PNO-I-93-059, on 931026,unexpected Drop of Section of Refueling Mast Occurred While Lowering Bundle in Core.Maint Investigated & Discovered Bend in Mast.Licensee Determined Fuel Bundle Did Not Drop During Event
| ML20059F639 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 10/29/1993 |
| From: | David Mannai, Jason White NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| References | |
| PNO-I-93-059, PNO-I-93-59, NUDOCS 9311050022 | |
| Download: ML20059F639 (2) | |
DCS No: 50387931026 Date: October 29,1993
.y PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE PN19359 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 I staff on this date.
. Facility:
Licensee Emergency Classification:
Pennsylvania Power & Light Co.
Notification of Unusual Event Susquehanna Unit 1 Alert Berwick, Pennsylvania Site Area Emergency General Emergency X
Not Applicable Docket No. 50-387 License No. NPF-14 Event No. N/A Event Location Code: POW
Subject:
FUEL HANDLING PROBLEMS DURING REFUELING On October 26,1993, at approximately 10:08 a.m., during refueling activities, an unexpected drop of a section of the refueling mast occurred while lowering a bundle into the core. Prior to the event, the operators experienced two Fault Lockout alanns on the bridge. The fuel bundle was above the core (Position 375") at the time. The fuel bundle and top guide were checked for interference and none was found. After bundle insertion, the mast was fully raised and lowered three times. A loud noise and jerk were experienced one time. Maintenance investigated and discovered a bend in the mast. The licensee detennined that the fuel bundle did not drop during the event. The Unit 2 refueling bridge was transferred to Unit I and the required surveillance test perfonned and core reload resumed.
On October 27, at 3:38 p.m., while transferring a double blade guide (temporarily inserted in the reactor core for control blade support while the fuel is removed) from the reactor vessel to the spent fuel pool, the blade guide contacted the vessel wall. The senior reactor operator noticed the blade guide was not lifted high enough to have sufficient clearance and alerted the reactor operator to stop. The bridge was stopped, however, momentum of the blade guide caused it to swing on the mast grapple and contact the vessel wall. The guide was raised to proper height and the blade guide placed in the proper location in the spent fuel pool. The mast was exercised and found to be vibrating more than previously noted. The licensee halted refueling operations. Procedure changes were made to ensure consistent fuel handling practices. The refueling mast was inspected and surveillances perfonned satisfactorily. The licensee resumed core reload.
On October 28, at 7:10 a.m., while attempting to grapple a new fuel bundle in the fuel pool, for reload into the core, operators heard a loud noise on the refueling bridge. The refueling bridge was aligned above the bundle and the mast lowered to grapple the bundle. Betwem 193" and 201.6" (just above the full down position for the spent fuel pool) two loud bangs were heard and a large amount of air bubbles were observed on the pool. The bubbles were observed for 5-10 sewnds then stopped. No radiation alanns were received during the event. The licensee suspended all refueling activities.
Based on the multiple continuing problems encountered during refueling operations, an Augmented Inspection Team (AIT) is being dispatched to the site. The team will consist of five members, including an NRR Human Factors Specialist and a Regional Operator Licensing Examiner. The licensee has 8 f suspended rAfaehrm activities pending AIT review and evaluation.
9311050022 931029
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. DCS No: 50387931026 O
Date: October 29,1993 A
PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE PN19359 The Commonwealth of Pennsylvania has been notified. The licensee is considering a press release and the Region I Public Affairs Office is ' prepared to respond to media inquiries. This notification is current as of 11:00 p.m. on October 29.
CONTACT:
J. White D. Mannai (215-337-5114)
(717-542-2134)
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- Ocncral het for sending PNs by FAX Region I Fonn 83 (Rev. August 1993) 1