PNO-IV-88-032, on 880423,control Element Assembly (CEA) Inadvertently Withdrawn W/Upper Guide Structure During Refueling Outage.Cause Still Under Investigation.Replacement of CEA Gripper & Extension Under Consideration

PNO-IV-88-032:on 880423,control Element Assembly (CEA) Inadvertently Withdrawn W/Upper Guide Structure During Refueling Outage.Cause Still Under Investigation.Replacement of CEA Gripper & Extension Under Consideration

ML20151W532
Person / Time
Site:	Waterford
Issue date:	04/25/1988
From:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
To:
References
PNO-IV-88-032, PNO-IV-88-32, NUDOCS 8805030418
Download: ML20151W532 (2)

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- * .* April 25, 1988 i PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE -- PNO-IV-88-32 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: Louisiana Power and Light Company Licensee Emergency Classification:

Waterford-3 Steam Electric Station Notification of Unusual Event DN: 50-382 Alert Site Area Emergency General Emergency

_X_ Not Applicable

SUBJECT:

CONTROL ELEMENT ASSEMBLY (CEA) INADVERTENTLY WITHDRAWN WITH UPPER GUIDE STRUCTURE DURING REFUELING OPERATIONS On April 23, 1988, while hoisting the upper guide structure (UGS) from the i reactor vessel, CEA No. 55 came out with the structure. The plant was in Mode 6 (refueling) and the licensee was in the process of removing components and structures from the reactor in preparatio.1 for off-loading fuel assemblies. This is the second refueling outage. Since the lift was about 75 tons, the added burden of the CEA was not detectable until the bottom of the UGS cleared the reactor vessel and the CEA became visible. By then it was clear of the core and could not be reinserted. With the use of a mini-sub containing a TV camera, the licensee was able to determine which CEA was withdrawn. Special tools were devised and the CEA was partially withdrawn into the CEA shroud in the UGS, so that the CEA and UGS could be moved away from the core, i

After the UGS was placed away from the core, the licensee lowered the CEA to the refueling pool floor, uncoupled the CEA from the extension, then while restraining the CEA with a nylon rope, raised the UGS until the CEA cleared the UGS. The CEA was then laid horizontally on the floor. Other than the CEA or the extension possibly being damaged, no other damage was apparent. The licensee intends to inspect both the CEA and the extension.

The licensee is investigating the cause of this incident to determine whether the gripper assembly just stuck to the CEA hub or if the gripper became partially engaged. While disengaging CEAs earlier in the process, some difficulty was encountered getting CEA No. 69 to break loose from the CEA extension, but no problems were experienced with CEA No. 55. Conbustion Engineering and the refueling contractor (Westinghouse) assisted in the recovery.

The licensee has a spare CEA and is contemplating replacement of the CEA gripper and extension.

The resident inspectors are monitoring the licensee's actions.

Neither the licensee nor the NRC plans to issue a press release.

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The state of Louisiana has been informed.  !

Region IV received notification of this occurrence by SRI / Project Section Chief from Waterford 3 at 9:00 a.m. (CDT) on April 23, 1988. Region IV has informed EDO, NRR, and PA.

This information has been confirmed with a licentee representative.

CONTACT:

DISTRIBUTION:

H. St. MNBB OWF MAIL: DCS (Original IE 34)

Chairman Zech XEOU PA'- UOT-(Trans only)

Com. Roberts EDO OGC Com. Bernthal ARM FAX: INPO Com. Carr NL OIA NSAC Comm. Rogers ES O! RRI SECY NMSS NRC OC CA NRR LICENSEE (Reactor Lic.)

PDR SLITP OGC-H S 5520: /M/88 0 N1) '

REGIONS & HQ

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