ML20033E881
| ML20033E881 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 03/05/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20033E879 | List: |
| References | |
| NUDOCS 9003150014 | |
| Download: ML20033E881 (3) | |
Text
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SMETY EVALUATION BY THE OFFICE OF HUCLEAR REACTOR REGULATION RLLATED T0- AMENDMENT NO. 36 TO FACILITY OPERATING LICENSE NO. NPF-42 WOLF CREEK _ NUCLEAR OPERATING CORPORATION WOLF CREEK GENERATING STATION DOCKETN0.;10_-482 INTRODUCTION By letter dated June 19, 1987 Wolf Creek Huclear Operating Corporation submitted proposed changes to Technical Specification 3/4.10.4 for the Wolf Creek Generating Station.
Technical Specification (TS) 3/4.10.4, Reactor Coolant Loops, is a special test exception that allows certain requirements to be suspended provided specific criteria are met. One of the requirements that may be suspended is TechnicalSpecification3.4.1.1,provided1)thethermalpowerdoesnotexceed the P-7 Interlock Setpoint, and 2) the Reactor Trip Setpoints on the OPERABLE Intermediate and Powe* Range' channels are set less than or equal to 25% of RATED THERMAL POWER.
This test exception is applicable for operations below the P-7 Interlock Setpoint, or during performance of hot rod drop time measurements. The reactor trip breakers'are opened if the thermal power exceeds the P-7 Interlock Setpoint during the performance of the startup and PHYSICS' TESTS.
The Surveillance requirements related to THERHAL POWER are as follows:
4.10.4.1 The THERMAL POWER must be determined to be less than the P-7 Interlock Setpoint at least once per hour during the startup and PHYSICS TESTS.
4.10.4.2 Each intermediate and Power Range channel, and P-7 Interlock shall be subjected to an ANALOG CHANNEL OPERATIONAL TEST within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> prior to initiating startup and PHYSICS TESTS.
The licensee requests that the above references to the P-7 Interlock be changed to reference the r-10 Interlock.
An evaluation of this request is presented-in-this safety evaluation.
EVALUATION The P-7 Interlock is a Reactor Protection System permissive that unblocks certain Reactor Trips when the indicated thermal power exceeds 10% of the unit rated thermal power. The P-7 interlock status is derived from a bistable circuit that uses the P-10 Interlock and the P-13 Interlock as input signals.
Either P-10 or P-13 will ar*--te e ? P 7 bistable circuit.
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The P-10 Interlock input signal represents the unit thermal power as measured by the neutron ficx in the reactor core. The P-10 permissive is actuated when r
nuclear power is above ten percent on two of four channels. This setpoint ensures that proper overlap exists between intermediate and power ranges before power level is increased. The P-10 Interlock allows manual blocking of
~ the power range l(low setpoint) reactor trip, the intermediate range reactor trip,:and the intermediate rod stops when the reactor power is above 10% of rated thermal power. The P-10 Interlock is also used as a backup to block the sourco range reactor trip. When power is reduced below the P-10 setpoint (10%ratedthermalpower),alloftheabovementionedtripsandtherodstops are automatically-reinstated.
Another indication of unit thermal power is the main turbine first stage impulse pressure. The F-13 Interlock provides a signal when one-of-two main l
turbine impulse pressure channels indicate an equivalent power greater than 10% of the unit rated thermal power.
l The main turbine is kept on the turning gear during operations under TS o
- 3/4.10.4 at the Wolf Creek Generating Station. With the main-turbine on the L
turning gear, the-P-13 Interlock will not actuate because the turbine first stage impulse pressure channels indicate zero thermal power.- Consequently, P-10 provides the only signal to the P-7 Interlock while the plant is-performing this Technical Specification.
Since the P-13 Interlock cannot trip.
1 the reactor, P-10 may be monitored instead of-P-7, and it is not necessary to perform the associated surveillance requirements for P-13.
Since the P-13 signal to the P-7' Interlock during operations under TS.3/4.10.4 tests indicates a constant 0% thermal power, the licensee request to perform surveillance only l
for the P-10 Interlock Setpoint is acceptable.
Any requests for Technical Specification changes that result in an increase in the P-10 Interlock Setpoint must show that the resulting increase in the i
thermal power threshold during operations under TS 3/4.10.4 does not impact the safe operation of the plant.
EtiVIR0ftliEllTAL_ C0flSIDERAT_ ION l
-The amendment involves a change in a requirement with respect to the installa-tion or use of a facility component located within the restricted area as.
defined in 10 CFR Part 20 and changes in surveillance requirements. The staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released.offsite,-and that there is no significant increase in individual or cumulative occupational radiation exposures. The Commission has previously issued a proposed finding that the amendment involver no significant hazards consideration and there has been no public comment on such finding. Accordingly, the amendment meets the eligibility criteria for categorical exclusion set 1
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forth in 10 CFR Section 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 the amendment.
CONCLUSION The staff has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the will not be endangered by operation in the proposed manner, and (2) public such activities will be conducted in compliance with the Comission'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.
Date:
March 5, 1990 L
Principal Contributors: Michael E. Waterman Barry S. Marcus I
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