ML19249C390
| ML19249C390 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 08/13/1979 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19249C388 | List: |
| References | |
| NUDOCS 7909100613 | |
| Download: ML19249C390 (1) | |
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SAFETY EVALUATION OF THE PR0 POSED CHANGES TO TECHNICAL S_PICIFICATIONS RE: DC ELECTRR XL POWER SYSTEM SURVEILLANCE REQUIREMENTS FOR CRYSTAL RIVER UNIT 3 JTAC11951)
INTRODUCTION The Florida Power Corporation, by letter dated May 23, 1979, submitted a request for changes to the Technical Specifications with respect to the surveillance requirements of DC electrical power system batteries in the Crystal River Unit 3.
The proposed Technical Specification changes are to eliminate the full electrolyte level correction to the specific gravity reading and to lower the specific gravity limit of the Unit 2 battery from 1.200 to 1.195.
EVALUATION The specific gravity of the battery electrolyte varies with changes in tempe rature.
Likewise the gravity will also vary as the electrolyte level falls and rises with the use and addition of water.
To accurately compare specific gravity readings taken at different times and at different temper-atures and electrolyte levels, such readings are corrected to the normal reference temperature of 770F (room temperature) and the nomal level (full electrolyte level specified by the manufacturer).
Specific gravity readings by the hydrometer vary with temperature and level in the same fully-charged cell.
The full electrolyte level correction should be taken intc nsidera-tion to determine the correct specific gravity. Therefore, the proposed change to eliminate the full electrolyte level correction is not acceptable.
A gradual lowering in the specific gravity of a cell is an indication of insufficient charge.
It may occur from several causes such as by an inade-quate float voltage. Ordinarily, when the float voltage is correct, the hydrometer reading will remain near the maximum value.
IEEE 450-1975, 3.4.(2) requires that "An equalizing charge should be given if the average specif:c gravity of all cells drops mcce than 0.010 from the acceptance test (Section 4.1: An acceptance test of battery capacity should be made either at the factory or upon initial installation...)".
IEEE Std. 484-1975, 5.3.l(8) requires that "Any cell that shows a specific gravity (corrected to 770F (250C)) less than 1.200 or more than 1.220, or a voltage lower than 0.04 V below the average, requires corrective action in accordance with the manufacturer's instruction".
Any lowering the specific gravity less than 1.200 is not acceptable.
CONCLUSION Based on our review of: (1) eliminating thn full electrolyte level correction in Specifications 4.8.2.3.2.a.2 and 4.8.2.3.2.b.2; and lowering the specific gravity of the battery cell from 1.200 to 1.195 for Unit 2 in Specifications 4.8.1.1.1.c.2.b, we find these channes not acceptable.
- c.
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