interfacing systems LOCA changed from 3.0 x 10*
per year to 7.8 x 10* per year which is less than the 1.0 x 10# per yearchangeidentifiedin the NRC RiskInformed Regulatory Guide.
Based on the analysis in the PRA, these valves have low safety significance for preventing an Inserfacing LOCA and/or containment isolation.
1 CC.4319 Banctor Coolant Pump CCW Supply IRC Check Valves his check valve provides a second barrier to rmre. ally open MOVs CC-0318 and CC-0291. The CCW MOVs are isolated upon receipt of a Phase B Containment Isolation signal. Since continued cooling to the RCPs is highly desirable, the isolation valves are permitted to remain opas as long as <maling is actually occurring. %ese valves are credited in the PRA for remaining open to provide reactor coolant pump cooling during an accident.
CCW is supplied to the motor air coolers, the lube oil coolers and to the thermal barrier heat exchanger for the RCPs. .Two additional check valves in the supply line to each RCP thermal barrier heat exchanger provides additional isolation capability. The supply to the motor and lube oil coolers is a closed system inside containment.
noseammemersc4 amwac
AUG-28-1998 14:58 NUCLEAR LICENSING 512 972 8298 P.27/28 e Attachment 5 NOC-AEA)00281 ;
Page 3 of 4 heam CCW to the RCPs is a closed system inside containment or backed up by additional check valves, and the PRA function requires the valves remain open, these check valves are not included in the analysis of the containment isolation function.
i 1-CV4026 CVCS Charging IRC Containment Isolation Check Valve i 1his valve provides an ' additional banier to nomially open MOV025. The MOV is autom ,
closed on aceipt of a Phase A Containment Isolation signal,1-CV-0026 is credited for l maintaining reactor coolant system water level (i.e., charging) by opening and remaining ope Since chargmg is desirable for accident mitigation, this isolation valve is credited in the PRA for '
reuniales open.
Because the CVCS system is a high-pressure system inalde containwnt with additional pressu isoladon pmvided by the normal charging supply check valves CV0001 and CV0002 (or CY0004 and CV0005), this line is not analyzed in the PRA and has no risk impact for LERF.
1 CV4158 CVCS Low Pressure Letdown IRC Containment Isolation Check Valve This penetrabon is not used during power operation and the manual valvc W-0157, is locked I closed. 'Iberefore, this valve is not analyzed in the PRA.
, 1-DW4082 RCB Demineralized Water Supply Header Check Valve
' Ibis containment penetration line is not used during power operation. 1-DW-0501 is a locked-closed manual valve located inside containment. 1-DW-0502 is a check valve inside hr For these reasons, this containment penetration is not modeled in the PRA.
1M4M3 FireProtectionIsolation 1-PP Op43 3 a check valve in series with normally closed MOV FP-0756. The MOV receives a Phase A ra=#mioment Isolation signal. Because the line is normally isolated during power oper 6ca, this containmant penetration is not modeled in the PRA.
1-IA4H1 Instranent Air Supply Isolation 1-IA 0541 backs up normally open fall closed, air-operated valve FV8565. FV8565 receives a Phase A rhaeminmant Isolation signal. The instrument air system is a closed high-pressure syness, which does not communicate with the containment atmosphere; therefore this cansaiarnent pers.Gon is not modeled in the PRA.
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I AUG-28-1993 14:59 NUCLEAR LICENSING 512 972 8298 P.28/28 O ,
O e Attehment 5 NOC-AE-000281 Page 4 of 4 14l4868 Nitrogen Supply '.o Safety Injection System Accumulator Tanks Check Valve
' Ibis line is usually isolated but is used periodically for accumulator nitrogen charging. Barriers include the check valve and air-operated, fail closed valve, FV3983, outside containn'ent.
FV3983 receives a Phase A Containment Isolation signal. Them is an additional solenoid-operased valve on each accumulator. Line pressum outside containment is higher than containment failure pressure. Themfom, this check valve is not modeled in the PRA.
In conclusion, from a risk perspective, the above valves have little impact on the frequency of a Large Early Release and no impact on core damage frequency. This is due, in part, to the plant design and the role the above check valves play in mitigating accidents.
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TOTAL P.28
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