ML18058B937

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LER 93-004-00:on 930630,failure of Fuel Rod & Dislocation from Fuel Assembly W/Cause Undetermined at This Time. Core Reload Plan developed.W/930730 Ltr
ML18058B937
Person / Time
Site: Palisades Entergy icon.png
Issue date: 07/30/1993
From: Hillman C, Slade G
CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-93-004, LER-93-4, NUDOCS 9308050191
Download: ML18058B937 (5)
v • d • e


Text

. I consumers Power GB Slade General. Manager POWEJllNli MICHlliAN'S PROliRESS

. Palisades Nuclear Plant: 27780 Blue Star Memo.rial Highway, Covert, Ml 49043 July 30, 1993

. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 DOCKET 50-255 - LICENSE.DPR PALISADES PLANT -

LICENSEE EVENT REPORT 93~004 - FUEL ROD FAILURE AND SUBSEQUENT LOSS OF SPECIAL NUCLEAR MATERIAL DISCOVERED FOLLOWING REFUELING OPERATIONS Licensee Event Report (LER)93-004 is attached. This event is reportable in accordance with 10CFR50.73(a)(2)(ii).

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Gerald B Slade General Manager CC Administrator, Region III, USNRC NRC Resident Inspector - Palisades Attachment 93oeoso 191 PDR S

ADOCK 6~865g PDR55

  • 1. ACMSENERGYCOMPANY*

NRC Form 366 U.S. NUCLEAR REGULATORY COMMISSION, 19*831 APPROVED OMB NO. 3160-0104 I EXPIRES: 8/31186 LICENSEE EVENT REPORT ILERJ I FACILITY NAME 111 DOCKET NUMBER 121 PAGE 131 Palisades Plant I *1 I I I I I o s o o o 2 s s 1 I OF o1 4 TITLE 141 FUEL ROD FAILURE.AND SUBSEQUENT LOSS OF SPECIAL NUCLEAR MATERIAL DISCOVERED FOLLOWING REFUELING OPERATIONS EVENT DATE 161 LER NUMBER ISi REPORT DATE 161 OTHER FACILITIES INVOLVED !Bl SEQUENTIAL REVISION FACILITY NAMES MONTH OAY. YEAR YEAR NUMBER NUMBER MONTH OAY YEAR N/A 01610101011 oI o . ob

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61 6 ~ 0 9 3 9 I3 ol o I 4 31 0 Q I~ N/A 0161010101 I

THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR I: /Cl><<lc OM,,,,,,_ of IN followingJ 1111 OPERATING N 20.4021bl 20.4061cl MOOE 191 I - 60.731*112lli*l* 73.71 (bl

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LICENSEE CONTACT FOR THIS LER I 121

60. 7 31*112ll*iiil1Bl 60.731*112llxl NRC Form 366Al NAME TELEPHONE NUMBER AREA CODE I Cris T. Hillman, Staff Licertsing Engineer s I , I* s 716141 - I aI sI , I 3 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT 1131 MANUFAC* REPORTABLE MAJNUFAC* REPORTABLE CAUSE SY.STEM COMPONENT TUR ER TO NPROS CAUSE. SYSTEM COMPONENT TUR ER TO NPROS I I I I I I I I I I I I I I I I I I I I I I I I.I I I I SUPPLEMENTAL REPORT EXPECTED 1141 MONTH OAY YEAR N

EXPECTED SUBMISSION a Is YES Vf Y"* campier. EXPECTED SUBMISSION OATEI DATE 1161

. nNO 3 lo 913 ABSTRACT IUmit ro 1400 _,, .... i.* .. *ppro*irMroly fiffHn ,,;ngi.-"* typewrirr.n lineal 1181 On June 30, 1993, at approximately 2300 hours0.0266 days <br />0.639 hours <br />0.0038 weeks <br />8.7515e-4 months <br />, while draining the refueling '.

cavity in preparation for re-attaching the reactor head to the reactor vessel, an object located in the reactor cavity tilt pit exhibited contact dose rates of approximately 7000R/hr. A review of a remote camera inspection video tape led to the postulation that the object was a piece of fuel rod. Further remote camera inspection of the t i1 t pit resulted in the discovery pf three additional pieces of what appeared to be a fuel rod. Review of the video tape revealed that one of the pieces had an end cap and the serial number was visible. Based on the serial number, it was determined that the *fuel rod came from a fuel assembly (1-24} that was in the reactor core.

The root cause for the failure of the fuel rod and .its dislocation from the

  • fuel assembly has not been determined at this time.

Corrective action will be developed when a root cause for the failure is determined. A core reload plan is being developed by selecting and modifying replacement fuel assemblies. The re~lacement fuel assemblie~ are being modified to withstand rine more operating cycle bas~d on the observed wear phenomena. ..

    • p
NRC Forn-- 3HA U.S. NUCLEAR REGUl.ATORY COMMISSION 11-831 APPROVED OMB NO. 3160~10*

EXPIRES: 8/31/16 LICENSEE EVENT REPORT (LERI TEXT CONTINUATION FACILITY NAME Ill DOCKET NUMBER 121 LER NUMBER 131 PAGE I" SEQUENTIAL REVISION YEAR NUMBER NUMBER Palisades Plant Q 5. Q Q Q . 2 5 5 9 3 - Q Q 4 - Q Q .Q 2 OF Q 4.

£VENT DESCRIPTION On June 30, 1993, at approximatelj 2300 hour~, ~hi~e dra1ning th~ refueling

  • cavity in preparatirin for. re-attaching the reactor head to the reactor vessel, radiological dose rates in the reactor cavity near the tilt pit [OF] exceeded the dose rates typically experienced during previou~ similar refueling cavitj draining evolutions. At the time of the event the reactor head was in place over the reactor vessel resting on shims. Typical dose rates at the floor level of the refueling cavity near the tilt pit {elev. 625-feet) are 200-300 mR/hr; however, during this* event the dose rate on the refueling machine bridge {elev. 649-feet) was 700 mR/hr with no water in the tilt pit. An

.object located on the tilt, pit floor {elev. 610-feet), exhibited contact dose rates of approximately 7000R/hr. T~e refueling cavity was immediately

  • evacuated and the radiological conditions assessed.*. Approximately two feet of.

water was added to the tilt:pit to provide shielding. - Proper radiological postings-and boundaries were establtshed, and access to the containment area was controlled.

  • At the time of the ev~nt the reactor was in a *refueling mode.

There was no radiological release to the environment as a result of this event, and there were n9 personnel exposures that exceeded either 10 CFR Part

  • 20 limits or.CPCo administrative limits. This event had no adverse effect on the health and safety of th~ publit.
  • .A remote cam_era inspection of the tilt pit was conducted and a cyl i ndri cal object approximately five {5) feet in.length and approximately four-tenths

{0.4) inch in diameter was id~ntified. It was suspected that the object was a piece of a fuel rod [AC].* On July 1. 1993 the NRC ~as notified of the possibility Qf a fuel rod in the reactor cavity tilt pit.

Further remote cameta inspection of the tilt pit resulted in the identification of three more pieces of what appeared to be a fuel rod~ The

. total length of all four pieces ~as estimated to be about 12 feet. A review of the video tape from the remote camera inspection of.the three additional objects revealed that one of the pieces had a~ end cap and the.serial number was visible.

  • Based on the serial number, it .was determined that* the fuel rod
  • came from fuel assembly I-24 which was in the reactor core. The I-24 fuel assembly had been removed from the_ reactor during refueling, taken to the tilt pit, rotated 180 degrees ~nd returned to its core position.
  • In response to these developments, CPCo formed a prriject team to develop an action plan for recovery of the fuel rod pieces from the tilt pit, recovery of the damaged fuel assembly from the reactor core, and analysis of the entire
    • event. - *

... :-.. - .....-~ -:r** *.*.* *--: -**

'NRC Form SHA U.S. NUCLEAR REGULATORY COMMISSION 11-831 APPROVED OMB NO. 31~10**

EXPIRES: 8/31186 LICENSEE EVENT REPORT !LERI TEXT CONTINUATION FACILITY NAME 111 DOCKET NUMBER 121 LER NUMBER 131 . PAGE 1*1 SEQUENTIAL REVISION YEAR NUMBER NUMBER .

Palisades Plant Q. 5. Q Q Q 2 5 5 9 J - Q Q 4 - Q Q Q J OF Q 4 On July 4, 1993 the three fuel rod fragments were retrieved and relocated to storage baskets in the tilt pit. It was determined the fourth piece was not a fuel rod fragment and it was not recovered. By July 6, 1993 a plan had been developed and approved by the_Plant General Manager and the NRC for the recovery of fuel assembly 1-24 from the reactor core. The reactor head was removed and placed on the reactor head stand. Preparations were theri ~ade to remove th~ Upper Guide Structure (UGS) from the reactor vessel. During the lift of the UGS, the load cell readout indicated and the remote camera inspection.of the underside of the UGS confirmed that a fuel assembly still in its core position was being lifted with the UGS. The UGS lift was halted and the containment.was evacuated. An Unu~ual Event was declared at 2254 hours0.0261 days <br />0.626 hours <br />0.00373 weeks <br />8.57647e-4 months <br /> on July 6, 1993. There was no radiological release to the environment as a result of the lifting of a fuel assembly with the UGS, .and there were no exposures that exceeded either 10 CFR Part 20 limits or CPCo administrative limits. The lifting of a fuel assembly with the UGS had no adverse effect on the health and safetj of the public. *

  • A closer examination of the location of the fuel assembly attached to the UGS indicated that the fuel assembly was attached to the UGS in a location where fuel assemblies had been stuck to the UGS on two previous occasions. (See LERs 88015, dated October 3, 1988 and 92017, dated March 30, 1992.) All _

reactor vessel work was stopped pending recovery of the fuel assembly stuck to the UGS. Containment integrity was established by closing the equipment hatch and routine work activities in the containment were suspended. Procedures were then d~veloped for the recovery of the stuck fuel assembly.

On July 8, 1993 the fuel assembly, while still in its core ~osition, was successfully removed from the UGS and the reactor.vessel core-support plate.

The UGS was then lifted without further incident and was placed in its storage location in the reactor cavity. Also on July 8, 1993~ an NRC Augmented Inspection Team (All) arrived at Palisades to investigate the broken fuel rod found in the reactor tavity tilt pit, the lifting of a fuel assembly during removal of the UGS, and other recent issues~*

On July 13, 1993 .fuel assembly 1-24 was removed from the reactor core. Prior to removal from the reactor core, fuel assembly 1-24 had been visually inspected to ensure*that additional fuel rods would not be damaged during I removal from the reactor core. The visual inspection of fuel assembly 1-24 .;; .

while it was in the reactor core was accomplished by removing an adjacent fuel_

assembly and an adjacent control rod. Prior to removal, it was noted that the upper end piete of the failed fuel rod ~as still contained within the uppermost spacer grid of the 1-24 fuel assembly. During the removal of the 1-24 fuel assembly from the reactor core, this piece of fuel rod dropped from the fuel assembly and landed on top of another fuel a~sembly tieplate in the core. The piece that had fallen from fuel assembly 1-24 was retrieved from

NRC .F0m"l811A U.S. NUCLEAR REGULATORY COMMISSION (8-831 APPflOV£0 OMB NO. 31 &O-<l10*

EXPIRES: "8/31/86

! LICENSEE EVENT REPORT (LERI TEXT CONTINUATION FACILITY NAME 11 l

  • OOCKET NUMBER l2l LEA NUMBER l3l PAGE l6l SEQUENTIAL REVISION YEAR NUMBER NUMBER

'Palisades Plant oI s IoIoIo I2 Is Is 9 '3 - o Io 14 - o lo oI 4 oF o 14

.the core and was stored with the other three fuel rod pieces ... The 1-24 fuel assembly was subsequently relocated to the spent fuel pool, alongwith the pieces of damaged fuel rod, where inspections by CPCo personnel and the fuel vendor could be conducted.

Inspection of the 1-24 fuel assembly and the broken fuel rod are ongoin~.

Inspection of the reactor core and lower vessel area for loose fuel pellets, other debris, and other indicatioris of fuel damage are ongoing. The results of these inspections will be used to determine a root cause for the failure of fuel assembly I-24 and to develop corrective actions associated with this event.

This event is reportable to the NRC in accofdance with 10CFR50.73(a)(2)(ii) as an event wherein a principal safety barrier (i.e., fuel cladding) was

  • seriously degraded .

. CAUSE OF THE EVENT The root cause for the failure of the fuel rod from fuel assembly 1-24 will be included in a formal root cause analysis performed by Consumers Power Company.

This event involved the failure of a principal safety barrier (fuel cladding) and is considered a failure of equipment important to safety.

ANALYSIS OF THE EVENT The root cause analysis for the failure of the fuel rod from fuel assembly 1-24 will contain a detailed analysis of the event.

CORRECTIVE *ACTION The root cause analysis for the failure of the fuel rod from fuel assembly I-24 will contain the corrective actions for this event.

ADDITIONAL INFORMATION None

(.*-

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