ML20072D980
| ML20072D980 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 06/17/1983 |
| From: | Westafer G FLORIDA POWER CORP. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| 3F-0683-09, 3F-683-9, TAC-51342, NUDOCS 8306230465 | |
| Download: ML20072D980 (2) | |
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June 17,1983 3F-0683-09 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555
Subject:
Crystal River Unit 3 Docket No. 50-302 Operating License No. DPR-72 Supplemental Information in Support of Technical Specification Change Request No. 82
Dear Mr. Denton:
This provides additional information in support of Cycle 5 operation with Reactor Coolant Pump Power Monitors (RCPPM's).
The proposed Cycle 5 Technical Specifications submitted on March 31,1983, for operation with RCPPM's include additional time delay to preclude spurious plant trips associated with disturbances external to the RCPPM system.
The total trip delay time to start of negative reactivity insertion has been increased from the 620 ms used during Cycle 4 to 1.5 seconds for Cycle 5.
As a result of the spurious trips, authorization was obtained for continued operation in Cycle 4 at lower power levels with RCPPM's bypassed. Equipment was then installed for measurement of the duration of disturbances which would have caused actuation of the I
RCPPM function. A total of nine disturbances were identified which would have caused I
actuation of the RCPPM trip function with the trip delay time previously in use. None of these would have caused RCPPM trip actuation with the currently proposed 1.5 second trip delay time.
An analysis was also performed by B&W during Cycle 4 to determine minimum DNBR for a 4 pump coastdown transient as a function of RCPPM trip delay time.
i The results of this analysis show:
Trip Delay Minimum Time DNBR 4 pump coastdown from 4 pump operation 1.5 sec l.97 1.88 sec.
l.83 8306230465 830617
, i (0 fRADOCK 05000302 PDR General Office 3201 Tnirty-sourth street soutn. P.O. Box 14042, st. Petersburg. Florda 33733 813-866-5151
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These results show that substantial margin is associated with the proposed 1.5 se' ond trip V c
delay time. A trip delay time as long as 1.88 seconds provides acceptable ~rninimum DNBR. The trip delay time of 1.5 see in the proposed Technical Specifications provides,at least 380 ms margin in response time (1.88 see. l.50 see) for the RCPPM trip.
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'f i For this reason Florida Power Corporation now belieges that the requirement for testing %
i of the RCPPM system potent!al transformers, current transformers, and watts trensducer Q 7
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time response, which was identified in the NRC Safety Evaluation supporting Amendmentscq J No. 55 is no longer necessary and should be removed. Measurement of the time response N
for a complete RCPPM channel [ including sensor requires trip of a reactor coolant pump.
y Florida Power Corporation consitQrs this test to be potentially destruefive to pump seals. s ;
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Florida Power Corporation now considers the findings associated with RCPPM response time testing which were identified in the NRC Safety Evaluation'.. associated with Amendment No. 55 have now either been satisfied or are no longer appliccble.
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N A correction is required to Table 3.3-2,. Item-No. 8, in the proposedaTechnical Specifications.
The response time for pump status based on RCPPM', trip should be t
1 1.44 seconds. This is the 1.5 second total response time minus the 60 ms;fcr release of f
the control rod drive roller nut from the lead screw.
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Sincerely,.
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G. R. Westafer Monoger k
Nuclear Licensing and Fuel Management DMO:mm f
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