PNO-II-87-019, Region II Will Dispatch Augmented Insp Team on 870319 to Review Circumstances Associated W/Problem Re Possible Corrosion Caused by Deposits of Crystalline Boric Acid on Reactor Head & Surrounding Areas

PNO-II-87-019:Region II Will Dispatch Augmented Insp Team on 870319 to Review Circumstances Associated W/Problem Re Possible Corrosion Caused by Deposits of Crystalline Boric Acid on Reactor Head & Surrounding Areas

ML20205N151
Person / Time
Site:	Saint Lucie
Issue date:	03/18/1987
From:	Christensen H, Wilson B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
References
PNO-II-87-019, PNO-II-87-19, NUDOCS 8704020605
Download: ML20205N151 (2)

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. n March 18, 1987  ;

i PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE PNO-II-87-&7-19 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or I public interest significance. The information is as initially received without verifi-cation or evaluation, and is basically all that is known by the Region II staff on this date.

FACILITY: Florida Power & Light Company Licensee Emergency Classification:

Turkey Point Unit 4 Notification of Unusual Event l

! Docket No. 50-389 Alert Homestead, Florida Site Area Emergency General Emergency X Not Applicable

SUBJECT:

AIT DISPATCHED TO TURKEY POINT i Region II is dispatching an Augmented Inspection Team to Turkey Point the morning of Thursday, March 19, 1987, to review the circumstances associated with a problem identified by the licensee with possible corrosion caused by deposits of ctystalline boric acid on l the reactor vessel head and surrounding areas.

I The Unit has been operating since its last outage (September,1986) with a small reactor '

coolant system leak on the flange connection o' an instrument penetration to the reactor vessel head. The leak is on a mechanical clamp (conoseal) on the instrument port assembly.

The licensee conducted a safety evaluation which concluded that the leak was not a pressure boundary fault, was within technical specification limits, and did not involve an unreviewed safety question. Boric acid corrosion of the carbon steel clamp was considered with a recommendation that the clamp assembly should be inspected within six months. A-reinspection during an October, 1986 outage did not identify a significant problem with boric acid accumulation.

l The Unit was shut down on March 11 because of an unrelated problem. The clamp assembly I was inspected during this outage and revealed an extensive buildup of crystalline boric acid on the reactor vessel head and surrounding areas.

The NRC resident inspector personally inspected the vessel head area on March 16. Boric acid buildup in the area may be as much as 1,000 pounds. Corrosion damage was observed on

! the threadscooling mechanism of several fans.vessel head closure studs and the ductwork of the control rod drive The licensee is cleaning the area. The licensee has enlisted the aid of Westinghouse and Babcock & Wilcox representatives in evaluating the situation and developing a plan of corrective' action. (The Unit utilizes a Westinghouse nuclear steam supply system.)

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It is not know at this time if the vessel head will have to be removed.

Unit 3 is currently in a refueling outage, has not experienced similar leakage, and is unaffected by this problem.

The licensee is considering issuance of a press release. Both the licensee and the NRC 1

are prepared to respond to media inquiries.

The state of Florida has been informed.

l 8704020605 870310 ( i h-I-87-019 PDR

. . e This information is current as of 4:00 p.m. (EST) on March 18.

l Cantact: H. Christensen, RII 242-4197 B. Wilson, RII 242-5505 l DISTRIBUTION:

l H. Street MNBB Phillips E/W Willste MAIL:

Chairman Zech E00 NRR TF NMSS ADM:0MB Comm. Roberts PA OIA RES 00T: Trans Only Comm. Asselstine MPA AE00 Applicable State Comm. Bernthal ELD Comm. Carr Air Rights INPO /2:o r .

l SECY SP NSAC ACRS l

R Regions: El - // .' / a I li t o V N' Licensee:

n:ri (Reactor Licensees)

Applicable Resident Site //l'9 i

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