ML20032D468
| ML20032D468 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 11/02/1981 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20032D466 | List: |
| References | |
| NUDOCS 8111170061 | |
| Download: ML20032D468 (7) | |
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_h UNITED sTATFs yQ%3 i NUCLEAR REG _ULATORY COMMISSION j..r wasWNGTON, D. C. 20$$$.
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gv SAFETY EVALUATION BY THE OFFICE OF NUCLEAP. REACT 0R REGULATION SUPPORTING AMENDMENT NOS. 58 AND 40 TO FACILITY OPERATING LICENSES NOS. DPR-53 AND OPR-69 BALTIMORE GAS AND ELECTRIC COMPANY CALVER' TIFFS NUCLEAR POWER PLANT UNIT NOS.1 & 2 DOCKET N05. 50-317 AND 50-318 Introduction I
27,1930, Baltimore Gas and Electric Company By application dated June (BGLE) requested changes to the Technica'l Specifications (TS-) for Calvert Cliffs Units 1 and 2 in order to allow the use of an installed 69 kV offsite power source in place of a required 500 kV offsite pcwer source.
In additien, by application dated July 20, 19812 BGLE requested changes to the TS for Calvert Cliffs Units 1 and 2 to provide for:
(1) use of an installed
" reserve battery" as a part of the safety related 125-volt D.C. power system, (2) modification of the recuired remedial acticn associated with the decrease in the single cell voltages of the safety-related 125-volt D.C. batteries and (3) modification of the existing Limiting Conditions-for 0:eration associated with the battery chargers. The safety and envircn-mental issues associated with tr.e June 27, 1930 and July 20, 1981 applicaticns fcr license amencrent are censiderec nerein.
In the course of reviewing the June 27, 1950 and July 20, 1981 applications, we have found it ne:assary to make changes in the Technical 5;ecifications that nere ;rcocsed by EGLE.
These Changes were disc ssed aith, and appfcVed by, representatives of 3GLE.
Disc;ssicn and Evaluation The issues associated with the June 27, 1930 and July 20 -1951 applicaticns are censidered, secarately, below.
Limitin: Conditions for Oceraticn and Surveillance Re:uirements for the 69 a (SFECO) Power Source - Acclicaticn cated June 27, 1980.
On January 14, 19773, the NRC issued Amendment Nos. 19 and 5 for Calvert Cliffs Units 1 and 2, respectively.
These license amencments approved the installation and use of a 69 kV offsite ocwer source owned by Scuthern Maryland Electric Cooperative (SMECO).
Limiting Conditions for O'peration (LCO's) and Surveil-lance Requirements (SR's) for the SMECO line were not considered at that
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time.
By application dated June 27, 1930, SGLE procosed LCO's for use of the SMECO line as a creferred source of offsite A.C. electrical power. Specifically, 811117o061 811102 PDR ADOCK 05000317 P
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_. EG&E proposed that,the SMEC0 line.be permitted to be used.as_a substitute.for one, preferred, 500 kV, offsite power, circuit tr. action statements.a...b.,
and c. for Calvert Cliffs Units 1 and 2 Technical Specification 3.8.1.1.
In this regard, our safety evaluation of January 14, 1977 concluded that the SMEC0 lina meets our requirements for use as an independent, preferred, source of offsite electrical power as stated in General Design criterion 17, Appendix A to 10 CFR Part 50.
Although no SR's'dre proposed by SGLE for the SMECO offsite electrical power source, BGLE has committed to perform the following surveillance:
(1) within one hour of use of the SMECO power source in place of a 500 kV offsite power source, and at.least every.8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter during use, perform SR 4.,8.1.1 la (availability and proper breaker alignment).
(2J at least every 18 months, perform SR 4.8.1.1.lb (nanual and automatic power supply transfer).
The above tests are also presently applicable to the preferred, 500 kV, offsite power sources.
Based upon our findings contained in Amendments Nos. 19 and S for Calvert Cliffs Units 1 and 2, dated January 14, 1977 we concluded that the SMEC0 pcwer source met our requirements for use as a preferred offsite power source.
Furthermore, based upon our evaluation of the propcsed Technical Specifications, substitutien of the SMECO power source for a single preferred, 500kV, offsitr:, pcwer source, does not decrease the availability of the offsite power sources for Calvert Cliffs Units 1 and 2.
In the course of our review cf Technica'l Specificaticns associated ~with A.C.
power sources, we have found that existing Ca: vert Cliffs Units 1 and 2 Technical Specification 3.8.1.lb requires c'arification. This specification addresses ' operability of diesel cenerators including "..a swing diesel
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generator capable of serving both Unit 1 and Unit 2..."
The cesign of the Calvert Cliffs ensite A.C. power distribution incorporates 3 diesel generators.
l Diesel cenerators 11 and 21 ray each supply ccwer to two 'cne for each unit) of four il60 volt engineered safety features cases. Diesel generator 12, the "s.iing diesel", may supply PCwEr to any of the fcur al60 volt engineered safety features buses but only one bus at any given time.
The statement in Technical Specification 3.8.1.lb, that the swing diesel is capable of serving coth Unit i and Unit 2 might be incorrectly interpreted to mean that the swing diesel can supply more than.cne of the four 4160 volt engineered safety feature buses, simultaneously. Accordingly, the phrase "... serving botn Unit 1 and Unit 2..." should be changed to " serving either Unit 1 cr Unit 2".
This change does not impact the requirenents on operability or surveillance of the diesel generators but rather clarifies the function and capabilities of the swing diesel.
. Limitino Ccnditions for ODeration and Surveillance Recuirements fer the Staticn Reserve Battery, Battery Chargers, ana Single Cell Voltage By applicatien dated July 20, 1931, BGLE requested changes to the Calvert Cliffs Unit 1 and Unit 2 Technical Specifications :n thc subjects of the
" Reserve Battery", single cell voltage, cad Limiting Ccnditions for Operation associated with the I25-volt D.C. battery chargers.
On July 31, 19794 Ene NRC issued Acendments Nos. 40 and 22 to.the Facility Operating Licenses for Calvert Cliffs Units 1 and 2, respectively.
These license amendments provided Technical Specificaticns for use of a ten.porary
" Reserve Battery" to allcw battery capacity testing durina cperation of Calvert Cliffs Units 1 and 2.
At the time of issuance of' Amendments Nos.
40 and 22, the fully qualified "safdty grade" reserve battery was seated en a 1/2 inch thick pTywood and 1/4 inch thick rubber mat directly on the turbine deck, and enclosed by a temporary barrier.
The tempcrary cables from the battery to its 1200 ampere disconnect switch were routed above a drop ceiling until they cropped into the pernanent conduit. All switchine equipment was located in the cable screading room where the existing DC
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switchgear is located. Subsequent modifications were undertaken to locate the reserve battery in a permanent location. The application fcr license amendment, dated July 20, 1931, requests Technical Specificaticn changes that would allow the reserve tattery to be used as a re;lacement for any of the 4, 125-volt D.C. station batteries, on an unrestricted basis.
InoQrSafetyEvaluatieninsupp:rtofAmendments40and22,weconclud$d that the reserve battery anc ass::iated interconnecti:ns were fully " safety grads".
Accordingly, we herein address cnly these iss es ass 0:iatac with
- ermanent installatien and use cf the reser.e battery.
The reserve cattery is located in a cubicle situated in the Auxiliary Euilding. The fire rating cf the r :: is 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> and, as such, is equivalent cr supericr to that of the other 125-volt D.C. ' existing) batteries at Calvert Cliffs. Scth existing and reserve catteries are cuntec :n corrcsien-resistant, earth ;ake-;rcof racks suitable for use :. ring desi;n basis earthc ake accelerations.
The tatteries are 1:ca:e: in a Seismic Class I structure and ea:n tattery is ic:ated in a separate recm.
The battery rccms share'a /entilation systs' censistirg of :ne su;;1y duct, one exhaust duct, cra battery rcem supply f an, and cne battery rcom exhaust fan. The two f ans are asscciated with redundant lcad groups. Upcn loss of either fan, sufficient ventilation is provided by the renaining fan to preclude the possibility of hydrogen accumulaticn within the battery rooms.
Access for battery hockup is via cabinets located il the Unit 1 and Unit 2 cable spreading rooms. Hcckup cables, to connect the reserve battery to one of the four 125-volt D.C. busses, are available in a protected storage iccation wher-e other safety-related equipment is kept.
_ The licenset has performed seismic scoping calculations and has.ietermined that the hookup cables will not be dislodged by the design basis seismic event. With regard to use of the battery, we have reviewed the procedure for use of the reserve battery, STP-M-550.
'r.'e conclude that sufficient administrative controls exist to ensure proper use of the reserve battery.
In this regard, it should be noted that the reserve battery is equipped with a single non-safety grade battery charger. Administrative controls prevent the use,of this battery charger on a 125-volt D.C. bus.
The proposed Technical Specifications for use of the reserve battery are contained in Calvert Cliffs Units 1 and 2 Technical 3pecification 3.S.2.3 which governs overall operability of the 125-volt D.G power system. At the present time, if a 125-volt D.C. battery is inoperable (except for reasons due to surveillance'testingJ, the battery must be made operable within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> or the~ plant must be in hot standby in six hours and in cold shutdown within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
The proposed Technical Speci-fication 3.8.2.3, action statement b., would allow an additional 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> for hookup of the reserve battery, in the event of inoperability of a 125-volt D.C. battery.
Experience has shown that the proposed four hour period is sufficient for diagncsis of battery incperability and subsequent hockup of the reserve battery. Moreover, it is unlikely that the 125-volt D.C. power system will be challenged to perform its safn y function in the 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> permitted for battery diagnosis and subsequent hockup of the reserve battery.
A second proposed change to Technini specifiut ten 3.8.2.3, action statement e.,
addresses the use v reserve batter, during surveillance testing. The ter1 " temporary battery" had been previcusly used in the Technical 5;ecificaticns to reflect the tercerary nature of the battery installaticn.
The term " reserve battery" is nca preposed fcr use in substitutien fer " temporary battery".
Inis change has
.) effect en the require ents contained in Technical Specification 3.5.2.3, acticn statement e., and is apprcpriate in that it mere clearly reflects the permanent nature of tk reserve battery installaticn.
Based ucon the above infc7.ation regarding the reserve battery, we find thac the reserve ba-*ery installation pecv' des prctecticn fcr the reserve battery that is equivalent tc the existing 125-volt D.C. battery installaticns at Calvert Cliffs.
Yoreever, the croposed Technical Specifications allow sufficient time to heckup the reserve battery without significantly degrading the 125-vcit D.C. ocwer supply system.
Since the reserve battery is subject to the sama surseillance requir:
of the existic; batteries, scecifically Technical Specification 4.8.2.3.2, there is a high cegree of assurance that the reserve battery can perform its safety function, if required.
With regard to the status of the 125-volt D.C. battery chargers, an inconsistency pre 3ently exists in Calvert Cliffs Units 1 and 2 Technical Specifications 3.3.2.3, action statement b.
Each of the 4 125-volt D.C.
buses is powered by a 125-vol' C battery and servicea by 2 full-capacity, safety-grade, battery chargers
' N Technical Specification 3.8.2.3 recuires that-cnly I full cap.
ger is required to be coerable per bus, Technical Specificatien -
action statement b. re;uires tnat remedial acticn be taken when 2 gle battery charger beccTes incperable,
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even if the second battery charger is operatie. Thus, we find that " credit" is not given for the presence of the second enarger en each of the 4 125-volt 0.C. buses. Accordingly, it is appropriate to change Technical Specificaticn 3.8.2.3, action statement b. to require remedial action to be taken only if both 125-volt D.C battery chargers, on a 125-volt 0.C. bus, are inoperable.
Since the remedial action to be taken has not changed, the availability of the 125-volt D.C. system, to perform its safety function, has not been
' changed. The new action statement becomes item "c".
Thefinalissuead5'ressedhereininvolvesthesinglecellvoltagesassociated with the 125-volt D.C. batteries. Each 125-volt battery contains approxi-mately 59 lead-acid cells electrictlly connected in series so as to establish a nominal 125-volt power suppb.
Experience at Calvert Cliffs has shown that, over a pericd of yeans, single cell voltages tend to decrease as a result of various electro-chemical effects.
At the present time, Calvert Cliffs Units 1 and 2 Technical Specificatien 4.8.2.3.2.b.1 requires that:
"The voltage cf each connected celi is > 2.10 volts under float charge and has not decreased more than 0.10 volts from the value observed durir:p the original, acceptance test."
The licensee has found that a call whose voltace is > 2.10 volts but has decreased more than 0.10 volts from its original acce?tance (new) condition is still viable in that it can perform its design function and, in some cases, can be rocharged to a substantial degree.
By referencing the 0._10 volt. criteria to the 50 month performance discharge test, Technical Speci-fication 4.3.2.3.2.e, rather inan the original acceptance test, a ccre reascna le criteria fcr iudging cell viability is permitted. Since the tests wnich actually ce: ermine the abi',ity of the battery :: perfor.- its design function, scecifically the 18 month capacity and 60 month ;erfor-mance discharge tests, ce not chance, no decrease in repuired battery perfernance res 1ts fecm this change.
Accordingly, it is apprc:riate to
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subs:itute :he :nrase, " latest :erformance discha ge test" fcr the chrase "origioal acceptance test (4.S.2.3.2.e)" ir. Technical Specification 4.8.2.3.2.b.l.
Environmental Consideration We have determined that the amendments do not authorize a char-- in effluent tyces or total amounts nor an increase in power level'2ad will not result in any significant environmental impact. Having made this determination, we riave further concluded that the amendments involve an action which is insignificant from the standpoint of environmental impact and, pursuant to 10 CFR $51.5(d)(4), that an enviresrental impact statement or negative declaration and environ-mental impact appraisal neet not be prepared in connection with the issuance of t.ese amendments.
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Conclusion We have concluded, based on the cor.siderations discussed above, that: ~
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(1) because the arendments do not ir.volve a significant increase -
2 in the probability or consequences of accidents previously cons 3dered i
and do not involve a significant decrease in a safety margin, the x
amencments do not involve a significant hazards consideratior., (2) there is reasonable assurance that the health and safety of the public s
will not be endan,gered by operation in the proposed manner, and,(3)
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such activities will be conducted in compliance with the Ccmission's res;1ations and the issuance of these amendments will not de inimical.
to the common defense and security or to the health and safety of the public.
Date: November 2, 1931 p
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- 1. 4 tdtdvall', A.!E. (SG5f), Letter end applicaticn for license amentaent N.
tvihl,.' Denton (EC),.br, 27, 1950.
Lundvall,'s. d. (isb&E), !.L er and application for license amendment u
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2.
t o R.' R. Denten (MC), July 20, i?81.
3.
fiemann,D.L..h,3C),LettertoA.E.Lundvall(BGLE) transmitting
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m licepse scendo:nts 19 a00 5.for Calvert Cliffs 1 and 2, respectively, n
Januatj If., 1977.
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, n 4h Reid, R. W. (>:?.C), Letter to A.-E. Lurtavall (BG&E) transmitting license J
Amendments 4') and-22 for Calvert Cliffs 1 and 2, respectively, July 31, 1979.
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