ML030350162
| ML030350162 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 02/04/2003 |
| From: | Vissing G NRC/NRR/DLPM/LPD1 |
| To: | NRC/NRR/DLPM |
| Vissing G, NRR/DLPM, 415-1441 | |
| References | |
| TAC MB6989, TAC MB6990 | |
| Download: ML030350162 (5) | |
Text
February 4, 2003 MEMORANDUM TO: Biweekly Notice Coordinator FROM: Guy S. Vissing, Senior Project Manager,Section I /RA/
Project Directorate I Division of Licensing Project Management
SUBJECT:
REQUEST FOR PUBLICATION IN BIWEEKLY FR NOTICE -
NOTICE OF CONSIDERATION OF ISSUANCE OF AMENDMENTS TO RENEWED FACILITY OPERATING LICENSES, PROPOSED NO SIGNIFICANT HAZARDS CONSIDERATION DETERMINATION, AND OPPORTUNITY FOR A HEARING (TAC NOS. MB6989 AND MB6990)
Calvert Cliffs Nuclear Power Plant, Inc., Docket Nos. 50-317 and 50-318, Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2, Calvert County, Maryland Date of amendments request: December 13, 2002 Description of amendments request: The proposed amendments would revise Technical Specification 3.5.2, Emergency Core Cooling System - Operating, by removing the Note that modifies the Limiting Condition for Operation. The proposed change would remove the requirement to have the charging pumps operable when thermal power is greater than 80%
of rated thermal power (RTP). The proposed change would also remove Surveillance Requirement 3.5.2.4 for verifying the required charging pump flow rate.
Basis for proposed no significant hazards consideration determination: As required by 10 CFR 50.91(a), the licensee has provided its analysis of the issue of no significant hazards consideration, which is presented below:
- 1. Would not involve a significant increase in the probability or consequences of an accident previously evaluated.
The charging pumps were credited in the previous analysis to mitigate the consequences of a small-break loss-of-coolant accident (LOCA) above 80%
of rated thermal power (RTP). The charging pumps were not considered to be an initiator of the accident. The new analysis for the small-break LOCA does not assume the charging pumps are initiators of the accident.
Therefore, removing the requirement to maintain the charging pumps
Biweekly Notice Coordinator operable above 80% RTP and removing Surveillance Requirement 3.5.2.4 from the Technical Specification does not involve a significant increase in the probability of an accident previously evaluated.
The consequence of a small-break LOCA is the potential for inadequate core cooling and decreased negative reactivity such that the reactor core is not protected after the design basis event. The previous analysis for the small-break LOCA above 80% RTP assumed unborated flow from a single charging pump to ensure there was adequate cooling flow delivered to the Reactor Coolant System. The revised small-break LOCA analysis was performed such that flow from the charging pumps was not credited. Since the charging pump flow is no longer credited in the small-break LOCA analysis, the proposed changes do not involve a significant increase in the consequences of a small-break LOCA.
Therefore, the proposed Technical Specification changes do not involve a significant increase in the probability or consequences of an accident previously evaluated.
- 2. Would not create the possibility of a new or different [kind] of accident from any accident previously evaluated.
This request[ed] change does not involve a change in the operation of the plant and no new accident initiation mechanism is created by the proposed changes. Since the charging pump flow is no longer credited in the small-break LOCA analysis, the requirement to have the charging pumps operable above 80% RTP and the charging pump Surveillance Requirement 3.5.2.4 can be removed from the Technical Specification. The proposed change does not involve a physical alteration of the plant (no new or different type of equipment will be installed) or a change in the methods governing normal plant operation. Therefore, the proposed changes do not create the possibility of a new or different kind of accident from any previously evaluated.
- 3. Would not involve a significant reduction in a margin of safety.
The safety function of the Emergency Core Cooling System is to provide core cooling and negative reactivity, to ensure that the reactor core is protected after design basis events. For a small-break LOCA, the previous analysis credited flow from the charging pumps above 80% RTP to supply supplemental cooling flow to the Reactor Coolant System. Credit for flow from a single charging pump was only taken for the water inventory.
The revised small-break LOCA analysis was performed using the newest Nuclear Regulatory Commission accepted versions of the Westinghouse evaluation models for Combustion Engineering designed pressurized water reactors. The revised small-break LOCA analysis incorporated several changes to plant parameters used in the analysis, one of which was the elimination of the need to credit the charging pump flow above 80% RTP.
Biweekly Notice Coordinator Since the charging pump flow is no longer credited in the small-break LOCA analysis, the requirement to have the charging pumps operable above 80%
RTP and charging pump Surveillance Requirement 3.5.2.4 can be removed from the Technical Specification.
The proposed change to Technical Specification 3.5.2 does not modify any other charging pump requirements specified in the Technical Requirements Manual (e.g., requirements on charging pump availability for boration and cooldown remain in effect).
Therefore, the safety function of the Emergency Core Cooling System is maintained and the margin of safety is not significantly reduced by the proposed changes.
The NRC staff has reviewed the licensees analysis and, based on this review, it appears that the three standards of 10 CFR 50.92(c) are satisfied. Therefore, the NRC staff proposes to determine that the amendments request involves no significant hazards consideration.
Attorney for licensee: Jay E. Silberg, Esquire, Shaw, Pittman, Potts and Trowbridge, 2300 N Street, NW., Washington, DC 20037.
NRC Section Chief: Richard J. Laufer
Biweekly Notice Coordinator Since the charging pump flow is no longer credited in the small-break LOCA analysis, the requirement to have the charging pumps operable above 80%
RTP and charging pump Surveillance Requirement 3.5.2.4 can be removed from the Technical Specification.
The proposed change to Technical Specification 3.5.2 does not modify any other charging pump requirements specified in the Technical Requirements Manual (e.g., requirements on charging pump availability for boration and cooldown remain in effect).
Therefore, the safety function of the Emergency Core Cooling System is maintained and the margin of safety is not significantly reduced by the proposed changes.
The NRC staff has reviewed the licensees analysis and, based on this review, it appears that the three standards of 10 CFR 50.92(c) are satisfied. Therefore, the NRC staff proposes to determine that the amendments request involves no significant hazards consideration.
Attorney for licensee: Jay E. Silberg, Esquire, Shaw, Pittman, Potts and Trowbridge, 2300 N Street, NW., Washington, DC 20037.
NRC Section Chief: Richard J. Laufer DISTRIBUTION:
Non-public PDI-1 R/F RLaufer GVissing SLittle OGC G:\PDI-1\CC1-2\MB6989.bwn.wpd Accession Number: ML030350162 OFFICE PDI-1/PM PDI-1/LA PDI-1/SC NAME GVissing SLittle RLaufer DATE 2/4/03 2/3/03 2/4/03 OFFICIAL RECORD COPY