ML20214H276

Application for Amend to License DPR-66,deleting Applicability Requirements for Modes 2 & 3 & Replacing 7-day Test Frequency w/120-day Test Frequency

ML20214H276
Person / Time
Site:	Beaver Valley
Issue date:	05/15/1987
From:	Carey J DUQUESNE LIGHT CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
Shared Package
ML20214H277	List: ML20214H276 ML20214H317
References
TAC-62942, NUDOCS 8705270336
Download: ML20214H276 (3)

Text

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y Telephone (412) 393-6000 Nuckar Group

. P O. Bos 4 Shippmgport, PA 15077*

May 15, 1987 4

i U. S. Nuclear Regulatory Commission-Attni Document Control Desk Washington, DC' 20555

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Referencei Beaver Valley Power Station, Unit No. 2 in Docket No. 50-412 yo. 3 3q Turbine Overspeed Testing i

i Gentlemen:

1 l'

'During the BV-2. Technical Specification review process, a request-was made to justify a

31 day. test frequency.

We have performed-F additional reviews on this subject and revisad our previously i

proposed specification.

This.is submitted as an enclosure to this F

letter.

We have proposed additional changes beyond.that originally

^

. proposed and our justifications are provided herein:

1.

, Delete the " Applicability" requirements for Modes 2 and 3.

i Basis a

The Standard Technical Specification requires valve testing from the- " running position", which is open.

To open the 16 t

turbine

valves, the turbine must be latched to pressurize the ~ hydraulic. fluid to open the valves.

This would require that the reactor trip breakers also be closed to clear the turbine' trip signal on a reactor trip. signal.

Upon turbine latching the intercept,' reheat stop, and governor valves go full.open and unless the throttle valves and~ reheat steam isolation valves are 100% leak-tight the turbine will roll' l

off the turning gear and a primary system cooldown will be initiated that will be proportional to the steam flow.

J This is an undesirable condition. in that an uncontrolled cooldown could be initiated which could result in a safety system actuation and act to insert positive reactivity from the cooldown.

4 1

Therefore, this test should only be conducted in Mode 1 where reactor power should be adequate to accommodate small j

amounts of steam leakage through the isolation valves.

8705270336 B70515

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fDR ADOCK 05000334 ACOf l

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r Beaver Valley Power Station,. Unit No. 1 Docket No. 50-334, License No. DPR-66 Turbine Overspeed Testing Page 2 2.

Replace the 7

day test frequency with a 120 day frequency

)

and insert the caveat for delaying test performance.

Basis

.The' performance of the

testing, even at the 31 day-i frequency, is considered excessive.

The stroking of 16 l

valves, each

week, equates to 832 cycles on the valves and the entire balance of plant equipment on an annual basis.

Each time any of the valves are cycled, the steam flow through the turbine is-abruptly altered.

This radical change has a

demonstrated ability to create high turbine bearing vibration

.(>

15 mil) during the governor valve testing.

We.believe the vibration is due to changes in the steam flow pattern, arc emission, through the high pressure turbine.

This introduces a vertical lifting component on the rotor which tends-to unload the number one bearing resulting in oil whip-induced vibration.

In

addition, these sudden changes in~ steam flow cascade throughout the extraction steam, heater drain, reheat steam, reheater ' drain and main steam systems _with each valve cycle.

This causes additional thermal, pressure and dynamic

-cycles throughout the balance of plant components and challenge numerous control and protective features on the entire plant at a rate of 832 cycles per year.

The deferral of the-test frequency, based on Station Manager

approval, "due to plant operating conditions",

was previously accepted by the NRC with the Farley Nuclear Plant " Turbine Overspeed Reliability Assurance Program".

We believe this testing is in direct conflict with industry and NRC-initiatives directed towards improving domestic nuclear plant reliability and reducing reactor trips.

We would strongly recommend that this test frequency be reduced to performance during "each

- startup if not performed in the previous 7 days".

The staff

position, SRP 10.2, on valve testing should be re-evaluated:for the reasons expressed.

We believe this technical specification contains the key elements of the Farley and BV-1 programs and should be found acceptable by the staff.

Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 Turbine Overspeed Testing Page 3 Please contact my office for a conference call as soon as the review on this specification is complete.

Very trul

yours, J. J.

arey Senior Vice President, Nuclear Attachment cc: Mr. S. M. Pindale, Resident Inspector U. S. Nuclear Regulatory Commission Beaver Valley Power Station Shippingport, PA 15077 U. S. Nuclear Regulatory Commission Regional Administrator Region 1 631 Park Avenue King of Prussia, PA 19406 Mr. Peter S. Tam U. S. Nuclear Regulatory Commission Project Directorate No. 2 Division of PWR Licensing - A Washington, DC 20555

- Mail Stop 316 Addressee only Director, Safety Evaluatien & Control Virginia Electric & Power Company P.O. Box 26666 One James River Plaza Richmond, VA 23261