ML17329A274
| ML17329A274 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 11/20/1991 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17329A273 | List: |
| References | |
| NUDOCS 9112090381 | |
| Download: ML17329A274 (4) | |
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UNITEDSTATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 159 TO FACILITY OPERATING LICENSE NO.
DPR-58 AND AMENDMENT NO. 143 TO FACILITY OPERATING LICENSE NO. DPR-74 INDIANA MICHIGAN POMER COMPANY DONALD C.
COOK NUCLEAR PLANT UNIT NOS.
1 AND 2 DOCKET NOS.
50-315 AND 50-316
- 1. 0 INTRODUCTION By letter dated September 10, 1990, the Indiana Michigan Power Company (the licensee) requested amendments to the Technical Specifications (TS) appended to Facility Operating License Nos.
DPR-58 and DPR-74 for the Donald C. Cook Nuclear Plant, Unit Nos.
1 and 2.
The proposed amendments would reduce the allowable control room,air temperature from 120'F to 95'F and also change the related Bases to the TS.
2.0 BACKGROUND
During the period of September 15-19, 1986, a survey was conducted of the control room ventilation system at the D. C.
Cook Nuclear Plant.
The survey team was led by J.
Hayes of the NRC, with assistance from contractors from Argonne National Laboratory.
The team's review included control room habitability TS changes that the licensee had submitted in July 1986 as a
result of NUREG-0737, Item III.D.3..4 and the subsequent Generic Letter 83-37.
The team found problems with the TS submittal and with the control room habitability analyses that supported the change.
As a result, the licensee withdrew their proposed TS changes by letter dated April 29, 1988.
By letter dated October 11, 1988, the licensee provided revised control room habitability analyses and by letter dated June 29, 1989, provided proposed revised control room habitability TS changes.
N The June 29, 1989 TS submittal was to address the concerns of the survey team except for one item regarding the maximum control room temperature.
The TS have always limited the control room temperature to 120'F.
This value remained unchanged throughout previous licensee TS submittals.
The survey team, in their report, asked two questions concerning the adequacy of this temperature, specifically: (1) Is the temperature consistent with equipment qualification temperatures and (2) Does the temperature limit consider that temperatures inside various panels,may be much higher than the ambient room temperature?
91i209038i 9iii20 PDR ADOCK 050003i5 P
In their June 29, 1989 submittal, the licensee committed to perform a study of the control room temperature limit and to propose any necessary changes by September 1990.
The licensee completed their study and determined that a
temperature limit of 95'F is more appropriate.
The licensee's June 29, 1989, submittal remains under staff review and will be the subject of separate correspondence.
3.0 EVALUATION The Bases for TS 3/4.7.5.1, describe the purpose of the control room temperature limit as ensuring that the ambient air temperature does not exceed the allowable temperature for the continuous-duty rating for the equipment and instrumentation cooled by the control room ventilation system.
In researching the adequacy of the 120'F limit, the licensee considered the sensor location and the ambient room temperature which were both concerns of the survey team.
The non-Westinghouse critical instruments are located in open racks and not enclosed panels.
These devices are all continuous-duty rated above 120'F.
The control room temperature probe used for determining the TS temperature (the DTU panel probe) is nested in the open rack behind the control room DTU panel.
The temperature measured at this probe location was found to be within I I/2 degrees of the temperatures measured at the other critical locations within the racks.
The Westinghouse panels are temperature rated as a complete unit based on the control room ambient temperature, not the temperature inside the panel.
As the ambient temperature
- rises, the rated life of the equipment in the panel decreases.
During the testing, the ambient temperature measured at each Westinghouse panel was at or below the control room temperature at the DTU panel probe.
The DTU panel indicates a temperature very close to the ambient temperature 'surrounding the Westinghouse panels.
The DTU panel readout, provides an appropriate temperature to be used to determine TS temperature.
The panels are well ventilated and during testing, temperature rises through the panels were observed to be low.
As discussed
- above, the critical non-Westinghouse equipment is continuous-duty rated for room ambient temperatures above 120'F.
Regarding the Westinghouse equipment, the panel with the highest expected ambient temperature would have a rated life of approximately 15,000 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> at 95'F.
At 80'F, equipment life exceeds the life of the plant.
The control room ventilation system typically maintains the control room at an average temperature of approximately 75'F year round.
The licensee has stated that the control room temperature has been above 80'F as measured at the DTU panel only on rare occasions, for limited time periods.
I 1
Although the licensee's proposed TS change to 95'F for the control room temperature limit is higher than the continuous-duty rating of 80'F for Westinghouse equipment, rated equipment life at this temperature (15,000 hours0 days <br />0 hours <br />0 weeks <br />0 months <br />) is sufficiently long to provide reasonable assurance that the rated life will not be exceeded.
Based on the above considerations, the staff.has determined that the licensee will acceptably resolve the equipment qualification concerns for control room instrumentation with the proposed lower temperature set point.
4.0 ENVIRONMENTAL CONSIDERATION
The amendments change the requirements with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 or changes in surveillance requirements.
The staff has determined that the amendments involve 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 cuoalative occupational radiation exposure.
The Commissiori has previously issued a proposed finding that these amendments involve no significant hazards consideration and there has been no public comment on such finding.
Accordingly, these amendments meet the eligibility criteria for categorical exclusion set 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 these amendments.
5.0 CONCLUSION
The staff has concluded, based on the considerations discussed above that
-(I) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed
- manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of these amendments will not be inimical to the common defense and security or to the health and safety of the public.
Date:
November 20, 1991 Principal Contributor:
T. Colburn