ML17332A821
| ML17332A821 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 06/23/1995 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17332A820 | List: |
| References | |
| NUDOCS 9506300218 | |
| Download: ML17332A821 (3) | |
Text
gPR RE00 P0 Cy A,0 o~$
c-,
<r~
~O
~+*++
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO, 195 TO FACILITY OPERATING LICENSE NO.
DPR-58 ND AMEND ENT 0.
181TO FACILITY OPERATING LICENSE NO, DPR-74 INDIANA MICHIGAN POWE COMPANY DONALD C.
COOK NUCLEAR PLANT UNIT NOS.
1 AND 2 DOCKET NOS. 50-315 AND 50-316
- 1. 0 INTRODUCTION By letter dated March 31, 1995, 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 revise the Limiting Condition for Operation (LCO) for TS 3/4.6. 1.7 to redefine the conditions under which it is permissible to operate the containment purge system in Modes 1, 2, 3, and 4.
The proposed modification to the LCO would read:
"The containment purge supply and exhaust isolation valves shall be closed except when operation of the containment purge system is required for pressure
- control, ALARA [as low as is reasonably achievable],
and respirable air quality considerations for personnel entry and for surveillance testing and maintenance activities."
Additionally, the Bases for TS 3/4.6. 1.7 would be revised to address the changes to the LCO, to increase the allowable annual purge time from 200 hours0.00231 days <br />0.0556 hours <br />3.306878e-4 weeks <br />7.61e-5 months <br /> to 240 hours0.00278 days <br />0.0667 hours <br />3.968254e-4 weeks <br />9.132e-5 months <br />, to add a reference to the ability of the purge isolation valves to close against loss-of-coolant accident (LOCA) forces in order to meet 10 CFR Part 100 guidelines, and to delete an unnecessary footnote.
2.0 EVALUATION The purge supply and exhaust system is designed to reduce airborne
'adioactivity within the containment structure to safe levels prior to entry.
Purge air is supplied to the containment through two fans with associated filters and heating coils.
Purge air is exhausted to the plant vent where it is radiation-monitored before release to the atmosphere.
There are four
'ontainment penetrations for this system:
one supply and one exhaust air penetration into the upper containment and one supply and one exhaust air penetration into the lower containment.
Each penetration has two air-operated fail-closed isolation valves (one on either side of the penetration).
The valves will receive a containment ventilation isolation signal on both 950b3002ia 950b23 PDR nDCICX 050003l5 PDR
safety injection and high radiation signals and close within 5 seconds.
These valves are normally closed when the purge system is not in operation.
The purge system does not have short-term function if there is a
LOCA.
The purge system may be energized so that entry may be made.
The maximum purge rate is approximately 1', air changes of the total containment volume per hour.
The proposed change to LCO 3.6. 1.7 would allow use of the containment purge system for pressure
- control, ALARA, and respirable air quality considerations for personnel entry and maintenance and surveillance activities.
Currently, use is only allowed for "safety-related reasons."
"Safety-related reasons" is defined in the Cook TS Bases as "the need to improve containment working conditions, e.g.,
reduce airborne activity, to perform surveillance and/or maintenance on a safety-related system or piece of equipment."
The licensee states that the limitation of safety-related reasons to surveillance and/or maintenance on safety-related (emphasis added) systems or equipment has inhibited the use of containment purge for personnel work on "non-safety" equipment.
This potentially exposes personnel to an unnecessarily hazardous environment.
The licensee has stated that the containment purge system at Cook has been designed in accordance with NRC Branch Technical Position CSB 6-4, Rev. 1, and demonstrated to be capable of closure against the dynamic forces associated with a LOCA.
In accordance with the Branch Technical Position, the potential site boundary doses were calculated based on the original analysis used to determine the radiological consequences of a LOCA.
The results of this analysis indicated a total thyroid dose of 165 rem for the 0-2 hour site boundary dose and a whole-body dose of 9.32 rem.
Since physical changes will not result from the proposed amendments, the site boundary dose guidelines of 10 CFR Part 100 will not be exceeded in the event of an accident during containment purging operations.
The proposed change is consistent with NUREG-1431, the improve'd Standard Technical Specifications Westinghouse
- Plants, September 1992 (iSTS).
The iSTS require the purge valves to be closed except when "open for pressure
- control, ALARA or air quality considerations for personnel entry, or Surveillances that require the valves to be open."
Based on the facts that compliance with 10 CFR Part 100 is not affected by the proposed change and the change is consistent with the iSTS and other TS issued by the staff, the proposed change to LCO 3.6. 1.7 is acceptable.
The licensee has also proposed changes to TS Bases 3/4.6. 1.7.
The most significant is to increase the current purge limit of 200 hours0.00231 days <br />0.0556 hours <br />3.306878e-4 weeks <br />7.61e-5 months <br /> per year to 240 hours0.00278 days <br />0.0667 hours <br />3.968254e-4 weeks <br />9.132e-5 months <br />.
The original limit was calculated based on a unit capacity factor of 77%.
As a result of longer operating cycles and improved plant performance, the Cook Nuclear Plant capacity factor is now forecasted to be 93%.
Utilizing the same calculation which established the 200-hour limit, and increasing the capacity factor to 93%, yields a value of 240 hours0.00278 days <br />0.0667 hours <br />3.968254e-4 weeks <br />9.132e-5 months <br />.-
The licensee has stated that the addition of 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> of allowable annual purge time will not result in a significant increase in the amount of effluent released.
Licensee compliance with the Offsite Dose Calculation Manual (ODCM)
will ensure that the dose rate at any time at the site boundary from gaseous effluent from all units on the site will be within the annual dose limits of 10 CFR Part 20, Appendix B, Table 2, Column 1 for Unrestricted Areas.
This change is consistent with TS issued for other facilities and is within the guidance of the iSTS which provides no specific limitation of the allowable time per year for purging operations.
Based on the licensee's commitment per its ODCH to monitor and, as appropriate, limit offsite
- releases, the proposed change to increase the purge limit is acceptable.
The other proposed changes to Bases section 3/4.6.1.7 support the previous changes and are, therefore, acceptable.
3.0 STATE CONSULTATIO In accordance with the Commission's regulations, the Michigan State official was notified of the proposed issuance of the amendments.
The State official had no comments.
- 4. 0 ENVIRONMENTAL CONSIDERATION The amendments change requirements with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.
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 cumulative occupational radiation exposure.
The Commission has previously issued a proposed finding that the amendments involve no significant hazards consideration and there has been no public comment on such finding (60 FR 20520).
Accordingly, the amendments meet 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 the amendments.
- 5. 0 CONCLUSION The staff has concluded, based on the considerations discussed above, that:
(1) 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 the amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
John B. Hickman Date:
June 23, 1995