ML19210C351
| ML19210C351 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 10/26/1979 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19210C348 | List: |
| References | |
| NUDOCS 7911140123 | |
| Download: ML19210C351 (2) | |
Text
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ff UNITED STATES y 'f -,
g NUCLEAR REGULATORY COMMISSION 3 gQ-jjy WASHINGTON, D. C. 20555
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SAFETY EVALUATION BY THE
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OFFICE OF NUCLEAR REACTOR REGULATION REGARDING OPERATION WITH A PROTOTYPE CEA BALTIMORE GAS & ELECTRIC COMPANY CALVERT CLIFFS UNITS NOS.1 AND 2 FACILITY OPERATING LICENSE NOS. DPR-53 AND 69 DOCKET. N,0S. 50-317 AND 318 Introduction By letter dated February 23, 1979, Baltimore Gas & Electric Company (BG&E or the licensee) made application for an amendment to authorize operati, of Calvert Cliffs Nuclear Power Plant Unit No.1 (CCNPP-1) for a fourth ycle.
A portion of this application, as supplemented by proprietary report CEN-105 (B)-P submitted on March 5,1979, was to use a prototype control element assembly (CEA). However, BG&E decided not to install the prototype CEA in CCNPP-1 Cycle 4 but to hold it as a spare CEA for possible installation in the next cycle of CCNPP-2. The purpose of this Safety Evaluation is to document our review of the prototype CEA to be used as a spare CEl. at the discretion of the licensee.
Discussion and Evaluation The prototype CEA incorporatas 3 design changes from the standard CEA used in facilities designed by Combustion Engineering (CE). The first change involves a change in cladding material. The second design change involves the tip design of the outer 4 control elements in the CEA. Both the above changes are being made for reasons of economics and improved material availability. The third change being implemented on the prototype CEA is the method of connection of the 4 outer control elements to the CEA spider.
The new method of attachment permits removal and replacement of CEA rods during normal refueling outages so that the CEA can be used continuously.
The licensee has verified that this prototype CEA will have essentially the same vibratory characteristics as the standard CEA. Therefore, the CEA guide tube wear problem, that has been experienced at CE facilities and corrected on an intem basis by sleeving of the guide tubes, will not be adversely affected. BME will, in addition, install the prototype CEA in a typically low guide tube wear location. We find the CEA mechanical design to be acceptable.
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. The licensee has verfied the prototype CEA meets the same design criteria and has the same design margin as the CEAs presently in use. The change in rod worth for the prototype CEA considering the changes to the cladding and the changes to the tips of the outer 4 control elements is less than 0.5 percent of the rod worth. This will have a minimal impact on anticipated operational occurrences and accident analyses. We find this small change in rod worth acceptable.
Conclusion We have concluded, based on the considerations discussed above, that operation of either Clavert Cliffs unit with the prototype CEA installed in a typically low guide tube wear location is acceptable.
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