PNO-IV-87-009A, on 870311,steam/water Hammer Event Occurred in Component Cooling Water Lines Servicing RHR HX Trains B & C.Caused by Operational Errors.After Cooldown from Hot Functional Testing,Sys Damage Will Be Repaired

PNO-IV-87-009A:on 870311,steam/water Hammer Event Occurred in Component Cooling Water Lines Servicing RHR HX Trains B & C.Caused by Operational Errors.After Cooldown from Hot Functional Testing,Sys Damage Will Be Repaired

ML20207S374
Person / Time
Site:	South Texas
Issue date:	03/13/1987
From:	Constable G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
To:
References
PNO-IV-87-009A, PNO-IV-87-9A, NUDOCS 8703190326
Download: ML20207S374 (2)

_ _ _ _ _ _

.-

• March 13, 1987 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE -- PNO-IV-87-09A This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information is as initially received without verification or evaluation, and is basically all that is known by the Region IV staff on this date.

FACILITY: Scuth Texas Project Unit 1 Licensee Emergency Classification:

Bay City TX Notification of Unusual Event Houston Power & Lighting Alert DN: 50-498 Site Area Emergency General Emergency

_X,_ Not Applicable

SUBJECT:

WATERHAMMERINCOMP0NENTCOOLINGWATERSYSTEM(UPDATE)

At about 11:00 p.m. (CST) on 3/11/87, during Hot Functional Testing (HFT) with the primary system at 350'F and 350 psig, a steam / water hamer event occurred in the Component Cooling Water (CCW) lines servicing the Residual Heat Removal (RHR) heat exchanger Trains B and C. Operational errors occurred while placing the RHR system in service which led to an approximately 10-minute delay in establishing CCW ficw after the primary flow had been established to the B RHR heat exchanger.

A shorter delay occurred in Train C. The results were an extreme fluctuation in CCW surge tank followed by loud banging associated with both Trains B and C systems.

These systems were secured and an evaluation started. On 3/12, the engineering review determined that 30 hangers / supports were damaged and two dents in the CCW pipe were identified. All apparent damage was limited to Train B. Engineering analysis indicates that the pipe was not overstressed. A satisfactory leak test was perforr.ied on the Train 8 and C RHR heat exchangers. Additionally, chemistry samples were analysed for cross-contamination and found to be negative. Early 3/13/87, the licensee resumed HFT which is scheduled to be completed Sunday, March 15. Af ter cooldown from HFT, system damage will be repaired. Further analysis of the occurrence will continue by the licensee and site contractors.

(cont'd on next page)

DISTRIBUTION:

MAIL:

H. St. MNBB E/W Willste IDMIDMB (Originol)

Chairman Zech EDO IE NMSS D0T:(Transonly)

Com. Bernthal PA OIA RES Com. Roberts ELD AE00 FAX:

Com. Asselstine MPA VIB TI&O Com. Carr NSAC ACRS SP (Air SECY Phillips Rights)

CA NRR RRI ___

FDR DCS NRC OC LICENSETi~

Regional Offices (ReactorVcinsee)

D:DRS[

I EHJohnson:cs n 3/13/87 3 3/87 yf3y0g h3 26 070313 Transmitted via 5520 PNO-IV.07-OO9 PDR j

.- 's RIV PNO-87-09A The licensee has issued a press release and held interviews with Houston TV and radio stations. As a result of an article in the Wall Street Journal, there has been a high level of interest in this event by financial analysts who are interested in whether this event could delay facility operation. While it is possible that the needed repairs may cause a short delay. There is no present indication that any delay will be needed.

The state of Texas has been informed.

This information has been confirr.ed with a licensee representative.

CONTACT: G.L. Constable (FTS 728-8151) i