ML20126F770

Discusses Postulation of HELB in Intermediate Bldg That Could Result in Temps Exceeding Environ Qualification Limits

ML20126F770
Person / Time
Site:	Crystal River
Issue date:	12/16/1992
From:	Silver H Office of Nuclear Reactor Regulation
To:	Beard P FLORIDA POWER CORP.
References
TAC-M82173, NUDOCS 9212310131
Download: ML20126F770 (4)

Text

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December _16,c1992 Docket No. 50-302-Mr. Percy M. Beard, Jr.

Senior Vice President, Nuclear Operations Florida Power Corporation ATTN:. Manager, Nuclear Operations Licensing

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P.O. Box 219-NA-21 Crystal River, FL 32629.

SUBJECT:

CRYSTAL RIVER UNIT 3 INTERMEDIATE BUILDING'HIGH' ENERGY LINE BREAK (TAC NO. M82173)

During implementation of your high energy line break (HELB)1 program:at Crystal:

River Unit 3 '.(CR-3), you identified a postulated HELB in the = Intermediate.

Building that could-result.initemperatures--inJexcess.of the: enviro'nmental:

qualification limits specified for certain emergencyifeedwater: initiation and-control (EFIC); system electrical components. -You met:with us(on December 4,~

4 1991, to present your plan to-address this concern.

Your letter dated April ~ 21,1992,L provided the results of'the' evaluation and conclusionstwith respect to this postulated high energy pipe-break. During our: review offyour April 21, 1992, letter,-we had identified several concerns,which we discussed"

.with your representatives on July 21,71992. You:respondedito those concerns.

by letter of August 8a 1992.

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The break' of concern is a postulated terminaliend. break in the:62 inch -

emergency. feedwater pump turbine steam s.upply lines at their connection to the; 24-inch main steam line.. These'are steam supply linesfattached tol6-inch' weldolets at the main steam 1ine which are:directly welded to:6-inch by-3-inch-reducers at-th'e inlet to valves MSV-55'and MSV-56. -Thefguidelines;for

. selection of location:for terminal end breaks would require: postulation off a r break at the 6-inch weldolet.

According totyour-evaluation, a break in the weld..on the 3-inch end of the, reducer does not-produce _an unacceptable. environmental temperature, whereasLa break in the 6-inch end:of-the reducer or the weldolet does. lYou argue that,.

for--_a given load or bending: mo'mentf on; the supplyiline, the1 stresses -on'.thef 3-' inch end: weld are much greater than-the stresses :in the 6-inch end weld,:the;

weldolet; or the connection of the weldolet to the'24-inch line. You alsol

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Mr. Percy M. Beard' Dscambar 16, 1992-satisfactorily addressed our concerns about thermal stresses in the piping:

components. 10n this basis, you. conclude that the greatest potential for a i

postulated terminal end pipe rupture occurs in the 3-inch end of the reducer, for which break the electrical components of concern would be' qualified.

We had also questioned whether additional examinations and fracture mechanics:

analyses are necessary to support your conclusion.

Based on the additional information presented in your letter of August 8,1992, we agree that fracture mechanics analyses are not necessary.

However, we feel that additional-examinations are necessary to support your postulation of the break at the 3-inch end of the reducer.

Your argument for selecting the break location _at the 3-inch end of the reducer hinges on that location having the highest stresses and thus having the greatest potential for a pipe ~ break. The evaluation of the stresses assumes that no flaws exist at the weld joints.

We recommend that this'be~ confirmed by both surface and volumetric NDE of-the-weldolet to main steam header and weldolet to the 6-inch end of the reducer welds.

If the NDE examination of these weld. joints shows no indications requiring acceptance by ASME Section XI analysis, then we would agree with your conclusion that the 3-inch end of the reducer has'the greatest potential for a terminal end pipe break.

0n the basis of the review of the submittals discussed above, we conclude that, pending acceptable results u the NDE examinations of the weld joints discussed above, the postulation _of the terminal end break location at the'3-inch end of the reducer on the emergency feedwater pump steam supply lines is acceptable.

Since there does not appear to be any immediate safety concern, and the NDE--

examination would have to be performed with the plant shut down,' this examination may be performed at the next appropriate scheduled plant outage.

Please notify us of the schedule for this effort within 60 days and the results of the examination.

This requirement affects fewer than 10 respondents and, therefore, is= not subject to Office of Management and Budget review under P.L.96-511.

Sincerely, (Original Signed By)

Harley Silver,-Senior Project Manager Project Directorate II-2 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation cc: See next page Distribution 7,

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,..y Mr..Percy M. Beard Crystal River Unit No.3 Florida Power Corporation-Generating P1 ant F

Mr. A. H. Stephens

_Mr. Robert G. Nave, Director General Counsel Emergency Management Florida Power Cnrporation Department of Community Affairs MAC-A50 2740 Centerview Drive P. 0. Box 14042 Tallahassee, Florida 32399-2100 St. Petersburg, Florida 33733 Mr. Bruce J. Hickle, Director Chairman Nuclear Plant Operations Board of County Commissioners Florida Power Corporation Citrus County P. O. Box 219-NA-2C 110 North Apopka Avenue Crystal River, Florida 34423-0219 Inverness, Florida 32650 Mr. Robert B. Borsum Mr. Rolf C. Widell, Director B&W Nuclear Technologies Nuclear Operations Site' Support 1700 Rockville Pike, Suite 525 Florida Power Corporation Rockville, Maryland 20852 P. O. Box 219-NA-21 Crystal River, Florida 34423-0219

_ Regional Administrator, Region II U. S. Nuclear Regulatory Commission Senior Resident Inspector 101 Marietta Street N.W.,

Suite 2900 Crystal River Unit.3 Atlanta, Georgia 30323 U.S.-Nuclear. Regulatory Commission Mr. Jacob Daniel Nash 6745 N. Tallahassee Road Office of Radiation Control-Crystal River, Florida 34428 Department of Health and Rehabilitative Services Mr. Gary Boldt 1317 Winewood Blvd.

Vice President - Nuclear Tallahassee, Florida 32399-0700 Production Florida Power Corporation Administrator P.O. Box 219-SA-2C Department of Environmental Regulation Crystal River, Florida 34423-0219 Power Plant Siting Section State of Florida 2600 Blair Stcae Road Tallahaseee, Florida 32301 Attorney General Department of Legal Affairs The Capitol Tallahassee, Florida 32304

4 Hemorandum Dated D3errnber 16, 1992 DISTRIBUTIQB

" Docket File-NRC & Local PDRs PD!l-2 RF S. Varga G. Lainas H..Berkow D. Hiller H. Silver OGC J. Fair JrcNorberg ACRS (10)

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