PNO-V-85-076, on 851108,licensee Reported That Studs in RCS Line Stops a & B Did Not Meet Hardness Requirements.Relief from 10CFR50,App A,Gdc 4 Requested to Preclude Retorquing Studs

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PNO-V-85-076:on 851108,licensee Reported That Studs in RCS Line Stops a & B Did Not Meet Hardness Requirements.Relief from 10CFR50,App A,Gdc 4 Requested to Preclude Retorquing Studs
ML20136A679
Person / Time
Site: Palo Verde  Arizona Public Service icon.png
Issue date: 11/13/1985
From: Miller L, Zimmerman R
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
To:
References
PNO-V-85-076, PNO-V-85-76, NUDOCS 8511200006
Download: ML20136A679 (2)


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PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL CCCURRENCE--PNO-V-85-76 Date: 11/13/85 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public int: rest significance. The information presented is as initially received without verification er cvaluation and is basically all that is known by Region V staff on this date.

FACILITY: Arizona Nuclear Power Project Emergency Classification Palo Verde Units 1, 2 and 3 Notification of Unusual Event Docket Nos. 50-528, 50-529, 50-530 Alert Site Area Emergency General Emergency XX Not Applicable 8

SUBJECT:

EXTENDED PLANT SHUTDOWN WHILE ASSESSING ADEQUACY OF REACTOR COOLANT SYSTEM LINE STOP FASTENERS .

Tha licensee reported on November 8, 1985, that 29 out of 64 studs installed in the Unit 2 rc ctor coolant system (RCS) line stops A and B did not meet"the' hardness requirements for ASTM A540, Grade 23, Class II materials. The line stops serve to minimize the effects of pip 2 whip in the event of a RCS line break. A total of 32 similar studs destined for Unit 3, (Line Stops A and B) but not yet installed, also were found to have hardness values less th n required. Subsequently, the licensee checked the studs installed in the Unit I rccctor coolant system line stops A and B and found that approximately one-half of the ctuds had hardness values less than required. The ASTM AS40 studs with the questionable hardness values were supplied by Ametek-Straza Co., a distributor. These ASTM AS40 ctuds were manufactured by the Southern Bolt Company and were received at Palo Verda in 1979 with a material test report certifying the studs met ASTM A540, Grade 23, Class II r;quirements. Additionally, the licensee has determined that the installation method for all the studs and anchor bolts, on all of the reactor coolant system line stops, for Unit I was inadequate, in that the acceptance criteria for the tensioning of the studs and cnchor bolts was specified in terms of elongation rather than the appropriate predetermined force. There are 22 line stops per unit, for a total of 800 studs and bolts.

Currently Unit 1 is shutdown. The licensee has contacted NRR for relief from 10CFR50, App:ndix A, GDC-4 to preclude retorquing the anchor bolts and studs on all the line stops to verify their ability to perform as intended by design. The licensee's basis for r questing relief stema from the fact that NRR is currently reviewing the licensee's rcquest that the line stops be removed from Units 2 and 3, based on a Combustion Engineering study that has determined that the line stops are not required.

Prcrently the licensee is proceeding with their relief request and also starting to ratorque all studs and anchor bolts on all of the line stops on Unit 1. This effort is cctimated to take approximately three weeks.

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o M a U PNO-V-85-76 11/13/85 Tha licensee has discussed the situation with local media.

Thio information is current as of 10:00 am (PST) November 13, 1985.

CONTACT: L. Miller R. Zimmerman FTS 463-3869 (602) 386-5260 DISTRIBUTION 11 S t . HNBB Phillips E/W Willste Air Rights _ Mail Chairman Pallidino EDO NRR IE NMSS ADM:DMB Comm. Zech PA OIA RES DOT:Trans only C:mm. Bernthal MPA AEOD Comm. Roberts ELD Comm. Asselstine Regions:

SECY INP0f/V/ NSAC 7/o J ACRS Licensee: < 'c?

CA (Reactor Licensees) REGION V: FORM 211 PDR Resident Inspector _ (Revised 3/14/83)