ML19296B141
| ML19296B141 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Quad Cities  |
| Issue date: | 02/01/1980 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19296B140 | List: |
| References | |
| NUDOCS 8002200145 | |
| Download: ML19296B141 (1) | |
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UNITED STATES
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NUCLEAR REGULATORY COMMISSION
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SAFETY EVALUATION BY THE OFFICE OF flVCLEAR REACTOR REGULATION SUPPORTING AMENDMENT fl0. 46 TO PROVISIONAL OPERATING LICENSE fl0. DPR-19 AMENDMENT NO. 40 TO FACILITY OPERATING LICENSE N0. DPR-25 AND AMENDMENT NO. 55 TO FACILITY OPERATING LICENSE N0. DPR-29 COMMONWEALTH EDISON COMPANY DRESDEN NUCLEAR POWER STATION, UNIT N05. 2 AND 3 QUAD CITIES STATION, UNIT NO. 1 DOCKET NOS. 50-237, 50-249 AND 50-254 Introduction By letters cated January 24 and January 28, 1980, Commonwealth Edison
' Company (CECO), the licensee, proposed to amend Appendix A. Technical Specifications, for Ope. ating Licenses DPR-19, DPR-25 and DPR-29 for Dresden Units 2 and 3 and Quad Cities Unit 1, respectively.
In their review of IE Bulletin 80-01, the licensee raised several questions on the seismic design of the Automatic Depressurization System (ADS). Therefore, the licensee has proposed more restrictive Technical Specifications until these seismic questions on ADS are resolved. Quad Cities Unit 2 will be modified before restart from the current refueling outage, and Dresden Unit 1 does not have ADS.
This addresses all the licensee's plants which are to respond to IE Bulletin 80-01. All responses to this bulletin are currently being addressed by the Office of Inspection and Enforcement.
Discussion and Evaluation ADS is a redundant part of the emergency core cooling system (ECCS) and is designed to depressurize the reactor coolant system for the small break loss of coolant accident (LOCA) in the event of a failure of the High Pressure Coolant Injection (HPCI) system.
IE Bulletin 80-01 required that the licensee review the seismic qualifica-tion of ADS air supply system. At each of the Dresden and Quad Cities Units (except Dresden 1), one out of the five ADS valves is a Target-Rock valve which uses an air supply system.
In order to provide conservative Technical Specifications while the seismic review is performed, the licensee has performed a reanalysis of the small break LOCA with the air supplied ADS valve assumed increrable.
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. From this reanalysis, the licensee has proposed reduction in maximum average planar linear heat generation rate (MAPLHGR) Technical Specification limits for all fuel types. The reanalysis was plant specific for breaks of 0.1 ft2 and smaller in the recirculation suction line. Breaks in this size range are those most affected by the loss of ADS capacity. The analysis assumed one core spray (CS) and two low pressure coolant injection (LPCI) pumps would be available together with four of the ADS valves. This established a conservative small break spectrum analysis which assumed a DC power source failure as the limiting single failure. The analysis was performed for only the limiting fuel type and exposure value.
These assumptions were verified by sensitivity studies.
This analysis is consistent and conservative with respect to currently accepted ECCS methodology. The results of this analysis show that the peak clad temperatures remain below the Appendix K limit of 2200 F when MAPLHGR limits are reduced to 86.8% for Dresden 2 and Quad Cities 1 and to 95.4% for Dresden 3, of those given in Section 3.5 of the Technical Specifications for each unit.
On the above bases, we conclude that the proposed amendments to plant Technical Specifications are acceptable.
Environmental Considerations We have determined that these amendments do 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 determinations, we have further concluded that these amendments involve an action which is insignificant from the standpoint of environmental impact, and pursuant to 10 CFR Section 51.5(d)(4) that an environmental impact statement, or negative declaration and environmental impact appraisal need not be prepared in connec-tion with the issuance of these amendnent.
Conclusion We have concluded, based on the considerations discussed above, that:
(1) be-cause the amendments do not involve a significant increase in the probability or consequences of accidents previously considered and do not involve a signifi-cant decrease in a safety margin, the amendments do 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 these amendments will not be inimical to the common defense and security or to the health and safety of the public.
Dated:
February 1, 1980