ML19323G087

LER 80-040/03L-0:on 800514,during Insp of Reactor Core Prior to Placement of Reactor Vessel Upper plenum,hold-down Spring on Fuel Assembly Found Damaged.Cause Unknown.Corrective Actions Will Be Determined When Cause Has Been Identified

ML19323G087
Person / Time
Site:	Davis Besse
Issue date:	05/23/1980
From:	Lingenfelter J TOLEDO EDISON CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML19323G086	List: ML19323G085 ML19323G087
References
LER-80-040-03L, LER-80-40-3L, NUDOCS 8005300361
Download: ML19323G087 (3)

Text

NRC FORM 3C6 U. S. NUCLEAR REGULATORY COMMISSloN B77) .

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LICENSEE EVENT REPORT CONTROL DLOCK: l l l l l l lh (PLEASE PRINT OR TYPE alt REQUIRED INFORMATION) 1 6

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by 61 COCKET P.UvaER 6d 69 EVENT DATE 74 75 REPORT DATE 80 EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h J o 121 l (NP-32-80-08) On 5/14/80 during an inspection of the reactor core prior to the place- l 9o;3; gment of the reactor vessel upper plenum, the hold-down spring on a fuel assembly was l jo ja j j found to be damaged. The f ucl assembly was one of the assemblies in the Cycle 1 core. l

o93; l A total of sbc additional failed springs have been identified and several other poten- l 1016 I l tially f ailed springs have been identified. This is being reported under T.S. 6. 9.1. 8.li .

I O l 7 l lThere was no danger to the public or station personnel. NOne of the fuel assemblies l ig,g; jexamined to date show any indication of movement within the core. I SYSTEM CAUSE CAUSE COYP. VALVE CODE CODE SUBCODE COMPONENT CODE SUSCODE SUBCODE jol9l i a l Rl Al@ l B l@ [ A l@ l X l X l X l X l X l X l@ l Zl@ 20lZ l@

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44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h lil0l]The cause of this occurrence has not yet been determined. Investigation of the fail- ]

[ilil lures is continuing. Several of the hold-down springs will be analyzed by Babcock and I

,,;7ylWilcox. The actions necessary to correct this problem will not be determined until I i,;3, lthe exact cause of the occurrence has been identified. l

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• 80 SA S  % POWE R oTHER STATUS ISCO RY DISCOVER) DESCRIPTION i s W@ l 0 l 0 l 0 l@l NA l U hl Following Refun1ine  !

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80-082 NAME OF PREPARER que b Mnfe b P ION E: (419) 259-5000, Ext.~291{

TOLEDO EDISON COMPANY DAVIS-BESSE NUCLEAR POWER STATION UNIT ONE SUPPLEMENTAL INFORMATION FOR LER NP-32-80-08 DATE OF EVENT: May 14, 1980 FACILITY: Davis-Besse Unit i IDENTIFICATION OF OCCURRENCE: Failed Fuel Assembly Hold-down Springs Conditions Prior to Occurrence: The unit was in Mode 6, with Power (MWT) = 0 and Load (Gross MWE) = 0.

Description of Occurrence: During an inspection of the reactor core prior to the placement of the reactor vessel upper plenum, the hold-down spring on a fuel asseia-bly was found to be damaged. The fuel assembly was one of tite assemblies in the Cycle 1 core.

A review of video tapes taken immediately after the plenum removal prior to refueling shows that the spring was broken before refueling.

The hold-down springs on all accessibic irradiated fuel assemblics have been inspected (those assemblies in the reactor vessel containing control components have not been inspected) to determine if additional spring failures had occurred. A total of six additional failed springs have been identified and several other potentially failed l springs have been identified.

Designation of Apparent Cause of Occurrence: The cause of this occurrence has not yet been determined. Investigation of the failures is continuing. Several of the hold-down springs will be analyzed by Babcock and Wilcox.

Analysis of Occurrence: There was no danger to the health and safety of the public or to station personnel. None of the fuel assemblies examined to date have shown any indication of movement within the core.

Corrective Action: The actions necessary to correct this problem will not be deter-mined until the exact cause of the occurrence has been identified.

Failure Data: There have been no previous similar reportable occurrences.

LER #80-040 i

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TELECOPY Sg'Rocuivac Verified. Receipt: yes/no page .$~-/f -80 Time Y'OO hours May 14, 1980 Initials AM -

TO: U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region III Attention: Tom Tambling 4

SUBJECT:

Reportable Occurrence Per Technical Specification 6.9.1.8.1 Davis-Besse Nuclear Power Station Unit 1 Mode 6, Power (MVT) = 0 and Load (Gross MWE) = 0 .

During an inspection of the reactor core prior to the placement of the reactor vessel upper plenum, the hold-down spring ca a f*11 assembly was found to be damaged. The fuel assembly was one of the assemb.ies in the Cycle 1 core.

A review of video tapes taken immediately after the plenum removal prior to refueling shows that the spring was broken before refueling. An initial inspec-tion of the broken spring indicates, however, that the damage occurred after shutdown.

The exact cause of the failure is not yet known. Investigation is continuing.

Tom Tambling, currently on site,was not.ified at 1200 hours0.0139 days <br />0.333 hours <br />0.00198 weeks <br />4.566e-4 months <br /> on May 14, 1980.

i-Terry D. Murray '

Station Superintendent -

Davis-Besse Nuclear Power Station Toledo Edison Company TDM/JRL/lj k ~

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