3F1294-18, Informs of Changes Made to Surveillance Procedure for Refueling Interval Integrated Plant Response to Engineered Safeguards Actuation
| ML20078S282 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 12/13/1994 |
| From: | Beard P FLORIDA POWER CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 3F1294-18, NUDOCS 9412280208 | |
| Download: ML20078S282 (3) | |
Text
O Florida Power 55d H
December 4,' 1994 3F1294-18 Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555
Subject:
Emergency Diesel Generator Testing
References:
FPC to NRC letter, 3F0994-01, dated September 9, 1994
Dear Sir:
This letter supplements the reference letter and documents the information discussed in a phone conversation with members of the NRC Staff on November 22, 1994.
As stated in the reference letter, Florida Power Corporation (FPC) has made changes to the surveillance procedure for the refueling interval integrated plant response to an engineered safeguards actuation. The changes were made as part of the conversion of Crystal River 3 (CR-3) to Improved Technical Specifications (ITS).
This procedure was changed because of a the new requirement in the ITS to verify that the diesel generator could start and energize the permanently connected loads in s 10 seconds. The test demonstrates the capability of the ES systems (including the diesel generators) to respond to an ES actuation signal and a loss of off-site power and satisfies the requirements of Technical Specification 3.8.1.10. Requirements under our previous technical specifications were satisfied by surveillance tests that were not designed to demonstrate this capability.
The attachment to this letter provides specific technical details as to how the test was run previously and how it is run now.
Sincerely, M
.M Beard, Jr.
Senior Vice President Nuclear Operations Attachment PMB:AEF xc: Regional Administrator, Region II i
Senior Resident Inspector i
CRYSTAL RIVER ENERGY COMPLEX
- 15760 W. Power uno Street
- Crystal River
- Florida 34426-6708 * (904) 795-6486 9412280208 941213 Mk' \\
PDR ADOCK 05000302 P
PDR 1 V" vs
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U. S. Nuclear Regulatory Commission 4
Attachment to 3F1294-18
,Page'l of 2 Description of Changes to SP-417 Refueling Interval Integrated Plant Response To an Engineered Safeguards Actuation SP-417 Refueling Interval Integrated Plant Response To an Engineered Safeguards Actuation, tests the plant response to an engineered safeguards (ES) actuation signal in conjunction with a loss of off-site power (LOOP) signal.
The ES actuation consists of a Reactor Building high pressure signal (4 psig) and a Reactor Building high-high pressure signal (30 psig).
These signals are generated by actuating the associated Reactor Building pressure test switches in th ES Actuation Channel Test Cabi ets. The LOOP signal is generated by removing potential from the Second Level l iervoltage Relays (SLUR). Thus, the ES signal is an " actual" signal while the L OP signal is " simulated."
This is in keeping with the current Technical Specification requirement which
- states,
" Verify on an actual or simulated loss of offsite power signal in conjunction with an actual or simulated ES actuatior. signal:
a.
De-energization of the emergency buses; b.
Load shedding from the emergency buses; c.
EDG auto-starts from standby condition and:
1.
energizes permanently connected loads in s 10 seconds,..."
In previous tests, a design feature of the SLUR scheme was defeated. This design feature, if left in place, would bypass a 13 second first level undervoltage relaying (FLUR) timer interlock during an ES actuation together with a SLUR actuation.
This bypass trips the FLUR relaying scheme directly.
When this happens, the 4160 volt ES buses are stripped and a 3 second emergency diesel generator (EDG) output breaker close permissive timer is started. By defeating this bypass interlock, the test had an additional 13 seconds of dead bus from the FLUR timer prior to energizing the 3 second EDG output breaker close permissive timer.
The timing of the events was as follows:
Time (sec.)
Event 0
ES actuation / Simulated LOOP /EDG start signal (from ES) 5 SLUR timeout - ES bus is r, tripped 18 FLUR timeout - EDG breaker close permissive timer starts 21 EDG breaker close permissive times out - breaker closes
ve:
5 b
e' U. S. Nuclear Regulatory Commission
' Attachment to 3F1294-18 jPage*2of2 1
The total dead bus time is 16 seconds. This time should have'been sufficient to allow rotating equipment to come to a stopped or near stopped condition.
Therefore, the loading of the EDG was closer to a true dead bus EDG pickup, but because of the timers delaying diesel breaker closure, the permanently connected loads were not energized in s 10 seconds as required by the Improved Technical Specification.
To meet the new requirements, the circuit that bypasses the 13 second FLUR timer interlock must be left in place.
The timingsof the events under the revised procedure is as follows:
Time (sec.)
Event 0
ES actuation / Simulated LOOP /EDG start signal.(from ES) 5 SLUR timeout - ES bus is stripped EDG breaker close permissive timer starts 8
EDG breaker close permissive times out - breaker closes The total dead bus time is 3 seconds. This is probably not sufficient time for rotating equipment to coast down to a stopped condition prior to being energized by the EDG.
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