ML20083C087
| ML20083C087 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 12/16/1983 |
| From: | Howe P CAROLINA POWER & LIGHT CO. |
| To: | Vassallo D Office of Nuclear Reactor Regulation |
| References | |
| LAP-83-575, NUDOCS 8312220101 | |
| Download: ML20083C087 (7) | |
Text
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Carolina Power & Ught Company DEC 161983 Director of Nuclear Reactor Regulation At tention:
Mr. D. B. Vassallo, Chief Operating Reactors Branch No. 2 Division of Licensing United States Nuclear Regulatory Commission Washington, DC 20555 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NO. 2 DOCKET NO. 50-324 LICENSE NO. DPR-62 REQUEST FOR LICENSE AMENDMENT BATTERY CAPACITY TEST ADDITIONAL INFORMATION
Dear Mr. Vassallo:
In a letter dated December 7,1983 (LAP-83-564) Carolina Power &
Light Company (CP&L) requested a change to the Technical Specifications (TS) for the Brunswick Steam Electric Plant (BSEP) Unit No. 2.
This revision af fects the surveillance requirements for the 125 volt battery (bank 2A-2) contained in TS 4.8.2.3.2, paragraph d.2.a.
Following several telephone conversations with your staf f, CP&L was asked to provide some additional information concerning the above submittal.
Please find enclosed the information you requested.
Should you have any questions concerning this letter, please do not hesitate to contact a member of our licensing staff.
"our very t uly W P. W. Ilowe Vice President Brunswick Nuclear Project PFC/ccc (9083PPC)
Enclosure cc:
Mr. D. O. Myers (NRC-BSEP)
Mr. J. P. O'Reilly (NRC-RII)
Mr. M. Grotenhuis (NRC) 8312220101 831216 PDR ADOCK 05000324 p
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411 Fayetteville Street
- P. O. Box 1551
- Raleigh, N C. 27602 g
REQUEST FOR LICENSE AMENIHENT (83TSB37)
BATTERY CAPACITY TEST ADDITIONAL INFORMATION f
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Question 1: Please provide a chronulogy of the events which lead to 1) the replacement of battery 2A-2 and 2) the subsequent license amendment request.
i An swer:
Please find below a detailed sequence of events from October 23, 1983 to December 11, 1983:
Sequence of Events - BSEP Battery 2A2 Pre Outage 10/23 Rattery placed on Equaliser Charge 10/26 Battery placed on float i
Outage 11/9 Battery placed on Equalizer Charge 11/12 Battery placed on float 11/17 Battery tested - f ailed PT Test was run twice One cell was bad and was subsequently replaced Battery placed on 120 hour0.00139 days <br />0.0333 hours <br />1.984127e-4 weeks <br />4.566e-5 months <br /> (5 day) equalizer charge 11/20 Problems developed with the battery charger - Charge interrupted Power Amplifier Board replaced Equalizing charge resumed f
L 11/23 Battery placed on float 11/25 Replacement cell f ound to be not responding well Although within specification, cell replaced for a second time on vendor recommendation Battery placed on float 11/26 Battery tested - f ailed PT Test was run twice t
I 11/27 Task force assembled - Three parallel paths embarked upon 1.
I&C and Engineering began procurement of a new battery 2.
Vendor recommended deep cycle test.
Deep cycle was initiated with 120 hour0.00139 days <br />0.0333 hours <br />1.984127e-4 weeks <br />4.566e-5 months <br /> equalizer charge
'3.
Engineering began a review of the current Technical Specification 11/27 - New Battery was located 11/28 Preliminary review of battery specifications conducted Purchase Order was issued Vendor told to ship the battery (9083PPC/ccc)
11/29 QA and Engineering flew to the f actory in Ft. Smith, Arkansas to conduct receipt inspection prior to shipment 11/30 Battery shipped by truck (Vendor recommended not to use air f reight) 12/2 Battery received and installed 12/3 Battery tested - f ailed PT Replaced five cells on vendor's recommendation Reworked interconnections 12/4 Tested battery - f ailed PT On vendor's recommendation placed on equalizer charge Mini-test to be run every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> (15-20 second discharge) 12/5 Mini-test run Very little improvement noted - would never reach point of passing the PT 3
Vendor recommended a deep cycle discharge 12/6 Mini-test run at 1085 amps Marginal results on 3 tests Engineering evaluation of Technical Specification complete Initiated action for Technical Specification relief 12/7 initiated deep discharge and subsequent equalizer charge One cell failed af ter one hour and was replaced Request for Technical Specification change signed out of CP&L 12/7 Battery placed on equalizer charge 12/10 Battery tested - failed PT at 1086 amps (1074.9 amps + 1%)
12/11 Decided to obtain constant amperage battery charger (vice constant voltage type) and perform a third deep cycle to complete preconditioning.
(9083PPC/ccc)
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Question 2: In a telecon with Mr. S. D. MacKay (USNRC-NRR) CP&L was asked to provide some additional information concerning Attachment 1 to the December 7, 1983 letter.
In particular, CP&L was asked to clarify the analyses for item 2 and 3 of the above attachment.
An swers :
Item #2: To clarify further the information presented in the basis for deletion of this load the following points should be noted:
a)
E41-F007 is always open except when testing the F006 valve.
Testing of the F006 valve is only performed during cold shutdown.
b)
Under no circumstances would the F007 be closed and the F008 and F011 be open at the same time. The worst case current draw would be if the F008 and F011 were open and a trip signal is received to close these valves.
During this period the F007 would receive the same trip signal to open.
Since the F007 valve would already be open, the current drawn by the F007 valve may be deleted.
c)
Indication lights are provided in the control room for all of the above listed valves.
d)
In addition to indications provided in the control room, the Brunswick Procedures require independent verification of valve positions for valves that have been operated af ter the performance of periodic tests on safety related systems.
Item #3: To clarify further the information presented in the basis for deletion of this load the following points should be noted:
a)
E41-F041 and E41-042 are normally closed valves which will open on one of the following two conditions:
1) low CST level
- 2) high torus level U ing the most conservative scenario, the open setpoints for these valves s
would be reached after the first 60 seconds.
Because the current drawn by these two valves is not present during this time period, they can be deleted from the 1 minute period profile.
b)
Indicating lights are provided in the control room for these two valves.
c) In addition to indications provided in the control room, the Brunswick Procedures require independent verification of valve positions for valves that have been operated after performance of periodic tests on safety related systems.
In conclusion, although items 2 and 3 do not have electrical logic interlocks, the postulated worst case system parameters positively ensures that these loads will not exist during the first 60 seconds following initiation of the event.
(9083PPC/ccc)
Question 3: What are the long term implications of the deep cycling (pre-conditioning) with respect to having it as a necessity to pass the profile test.
An swer: Per conservations with the battery vendor, the deep cycling being performed on the 2A2 battery bank is to continue the pre-conditioning that typically would have occurred at the vendor site.
The nominal pre-conditioning at the factory would have included four deep discharge cycles. The batteries on site were cycled two times at the factory. The third deep cycle is presently in progress at BSEP Unit No. 2.
With the technical specification revision it is expected that a total of 3 cycles will be satisfactory for successful completion of the profile test.
Preconditioning permanently alters the battery and is not a prerequisite to satisfactorily perform subsequent profile tests.
Briefly, the preconditioning activities discharge the battery and then recharge the battery at a constant amperage value. Maintaining the constant amperage causes increased agitation of the electrolyte at the battery plate surfaces and increases the porosity of the battery plates, hence increasing the ef fective surf ace areas. For electrolyte reaction as such, this increased porosity is a permanent material change.
(9083PPC/ccc)
Question 4: Provide a brief schedular history of Surveillance Requirement 4.8.2.3.2.d.2.a.
Answer: The above surveillance requirement was successfully performed on February 8,1982. This surveillance requirement is required to be performed, while shutdown, every 18 months. Therefore, the next due date would have been August 8, 1983. However, on August 8,1983 the BSEP Unit No. 2 was operating and the surveillance test could not be performed.
Since the next schedule outage was planned for November 1983, the surveillence requirements was delayed per TS 4.0.2 (TS 4.0.2.a allows a 25% extension to the surveillance interval). The extension would allow the surveillance requirement to be p.9rformed on or before December 23, 1983.
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