ML20207R965
| ML20207R965 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 03/03/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20207R964 | List: |
| References | |
| NUDOCS 8703180364 | |
| Download: ML20207R965 (4) | |
Text
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NUCLEAR REGULATORY COMMISSION 5
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 16 TO FACILITY OPERATING LICENSE NO. NPF-38 LOUISIANA POWER AND LIGHT COMPANY WATERFORD STEAM ELECTRIC STATION, UNIT 3 DOCKET NO. 50-382
1.0 INTRODUCTION
By application dated February 12, 1987, Louisiana Power and Light Company (the licensee) requested changes to the Technical Specifications (Appendix A to Facility Operating License No. NPF-38) for the Waterford Steam Electric Station, Unit 3.
The proposed change would revise the specification on Moderator Temperature Coefficient (MTC) to allow applicability of a special l
test exception while in Mode 1.
2.0 DISCUSSION During core physics testing associated with post refueling ascension to power, it was detemined that the MTC was positive at 70% power level. This slightly exceeded the predicted value and the technical specifications for operation beyond 70% power. Corrective action involves continuing testing until the MTC is negative beyond 70% power level. The period of time necessary to bring the MTC into specification is inversely proportional to power level.
In order to minimize the delay in power ascension the licensee proposes continuing the testing under the Special Test Exception pemitting testing to not to exceed 85% power.
The proposed change would revise Technical Specification 3.1.1.3 so that Technical Specification 3.10.2, the Special Test Exception on group height, l
insertion and power distribution limits, would apply in Mode 1, that is, for power operation above 5% power. Reactor power is presently limited to 70%
because, with the present fuel loading, soluble boron content, and control rod insertion limits, the MTC is projected to be more positive than the requirements of Technical Specification 3.1.1.3b.
Therefore, this Special Test Exception is needed by the licensee in order to pemit
. testing at 85% power.
If the exception is not granted, the licensee have to wait an extended period of time before being able to escalateg y above 70% because of the requirements imposed on the MTC (Technica] p fication 3.1.1.3).
8703180364 870303 PDR ADOCK 05000382 P
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3.0 EVALUATION ThepresengTechnicalSpecification3.1.1.3allowsamaximumpositiveMTCof
+0.5 x 10~ delta k/k/*F at and below 70% power and a maximum MTC of zero above 70% power. TheTechnicalSpgificationalsostatesthattheMTCshall be no more negative than -3.3 x 10 delta k/k/*F. This Technical Specification was approved by the staff for Cycle 2 operation and issued January 16, 1987 as Amendment No. 13 to the Waterford 3 operating license.
The licensee is presently in the process of perfoming physics startup tests at Waterford 3 for the Cycle 2 reloaded core.
In perfoming th zero power, the licensee found that the MTC exceeded +0.5 x 10~g MTC test at delta k/k/*F.
Thelicenseeadjustedthesolubleboroncongentrationofthecorewitha consequent change in the MTC to +0.45 x 10~ delta k/k/*F. The licensee detemined, from an extrapolation of the data, that the MTC would be slightly positive between 70% power and about 81% power, zero at about 81% power and negative for reactor power above 81% power.
This slightly positive MTC between 70% and 81% power prevents the licensee from increasing power to 85%, where additional physics testing would be conducted, without waiting for an extended period for time for additional fission products to build in. This additional operation at 70% power would allow the licensee to reduce the soluble boron concentration by about 30 ppm which would be sufficient to meet the MTC technical specification requirement.
i However, in order that the physics testing at 85% power may be performed now, the licensee proposes the Special Test Exception of Technical Specification 3.10.2 to apply to Mode 1 for Technical Specification 3.1.1.3.
ThelicenseeassessedtheimpactofaslightlyggsitiveMTCabove70% power.
The MTC was assumed to be a ramp from +0.5 x 10 delta k/k/*F at 70% power to zero at 90% power. This functional dependence of the MTC would bound the MTC values extrapolated from data between 70% and 85% power. The licensee i
reevaluated the transients and accidents sensitive to the MTC including the l
following:
(1) control element assembly (CEA) withdrawals, (2) loss-of-coolant flow. (3) loss of external load. (4) turbine trip (5) loss of i
feedwater, (6) CEA ejection, (7) loss of condenser vacuum, (8) loss of AC power, (9) and large and small break Loss-of-Coolant Accident (LOCAs).
With an MTC within the newly analyzed ramp from 70% to 90% power, the Doppler reactivity coefficient is sufficiently negative to assure a negative prompt reactivity coefficient in the power operating range in accordance.
with GDC 11. The licensee states that previous analyses of these and 6ther I
events evaluated remain bounding. Therefore, all applicable safety criteria are met if the Special Test Exception of Technical Specification 3.10.2 is granted for Technical Specification 3.1.1.3 for Mode 1 operation so that physics testing may be perfomed now at 85% power.
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The staff has reviewed the licensee's request and concludes that the proposed i
l modification of Technical Specification 3.1.1.2 to pemit the Special Test Exception of Technical Specification 3.10.2 to apply to Mode 1 operation is acceptable during startup for Cycle 2. Staff approval of the request was granted to the licensee by phone on February 13, 1987.
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4.0 FINAL NO SIGNIFICANT HAZARDS CONSIDERATION
DETERMINATION i
The staff has reviewed the licensee's proposed changes as they relate to the three criteria of 10 CFR 50.92.
This change is proposed to accommodate the wider range in MTC values necessary to prevent derating at the beginning of Cycle 2.
The ESAR Chapter 15 events that are limiting with respect to MTC have been reviewed and found to remain valid with respect to the expected Waterford 3 operating window and the proposed change, which would allow applicability of Special Test Exception 3.10.2 while in Mode 1.
Therefore, a significant increase in the probability or consequences of any accident previously evaluated will not result from implementation of the proposed change.
i This revision addresses minor changes in values of core parameters as detemined from measurements taken during low power physics testing. As i
such, no new failure or accident path is created. Therefore, this change 1
does not create the possibility of any new or different kind of accident.
The intent of this change is to limit the potential derating of Waterford 3 while ensuring that the assumptions used in the FSAR Chapter 15 accident analyses remain valid. The accident analyses have been reviewed assuming the proposed MTC limits. This review has shown that all of the events remain bounded by the results shown in the Reload Analysis Report for Cycle 2 operations (approved by NRC letter dated January 16, 1987, tothelicensee) i.
and, consequently, comply with the applicable acceptance criteria in the Standard Review Plan. Therefore, this change will not involve a significant reduction in a margin of safety.
The staff, therefore, concludes that operation of the facility in accordance with the proposed change does not represent a significant hazards consideration.
5.0 CONTACT WITH STATE OFFICIAL The NRC staff advised the A kinistrator, Nuclear Energy Division, Department i
of Environmental Quality, State of Louisiana of the final detemination of no significant hazards consideration by phone on February 13, 1987. The State had no comments on this detemination.
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6.0 ENVIRONMENTAL CONSIDERATION
This amendment involves changes in the installation or use of facility components j
located within the restricted area. The staff has detemined that the amendment involves no significant increase in the amounts and no significaat change l
in the types of any effluents that may be released offsite and that there is no significant increase in individual or cumulative occupational 4adiation i
exposure. Accordingly, the amen hent meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of this amendment.
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7.0 CONCLUSION
Based upon our evaluation of the proposed change to the Waterford 3 Technical Specifications, we have concluded that:
there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and such activities will be conducted in compliance with the Commission's regulations and the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
We, therefore, conclude that the proposed change is acceptable.
Principal Contributor:
D. Fieno Dated:
Nhrch 3, 1987 I
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