ML081630203
| ML081630203 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 06/05/2008 |
| From: | Scherer A Southern California Edison Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML081630203 (19) | |
Text
A. Edward Scherer SEDISON SOUTHERN CALIFORNIA Director V 1________ Nuclear Regulatory Affairs An EDISON INTERNATIONAL Company June 5, 2008 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001
Subject:
Docket Nos. 50-361 and 50-362 Response to Request for Additional Information on Battery and DC Sources Upgrades and Cross-Tie License Amendment Request and Replacement Technical Specification Pages San Onofre Nuclear Generating Station, Units 2 and 3
References:
- 1. April 9, 2008 letter from N. Kalyanam (NRC) to R. M. Rosenblum (SCE),
Subject:
San Onofre Nuclear Generating Station, Units 2 and 3 - Request for Additional Information on Battery and DC Sources Upgrades and Cross-Tie License Amendment Request (TAC NOS.
MD8213 and MD8214)
- 2. November 30, 2007 letter from B. Katz (SCE) to Document Control Desk (NRC),
Subject:
Docket Nos. 50-361 and 50-362, Proposed Change Number (PCN)-548, Revision 3, Battery and DC Sources Upgrades and Cross-Tie, San Onofre Nuclear Generating Station, Units 2 and 3
Dear Sir or Madam:
By letter dated April 9, 2008, the Nuclear Regulatory Commission staff issued a request for additional information (Reference 1) regarding Proposed Change Number (PCN) 548, Revision 3, Battery and DC Sources Upgrades and Cross-Tie (Reference 2).
Enclosure 1 provides Southern California Edison's (SCE's) response.
SCE's responses to NRC Questions 2 and 3 require two changes to the previously submitted proposed Technical Specification (TS) pages. Enclosure 2 provides the required replacement TS pages for Attachments C, D, E, and F of PCN 548, Revision 3 (Reference 2). No other changes are required. There is no change to the No Significant Hazards Evaluation submitted with Reference 2 as a result of these changes.
P.O. Box 128 San Clemente, CA 92674
Document Control Desk June 5, 2008 There are no new commitments contained in this letter or its enclosures.
The draft TS bases require changes associated with the responses in Enclosure 1 but are not included in this letter.
If you have any questions or require additional information, please contact Ms. Linda T.
Conklin at (949) 368-9443.
I declare under penalty of perjury that the foregoing is true and correct.
Executed on 4 /Alaw
Enclosures:
- 1. Response to Request for Additional Information on Battery and DC Sources Upgrades and Cross-Tie License Amendment Request
- 2. Replacement Technical Specification pages for Attachments C, D, E, and F of PCN-548, Revision 3 cc: E. E. Collins, Regional Administrator, NRC Region IV N. Kalyanam, NRC Project Manager, San Onofre Units 2 and 3 G. G. Warnick, NRC Senior Resident Inspector, San Onofre Units 2 and 3 S. Y. Hsu, California Department of Public Health, Radiologic Health Branch
Enclosure 1 Response to Request for Additional Information on Battery and DC Sources Upgrades and Cross-Tie License Amendment Request
NRC Question 1:
On page 20 of the license amendment request (LAR), the licensee stated that the spare battery charger is to be connected to a diesel-backed source in less than or equal to 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> if non-i E power is lost. Please describe the basis for the 4-hour Completion Time and how this time constraint will be reflected in SONGS licensing basis.
SCE Response:
The 4-hour time limit to connect the spare battery charger to a diesel-backed source is based on the Class 1E battery design for the coping duration of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> for Station Blackout and is described in the proposed SONGS Technical Specification (TS) bases.
NRC Question 2:
The licensee has requested replacing the specific value for existing Surveillance Requirement (SR) 3.8.4.6 with the word "rated." Please provide the basis for the proposed change.
SCE Response:
Based on phone discussion with NRC staff, SCE proposes to add two notes to SR 3.8.4.2 to specify the rated amps of the two different sizes of battery chargers. (Note: Existing SR 3.8.4.6 is modified and renumbered to SR 3.8.4.2). Using the existing SONGS TS SR wording, new text is shown underlined and deleted text is shown in strikeout, as follows:
--------- NOTES ----------------
Credit may be taken for unplanned events that satisfy this SR.
- 1. The dedicated battery charger is rated at 300 amps.
- 2. The swing battery charger is rated at 400 amps.
Verify each battery charger supplies > rated 3Wo amps at > the minimum established float voltage 1-29-V for > 8 1-2 hours.
This change is provided in the replacement TS pages in Enclosure 2.
NRC Question 3:
On page 28 of the LAR, the licensee stated that they do not intend to use separate service and performance tests for the new 1800 amp-hour rated batteries. However, the service and performance tests are still identified in the proposed revised TS for SR 3.8.4.4 and SR 3.8.6.7. Explain the apparent discrepancy.
Page 1 of 5
SCE Response:
SCE previously proposed using the standard TS wording for both the 1260 amp-hour and 1800 amp-hour rated batteries. As stated in the PCN-548, Revision 3 submittal, the modified performance discharge test was the test intended to be performed on 1800 amp-hour rated batteries. Based on phone discussion with NRC staff, SCE will reword SR 3.8.4.4 to use, in the future, only the modified performance discharge test for the 1800 amp-hour rated batteries. SR 3.8.4.4 is shown as new underlined text as follows:
NOTES---------------
- 1. The modified performance discharge test in SR 3.8.6.7 will be performed for batteries rated at 1800 amp-hours.
- 2. Completed service tests and performance discharge tests remain valid until the new modified performance discharge test is performed at its required frequency.
Verify capacity of the 1800 amp-hour rated battery is adequate to supply, and maintain in OPERABLE status, the required emergency loads for the design duty cycle when subiected to a modified performance discharge test.
This change is provided in the replacement TS pages in Enclosure 2.
NRC Question 4:
On page 32 of the LAR, the licensee stated that the accuracy and reliability of the float current reading will generally hold true over the expected life of the batteries (i.e., 20 years).
Please explain if the TS float current value will remain valid for the life of the plant.
SCE Response:
The TS float current value will remain valid until the batteries are replaced. The float current value is dependent on the battery manufacturer and the rated capacity of the installed battery.
NRC Question 5:
Please describe the pilot cell selection process utilized at SONGS.
SCE Response:
Repetitive Maintenance Orders for SONGS Units 2 and 3 currently require annual pilot cell redesignation. The next consecutively higher numbered cell in the battery bank is chosen for this designation.
Page 2 of 5
As part of implementation of this License Amendment Request, pilot cell selection is being modified to select the two lowest voltage cells in the battery. This is consistent with current industry guidance.
NRC Question 6:
Please describe how electrical isolation will be maintained in accordance with Regulatory Guide 1.75, "Physical Independence of Electric Systems," between non-Class 1E and Class 1E circuits when an alternate means (i.e., non-Class 1E spare battery charger) is maintaining the charge on the Class 1E battery. If double isolation (e.g., two breakers in series, a breaker and a fuse, or a breaker supplied with a loss-of-offsite power signal) is not used, please provide a detailed discussion on how a fault on the non-Class 1 E electrical circuit will not propagate to the Class 1E electrical circuit.
SCE Response:
SONGS does not credit double isolation to isolate a spare battery charger from a Class 1 E DC subsystem. Spare battery chargers were procured as Class 1E qualified equipment and are equivalent in rating and performance to the Class 1 E dedicated battery chargers. Each spare battery charger is equipped with a current limit feature which qualifies it as an acceptable isolation device per IEEE Standard 384 and Regulatory Guide 1.75.
NRC Question 7:
Please describe the load profile that will be used to test the batteries (i.e., independent subsystem or cross-connected subsystems).
SCE Response:
For the 1800 amp-hour batteries, the same-train cross-connected load profile will be used for testing. For the 1260 amp-hour batteries, the independent subsystem load profile will be used for testing.
NRC Question 8:
The licensee proposed revising the time period that the battery chargers are capable of recharging the batteries from 12 to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Please describe the basis for the original 12-hour duration and any impact the increased time duration may have on the ability of the chargers to perform their design function.
Page 3 of 5
SCE Response:
The 12-hour duration is from the original approved licensing basis for the plant. The Updated Final Safety Analysis Report (UFSAR) for SONGS 2&3, Section 8.3, Onsite Power Systems, identifies this as a design feature which complies with the requirements of Regulatory Guide (RG) 1.32, Criteria for Safety-Related Electric Power Systems for Nuclear Power Plants.
The proposed change to the 24-hour charging duration complies with the same RG 1.32 requirements and therefore is also acceptable. The battery chargers can operate continuously at rated output current. Therefore, the 24-hour charging duration will allow the chargers to maintain their ability to perform their design function.
NRC Question 9:
On page 6 of the PRA attachment I, it was stated "the CCF probabilities for batteries are modified upward for corrective maintenance." However, no information/justification was provided about the selection of the magnitude of this increase. Please provide the necessary justification.
SCE Response:
The SONGS Probabilistic Risk Assessment (PRA) fault tree model for each of the four Class 1E batteries has basic events for independent failure and common-cause failure (CCF) combinations with the other batteries. SONGS models CCFs using the alpha factor method.
The equation below represents a battery's independent failure probability and its common-cause failure probability with other batteries (see Note below).
P Battery Failure = P Independent Failure + P CCF, 2 batteries
= 4.OOE-4 + 3.15E-6
- Where, P CCF, 2 batteries = P Independent Failure
- cXCCF, 2 batteries = 4.00E-4
- 7.87E-3
= 3.15E-6 Note: Terms for three and four battery CCF are similar and are in the SONGS PRA model but are not shown here for simplicity of explanation of SONGS CCF treatment.
However, if another battery is out-of-service for corrective maintenance, the independent failure probability of the out-of service battery in the CCF calculation (P CCF) for the available battery is changed from 4.OOE-4 to 1.0.
P CCF, Corrective = P Independent Failure
- aCCF, 2 batteries = 1 .0
- 7.87E-3
= 7.87E-3 Page 4 of 5
In this case, instead of a normal CCF failure probability for two batteries of 3.15E-6, the CCF probability for the corrective maintenance case increases to 7.87E-3. Similar calculations are performed for CCF of three and four batteries.
NRC Question 10:
The new installed batteries have higher capacity compared to the old ones. Is there any expected increase in the hydrogen production in the battery room during the effective lifetime of the new batteries? If yes, are there any planned changes in SONGS fire PRA or the ventilation system in the battery room?
SCE Response:
During normal battery operation, including discharge, the amount of hydrogen produced is insignificant. Hydrogen is produced during equalizing and/or recharging of the battery, as it approaches a full charge. The new, larger 1800 amp-hour rated batteries produce more hydrogen than the smaller rated batteries. However, evaluation of the battery rooms with the larger batteries concluded that no changes were required to the ventilation systems or the hydrogen detector setpoints.
Because there were no changes to the ventilation systems or the hydrogen detector setpoints, the SONGS fire PRA was not changed.
Page 5 of 5
Enclosure 2 Replacement TS pages for Attachments C, D, E, and F to Enclosure 3 of PCN-548, Revision 3
ATTACHMENT C Proposed Change Notice (PCN) 548, Rev. 3 Proposed Technical Specification pages, Underline and Strikeout, Unit 2 Replacement TS pages 3.8-26a, 3.8-26b
DC Sources--Operating 3.8.4 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.8.4.4 Reiiuve visible Lbt illdl LUIrU>iul I ver iFy 24 ,iluntItr c ll ta a t1l~rd l d Ii d duld trdldLylhL, Lr i dr* cute lid]Laetu LUdLed L LI I dI wiIUil 771i-LUIr uI I IIlia Lt! Iae .
SR 3.8.4.5 Veri Fy LnIIeLLWuil Ire 1bLdllLe ib 24 lnuiltLTi
-*-5iGx u11ii Fur 1IfLte -L0I1 LUIIIICLLeiuI, 14t50 1O
- 15exiO* uliiFur ul.ii Fur iiiI Le*r-r Lenr-L Lk e cUnIieL uiun LUIIIIei.L iuI u-r'd-l GFru U iO- Ler ill LUIIIICLL uII .
SR 3.8.4.2f ------------------- NOTES-------------------
-C tdoL i dy be tdktnn fut uJ drillel d tvtrLrt LIraL ZQLi L y LlniP SR.
- 1. The dedicated battery charger is rated at 600 amps.
- 2. Mhe swln battery charger *is rated at 4UU amps..
Verify each battery charger supplies > 24 months,,
rated 3Ou amps at > the minimum estabTished Tioat voltage t29V-Tor : 8 T_- hours.
SR 3.8.4.3 ------------------- NOTE-----------------
t.- The battery performance discharge test inM I.0.7*5b./ may De perTormea in lieu of SR 3.8FT.4t3 once per 48 months for batteries rateU at 1260 amp-hours:
- 2. Tisl SuivillIiLc shall nut be perfuriiied in MODE 1,2,3, ur 4.
- 3. CrediLt i,,y be Ldke,, Fur ui dilld even Lt LIciL Zal_ Fy Llhis SR.
Verify bdLca[Y capacity of the 1260 am - 24 months hour rated battery is adequate to supply, and maintain in O'ERABLE status, the required emergency loads for the design duty cycle when subjected to a battery service test.
(continued)
SAN ONOFRE--UNIT 2 3.8-26a Amendment No. t2t
DC Sources--Operating 3.8.4 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY i
SR 3.8.4.4 ---------- NOTES- -------------------
- 1. The modified performance discharqe test in KR. 6. .b./ will De -erTormea tor oatteries rated at IbUU amp-hours.
- 2. Completed service tests and perTormance discharqe tests remain valia untii tne new moaiTiea pertormance discharqe test is perTormea at its required Trequency.
Verify capacity of the 1800 amp-hour rated 30 months pattery is adequate to supply and maintain in UFLKAbLL status. the required emergency l~oads Tor Thle design duty cy cle whlen sub,]ected to a moditied perTormance dlscharge test.
ýK i 6 4 6 -------------------- M01 rý -------------------
t1 T! ii, SUrVt Il llc L,(2 bild 1 1 iuL bt IUI lllU Ii H iUUL 1, L.C, J , UI '-t.
- 2. ei ed i t iidy- -be takeni fui Ullpi dHied Vfvelltý tlldL ý,dL ffy tliti 5 R.-
V12r ily bdLtery Udd~ltiy 7, -2!6M6' Ul tilt i1iCHiICictLLUi Ui 'ý I CIL Ilily .V Iicil ýýU UJ-LLU LU C1 t I U!IidlllCl(t U I ý,(Hdf Yt Ltfý L.
NOTE-----. -
bily dpp*iliLdble Whiel batteiy degyddi.Liul U1 ild r edLled 85t uf the expeLted t? I ulLtfe SAN ONOFRE--UNIT 2 3.8-26b Amendment No. tff
ATTACHMENT D Proposed Change Number (PCN) 548, Rev. 3 Proposed Technical Specification pages, Underline and Strikeout, Unit 3 Replacement TS pages 3.8-26a, 3.8-26b
DC Sources--Operating 3.8.4 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.8.4.4 Remouve v ible Len,,ind] causu iun,, velriFy 24 ,runtf*
UL l 1 Lu Ull 1 dld teir ,inal culrlLL u,, adiC l ta,, anrd LiylL, aId It ( ucu Led ill,I dIILi-Lu ,u U I I I ,iIaLtI a .
SR 3.8.4.5 Ve, iFy 15l0U 1lLy,- 4 uliii tiuLLiuI Fur I iie Ler-cell sita IcIt in cu,,,,ec Luiu,, 24-fulftT,
~-150ti0
_ u uhli,, Fur i,,ter -i ak cU,,,,ecL Du,,,
ulg FuI in , tr-Li cuII.ecLiu ,, ,
I - 1 1 U,,507 Fur LI, i, ,al cu nuilect Li u,,s SR 3.8.4.2t -------------------- NOTES------------------
Crftdi L ,,,ay be take,, Fur-ull ai,,iid events LIaL Li L IFy L,Iis SR.
- 1. The dedicated battery charger is rated at 300 amps.
- 2. The swing battery charger is rated at 400 amps.
Verify each battery charger supplies > 24 months rated 3 amps at > the minimum estabTished TT6aT voltaqe t29-V-tor > 8 t hours.
SR 3.8.4.3 ------------------- NOTES----------------
. The battery performance discharge test in SR 3. . may be pertormed in "li-e-u of SR 3. BTzFt._.3 once per 48 months for batteri-es rated at 1260 amp-hours.
- 2. TII is Sun veilldnaLce shall ,nuL be t I fu, I,d MOD '4 1,,1 14.ll
- 3. Cr~ iL ,',y b* Lak , uT,,l ,,S eve,,ts tIa t Sd i y tLI,i SR.
Verify haL-y capacity of the 1260 ami- 24 months hour rated battery is adequate to supply, and maintain in UFERABLE status, the required emergency loads for the design duty cycle when subjected to a battery service test.
(continued)
SAN ONOFRE--UNIT 3 3.8-26a Amendment No. ttfr I
DC Sources--Operating 3.8.4 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.8.4.4 ----------------------
NOTES----------
- 1. The modified performance discharqe test in Ml6 .0.b.1 Will De perTormed Tor Datteries rateo at ibuu amp-nours.
- 2. Completed service tests and oerTormance discharqe tests remain valid untll tne new mOdlTied DerTormance discharoe test is Dertormed at its reauired Treauency.
Verify capacity of the 1800 amp-hour rated 30 months battery is adequate to supply, and maintain in OPERABLE status, the required emergency loads Tor the design duty cycle when subiected to a moditied Dertormance dischar-e test 4-It r?
Jl\
IT J.U*
x " x
-r
- U
II -
fu I I.
- i. 1llllS 3UrV I I IcI LC S2lldl.1 IIUL UW p-, Furied in MODE 1, 2., 3, ur 4.
fL * ~ , I U IL lildy Ut LdRCttII I UI UlpI CHIIItU eveillt thiat satis fy this SR.-
Ve fy bdattry capacity is) - 80t of t1T IIdIU fdcLtU t~r ' r)dt i y VVIiel s)ubjUcLed Lu d 60 ,,un,-h-t Perl Ful ricirice d i L!Idf Y LL. tt, Oily dpPl iLdble when baifLLery d i, ada 1 ,,1 uVI id l I dciled 85t u tie expectLed 1*-Fe SAN ONOFRE--UNIT 3 3.8-26b Amendment No. ttt
Attachment E Proposed Change Number (PCN) 548, Rev. 3 Proposed Technical Specification pages, Unit 2 Replacement TS page 3.8-25
DC Sources--Operating 3.8.4 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.4.1 Verify battery terminal voltage is greater 7 days than or equal to the minimum established float voltage.
SR 3.8.4.2 ----------------- NOTES----------------
- 1. The dedicated battery charger is rated at 300 amps.
- 2. The swing battery charger is rated at 400 amps.
Verify each battery charger supplies 24 months
Ž rated amps at > the minimum established float voltage for Ž 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
SR 3.8.4.3 ------------------NOTE-----------------
The battery performance discharge test in SR 3.8.6.7 may be performed in lieu of SR 3.8.4.3 once per 48 months for batteries rated at 1260 amp-hours.
Verify capacity of the 1260 amp-hour rated 24 months battery is adequate to supply, and maintain in OPERABLE status; the required emergency loads for the design duty cycle when subjected to a battery service test.
SR 3.8.4.4 ----------------- NOTES------------------
- 1. The modified performance discharge test in SR 3.8.6.7 will be performed for batteries rated at 1800 amp-hours.
- 2. Completed service tests and performance discharge tests remain valid until the new modified performance discharge test is performed at its required frequency.
Verify capacity of the 1800 amp-hour rated 30 months battery is adequate to supply, and maintain in OPERABLE status, the required emergency loads for the design duty cycle when subjected to a modified performance discharge test.
SAN ONOFRE--UNIT 2 3.8-25 Amendment No.
Attachment F Proposed Change Number (PCN) 548, Rev. 3 Proposed Technical Specification pages, Unit 3 Replacement TS page 3.8-25
DC Sources--Operating 3.8.4 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.4.1 Verify battery terminal voltage is greater 7 days than or equal to the minimum established float voltage.
SR 3.8.4.2 ----------------- NOTES-----------------
- 1. The dedicated battery charger is rated at 300 amps.
- 2. The swing battery charger is rated at 400 amps.
Verify each battery charger supplies 24 months
Ž rated amps at > the minimum established float voltage for Ž 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
SR 3.8.4.3 ----------------- NOTE-----------------
The battery performance discharge test in SR 3.8.6.7 may be performed in lieu of SR 3.8.4.3 once per 48 months for batteries rated at 1260 amp-hours.
Verify capacity of the 1260 amp-hour rated 24 months battery is adequate to supply, and maintain in OPERABLE status, the required emergency loads for the design duty cycle when subjected to a battery service test.
SR 3.8.4.4 -----------------NOTES------------------
- 1. The modified performance discharge test in SR 3.8.6.7 will be performed for batteries rated at 1800 amp-hours.
- 2. Completed service tests and performance discharge tests remain valid until the new modified performance discharge test is performed at its required frequency.
Verify capacity of the 1800 amp-hour rated 30 months battery is adequate to supply, and maintain in OPERABLE status, the required emergency loads for the design duty cycle when subjected to a modified performance discharge test.
SAN ONOFRE--UNIT 3 3.8-25 Amendment No.