ML20097F359
| ML20097F359 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 06/08/1992 |
| From: | Beck G PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20097F362 | List: |
| References | |
| NUDOCS 9206150261 | |
| Download: ML20097F359 (5) | |
Text
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PliILADELPIHA ELECTRIC COMPANY j
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. NUCLEAR GROUP HEADQUARTERS 955-65 CHESTERBROOK BLVD.
WAYNE, PA 19087-5691 (215) 640-6000 NUCLEAR ENGINEERINO & SERVICE.S DEPARTMENT June _8, 1992 Docket Nos.
50-277 50-278 License Nos. DPR-44 DPR-56 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 3
Peach Bottom Atomic Power Station, Units 2 &
SUBJECT:
for Temporary Walver of Compliance from the Request
" Minimum Low Technical Specifict.tions Section 3.5.F.1, Pressure Cooling and Diesel Generator Availability" and TS 4.5.F, Minimum Low Pressure Cooling and Diesel Generator Availabilit'f.
Dear Sir:
As discussed with the NRC on June 5, 1992, this revision to our previously submitted request for a Temporary
' Waiver of. Compliance is being submitted to include the approved suspension of testing of the remaining Diesel Generators for-the Changes included in duration of the E-4 Diesel Generator outage.
this revision are indicated by boldface type.
In accordance with the guidance contained in the February 22, 1990. memo from T. E. Murley (Director, Office of Nuclear Reactor Regulation), Philadelphia Electric Company (PECo) requests a Temportry Walver of Compliance from the requirements of Peach Bottom Atomic Power Station, Units 2 & 3 Technical Specifications (TS) Section 3.5.F.1, " Minimum Low Pressure Cooling and Diesel Generator Availability" and TS 4.5.F.1,
" Minimum Low Pressure Cooling and Diesel Generator Availability."
Technical Specification 3.5.F.1 states:
"During any period when one diesel generator is inoperable, continued reactor operation is permissible only during the succeeding seven days unless such. diesel generator is sooner made operable provided that the remaining diesel generators and the low pressure core and containment cooling systems which are powered by the If this requirement l
remaining diesel generators are operable.
t 9206150261 920608 PDR ADOCK 05000277 P
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' June 8, 1992 4
U.S. Nuclear Regulatory Commission Page 2 Temporary Waiver of Compliance an orderly shutdown shall be initiated and the cannot be met, reactor shall be placed in the Cold Shutdown Condition wachin 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />."
TS~4.5.F states: "When it is determined that one diesel generator is inoperable, the operable diesel generators shall be demonstrated to be operable immediately and daily thereafter."
PECo is requesting a Temporary Waiver of Compliance from-these Technical Specification requirements so the E-4 Diesel Generator allowable out of service time can be extended 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> and during the time the E-4 Diesel is not operable, testing in accordance with TS 4.5.F.1 can be temporarily suspended.
The February 22, 1990 memo requerts Licensees to provide the following:
A discussion of the requirements for which a waiver is 1) requested Technical Specification 3.5.F.1 states:
"During any period when one diesel generator is inoperable, continued reactor operation is permissible only during the succeeding seven days unless such diesel generator is sooner made operable the remaining diesel generators and the low provided that pressure core and containment cooling systems which are If powered by the remaining diesel generators are operable.
this requirement cannot be met, an orderly shutdown shall be initiated and the reactor shall be placed in the Cold "When Shutdown-Condition within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />." TS 4.5.F states:
is determined that one diesel generator is inoperable, it the operable diesel generators shall be demonstrated to be operable -immediately and daily thereaf ter."
We are requesting that this seven day period and the suspension of Diesel Generator testing be extended 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> and during the time-the E-4 Diesel is not operable, testing 5
in accordance with TS 4.5.F.1 can be temporarily suspended.
i A discussion of the circumstances surrounding the-situation 2)-
including the need for prompt action, and a description of why the situation could not have been avoided.
The Peach Bottom Atomic Power Station (PBAPS) Emergency Diesel Generator (E-4) was removed f rom service on June 1, 1992 at 00:01 hours to replace all 12 cylinder liners as recommended by the manufacturer.
In addition to the liner the mechanical portion of the normal periodic replacement, The maintenance inspection was scheduled to be performed.
decision to include the mechanical inspection was made in l
order to reduce future unavailability of the E-4 Diesel Generator during its periodic maintenance inspection.
A detailed schedule was developed, extensive mock-up I
training was conducted on 'our training diesel engine, and pre-staging of liners and associated parts was completed i
m.
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3 June 8, 1992 U.S. Nuclear Regulatory Commission Page 3
. Temporary Waiver of Compliance
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l prior to taking the E-4_ Diesel Generator out of service.
1
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The cylinder' liner replacement and mechanical portion of the periodic maintenance inspection would not have required.more
-than the allowable seven days to complete; however, several leaks were identified on the jacket coolant lines and the cylinder inlet adapters and a bearing on the vertical drive of found to be out of tolerance which increased the out was service time and added an estimated 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> to an already aggressive schedule.
Up to the point of hydrostatic testing of the diesel generator, the outage was progressing well and 3
on schedule.
Additional time was required to repair the leaks, replace a bearing on the vertical drive, and perfort additional hydrostatic tests.
Philadelphia Electric is requesting an additional 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> to return the E-4 Diesel CLnerator to service.
The additional time is needed to complete necessary engine run-in tests (36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />) required by the manuf act urer whenever eagine wear-in parts are replaced (e.g. cylinder liners).
3)
A discussion of_ compensatory actions Activities which may challenge the availability of redundant or critical plant equipment have been minimized.
This
~r includes Instrument and Controls (I&C) work, as well as pre"'ntative maintenance on the high and low pressure station batteries and the eme_gency core cooling systems, Emergency Service Water, Emergency Cooling battery chargers, J
Water system and discretionary work at the North and South Substations.
To further assure reliability of the off site power supply the Load Dispatcher responsible for the two incoming supplies has been requested to minimize-switching and other activities which may jeopardize the reliability of the of f-site power supplies.
4)
[_ preliminary evaluation of the safety significance and potential consequences of the proposed request Both units are currently operating at steady state.
Initiating a dual unit shutdown would subject the plant to problems / challenges that operating at steady state conditions would not.
This is especially relevant because PECo believes _ the E-4 Diesel Generator will be available for approximately half of the duration of the extension request and will be fully operable within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> of exceeding the LCO.
If a shutdown were required, both units would be returned to their previous power levels when the Diesel l
l Generator is returned to service.
This power cycling is a j
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U.S. Nuclear Regulatory Commission June 8, 1992 Page 4-Temporary _ Waiver-of Compliance challengo to the plant which could be avoided by the continued steady state operation of both units.
A probabilistic risk assessment has been conducted to determine the increase in the probability of a core damage There is an insignificant increase in the already accident.
extremely low likelihood of a core damage accident with one Diesel Generator out of service for an additional two days.
By waiving the requirements of TS 4.5.F.1 the remaining diesel generators are not subjected to the wear and possible failure mechanisms associated with demonstrating their operability on a daily basis.
Further, because of the high degree of reliability of our diesel generators, we believe that they will be available to respond as designed if they The reliability of the.4Ky system'will be are required.
enhanced because the normal system line up will not be Further, deletion of the accelerated testing is disturbed.
consistent with our pending TS Change Request 88-08 and with Standard TS requirements.
A discussion which iustifies the duration of the request 5)
We are requesting a tcmporary waiver of compliance for an additional two days to the 7 day LCO.
These two days will allow the staf f at Peach Bottom to complete the Diesel Generator maintenance and testing. It is expected that repairs and restoration will be completed by the end of the existing LCO' and the run-in testing will_ take an additional 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.
It should ba nated in comparison that an orderly shutdown and cooldown as required by Technical Specitication 3.5.F would be completed in approximately one day.
6)
The basis for the licensee's conclusion that the request docs not involve significant hazards consideration The proposed temporary waiver of compliance to Technical Spec fication 3.5.F does not involve a significant hazards i
-consideration because operation of Peach Bottom Atomic Power Station with this -change does not:
involve a significant increase in the probability or (1) consequences of an accident previously evaluated.
Continued steady state operation is less of a challenge to equipment and personnel _than a required dual unit The Peach Bottom standby AC power system is shutdown.
designed with suf ficient redundancy such that one diesel generator may be removed from service for testing, inspection, or repairs in the time provided in the current Technical Specifications.
The remaining three diesel generators are still ccpable of carrying sufficient loads to mitigate the consequences of an accident and maintain the Units in the safe shutdown 1
y
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U.S. Nuclear Regulatory Commission June 8, 1992 TemporaryjWaiver of Compliance Page 5 7
Q condition.
Therefore, the probability or consequences of an accident previously. evaluated is not significantly increased by the additional time requested.
(2) create the possibility of a new or different kind of accident from any accident previously evaluated.
The requested temporary waiver does~not-involve any changes to plant equipment or effect any accident precursors and therefore in ar.d of itself does not create the possibility of a new or different kind of accident..
(3) involve a significant reduction in a margin of safety.
The Peach Bottom standby AC system is designed with sufficient-redundancy such that one diesel generator may be removed from_ service for testing, inspection or repairs and the remaining three diesel generators are capable of carrying sufficient loads-to satisfy the Updated Final Safety Analysis Report requirements for shutdown of both units.
Considering this fact, as well as the high reliability of the remaining diesel generators.and off-site power sources, adding two days to:the existing LCO and suspending the testing requirements coes not reduce the margin of safety.
7)
The basis for the licensee's conclusion that the request does not involve irreversible environmental consequences.
The proposed temporary waiver of compliance to the Technical Specifications does not have an environmental impact since the change will not result in any increase in-the amount or result in any change in the type of effluent which may be released off-site, and there will be no significant increase
-in individual occupational radiation exposures.
The Plant Operational Review Committee has reviewed l
-this proposed temporary waiver of compliance and have concluded that it does not involve a significant hazards consideration and b
will not endanger the health and safety of the public.
Very truly-yours, l
G.
J. Beck Manager Licensing Section Nuclear Engineering & Services cc:
T.
T.
Martin, Administrator, Region I, USNRC J.
J. Lyash, USNRC Senior Resident Inspector, PEAPS
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