ML18153C693
| ML18153C693 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 08/07/1991 |
| From: | Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9108140295 | |
| Download: ML18153C693 (8) | |
Text
VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 August 7, 1991 United States Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 Gentlemen:
VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION UNITS 1 AND 2
. REPLY TO A NOTICE OF VIOLATION Serial No.:
91-400 SPS/RCB Docket Nos.: 50-280 50-281 License Nos. :DPR~32
- DPR-37 NRC INSPECTION REPORT NOS. 50-280/91-1"4 AND 50-281/91-14 We have reviewed your Inspection Report Nos. 50-280/91-14 and 50-281/91-14 dated July 8, 1991. We understand your concerns over procedure and corrective action program adequacy and are taking steps to strengthen those programs in an effort to avoid such occurrences in the future.
An overview -of our" problem/issue review
-process is described below, and specific actions are described in the attached
. response.
. The process for-reviewing events which have occurred at one of the Virginia Power stations for applicability at the other includes the following:
Significant events or issues are discussed on the daily conference calls held
. among management personnel at both stations ~nd the corporate office.
In-depth reviews of significant events are normally _conducted by Corporat.e Nuclear Safety personnel and documented -in
- formal reports.
These assessments consider the applicability of the event causes to the other station.
Reports of significant events are provided to the other station and corporate management.
The Station Nuclear Safety group reviews these reports to identify issues that require prompt resolution.
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The Corporate Nuclear Safety Section now performs a formal, in-depth analysis of
- NRC violations, Licensee Event Reports, Root Cause Evaluations, and Human Performance Enhancement Evaluations as a part of the Operating Experience Review Program. This review, which is documented in an Analysis Report, focuses on actions
. needed to preclude_ recurrence of the problem at. the other station.
Any recommendations resulting from the above reviews are evaluated by management and, if approved, are tracked to verify effective implementation.
If you have any further questions, please C(?ntact us.
Very truly your, 1W-\\rC-fr-S.-
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,:,-,.1,v W. L. Stewart Attachment cc:
U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, N.W.
Suite 2900 Atlanta, Georgia 30323 Mr. M. W; Branch NRC Senior Resident Inspector Surry Power Station
REPLY TO A NOTICE OF VIOLATION NRC INSPECTION CONDUCTED MAY 12 - JUNE 8. 1991 SURRY POWER STATION UNITS 1 AND 2 INSPECTION REPORT NOS. 50-280/91-14 AND 50-281/91-14
. NRC COMMENT:
During an NRC inspection conducted on May 12 - June 8, 1991, violations. of NRC requirements were identified.
In accordance with the "General Statement of Policy and Procedure for NRC Enforcement Actions," 1 O CFR Part 2, Appendix C (1991 ), the violations are listed below:
A.*
1 O CFR 50, Appendix B, Criterion V, as implemented by Operational.Quality Assurance Program Topical Report (VEP 1-5A, Section 17.2.5), requires, in part, that activities affecting quality be prescribed by documented instructions or procedures appropriate to the circumstances.
Contrary to the above, activities affecting quality were not prescribed by adequate instructions and/or procedures, as evidenced by the following examples:
- 1.
Technical Specification 3.11, Radioactive Gas Storage, was re.vised on April 17, 1991 and theri implemented without providing instructions on how to
, accomplish the required actions. This resulted, on May 24, 1991, in the failure to immediately reduce the oxygen concentration in the A waste decay tank as required by Technical Specification 3.11.A.1.b.
- 2.
Use of a turbine load limiter as described in Section 14.2.8 of the UFSAR, was not incorporated into station procedures. This contributed to a June 6, 1991, Unit 1 power increase to 103 percent, which exceeded licensed power limits.
- due to improper setting of the turbine load limiter.
This is a Severity Level IV violation (Supplement I).
B.
1 O CFR 50, Appendix B, Criterion XVI, as implemented by Operational Quality Assurance Program Topical Report (VEP 1-5A, Section 17.2.16), requires, in part, that measures shall be established to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, and defective equipment are promptly identified and corrected.
. Contrary to the above, conditions adverse to quality associated with.the reoccurrence of seal head tank low level alarms on Unit 1 outside recirculation spray pump 1-RS-P-2.A and Unit 2 low head safety injection pump 2-SI-P-1A were not promptly identified and corrected. This condition was identified on or before February 1990 and had not been corrected as of June 6, 1991.
This is a Severity Level IV violation (Supplement I).
REPLY TO A NOTICE OF VIOLATION NRC INSPECTION CONDUCTED MAY 12.
- JUNE 8, 1991 SURRY POWER STATION UNITS 1 AND 2 INSPECTION REPORT NOS. 50-280/91-14 AND 50-281/91-14 RESPONSE JO ITEM A.f:
( 1)
Reason for the Violation, or, if Contested, the Basis for Disputing the Violation The violation was caused by inadequate implementation of revised Technical Specification (TS) requirements; The Company initiated TS changes on May 25, 1990, to impose more restrictive requirements concerning potentially flammable gas mixtures in the Waste Gas Holdup System. The proposed changes were is~;ued by the NRC as License Amendments 154 and 153 on April 17, 1991.
The revised TS requires that the concentration of oxygen in the Waste Gas Holdup System be maintained at less than or equal to 2 percent by volume whenever hydrogen concentration exceeds 4 percent by volume. With the concentration of oxygen greater than 2 percent by volume, but less than or
- . equal to 4 percent, the TS requires that oxygen be restored to within the limit within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />. With the concentration of oxygen greater than 4 percent by
. volume, the TS requires immediate suspension of waste gas additions to the affected tank and reduction of oxygen concentration to less than or equal to 4 percent by volume. Instructions on rapidly reducing oxygen concentration in a Waste Gas Decay Tank (WGDT) were not incorporated into. operating procedures.
Previous operational methods to cope with gas constituents exceeding the concentration allowed by TS required suspending additions to the tank, sampling, releasing the contents, and purging the tank with nitrogen, if necessary. As a result, when oxygen concentration in the "A" WGDT was found on May 24, 1991, to exceed 4 percent by volume while hydrogen concentration exceeded 4 percent by volume, acUons taken by operators did not reduce oxygen concentration in the most expeditious manner possible.***:O~ierators immediately suspended waste gas additions to the "A" WGDT and promptly initiated action. to release the tank contents, in the belief that these actions conservatively addressed the issue of potentially explosive gas concentrations and were adequate to comply with the new TS requirements.
- However, releasing the WGDT prior to purging did not achieve an "immediate" redL:-=tion in oxygen concentration as required by the new TS action statement.
The TS change had been reviewed by the affected departments prior to submittal to the NRG in order to identify procedure changes needed. The specified changes were put in place to implement the more restrictive limits prior to receipt of NRG approval. However, the need for procedure changes specifying reduction of oxygen concentration by nitrogen addition in the WGDT as a required action in addressing explosive gas concentrations was not identified in this process.
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. (2)
Corrective Steps Which Have -Been Taken and the Results
- Achieved Oxygen concentration in the "A" WGDT was reduced to below 4 percent by
_ volume on May 25,' 1991, approximately 38 hours4.398148e-4 days <br />0.0106 hours <br />6.283069e-5 weeks <br />1.4459e-5 months <br /> after the out-of-specification
_ condition had been discovered. This was accomplished by releasing the tank contents and then purging the tank with nitrogen.
Annunciator response procedures were revised to require immediate suspension of waste gas additions and reduction of oxygen concentration in the event oxygen concentration exceeds 4 percent by volume in a WGDT.
Operating procedures were revised to provide instructions on the immediate reduction of oxygen concentration in a WGDT by nitrogen addition. Nitrogen addition is required prior to release of a WGDT unless unacceptable tank _
pressure would result. The revised procedures contain graphs which enable operators to quickly estimate the nitrogen addition needed to achieve a final oxygen concentration below 4 percent by volume. These changes will ensure that oxygen concentration in a WGDT will be reduced in the future in a timely manner should the TS limit be exceeded.
In addition, the process for reviewing events which have occurred at one of the Virginia Power stations for applicability at the other has been enhanced.
Reports of significant events are provided to *the other station's management and the station's Nuclear Safety group provides a timely review of these event reports to identify issues that require prompt resolution. The Corporate Nuclear Safety Section now performs a formal, in-depth analysis of NRC violations, Licensee Event Reports, Root Cause Evaluations, and Human Performance
- -Enhancement Evaluations as a part of the Operating Experience Review Program. This review, which is documented in an Analysis Report, focuses on actions needed to preclude recurrence of the problem at the other station. Any recommendations resulting from_ the reviews are evaluated by management and, if approved, are tracked to verify effective implementation.
(3) _ Corrective Steps That Will be Taken to Avoid Further Violations The development and implementation process for TS changes is-being enhanced to decrease the likelihood that procedure changes will be overlooked or that misinterpretation of a TS requirement will occur.
( 4)
The Date When Full Compliance Will be Achieved
- Full Compliance was achieved when annunciator response procedures and operating procedures were revised to provide instructions on the reduction of oxygen concentration in a WGDT in a more timely manner.
RESPONSE TO ITEM A.2:
( 1)
Reason for the Violation, or, if contested, the Basis for Disputing the Violation (2)
- The failure to incorporate the use of the turbine load limiter into station procedures as described by Section 14.2.8 of the UFSAR was due to a previous interpretation of the UFSAR requirement. The actual statement in the UFSAR reads, "For excessive loading by the operator or by system demand, the turbine load limiter keeps the maximum turbine load from exceeding 100% rated load."
The interpretation of this statement had been that "100% rated load" referred to the 100% position of the turbine load limiter.
Station procedures had incorporated this interpretation in that the maximum setting for the turbine load limiter was set at 100% rated turbine load. Based upon a review of the UFSAR Section 14.2.8 "Excessive Load Increase Incident," coupled with the factthat the
. turbine load limit for Surry is greater than the reactor thermal power limit, the appropriate interpretation should have been that "100% rated load" referred to the load equivalent to 100% reactor thermal power.
Corrective Steps Which Have Been Taken and the Results Achieved A shift order was written, which directed the turbine load limiter to be maintained
- just above governor valve position, while at steady state conditions. This corrective step was taken to ensure compliance with UFSAR requirements prior to completing changes to operating procedures.
Applicable operating procedures have been changed to ensure the turbine_ load limiter is set just above 100% reactor thermal power while operating at 100%
steady state load. Also, during unit operations, the procedures direct the turbine limiter be controlled so that it is _maintained, slightly above the governor valve position.
(3)
Corrective Steps That Will be Taken to Avoid Further Violations Operator training will be conducted on operation of the turbine load limiter and
- operator training programs revised, as appropriate.
( 4)
The Date When Full Compliance Will be Achieved Full compliance was achieved when operating procedures were revised to reflect the intent of the UFSAR.
RESPONSE TO ITEM B:
( 1)
Reason for the Violation, or, if Contested, the Basis for Disputing the Violation (2)
Seal head tank low leve'I alarms had been identified during surv~illance testing, and several Station Deviation Reports had been generated. The condition had been evaluated as having been caused by the design of the system and incomplete venting. Based on engineering's evaluation that pump operability had not been affected the alarms were considered a nuisance. Management did not place a sufficiently high priority on the resolution of this condition. The corrective action directed by procedure was to refill the head tank, and this action was routinely accomplished.
The Corrective Steps Which Have Been Taken and the Results.
Achieved Additional* engineering evaluations have* been performed which have reconfirmed our previous conclusions that the pumps remained fully operable
,during and after the problems with the seal head tank alarms. The design of the
- pumps is such that even if one of the seals were to fail producing a valid low level alarm, the other seal remains available to prevent the escape of pumped fluid to the atmosphere.
Procedure enhancements were identified to better direct operator actions should the low level alarm be received. The Annunciator Response Procedure has been revised to provide this guidance to the operator in the event a low level alarm is received either with the pump in standby, during testing, or during accident conditions.
(3)
Corrective Steps That Will be Taken to Avoid Further* Violations The seal head tank cooling system fill and vent procedure will be enhanced to*
ensure more thorough venting and to minimize introduction of air.
The applicable surveillance procedures will be changed to require refilling of the seal cooling system following testing.
Potential. modifications to the cooling coils are under evaluation.
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The Date When Full Compliance wm be Achieved Full compliance was achieved when the revised Annunciator Response Procedures were approved by the Station Nuclear Safety and Operating Committee and implemented in the plant.