ML20067A170

Application for Amend to License DPR-53 & Request for Exemption from 10CFR50,App J.Amend Changes Tech Spec Page 3/4 6-3 to Extend Local Leak Rate Test of Containment Isolation Valve 1-CVC-515 by 90 Days

ML20067A170
Person / Time
Site:	Calvert Cliffs
Issue date:	01/18/1991
From:	Creel G BALTIMORE GAS & ELECTRIC CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20067A174	List: ML20067A170 ML20067A175
References
NUDOCS 9101240279
Download: ML20067A170 (10)

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15 ALTIMORE OAS AND ELECTRIC l

CHARLES CENTER e P.O. DOX 1475 e DAL.TIMORE, MARYLAND 21203 1475 i

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OtORot C. CRtcL j

Vict Pass mgee, 1

NW6 tan rnettov m,>,..-.m January 18,1991 U.S. Nuclear Regulatory Commission

. Washington, DC 20555 ATTENTION:

Document Contr01 Desk I

SUDJECT:

Calvert Cliffs Nuclear Power Plant Unit No.1; Docket No. 50 317 Request for License Amendment and Exemption ham 10 CFR 50 Appendix J J

i Gentlemem Baltimore Ons and Electric Company hereby requests -temporary relief from the schedular requirements for perferming a local leak rate test (LLRT) for Containment Isolution Valve 1 CVC 515.

Accordingly, we. request a chanpc to the test intemil of Technical Specification 4.6.1.2.d, pursuant to 10 CFR 50.90. In conjunction with this license amendment, we i

request an exemption from 10 CFR 50 Appendix J, paragraph Ill.D.3, Type C tests, pursuant to the provisions of 10 CFR 50.12. This request applies only to the next scheduled LLRT for CVC 515, 4-presently due March 23,1991..

1.

REOUl:ST FOR 1,1 CENSE AMENDMENT 1

..A.

DISCUSSION Calvert Cliffs Unit 1 Technical Specification 4.6.1.2.d states:

• 1)pe B and C tests shall be conducted with gas at Pa (50 psig) at inten>als no greater than 24 months aceptfor tests im oh'mg p

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Document Control Desk January 18,1991 Page 2 Containment Penetration No. 2A, Letdown Lhw, is located in the Unit 1 West Piping Penetration Room. The letdown line is part of the Chemical Volume and Control System (CVCS), and its purpose is to provide for letdown of reactor coolant to CVCS components located outside containment. Inside containment, the letdown line taps off Reactor Coolant System (RCS) Cold Leg No.12, runs through two letdown stop valves (CVC.515 & 516), passes through a regenerative heat exchanger, and then exits the containment at Penetration 2A. The CVCS is described in greater detailin the Calvert Cliffs Updated Final Safety Analysis Report (UFSAR), Section 9.1.

CVC-515 and CVC 516 are two inch air operated globe valves and are also the containment isolation valves for Containment Penetration 2A, as shown in Figure 510, Sheet No. 3, Updated Final Safety Analysis Report (uttached). During numal power operations, CVCS is operating and these valves are fully open. During shutdown conditions, after the pressurizer bubble is collapsed, CVCS is secured and these valves are shut.

Calvert Cliffs Unit I started up on October 23,1990, following an extended outage, and is currently scheduled for a maintenance outage in the spring of 1991. Unit 2 is presently shutdown and is expected to start up in early 1991. The LLRT of Unit 1 CVC 515 is duc hiarch 23,1991, approximately three months earlier than the other Unit 1 containment isolation valves. The reason that the LLRT for CVC 515 comes due three months earlier than for the bulk of containment isolation valves is that maintenance had been performed on CVC 515 in March 1989, and a LLRT was conducted as part of post maintenance testing. All other valves were then tested in June 1989 (the prior tests were current only through spring 1990) in order to support Unit 1 operation through s? ring 1991. The spring 1991 outage originally and until recently had been schedule ( to begin in early March 1991, consistent with the LLRT interval for all valves, including CVC 515. Due to the recent delays in the startup of Unit 2 and in view of the area's electric iwcr supply needs as projected for the near term, the Pennsylvania New Jersey Ma land (PJM) Network has recently requested that we not shut down Unit I any earli r than late March. Otherwise, according to the PJM, other electric generating stations may need to be brought out of lay.up to provide replacernent power.

I Furthermore,it is our desire to coordinate the forthcoming startup of Unit 2 with the subsequent Unit 1 maintenance outage in a manner that assures that the availability of supporting plant staffis optimized for both of these evolutions.

In summary, this relief will provide flexibility in our regional power supply planning, and will provide for improved coordination of plant resources by assuring that the Unit 1 and 2 outages do not unnecessarily overlap. A 90-day extension to the LLRT will also provide substantial f!cxibility in establishing the sequence of events to be conducted within the Unit 1 outage, and will permit us to

,crform the test in conjunction with the other LLRTs coming due in June. This wil place the CVC 515 test interval back into sequence with these other valves.

Document Control Desk January 18,1991 page 3 Technical Specification page 3/4 6 3 for Unit 1 is attached, marked up with the desired change, 11.

JETJFICATION As containment isolation valves, the safety function of CVC 515 and CVC 516 is to assure the capability to establish containment integrity following design basis events.

Automatic isolation of these valves upon receipt of a Safety Irdection Actuation Signal (SIAS) prevents the release of fission products to the environment. Valve redundancy is provided to ensure that in the event of a single failure, isolation capability is not comproinised. local leak rate tesis are periodically conducted at the containment design pressure of 50 psig to verify the continued leak. tight integrity of these valves. Individual leakage hmits are established for each valve pursuant to 10 CFR Part 50, Appendix J, to ensure compliance with overall containment leakage limits.

The CVCS is connected to the RCS and is not in communication with the containment atmosphere during normal plant operation. Following a loss of coolant accident, CVCS would only communicate with the containment atmosphere via the break in the reactor coolant pressure boundary and the remaining intact yrtion of the RCS piping and then only if the letdown piping did not remain tilled witi water.

Our review of the LLRT history of CVC 515 shows that the valve has exhibited very low leakage in relation to its assigned leakage limits. A limit of 10,(XX) standard cubic centimeters per minute (secm) is administratively established for CVC-515 for Type C local leak rate testing. Test results have never approached this limit.

CVC-515 was last leak tested on March 23,1989 with results of 13.43 scem. Table 1, below, provides the results of LLRTs for CVC 515.

TAllt.E I CYC 515 Test Date Leak Rate (scem)

May 1979 300 October 1980 240 May 1982 149 October 1983 3,500 April 1985 2,510 December 1986 28 April 1988 227 March 1989 13 i

Ibcument C<mtrol Desk January 18,1991 Page 4 The most recent Type A Integrated Leak Rate Test (ILRT) was performed on May 27,1988. The measured result for overall containment leak rate was 138,400 secm, which is well below the acceptance limit of 346,000 scem for a '!)pe A tests imposed by Technical Specification 3.6.1.2.a.1. The leakage history of CVC 516, the redundant valve in Containment Penetration 2A, is similar to that of CVC 515. The last LLRT result of 5,150 seem for CVC-516 is current through June 1991. See Table 2 below for details.

IAlllE 2 CVC 516 Test Date Ixak Rate (seemi May 1979 19 October 1980 136 May 1982 41 October 1983 24 April 1985 23 December 1986 650 June 1989 5150 Although neither CVC 515 or CVC 516 have ever failed an LLRT, failures have occurred for other valves. Our experience shows that while failures may occur for a variety of reasons, the primary cause of increased leakage rates at Calvert Cliffs has been gradual valve wear. In this case it is significant that Unit I was shutdown for most of this test interval. CVCS is generally not used during shutdown. When it is, the temperatures, pressures and flows to which the components are exposed are i

much lower than at full power. As a resuli, any corrosion or flow induced wear-and stress on these valves is less than it would have beca had the plant operated for 24 months at full power.

In summary, a 90-day extension for the Typc C test ior CVC-515 is justithd based on the following: (1) the valve has historical y exhibited low leakage relativt. to its leak rate test acceptance criterion; (2) a redundant valve (CVC 516) provides backup isolation for CVC 515 for which the leakage test results are current and within limits; (3) the operating environment for CVC 515 has been relatively benign during the current test interval; and (4) the likelihood of occurrence of a design basis event involving a containment pressurization during the extension period is extremely low.

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c Document Control Desk January 18,1991 Page 5 C.

PROPOECLJ)l?rERMINATION OF NO SIGNIFICANT llAZARI)S CONfiU))LtATIONS t

The aroposed change has been evaluated against the standards in 10 CFR 50.92 and has acen determined to involve no significant hazards cor:siderations, in that operation of the facility in accordance with the proposed amendment would not:

i 1.

involve a significant increase in the probability or consequences of an accident previously evaluated:

This change does not affect the arobebility of a previously evaluated accident.

Containment isolation valve lea cage, by itself, is not an accident evaluated in -

the Calvert Cliffs Updated Final Safety Analysis Report '(UFSAR). This 3

change could have an effect on overall containment-leakage rates, and-therefore the potential for this has been evaluated to ensure that the consequences of accidents involving containment pressurization with the potential for release of fission products to the environment we'ild not be i

significantly increased.

The function of CVC-515 and its redundant valve (CVC 516) is to assure the capability to automatically isolate the containment and thereby mitigate the consequences of design basis events. Leakage limits are established and local leak rate tests are periodically conducted to verify this capability. The required period f"r these tests is 24 months. This proposed change would incree this period for CVC 515 by 90 days on a one time basis only, to_ allow fictibility in scheduling the commencement of an upcoming Unit 1 outage.

An evaluation of past leak test results and recent operating environment for CVC 515, as m.,li as for its redundant valve, was performed. Evaluation (imlings are that: CVC 515 and CVC-516 have both historically exhibited low leakage relative to acceptance criteria; the test results for CVC 516 are

. current and will remain so during the proposed extension; the operating environment for both valves has been relatively benign during the current.

Interval due to the fact that the plant has been shutdown for most of it; and -

finally, the likelihood of occurrence of a design basis accident involving-containment pressurization during the period of extension is extremely low, In summary, the proposed change will in no way result in change in the leak-e thhtness of CVC-515 or of Penetration 2A as a whole. This, combined with the low likelihood of an accident occurring during the extension period,-

demonstrates that this change would not significantly increase the probability E

or consc<{uences of previously evaluated accidents.

u l '.

Document Control Desk January 18,1991 Page 6 2.

create the possibility of a rtew or different type of accident from any accident previously evaluated:

The proposed change will not represent a change in the configurcion or o)cration of the plant. Specifica!!y, no new hardware is being added to the p ant as part of the proposed change, no existing equipment is being modiGed, nor are any significantly different types of operations being introduced. Therefore, the 30ssible effects of th:s change are addressed by existing accident analyses anc no new or different accidents would be created.

3.

invoin a significant ret. action in a margin ofsafety; The Bm for Technical SpeciGeation 3.6.1.2 Containment Leakage, states bt tne Cultat 'ns on containment leakage rate ensure that the total ontain.nent 14 <ge volume will not execed the value assumed in the accident analyses at the peak accident pressure. As added conservatism, the measured overall integrated Ic kage rate is t'urther limited to 75% of this value during the performance ofleakage tests. This limit is 346,000 seem and includes margins to assure c.atisfaction of the assumptions in the safety analyses. The latest measured overall leakage of 138,400 seem compares very well with this limit. To ensure that individual valve leakage is maintained at n level that will prevent the overall leakage limit from being exceeded, thus reducing a margin of safety, a leakage " allotment" is made for cach valve, A value of 10,000 seem is established for CVC 515. Test results that execed this value do not alone comprise a reduction in the margin of safety assumed in the technical speciGcations, provided that overall measured leakage remains within established limits. Nonetheless, the individual va've leakage limits provide the means to monitor long term valve degradation as well as overall containment performance. The proposed change involves only a one time modiGention of an adminisirative requirement for test frequency. It does not change any leakage limits or any other acceptance criteria. Since the change in the frequency cou'Id not, by itself, result in an increase in leakage, and because substantial additional leakage could be accommodated before any margin begin to be affected, no reduction in a margin of safety is involvei Therefore, this change does not involve a significant reduction in a margin of safety.

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Document Control Desk -

January 18,1991; i,,

Page ?

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EXEMl"I'lON.

A.

1)lSCUSSION ANI) JUSTIFICATION 10 CFR 50, Appendix J, paragraph III.D.3 states:

'" Type C tests." Type C tests shall be performed during each y

reactor shutdown for-refueling but in no case at intervals greater than 2 years."

10 CFR 50.12 states that ' the Commission may grant exemptions from the requirements of regulations contained in 10 CFR 50 provided that: (1 the exemption is authorized by law;(2) the exernption will not present an un

-the public health and safety; (3) the exemption is consistent with the common defense and security; and (4)- special circumstances, as defined in-10 CFR 50.12(a)(2), are present, 1.

The Requested Exemption h Authorked by Lm

-We believe the Commission is authorized to grant this exemption. Similar exemptions have been granted for other facilities, as well as for Calvert Cliffs.

2.

The Requested Esemption Does Not Present an Undue Risk to the Public

- Health and Safety The historical leakage test results for CVC 515 have been low in the acceptable range. The most recent results for overall containment leakage were also low in the acceptable range. The LLRT of the redundant valve in

- this containment penetration is and will remain current. It is very unlikely that:any additional contribution:to containment leakage resulting from this-extension would place either individual valve or overall containment leakage outside of acceptance limits. Therefore, this one. time exemption does noi present an undue risk to the public health and safety. 'Please refer also to Section I.B of this request.

1 3.

The Requested Eremption Will Not Endanger the Common Defense and Security i

The common defense and security are not at issue in this exemption request.

Document Control Desk January 18,1991 Page 8 4.

Special Circumstances are Present Per 10 CFR 50.12 (a)(2), we believe the following special circumstances are present in that:

Compliance would result in hardship or other costs that are significantly in excess of those contemplated when the regulation was adopted [(a)(2)(iii)],

When the regulation was adopted a presumption was made that a two-year test interval would easily accommodate performance of these tests during a refueling outage, and that these tests would be conducted as a group, In this case, 'onc valve is out of sequence with the main group of valves, and compilunce would result in a plant shutdown earlier than can be accommodated by prevailing energy supply conditions. Specifically, strict compliance with this regulation would create considerable hardship by requiring reserve generating stations to be brought out of lay up within the PJM Network and placed into service.

This exemption would provide only temporary relief from the applicabic regulation and we have made a good faith effort to strictly cotaply with the regulation [(a)(2)(v)] This exemption is requested for a period of only 90 days.

We have exhibited diligence in performing the test during past refueling outages This request is not the result of any negligence on our part as we have previously performed the test during refueling outages as intended by the regulation, 11.

ENVillONMENTAL IMPA('I' This exemption will not result in the modification of any plant structures, systems or components. Neither will it result in a change in the way plant systems are operated.

This exemption involves an administratively. controlled surveillance test program.

-The requested one time extension to the tc~t interval for CVC-515 has been reviewed and we have determined that,in view of the above facts, it will not result in any increases in routine or post accident radiological releases or occupational exposures. Therefore, the environment will not be adversely impacted.

Document Control Desk January 18,1991 Page 9 j

111.

SAFE'IY COMMrITEE REVIEW The proposed determination of no significant hazards considerations for the proposed license amendment and the justification for the proposed exemption have both been reviewed by our Plant Operations and Safety Review Committee and our Off Site Safety Review Committee.

These committees concluded that this change will not result in an undue risk to the health and safety of the public.

Very truly yours, STATE OF MARYLAND 1

TO WIT I hereby certify that on the

/[ day of Tanua r t/

Cal] vert doand/

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, before me the subscriber, a Notary Public of the State of Maryland in and for~

personally appeared George C. Creel, being duly sworn, and states that he is Vice Plesident of the Baltimore Gas and Electric Company, a corporation of the State of Maryland; that he provides the foregoing information for the purposes therein set forth; that the statements made are true and correct to the best of his knowledge, information, and belief; and that he was authorized to provide the information on behalf of said Corporation.

- WITNESS my Hand and Notarial Scal:

Notary Public My Commission Expires:

M M'/

Datd GCC/BSM/DLS/dlm Attachments: (1) Proposed markup of Technical Specification page 3/4 6-3 (2) UFSAR Figure 5-10, Sheet No. 3

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Docurnent Control Desk January 18,1991 Page 10 cc:

D. A. Brune, Esquire J. E. Silberg, Esquire R. A. Capra, NRC D. O. Mcdonald, Jr., NRC T. T. Martin, NRC L E. Nicholson, NRC R. I. McLean, DNR l: