ML20097G272
| ML20097G272 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 06/12/1992 |
| From: | Link B WISCONSIN ELECTRIC POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| CON-NRC-92-063, CON-NRC-92-63 VPNPD-92-216, NUDOCS 9206170001 | |
| Download: ML20097G272 (6) | |
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Wisconsin Electnc
. POWER COMPANY 231 W McNgon Po (K;x 2046. MMume. Wi $3201
{M4) 2212M5 VPNPD-92-216 NRC-92-063 June 12, 1992 FEDERAL EXPRESS U.
S.
NUCLEAR REGULATORY COMMISSION Document Control Desk-Mail Station P1-137 Washington, D.
C.
20555 Gentlemen:
DOCKETS 50-266 and 50-301 REOUEST FOR NRR WAIVER OF COMPLIANCQ TECHNICAL SPECIFICATION REOUIREMENT 15.4.6.A.2
-POINT BEACH NUCLEAR PLANTS. UNITS 1 AND 2 The purpose of this letter is to dccument the basis for Wisconsin Electric Power Company's request for an NRR Waiver of Compliance from the requirements of Point Beach Nuclear Plant Technical Specification Section 15.4.6, " Emergency Power Systems Periodic Tests," Specification A.2.
BEOUTREMENT FOR WHICH WAIVER IS REOUESTED Point Beach Nuclear /?) ant Technical Specification 15.4.6.A.2 requires a test of the automatic start of each diesel generator, load shedding,.and restoration to operation of particular vital equipment initiated by an actual interruption of normal AC power supplies to~acsociated engineered safety system busses together with;a simulated-safety injection signal.
The tests specified are designed to demonstrate that the diesel generators will provide
. power for operation of equipment.
They also assure-that the emergency generator system. controls and the control systems for the s eafeg'u rds equipment will function automatically in the event of a i
loss?ct all normal AC station uervice power.
The acceptance criterion defined in the specification requires that.the emergency
-diesel 1 generator start and accept required safeguards loads in less than the_ time periods listed in PBNP FSAR Section 8.2,
" Electrical
-System."
On June 11, 1992, we determined that some required safeguards
-relays do not currently conform to PBNP Technical Specification requirements for the defined load sequencing.
This determination was made during final preparation'of a Licensee Event Report k
regarding improper sequencing of emergency safety features which
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occurred during performance of Operations Refueling Test (ORT-3),
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Document Control Desk Tunn 12, 1992 Page 2
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" Safety Injection Actuation With Loss of Engineered Safeguards AC,"
conducted on May 15, 1992.
PBNP Technical Specification Section 15.3, " Limiting Conditions for i
Operations" requires an affected unit, which is critical, to be
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placed in hot shutdown conditions within 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> if the conditions J
prescribed by an LCO cannot be satisfied.
Additionally, if the conditions which prompted the shutdown cannot be corrected and the ae neriod, the unit shall be LCO does not specify an additional n
placed into the cold shutdown cond firm sithin 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />.
The oasis for these general consi'9rati ons L
.a delineate action to be taken for circumstances not direc.ly provided for in the ection i
statements of the specific LCO and whose occurrence would violate the intent of the specification.
The tests required by PBNP Technical Specificacion 15.4.6.A.2 are performed during reactor shutdown for major fuel reloading.
We now conclude, based on our review of previous ORT-3 test data, that load restoration sequencing controlled by some safeguards time delay relays associated with both PBNP Units 1 and 2 are not in conformance with existing PBNP Technical Specification requirements.
Therefore, based upon our acknowledgement of ORT-3 test results And associated Technical Specification noncompliance, this condition would require action to be taken as specified in PBNP Technical Spccification 15.3.0.
Wisconsin Electric Power Company requests a Temporary Waiver of i{[
Compliance from the requirements of PBNP Technical Specification 15.4.6.A.2 and cascading Specification 15.3.0.
This request was discussed during a teleconference on the evening of June 11, 1992, with Nuclear Regulatory Commission NRR and Region III pcaff members and also with the PBNP Senior Resident Inspector.
The Temporary Waiver of Compliance is requested for a time duratic' "hich is required to issue revised FSAR section 8.2 and to ha PRNP Technical Specification Change Request #146 issued by the NRC.
These documents will provide load sequencing criteria and tolerances which have been determined acceptable for safe plant operation.
Following issuance of these documents PBNP will be in conformance with license conditions of Technical Specification 15.4.6.A.2.
CIRCUMSTANCES SURROUNDING THE SITUATION In 1985, when incorporating an unrelated change to the PBNP Technical Specifications, the phrase "in less than the time period listed in FSAR Section 8.2" was inadvertently deleted from PBNP Technical Specification 15.4.6.A.2.
This error was discovered and corrected in mid-1990.
Without this criterion for load start times
Document Control Desk June 12, 1992 Page 3
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to be less than those listed in the FSAR, we interpreted Specification 15.4.6.A.2 to allow load sequencing in accordance with the FSAR times within appropriate tolerances.
The tolerances implemented in our test procedures during this period ensured that
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under worst case conditions, no load would sequence on within one second of the previous load starting.
Test data during this period indicate that a one-second interval is sufficient for diesel generator voltage and frequency to recover prior to the next load starting.
Maximum allowable start times remained within the assumptions of FSAR Chapter 14, " Safety Analysis."
The current PBNP Technical Specification requirement that the loads sequence on in less than the time specified by the FSAR could allow simultaneous sequencing of consecutive loads on the diesel generator potentially resulting in a transient overload.
On August 9, 1991, we requested a change to our Technical Specifications.
This change will eliminate this requirement, thereby allowing us to implement the appropriate tolerances on the equipment start times.
These tolerances would be specified in the FSAR along with the required start times.
On June 11, 1992, we determined that the PBNP ORT-3, Appendix C, procedures continued to contain tolerance bands on the start times vice the current Technical Specification acceptance criteria.
Accordingly, we reviewed ORT-3 test results from the most recent Unit 1 and 2 outages.
From this review, we determined that three relays had measured setpoints which did not conform to Technical Specification and ORT-3 tolerance acceptance criteria.
These three relays include the Unit 1 and 2 time delay relays for service water pump P32D and the Unit 1 time delay relay for service water pump P32B.
These pumps were declared inoperable and the appropriate 24-hour LCO was entered due to service water pump P32F previously being taken out of service.
P32D relays were tested and
< appropriate adjustments made to bring the relay setpoints into procedural tolerance.
P32B relay was tested and the as found condition was within procedural tolerances.
The service water pumps were then returned to service.
We conclude that all appropriate safeguards relays not; conform to procedural tolerances.
However, 26 safeguard relays, when tested in the last two ORT-3 procedures or by special retest, do not conform with the current Technical Specification requirement to sequence on in times less than those defined in the FSAR.
We believe that this request is justified because the estaclishment and implementation of appropriate tolerances on the load sequence times provide greater assurance that the diesel generator and safeguard loads will function as designed.
This assessment was
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z Document Control Desk June 12, 1992 Page 4 delineated in our August 9, 1991, Technical Spec *fication Change Request #146.
DISCUSSION OF COMPENSATORY ACTIONS As previously described, the 3 relays which were identified as being outside procedural tolerances have been tested and adjusted appropriately.
The present configuration of the affected relays 4.s bounded by the FSAR accident analysis and provides increased assv.rance that the emergency diesel generators and safeguards equipment will function as required.
The license amendment which will permit operation in our present configuration has been approved.
No additional compensatory actions are considered to be necessary.
SAFETY SIGNIFICANCE ANQ POTEt!TIAL CONSEODENCES All equipment required to function in the event on an accident remains capable of performing its intended function as defined in the FSAR and is, therefore, operable.
The potential consequences of accidents previously evaluated are not impacted.
The health and safety of the public is assured.
JUSTIFICATION FOR DURATlON OF THE WAIVER The_ issuance of the applicable license amendments dated June 10, 1992, received on June 12, 1992, and the FSAR revision is expected to occur on June 12, 1992.
These revisions will permit operation under the current conditions.
Therefore, the duration of noncompliance is expected to be minimal.
Compliance will be achieved at the time of issuance of these documents.
NO SIGNIFICANT HAZARDS CONSIDERATION We have evaluated this waiver against the standards in 10 CFR 50.92 and have determined that the operation of Point Beach Nuclear Plant Units 1 and 2 in accordance with this waiver does not result in a significant hazard.
Criterion 1 Operation of the Point Beach Nuclear Plant in accordance with this waiver does not result in an increase in the probability or consequences of an accident previously evaluated.
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Document Control Desk June 12, 1992 Page 5 The present requirement that loads sequence on the diesel generator in times less than those listed in the FSAR could result in two or more major loads sequencing onto the diesel at the same time or prior to generator voltage and frequency recovering following the start of an earlier load.
This presents the possibility of overloading the generator, resulting in generator trip and unavailability of systems and components necessary for accident mitigation, thereby increasing the probability or consequences of an accident.
By establishing appropriate tolerances on the load sequence times, assurance is gained that sufficient time is allotted between equipment starts to allow generator voltage and frequency to return to nominal system voltage and frequency.
This decreases the porsibility of a transient diesel generator overload.
Maximum start times including the tolerances will remain within the times assumed in the FSAR safety analyses.
Test frequencies or conditions for the diesel generators will not change.
- Overall, since the probability of a diesel generator overload decreases while maintaining assurance that the diesel generator will start and energize loads within the maximum times prescribed by accident analyses, the probability or consequences of accidents previously analyzed will decrease.
Criterion 2 Operation of the Point Beach Nuclear Plant in accordance with this waiver cannot create the poss!bility of an accident different from any previously evaluated.
This change does not result from any physical change to the facility or its operation.
The operability or equipment that is necessary for safe shutdown or accident prevention and mitigation is not affected.
Testing intervals for the diesel generator will not change; so adequate assurance of diesel generator and system operability is maintained.
Load sequence times will remain within conservative accident analyses assumptions, and added assurance is provided that a generator overload will not occur.
Therefore, a new or different kind of accident cannot result, gr.iterion 3 Operation of the Point Beach Nuclear Plant in accordance with this waiver will not present a significant hazard since it does not result in a significant reduction in a margin of safety.
The surveillance interval for nesting the diesel generator and its capability to assume loads required for ace' dent mitigation are not changed.
Continued assurance of generator and system operability under scenarios of an accident coupled with a loss of offsite AC
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-Document Control Desk June 12, 1992 Page 6 power is_ maintained.
This acceptance criterion for load sequence times provides added assurance that a generator overload condition will not occur while maintaining load sequence times within accident analyses assumptions.
This may provide an added margin of safety under conditions where a diesel generator is required to assume accident loads.
Therefore, a margin of safety cannot be reduced and may be increased.
DISCUSSION OF ENVIRONMENTAL CONSEOUENCES Operation of the Point Beach Nuclear Planc in this condition does not result in a change in the instellation or use of facilities or components as described in 10 CFR e0.
There is no increase or change in-the types of effluent that may be released offsite, and no increase in individual or cumulative occupational radiation exposure.
Therefore, this waiver meets the categorical exclusion requirements of 10 CFR 50.22(c) (9) and does not therefore require an environmental review.
STATE NOTIFICATION STATEMENT The appropriate staff member of the Public Service Commission of Wisconsin (PSCW) is provided with a copy of this application in accordance with 10 CFR 50.91 (b).
SUMMARY
A quorum of the PBNP Manager'a Supervisory Staff has met to discuss this issue and concurred with the decision to request this waiver.
We t;ve received verbal approval of this request from your offices per our telephone conversation with John Zwolinski and other NRC staff members at approximately 9:30 p.m. on June 11, 1992.
Please contact us should you have any questions or require additional information regarding this request.
Sincerely, f
Bob Link Vice President Nuclear Power Copies to Regional Administrator, Region III Resident Inspector
.