ML20217J695
| ML20217J695 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 03/30/1998 |
| From: | Cruse C BALTIMORE GAS & ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9804060354 | |
| Download: ML20217J695 (8) | |
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Cnexs II. CnosE Baltimore Gas and Electric Company Vice President Calvert Cliffs Nuclear Power Plant Nuclear Energy 1650 Calvert Cliffs Parkway Lusby, Maryland 20657 410 495aM55 March 30,1998 U. S. Nuclear Regulatory Commission Washington,DC 20555 ATTENTION:
Document Control Desk
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit No.1; Docket No. 50-317 Reauest for Regional Enforcement Discretion Baltimore Gas and Electric Company (BGE) hereby requests regional enforcement discretion from certain requirements of Calvert Cliffs Unit 1 Technical Specification 3.8.1.1, "A.C. S^urces -
Operating " Action b of that Specification requires that, when in Modes 1-4 with less than tv o separate and independent diesel generators Operable, two diesel generators must be restored to r eraW u tus g
within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or Unit I must be placed 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 />. His letter documents the plant status at 12:15 a.m. on March 28,1998. Unit 1 is at full power and Emergency Diesel Generator (EDG) No. IB is inoperable due a malfunctioning governor found daring performance of a monthly surveillance test. Installation of a new governor is complete, it is functioning properly, and testing is ongoing. This evolution will not be completed prior to the expiration of the Allowed Outage Time (AOT) at 12:25 a.m. on Saturday, March 28,1998. Under our expected schedule, the EDG will be returned to Operable status by 6:25 a.m., March 28,1998.
Baltimore Gas and Electrh Company has evaluated this situation and determined that the minimal safety impact of a short extension of the EDG AOT does not warrant an unnecessary plant transient to shut down Unit 1. Requesting a license amendment would not be practical because the plant will be returned to compliance with the Technical Specification before a license amendment could be issued. Therefore, we are requesting enforcement discretion to allow BGE to not comply with an Action Statement time limit for a maximum of 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. This enforcement discretion will allow an extension of the AOT from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to a maximum of 78 hours9.027778e-4 days <br />0.0217 hours <br />1.289683e-4 weeks <br />2.9679e-5 months <br />, ending no later than 6:25 a.m., March 28,1998.
A discussion of the circumstances that led to this request and the safety basis for the request is contained in Attachment (1). The Determination of No Significant Hazards Considerations is contained in Attachment (2).
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ss 9804060354 980330 PDR ADOCK 05000317 G
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Document Control Desk March 30,1998 Page 2
- We have evaluated this change and determined that the proposed action will not result in an undue risk to the health and safety of the public and has no significant hazards considerations. The Plant Operating
. Safety Review Committee has reviewed the request and concurs with this conclusion.
Should you wish to discuss this request, please contact Mr. John Volkoff at (410) 495-3649.
Very truly yours, for C. H. Cruse Vice President -Nuclear Energy CIIC/JV/ dim
' Attachments: (1)
Description of Circumstances and Safety Basis (2)
Determination ofNo Significant Hazards cc:
R.S. Fleishman, Esquire H. J. Miller, NRC
' J. E. Silberg, Esquire Residentinspector, NRC A. W. Dromerick, NRC R. I. McLean, DNR Director, Project Directorate I-1, NRC J. H. Walter, PSC
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l ATTACHMENT (1)
DESCRIPTION OF CIRCUMSTANCES AND SAFETY BASIS Baltimore Gas and Electric Company Calvert Cliffs Nuclear Power Plant March 30,1998
ATTACHMENT m DESCRIPTION OF CIRCUMSTANCES AND SAFETY BASIS
, Calvert Cliffs Nuclear Power Plant is a two-unit site. The Unit 1 Emergency Safety Features electrical system relies on two Emergency Diesel Generators (EDGs). In addition, there is a non-safety-related Station Blackout 5400 kW EDG available.
At approximately 12:25 a.m. EST on March 25,1998, in preparation for taking No. I A Diesel Generator out-of-service for maintenance, operability testing (Surveillance Requirement 4.8.1.1.2.a.4) was performed on No. IB EDG as required by Action 3.8.1.1.b. During the test, the diesel did not start.
Unit I has remained in the 72-hour Action Statement of Limiting Condition for Operation 3.8.1.1, Action b since talhg the No.1B EDG out-of-service for testing.
Twelve hours of troubleshooting pointed to a possible problem with the di m governor. The governor was flown to the vendor for inspection and confirmation of the troubleshooting findings. Vendor inspection confirmed a piece of nylon in the shut down solenoid. Following this determination, Calvert Cliffs attempted to return the No. IB EDG to service using a spare governor. Installation of the spare governor was unsuccessful in returning the No. IB EDG to service.
A new governor has been installed and shown to be functioning properly, confirming that the root cause of the malfunction of the EDG was the governor. To accommodate testing of the new governor, Calvert Cliffs is requesting enforcement discretion in the form of a one-time 6-hour extension to the 72-hour Limiting Condition for Operation Action Statement allowed outage time (AOT). Without this discretion, Unit I must commence shutdown at 12:25 a.m. EST on March 28,1998.
Baltimore Gas and Electric Company has evaluated the extension of the period that the EDG would be out-of-servict; against the pobability of a design basis accident. We believe that the risk associated with this condition to be of small consequence due to its short duration and the availability of other mitigating equipment.
Baltimore Gas and Electric Company also evaluated the increase in EDG out-of-service time compared to the base AOT using the risk-based maintenance assessment tools available for this purpose. Baltimore Gas and Electric Company has judged this risk to be acceptable and comparable to the risk of maintenance activities routinely performed within the Technical Specification AOTs. We have also evaluated the effect of the additional EDG out-of-service time on annual risk and judged it acceptable.
Prior adoption of line item improvements in the Technical Specifications would not have obviated the need for this request. During the period that we are in non-compliance with the Technical Specification, we will implement a number of risk-management measures.
Baltimore Gas and Electric Company has ensured the No. l A EDG is operable.
Baltimore Gas and Electric Company has a non-safety-related 5400 kW No. OC EDG installed that can be aligned to either 4 kV vital bus. The No. OC EDG would be available if were to fait during an event where the No. IB EDG was required. Plant operators have the procedures and j
training to utilize No. OC EDG.
During the period that we are in non-compliance with the Technical Specification, we will not perform any discretionary maintenance or testing on any Unit I safety-related equipment.
We have reviewed with the plant operators the actions to be taken should a loss of offsite power occur while No. IB EDG is not available.
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J ATTACHMFNT (1) i DESCRIPTION OF CIRCUMSTANCES AND SAFETY BASIS
. If the plant is threatened by severe weather with the potential to interrupt offsite power during the e
period that we are in non-compliance with the Technical Specification, we will shut down Unit 1.
~ All four offsite circuits are available, though only two are required to be Operable by the Technical Specifications, During the period that we are in non-compliance with the Technical Specification, Baltimore Gas e
and Electric Company will not conduct maintenance or testing on the cffsite power system.
We have considered the possibility of significant hazards associated with this period of noncompliance with the Technical Specifications (See Attachment 2) and determined that there are none. We have determined that the requested period of noncompliance with the Technical Specification will not present an undue risk to the plant or to the health and safety of the public. Additionally, operation of Calvert Clifts Unit I during the period of noncompliance with the Technical Specifications will result in no adverse consequences to the environment in that there will be no significant change in the types or significant increases in the amounts of any effluents that may be released offsite, and in no significant increase in individual or cuaulative occupational radiation exposure. Therefore, we request that the NRC grant the requested Notice of Enforcement Discretion.
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ATTACHMENT (2)
DETERMINATION OF NO SIGNIFICANT IIAZARDS J
Baltimore Gas and Electric Company Calvert Cliffs Nuclear Power Plant March 30,1998
ATTACHMENT (2)
DETERMINAT10N OF NO SIGNIFICANT HAZARDS
, The proposed enforcemeu Mscrcion has been evaluated against the standards in 10 CFR 50.92 and has been determined to not involve a significant hazards consideration, in that operation of the facility during the period of the enforcement discretion:
1.
Would not involve a significant increase in the probability or consequences of an accident previously evaluated The Emergency Diesel Generators (EDGs) provide onsite electrical power to vital systems should offsite electrical power be interrupted. Calvert Cliffs Unit I has two safety-related EDGs.
Baltimore Gas and Electric Company is requesting Enforcement Discretion from the Nuclear Regulatory Commission to allow the No. IB EDG to be inoperable for 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> longer than the Technical Specification Allowed Outage Time (AOT) of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> without shutting down the unit. The additional time is needed to test a governor.
The EDGs are not an initiator to any accident previously evaluated. Therefore, this extended period of operation with the EDG out-of-service will not increase the probability of an accident j
previously evaluated.
He EDGs act to mitigate the consequences of design basis accidents that assume a loss of offsite I
power. For that purpose, redundant EDGs are provided to protect against a single failure.
During the Technical Specification 72-hour AOT, an operating unit is allowed by the Technical Specifications to remove one of the EDGs from service, thereby losing this single failure protection. This operating condition is considered acceptable. The consequences of a design basis accident coincident with a failure of the redundant EDG during the short period of Technical Specification noncompliance are the same as those during the 72-hour AOT.
Furthermore, as a compensatory action, we will institute not performing any discretionary maintenance or testing on any Unit I safety-related equipment during the period of noncompliance with the Technical Specifications. His will reduce the risk that other mitigating equipment would not be available in the event of a design basis accident. Therefore, during the period of noncompliance, there is no significant increase in consequences of an accident previously evaluated.
Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
2.
Would not create the possibility of a new or different type of accident from any accident previously evaluated.
During the period of noncompliance with the Technical Specifications, the plant will not be in a new configuration nor will any unusual operator actions be required. The EDGs are not an initiator to any accident, but are designed to respond should an accident occur.
l Therefore, the proposed change does not create the possibility of a new or different type of accident from any accident previously evaluated.
3.
Would not involve a significant reduction in a margin ofsafety.
During the period of the Technical Specification AOT when one EDG is out-of-service during power operation, the margin of safety is allowed to be reduced. This time period is a temporary l
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L ATTACHMENT (2) j DETERMINATION OF NO SIGNIFICANT HAZARDS relaxation of the single failure criteria, which, consistent with overall system reliability considerations, provides a limited time to repair the equipment and conduct testing. We are requesting a short extension to this limited time. We are also instituting a number of compensatory measures that will reduce the possibility of a plant transient or a loss of offsite power. We conclude that the period of noncompliance with the Technical Specifications beyond that allowed by the Allowed Outage Time will not result in a significant further reduction in the margin of safety.
Therefore, the proposed change does not involve a significant reduction in a margin of safety.
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