ML20207C954
| ML20207C954 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 12/22/1986 |
| From: | Berry K CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20207C957 | List: |
| References | |
| NUDOCS 8612300288 | |
| Download: ML20207C954 (4) | |
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@Mgg Consumers Power x aa ta w s rry Director Nuclear Licensing M M M W FCC General offees: 1945 West Parnall Road, Jackson, MI 49201 e (517) 788-1636 December 22, 1986
- Director, Nuclear Reactor Regulation US Nuclear Regulatory Commission Washington, DC 20555 DOCKET 50-155 - LICENSE DPR BIG ROCK POINT PLANT -
TECHNICAL SPECIFICATION CHANGE REQUEST -
STATION BATTERY SERVICE TEST Attached are three (3) originals and thirty-seven (37) conformed copies of a request for change to the Big Rock Point Technical Specifications. This change is being requested to resolve a contradiction of Station Battery Surveillance requirements and SEP Topic acceptance criteria as reported to the NRC in voluntary LER 86-004.
This proposed change revises the Station Battery design time interval from the incorrect eight hours to two hours.
Big Rock Point will implement this proposed change into technical specification surveillance testing scheduled to be completed during the 1987 refueling outage.
Pursuant to 10CFRl70.12(c) a check in the amount of $150.00 is remitted with this application.
$b m Y U 0 Kenneth W Berry Director, Nuclear Licensing CC Administrator, Region III, USNRC NRC Resident Inspector - Big Rock Point Attachment
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8612300288 861222 DR ADOCK 05000155 W[C[t8Ck PDR
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CONSUMERS POWER COMPANY Docket 50-155 Request for Change to the Technical Specifications License DPR-6 For the reasons hereinafter set forth, it is requested that the Technical Specifications contained in the Facility Operating License DPR-6, Docket 50-155, issued to Consumers Power Company on May 1, 1964, for the Big Rock Point Plant be changed as described in Section I below:
I.
Changes A.
Section 11.4.5.3.A.I.(h)
Revise the last sentence of Section 11.4.5.3.A.1(h) to read as follows:
"The design time interval for the RDS batteries is one hour and two hours for the station battery."
B.
Section 11.3.5.3/11.4.5.3 bases Revise the sixth and seventh sentences of the sixth paragraph of Section 11.3.5.3/11.4.5.3 bases to read as follows:
"The Station Battery has adequate capacity to supply and maintain in an operable status all of the emergency loads during a Loss of Coolant Accident plus an assumed Loss of AC Power for two hours."
II.
Discussion Big Rock Point License Amendment 10, dated June 4, 1976 added station battery service testing requirements to the Big Rock Point Technical Specifications.
In March 1986, an internal QA review raised a concern as to whether or not we were explicitly complying with the station battery service test surveillance requirement.
Retiew and evaluation of this. concern determined the following:
A.
The initial station battery service test was conducted in August, 1977. This test simulated a 61-minute load profile of Loss of Coolant Accident loads.
B, The 61-minute load profile was based on the original battery sizing analysis which assumed a Loss of Coolant Accident coincident with a Loos of Offsite Power.
It also assumed a maximum time without AC power of one hour.
C.
During review of the initial station battery servic test results it was determined that the 61-minute load profile was the correct load profile and it did verify that battery capacity is adequate to supply the emergency loads for its designed time interval. Action TS0B1286-0177-NLO4
Big Rock Point Plant-2 TSCR - Station Battery Service Test was initiated to submit a Technical Specification change, however, this action was not followed through to completion.
D.
A basis for why the eight hour design time interval was added to the Technical Specification could not be determined. Neither our change requesting Amendment 10 nor the NRC safety evaluation which issued Amer.dment 10 discussed a basis for the eight hour requirement. It appears that the eight hour requirement was added during NRC review of our change request but the basis for doing it
'did not get documented in the safety evaluation.
E.
The station battery service testing requirements were also reviewed under Systematic Evaluation Program Topic VIII-3.A.
This review concluded that the station battery service testing requirements satisfy modern licensing criteria. As stated In the Technical Evaluation Report for this topic, the acceptance criteria for Big Rock Point was a two hour battery service test. This conclusion may have been reached erroneously on the basis of the Technical Specification wording.
As a result of the above findings, Consumers Power Company concluded that the eight hour requirement was incorrect. We further concluded that the 61-minute load profile was the correct load profile and that battery service testing to this load profile does verify that the battery capacity is adequate to supply its actual emergency loads for the time interval for which it was designed.
To resolve the difference between the SEP Topic acceptance criteria and the service test we have been conducting at approximately annual intervals utilizing the 61-minute load profile, Consumers Power Company developed a new station battery load profile. The new profile assumes a Maximum Credible Accident (large break LOCA with Loss of Offsite Power) occurs at time zero and that a source of AC power is restored at the two hour point in time. This two hour assumption meets current licensing guidance utilized in the SEP Topic VIII-3.A evaluation. This produces a 121 minute load profile (120 minutes without AC power plus one minute to restore breaker lineup). As a result of revising the load profile, a battery sizing calculation was performed in accordance with IEEE Std. 485-1978 which shows that the installed Exide, Ironclad EHGS-17, 580 Ampere-hour battery is correctly sized to carry the loads required by the new load profile.
Based on these findings Consumers Power Company has concluded that the eight hour design time interval requirement is incorrect and therefore is requesting that the number be changed to two hours. The change to the basis section reflects the assumptions used for generating the new load profile.
III.
Analysis of No Significant Hazards Consideration This proposed change corrects an error in the technical specifications l
and does not involve the modification of any equipment or methods for j
conducting required testing. The original station battery design and sizing assumed a source of AC power was restored within one hour.
TSOB1286-0177-NLO4
Big Rock Point Plant 3
TSCR - Station Battery Service Test Subsequent to the original battery analysis, several loads have been removed from the battery, the battery has been replaced with a larger capacity battery (500 ampere-hour to 580 ampere-hour) and a second source of offsite AC power has been made available to the plant.
Historically Big Rock Point has not experienced a complete loss of AC which has lasted for longer than approximately 30 seconds (time it takes emergency diesel to start) over 26 years of operation. These factors combined allow the loss of'AC power assumption to be increased from one hour to two hours and the station battery load profile to be increased from 61 minutes to 121 minutes without significantly increasing the previously evaluated probability or consequences of an accident.
This proposed change increases the design time interval from one hour to two hours and does not alter the functional requirements of the battery system and its relationship to other plant systems, thus it does not create the possibility of a new or different kind of accident from any accident previously evaluated. Also the proposed change does not involve a significant reduction in a margin of safety.
Increasing the design time interval the plant can go without AC power from one hour to two hours increases the margin of safety. Consequently, this proposed change does not involve a significant hazards consideration.
IV.
Conclusion The Big Rock Point Plant Review Committee has reviewed this Technical Specification Change Request and has determined that this change does not involve an unreviewed safety question and therefore involves no significant hazards consideration.
This change has also been reviewed under the cognizance of the Nuclear Safety Board. A copy of this Technical Specification Change Request has been sent to the State of Michigan official designated to receive such Amendments to the Operating License.
CONSUMERS POWER COMPANY mg( " l4 By
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F%Buckman,VicePfesignt Nuclear Operations Sworn and subscribed to before me this 22nd day of December, 1986, h t ) Y /
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'llelen 1 Dempski, Not4ry Public Jackson County, Michigan My commission expires October 12, 1987 TSOB1286-0177-NLO4
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