ML17319A871
| ML17319A871 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 05/13/1981 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17319A872 | List: |
| References | |
| NUDOCS 8105260028 | |
| Download: ML17319A871 (4) | |
Text
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o UNITED STATES NUTBAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION AMENDMENT NO.
31 TO FACILITY OPERATING LICENSE NO.
DPR-74 INDIANA AND MICHIGAN ELECTRIC COMPANY DONALD C.
COOK NUCLEAR PLANT UNIT NO.
2 DOCKET NO. 50-316 Introduction In a letter dated May 1, 1981 to H.
R. Denton, Indiana and Michigan Electric Company (I8MEC) requested changes to the D.
C.
Cook Unit 2 Technical Specifi-cations for the Axial Power Distribution Monitoring System (APDMS) to,accomroadate a slightly different core power profile predicted for the Cycle 3 design of the reactor.
In addition in the May 1, 1981 letter ISMEC requested changes to the P-7 permissive (interlock) technical specification.
By letter dated May 7, 1981 I&MEC provided additional information with regard to the APDMS technical specification change requests.
Evaluation l.
Axial Power Distribution Monitoring System (APDMS).
Westinghouse Electric Corporation has performed calculations for the DE C.
Cook Unit 2 Cycle 3 reload which predict a slightly higher axial core power profile than the previous cycle.
The calculations used approved techniques for predicting the maximum height-dependent peaking factors expected during a reload Cycle 1
and 2.
There is no change in the peaking factor envelope (1.99 x the axial shaping curve) which must be maintained in normal operation of the power plant because these peaking factors are used as initial conditions in the LOCA analysis.
- However, above the power level which is defined as the ratio of the highest predicted axially dependent peaking factor to the LOCA envelope, additional survei.llance of the peaking factor is required in the form of 'the Axial Power Distribution Monitoring System (APDMS).
This level, called the APDMS turn on power i,s reduced to 81 percent of rated thermal power for the predicted Cycle 3 peaking factor envelope.
Because of the reduced APDMS turn on point, the axial flux difference limits'as a function of thermal power are also changed.
We have reviewed the change as well as the APDMS turn on point and find them satisfactory.
Since the proposed Technical Specification'hanges use approved techniques and changes do not reduce the safety margins required to meet 10 CFR 50.46 and Appendix K, we find them acceptable for Cycle 3 operation of D.
C.
Cook Unit 2.
2.
P-7 Permissive (Interlock).
The P-7 permissive (interlock) is applied to remove the automatic block to reactor trip (when reactor power increases a bove approximately 10 percent) from low reactor coolant flow in more than one loop, reactor coolant pump under voltage, reactor coolant pump under frequency, turbine trip, pressurizer low pressure and pressurizer high level.
A two out of four Power Range Neutron Flux channel trip or, a one out of the Turbine Impulse Chamber Pressure channel trip will remove the automatic block.
ISHEC in the recent refueling outage has modified the unit's high pressure turbine and has raised the Impulse Chambers Pressure channel trip setpoint to 66 psia (previously set at 55 psia).
The new trip setpoint will not violate the approximately 10 percent reactor power limit for removal of the automatic block to reactor trip.
We have reviewed the I8MEC proposed interlock P-7 trip setpoint
- change, in Table 3,3-1 of the technical specifications for D.
C.
Cook Unit 2 and find it acceptable.
Environmental Consideration We have determined that the amendment does not authorize a change in effluent types or total amounts nor an increase in power level and will not result in any significant environmental impact.
Having made this determination, we have further concluded that the amendment involves an action which is insignificant from the standpoint of environmental impact and, pursuant to 10 CFR 551.5(d)(4),
that an environmental impact statement or negative declaration and environmental impact appraisal need not be prepared in connection with the issuance of the amendment.
Conclusion We have concluded, based on the considerations discussed above, that:
(1) because the amendment does not involve a significant increase in the probability or consequences of accidents previously considered and does not involve a significant decrease in a safety margin, the amendment does not involve a significant hazards consideration, (2) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed
- manner, and (3) 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.
Mgy 1 8 1981
REFERENCES l.
"Fq Envelop Calculations,"
C.
E. Eicheldinger letter NS-CE-687 to D.
B. Yassallo (NRC) dated June 27, 1975.
2, "Justification of Peaking Factor Subcase Analysis,"
C.
E. Eicheldinger letter NS-CE-1749 to J.
F. Stolz (NRC) dated April 6, 1978.