ML20073J987
| ML20073J987 | |
| Person / Time | |
|---|---|
| Site: | Braidwood  |
| Issue date: | 05/16/1994 |
| From: | Saccomando D COMMONWEALTH EDISON CO. |
| To: | Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| NUDOCS 9410070243 | |
| Download: ML20073J987 (9) | |
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C:mmsnw:alth Edisen Braidwood Nuclear Power Station Route *1, Box 84 Braceville, Illinois 60407 Telephone 815/458-2801 May 16, 1994 Mr.
J. B. Martin l
Regional Administrator U.S. Nuclear Regulatory Commission Region III 801 Warrenville Road Lisle, Illinois 60532-4351
Subject:
Braidwood Station Unit 1 Request for Issuance of Notice of Enforcement Discretion to Technical Specification 3.8.1.1 NRC Docket Number 50-456
Dear Mr. Martin:
The purpose of this letter is to document the results of a teleconference between Commonwealth Edison Company (CECO) and the Nuclear Regulatory Commission (NRC) staff of May 16, 1994, in which CECO requested issuance of a Notice of Enforcement Discretion from Technical Specification (TS) 3.8.1.1 Action Statement (c) for Braidwood Unit 1.
At the time of the teleconference, Unit 1 was in Mode 1 and Unit 2 was in Mode 5.
On May 15, 1994, at 2123 hours0.0246 days <br />0.59 hours <br />0.00351 weeks <br />8.078015e-4 months <br /> (CDT), the Braidwood Unit 1, Train A (1A) Diesel Generator (DG) was declared inoperable as a result of the inability to maintain intake filter differential pressure within specification.
Since the Braidwood Unit 2, Train A (2A) DG was already inoperable due to planned maintenance, TS 3.8.1.1 Action Statement (c) required that either the 1A or 2A DG be restored to operable status within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> or Unit 1 must be placed in at 3 east Hot Standby within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and 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 />.
CECO requested that the 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> shutdown requirement be extended an additional 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> in order to allow time to restore the 1A DG to operable status.
With the restoration of the operability of the 1A DG, Braidwood will exit TS 3.8.1.1.
A Notice of i
i Enforcement Discretion was verbally approved by Region III at 0359 hours0.00416 days <br />0.0997 hours <br />5.935847e-4 weeks <br />1.365995e-4 months <br /> (CDT) on May 16, 1994.
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Mr. Martin May 16, 1994 The basis of the request is provided in the Attachment and includes:
The Technical Specification that will be violated; The circumstances surrounding the condition, including the need for prompt action; The safety basis for the request that enforcement. discretion be exercised, including an evaluation of the safety significance and potential consequences of the proposed course of action; Any proposed compensatory measure (s);
The justification for the duration of the request; t
The basis for the conclusion that the request will not have a potential adverse impact on the public health and safety and that a significant safety hazard is not involved; and The basis for the conclusion that the request will not involve adverse consequences to the environment.
If the 1A DG is not restored to operable status by 0323 hours0.00374 days <br />0.0897 hours <br />5.340608e-4 weeks <br />1.229015e-4 months <br /> (CDT) on May 17, 1994, Unit 1 will have already been brought to HOT STANDBY and will proceed to 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 />.
This request for Enforcement Discretion has been reviewed and approved by Braidwood On-Site Review Committee, in accordance with Braidwood Station procedures.
CECO sincerely appreciates the NRC staff's effort and participation in the review of this request.
Please direct any question to this office.
i Sincerely, W
%%d s
Denis
. Saccomando Nuclear Licensing Administrator Attachment cc:
S. DuPont, Resident Inspector-Braidwood R. Assa, Project Manager-NRR B. Clayton, Branch Chief-Region III NRC Document Control
l ATTACHMENT REQUEST FOR ENFORCEMENT DISCRETION j
BRAIDWOOD STATION UNIT 1 MAY 16, 1994 l
1.
TECHNICAL SPECIFICATION OR LICENSING CONDITION THAT WILL BE VIOLATED 4
Technical Specification (TS) 3.8.1.1 Action Statement (c.2) requires that with a Unit in MODES 1, 2, or 3 with a Train A Diesel Generator (DG) inoperable, the other Unit's j
Train A DG must be verified OPERABLE.
If the other Unit's
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Train A DG can not be verified OPERABLE within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />; the affected Unit must be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> 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 />.
Braidwood took the Unit 2, Train A (2. ) DG out-of-A service at 2030 hours0.0235 days <br />0.564 hours <br />0.00336 weeks <br />7.72415e-4 months <br /> on May 11, 1994, to conduct planned maintenance.
At 0806 hours0.00933 days <br />0.224 hours <br />0.00133 weeks <br />3.06683e-4 months <br /> on May 15, 1994, Braidwood Unit 1 Operating Surveillance Procedure (lBw05) 8.1.1.2.a-1, IA Diesel Generator Operability Monthly (Staggered) and Semi-Annual (Staggered) Surveillance, was commenced on the Unit 1, Train A (1A) DG.
At 2123 hours0.0246 days <br />0.59 hours <br />0.00351 weeks <br />8.078015e-4 months <br /> on May 15, 1994, the 1A DG was declared inoperable as a result of the inability to maintain the 1A DG intake filter Differential Pressure (DP) within specification.
This was apparently due to a blown rupture disc in the exhaust system.
To perform corrective maintenance on the damaged rupture disc, Braidwood is requesting a 22 hour2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> extension of the 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> shutdown requirement of TS 3.8.1.1 Action Statement (c).
2.
CIRCUMSTANCES SURROUNDING THF SITUATION During the performance of 1BwOS 8.1.1.2.a-1, a high intake filter DP occurred at 1042 hours0.0121 days <br />0.289 hours <br />0.00172 weeks <br />3.96481e-4 months <br /> on May 15, 1994.
The filters were changed and the surveillance was recommenced at 1359 hours0.0157 days <br />0.378 hours <br />0.00225 weeks <br />5.170995e-4 months <br /> on May 15, 1994.
At approximately 1759 hours0.0204 days <br />0.489 hours <br />0.00291 weeks <br />6.692995e-4 months <br /> on May 15, 1994, the high DP alarm was again received and the 1A DG was shutdown at 1809 hours0.0209 days <br />0.503 hours <br />0.00299 weeks <br />6.883245e-4 months <br /> on May 15, 1994.
An inspection of the DG muffler room revealed a blown exhaust line rupture disc.
The 1A DG was declared inoperable at 2123 hours0.0246 days <br />0.59 hours <br />0.00351 weeks <br />8.078015e-4 months <br /> on May 15, 1994.
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3.
EVALUATION OF SAFETY SIGNIFICANCE AND CONSEQUENCES j
l As required by Title 10, Code of Federal Regulations, Part 50 (10 CFR 50), Appendix A, General Design Criteria (GDC) 17, the design of the Alternating Current (AC)
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electrical power system provides independence and redundancy l
to ensure an available source of power to the Engineered l
Safety Features (ESF) systems.
The DGs function to provide the necessary power for accident mitigation in the event the preferred, offsite electrical power supply is unavailable.
Because the loss of the offsite power sources is considered an initial condition in the Updated Final Safety Analysis Report (UFSAR), Chapter 15, Accident Analyses, the DGs are relied upon in all applicable analyses for safe shutdown and j
transient mitigation.
1 The proposed extension of the TS 3.8.1.1 Action statenent (c) 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> shutdown requirement will have no physical impact on unit operation.
Adequate compensatory measures, and reasonable operator action will ensure that sufficient emergency power is available to Unit 1.
This is accomplished by ensuring that Unit 2 Bus 241 will be operable and capable of being crosstied to Unit 1 Bus 141.
In the unlikely event that a loss of offsite power occurs on i
I Unit 1, Bus 241 would be crosstied to Bus 141 to support l
l operation of the Unit 1 Motor Driven Auniliary Feedwater f
Pump.
The probability of an accident occurring will not be significantly affected by the approval of this enforcement discretion.
This request deals only with the allowed outage time and associated shutdown requirement of equipment assumed to operate for the mitigation of an accident.
The l
availability of this equipment is unrelated to the sequence i
of events leading to the initiation of a transient, and is therefore unrelated to the probability of occurrence for a transient initiating event.
Granting of this enforcement discretion will not create the possibility of a new accident.
No new system configurations will be introduced; this request deals only with the allowed outage time and associated shutdown requirement of the 1A DG.
The availability of Bus 241 will ensure that emergency power is available to the Unit 1 Motor Driven Auxiliary Feedwater Pump.
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granting of this requested enforcement discretion would allow for repairs of the 1A DG without I
shutting down Unit 1.
This would minimize the risk that is associated with placing the Unit in a transient condition during normal plant shutdown.
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4.
COMPENSATORY ACTIONS The following compensatory measures will be in place for the duration of the enforcement discretion:
No ESF electrical distribution equipment, either normal, standby, or reserve, will be taken out-of-service on Unit 1.
The Southern Division Load Dispatcher will be notified to maximize the availability of the offsite power lines servicing Braidwood.
The Southern Division Load Dispatcher will be notified to refrain from work activities in the Braidwood switchyard.
Unit I will not perform any load changes other than those required by Technical Specifications.
Availability of all Unit 1 safety related equipment will be maximized by prohibiting planned maintenance on safety related equipment (excepting the 1A DG).
Shift Management will review all surveillance and out-of-services for impact before authorizing the initiation of the activity.
If any Unit 1, Train B safety equipment becomes inoperable during the extension period, the extension will be terminated and Unit I will be placed in HOT STANDBY within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and 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 />.
Should Bus 241 become inoperable during the extension period, the extension will be terminated and Unit 1 will be placed in HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and 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 />.
Should Unit 1 experience a loss of all AC power, Braidwood Unit 1 Contingency Action Proccdure (lBwCA) 0.0,
" Loss of All AC Power", will be implemented by the shift operating crew.
1BwCA-0.0 implements Braidwood's response to the requirements of 10 CFR 50.63, Station Blackout Rule.
This response has been reviewed and accepted by the Nuclear Regulatory Commission (ERC).
Shift operating p2rsonnel will be notified of these compensatory actions via Daily Orders.
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5.
JUSTIFICATION FOR THE DURATION OF THE REQUEST TS 3.8.1.1 Action Statement (c.2) requires that with a Unit in MODES 1, 2, or 3 with a Train A DG inoperable, the other Unit's Train A DG must be verified OPERABLE.
The basis for this is to ensure the capability exists to manually transfer power for the Motor Driven Auxiliary Feedwater Pump in one unit to the corresponding DG power supply bus in the other unit.
This request will extend the shutdown requirement of TS 3.8.1.1 Action Statement (c) from 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> to 28 hours3.240741e-4 days <br />0.00778 hours <br />4.62963e-5 weeks <br />1.0654e-5 months <br /> on a one-time basis for the 1A DG.
The requested relief will expire at 0323 hours0.00374 days <br />0.0897 hours <br />5.340608e-4 weeks <br />1.229015e-4 months <br /> on May 17, 1994.
If the 1A DG has not been restored to OPERABLE status within that time frame, Unit 1 will have already been brought to HOT STANDBY and will prc:eed to 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 additional 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> is deemed sufficient to allow the required parts to arrive on site, to accomplish the desired maintenance, and to perform the required operability demonstration in a safe and controlled manner.
The 22 hour2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> extension is acceptable due to the compensatory actions taken to ensure maximum availability of safety related equipment as well as normal and alternate sources of power to Bus 141.
Therefore, the requested duration is justifiable, both on the bases of minimal risk and sufficient time to execute the desired restoration plan.
If at any time during the extension period it becomes obvious that significant additional work is required such that the extension is inadequate to restore the 1A DG, actions will be taken at that time to place Unit 1 in HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and 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 />.
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6.
EVALUATION OF SIGNIFICANT HAZARD CONSIDERATION:
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Commonwealth Edison has evaluated the proposed enforcement discretion and determined that it involves no significant hazards considerations.
According to 10 CFR 50.92(c), a proposed amendment to an operating license involves no significant hazards considerations if operation of the facility in accordance with the proposed amendment would not:
1.
Involve a significant increase in the probability or consequences of an accident previously evaluated; or 2.
Create the possibility of a new or different kind of accident from any accident previously evaluated; or I
3.
Invol're a significant reduction in a margin of safety.
TS 3.8.1.1 Action Statement (c.2) requires that with a Unit in MODES 1, 2, or 3 with a Train A DG inoperable, the other Unit's Train A DG must be verified OPERABLE.
If the other Unit's Train A DG can not be verified OPERABLE within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />; the affected Unit must be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> 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 />.
Braidwood is requesting that the shutdown requirement of TS 3.8.1.1 Action Statement (c) be extended from 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> to 28 hours3.240741e-4 days <br />0.00778 hours <br />4.62963e-5 weeks <br />1.0654e-5 months <br /> to allow completion of corrective maintenance on the 1A DG.
If the 1A DG has not been restored to OPERABLE status within that time frame, Unit I will have already been brought to HOT STANDBY and will proceed to 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 />.
If at any time during the extension period it becomes apparent that significant additional work is required such that the extension period becomes inadequate to restore the 1A DG, Unit 1 will be placed in HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> 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 />.
a.
The proposed enforcement discretion does not involve a significant increase in the probability or consequences of an accident previously evaluated.
t The probability of an accident occurring will not be significantly affected by granting this enforcement discretion.
This request deals only with the shutdown requirement of equipment assumed to be operated for the mitigation of an accident.
The availability of this equipment is unrelated to the sequence of events leading to the initiation of a transient, and is therefore unrelated to the probability of occurrence for a transient initiating event.
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The consequences of an accident, in terms of offsite dose, will not be significantly changed provided the mitigative actions credited in the i
accident analyses are accomplished in accordance with the analyses assumptions.
The analyses assume that all required mitigative equipment is operable at the onset i
of the transient.
No provisions are made for allowed outage times and associated shutdown requirements in the accident analyses.
The allowed outage times and associated shutdown requirements represent a. temporary relaxation of the single failure criterion.
Therefore, the requested enforcement discretion does not significantly increase the probability or consequences of an accident previously evaluated.
b.
The proposed enforcement discretion does not create the possibility of a new or different kind of accident fram any accident previously evaluated.
The proposed enforcement discretion will not impact equipment failures.
This request deals with equipment allowed outage times and associated shutdown requirements, not equipment operation.
No new system configurations are introduced, and no equipment is being operated in a new or different manner.
Accordingly, no new or different failure modes are being introduced, c.
The proposed enforcement discretion does not involve a significant reduction in a margin of safety.
The extension of the TS 3.8.1.1 Action Statement (c) 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> shutdown requirement is in a non-conservative direction.
The extension of the shutdown requirement represents additional relief from the single failure criterion, not a reduction in the margin of safety.
Adequate compensatory measures and reasonable operator action will ensure that there is sufficient emergency power for the operation of the Motor Driven Auxiliary Feedwater Pump.
This is accomplished by ensuring that Bus 241 is available and capable of being crosstied to Bus 141.
Therefore, the proposed enforcement discretion will not involve a significant reduction in a margin of safety.
Based on the review above, Braidwood concludes that this request for enforcement discretion does not involve a significant hazards consideration.
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4 7.
FNVIRONMENTAL ASSESSMENT:
Braidwood has evaluated the proposed enforcement discretion against the criteria for the identification of licensing and regulatory actions requiring environmental assessment in accordance with 10 CFR 51.21.
It has been determined that the proposed change meets the criteria for a categorical exclusion as provided for under 10 CFR 51.22 (c) (9).
This determination is based on the fact that this change is being proposed as enforcement discretion to a license issued pursuant to 10 CFR 50, and that the change requested involves extension of the allowed outage time and associated shutdown requirement of a component located within the restricted area, and the change involves no significant hazards.
There is no change in effluents that may be released offsite.
There is no signifi';nt increase I
in individual or cumulative occupational radiation exposure.
8.
APPROVAL BY ON SITE REVIEW:
t This request has been reviewed and approved by the Braidwood On-site Ra"lew Committee, in accordance with the Braidwood Station p.
edures.
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