ML18227D360

08/18/1978 Letter Response to Letter, Provide Information Re Reactor Vessel Atypical Weld Material

ML18227D360
Person / Time
Site:	Turkey Point
Issue date:	08/18/1978
From:	Robert E. Uhrig Florida Power & Light Co
To:	Schwencer A Office of Nuclear Reactor Regulation
References
Download: ML18227D360 (4)

Text

REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS >

DISTRIBUTION FOR INCOMING MATERIAL 50-25 /251 REC: SCHWENCER A ORG: UHRIG R E DOCDATE: 08/18/78 NRC FL PWR 8. LIGl.lT" DATE RCVD: 08/22/78 DOCTYPE: LETTER NOTARIZED: NO COPIES RECEIVED

SUBJECT:

LTR 3 ENCL 0 R-SPONSE TO NRC LTR DTD 08/14/78... FURNISHING INFO RE CONSEQUENCES OF THE POSSIBL'ITY OF EXTRANEOUS WELD MATERIAL BEING PRESENT IN UNIT 4 REACTOR VESSEL NOZZLE-BELT TO SHELL CIRCLE SEAM WELD.

PLANT NAME: TURKEY PT 43 REVIEWER INITIAL: X Ji l TURKEY PT 04 DISTRIBUTER INITIAL P+

DISTRIBUTION OF THIS MATERIAL IS AS FOLLOWS REACTOR VESSEL MATERIAL SURVEILLANCE (DISTRIBUTION CODE A021)

FOR ACTION: BR Cl-IIEF ORBOi BC44LTR ONLY(3) ZWETZIG++LTR ONLY<1)

INTERNAL: G F 44LTR ONLY(4.) NRC PDR4+LTR ONLY< 1)

-w>LTR ONLY(2> OELD44LTR ONLY(i>

MIPC>4LTR ONLY<i) HANAUER44LTR ONLY( 1)

MATERIAL ENG BR+>LTR ONLY(1) AD FOR SYS 5 PROJ>+LTR ONLY(1)

ENGINEERING BR4+LTR ONLY(1) REACTOR SAFETY BR4+LTR ONLY(i)

PLANT SYSTEMS BR4+LTR ONLY(i) EEB4+LTR ONLY(1)

HAZELTON44LTR ONLY< 1) HOGE44LTR ONLY(i)

R GAMBLE++LTR ONLY(1) ~

RANDALL4+LTR ONLY(i>

EXTERNAL: LPDR S MIAMI> FL+<LTR ONLY(1)

TERA++LTR ONLY(1)

NSI C++LTR ONLY < 1 )

ACRS CAT B>4LTR ONLY(16')

DISTRIBUTION: LTR 40 ENCL 0 CONTROL NBR 782340173 SI ZE: 2P *

~i.inc THE END

REt'ULAT".,,Y DOCKET I-"'E COvv FLORIOA POWER 8 LIGHT COMPANY August 'lsd'-78-274 Office of Nuclear Reactor Regulation Attention: Mr. A. Schwencer, Chief Operating Reactors Branch 81 Division of Operating Reactors U. S. Nuclear Regulatory Commission Washington, D. C. 20555

Dear Mr. Schwencer:

Re: Turkey Point Units 3 and 4 Docket Nos. 50-250 and 50-251 Reactor Vessel At ical Weld Material The following information is provided in response to your letter of August 14, 1978:

On August ll, 1978, Westinghouse Electric Corporation informed Florida Power 5 that they were evaluating the consequences of the Light Company (FPL) possibility of extraneous weld material being present in the Turkey Point Unit 4 reactor vessel nozzle-belt to shell circle seam weld. Westinghouse reported that this material could have an estimated initial RTNDT of 125 F, but would be located in a region where fluence is a factor of approximately 6-1/2 less than the limiting core region.

Since then, Westinghouse has met with the reactor vessel manufacturer to review the potential weld metal problem. Information was presented at the meeting to show that the extraneous weld material was not used in any Unit 3 reactor vessel welds and was not used in any Unit 4'reactor vessel welds other than possibly the nozzle-belt to shell circle seam weld. No information was presented to prove that the extraneous weld material was not used in the subject Unit 4 weld, therefore, for the purpose of evaluating the effect of radiation on that weld, it was assumed that the extraneous material was used.

However, even with this conservative approach, the assumed presence of the extraneous weld material has no adverse safety consequences because the subject weld is located in a non-limiting region. Furthermore, Westinghouse has determined that if it the extraneous weld material was used in the nozzle-belt to shell circle seam weld would be in the outside dian@ter of the weld.

The Unit 4 heatup and cooldown curves in the Technical Specifications are based on an- RTMDT of 281 F at the 1/4 thickness location and are applicable for up to 5 effective full power years of operation. The assumption that extraneous weld material exists in the reactor vessel nozzle-belt to shell circle seam weld has no effect on the use of these curves because the subject

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Office of Nuclear Reactor Regulation Page Two weld is located in a region where fluence is much less than in the limiting 1/4 thickness region and also because the extraneous material Aould be located in the outside diameter of the weld.

Based on the information presented above', the possible use of extraneous weld material in the Turkey Point Unit 4 reactor vessel nozzle-belt to shell circle seam weld does not require revised pressure/temperature limits. The existing Technical Specification heatup and cooldown curves are sufficient to provide the necessary reactor vessel integrity and to ensure continued safe operation of the facility. We will continue our discussions with Westinghouse in order to achieve final resolution of this issue.

Very truly yours, C

Robert E. Uhrig Vice President REU/HAS/GG/cpc cc: Mr. James P. O'Reilly, Region II Robert Lowenstein, Esquire