ML20235U591

Clarifies Util for Interim Approval of Request for Primary Component Support Snubber Elimination for Period of One Fuel Cycle to Allow Snubber Removal During Unit 2 First Refueling Outage.W/Revised Attachment to

ML20235U591
Person / Time
Site:	Beaver Valley
Issue date:	02/27/1989
From:	Sieber J DUQUESNE LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 8903090273
Download: ML20235U591 (3)

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{ Valley Power Station Shippingport, FA 16077@04 1

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ce Pr s P4uclear Gmp (412)641 6256 February 27, 1989 U.-S.

Nuclear Regulatory Commission t'

Attn:

Document Control Desk Washington, DC 20555 L

Reference:

Beaver Valley Power Station, Unit No. 2 Docket No. 50-412, License No. NPF-73 Primary Component Support Snubber Elimination

. Gentlemen:

The purpose of this letter is to clarify our letter of February

~24, 1989.

Duquesne Light Company (DLC) is requesting interim approval of' the subject request for a period of one fuel cycle.

It is our. understanding that~ interim approval will allow DLC to remove snubbers during the Beaver Valley. Unit 2 (BV-2) first refueling outage and the snubbers removed. '

operate for only one fuel cycle with Thei attachment is a revision to our letter dated February 24,

1989, as discussed between the NRC staff and K.

D.

Grada of Duquesne Light on' February 28,H1989.

As the above could result in severe economic impact to DLC, we request expeditious NRC review of our submittals so that final approval of our request can be granted in the near future.

If-there are any questions on this mattet, please conLuct my

. office.

Very truly yours, oh'~

J.

D.

Sieber 90227

1. l s{h30

{C 5000g2 >q Vice President p

Nuclear Group cc:

Mr. J.

Beall, Sr. Resident Inspector i

Mr.

W.

T. Russell, NRC Region I Administrator pl g

Mr.

P. Tam, Sr. Project Manager l' th Mr.

T.

P. Noonan Mr.

K.

D. Grada Mr.

B.

F. Sepelak i

ATTACHMENT 1 The. temperature differential between the pressurizer water temperature (Tsat) and the wide range hot leg temperature (Loop

,"C" Th) shall be $ 200*F when; draining the pressurizer during formation of a

pressurizer bubble or collapsing the pressurizer bubble through the use of the normal or auxiliary spray valves.

Action Statement If the temperature differential between the pressurizer water temperature (Tsat) and the wide range hot leg temperature (Loop "C"

Th) exceeds 200*F, then operations which are causing the increasing temperature differential shall be suspended and actions shall be immediately initiated to meet the 200'F differential criteria.

On

heatup, this would require stabilizing or reducing pressurizer pressure and heating up the reactor coolant system to meet the 200'F limitation.

On

cooldown, this would require shutting off the reactor coolant pumps while on the RHR system and performing an early depressurization.

Surveillance Requirements The following parameters shall be recorded every 15 minutes, during heatup and cooldown of the reactor coolant system or pressurizer:

1.

Wide range hot leg temperatures (A, B,

C) 2.

Pressurizer water temperature 3.

Pressurizer pressure 4.

Temperature differential between the pressurizer (Tsat) and the 1C loop hot leg temperature to verify that the 200*F criteria are met.

Basis Data recorded during Hot Functional Testing and Power Ascension Testing indicate that the pressurizer surge line is subjected to significant displacements during plant heatup.

Maximum displacements were recorded during draining of the pressurizer while forming a steam bubble.

During all other phases i

displacements were of a

lower magnitude.

This is presumably caused by constant outflow from the pressurizer during draining for an extended period of time.

During other phases of heatup, outsurge and insurge periods are short.

It is reasoned that collapse of the steam bubble during cooldown would also produce L.

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7., ;

.-Attachment 1.(continued)'

.c similar-effects on-the-piping.

By-' limiting-the temperature differential -between-the pressurizer and. hot-. leg-_ to 5 200*F, specifically duringl~ steam bubble formation-and collapse,.the

. piping ~ displacements. would be minimized thereby reducing-thermal stresses ~in;the. surge'line piping.

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