ML20084U208

Ro:On 750212,following Verification of Reactor core,mixed- Oxide Fuel Assembly Identification Number Stamped in Wrong Orientation Discovered.Caused by Mfg Error.Fuel Insp Procedure Changed to Verify Number Orientation as Correct

ML20084U208
Person / Time
Site:	Quad Cities
Issue date:	02/25/1975
From:	Kalivianakis N COMMONWEALTH EDISON CO.
To:	Oleary J US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20084U209	List: ML20084U208 ML20084U212
References
IEB-74-010, IEB-74-10, NJK-75-110, NUDOCS 8306270481
Download: ML20084U208 (1)

Text

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February 25, 1975 i Mr. John F. O' Leary, Director .?

E Directorate of Licensing Regulation

U. S. tJuclear Regulatory Commission Washington, D. C. 20545 k

REFEREf4CE: Quad-Ci ties fluclear Power Sta tion g Docket tio. 50-254, DPR-29 3_

Appendix A. Section 6.6.B.2.b r

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Dear Mr. O' Leary:

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The purpose of this letter is to report to you the details of an unusual

[ event that was discovered on February 12, 1975 This report is submitted to '

you in accordance with the requirements of Technical Specification 6.6.B.2.b.

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[ On February 11, 1975, Unit I was in cold shutdown with the pressure y vessel head, the steam dryer and the steam separatcr removed; and the reactor _.

" core was being verifed. The next day,during the nuclear engineers' review h of the video tape of the verification, it was noticed that mixed-oxide fuel I_ os m ily OC 100 *. lmd i L:, I Jc. . ; * .% o L

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tion. In the correct orientation, the bottom of the letters and numbers on .

g the assembly handle should point toward the corner of the assembly to which g the spring clip is attached. In this case, however, the letters and numbers faced the opposite way. The fuel assembly itself was observed to be in the

_ correct orientation in the core by observing the location of the spring clip, E the location of the orientation lug on the assembly handle, the pattern of

[ the gadolinium rods in the assembly, and the position of the channel spacers.

4~ The cause of this identifict. tion number misorientation was a manufacturing error.

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The safety implications of this event are minimized by the fact that the 5 assembly was oriented correctly in spite of the mis-stamped identification E number. Therefore there was no increase of the probability of fuel integrity b breakdown; and the health and safety of the public were not affected. As this 7 was the first case of a misoriented identification number cccurring at Quad-g Cities, there were no safety implications based on cumulative experience.

F F The Safety Analysis Report states in Section 3.4-2 that the number orien-tation is one means of determining the fuel assembly orientation. Therefore it would be possible to risorient this assembly if the identification number was the only method used. Because this bundle is a mixed-oxide test assembly, g it is especially important to have it oriented correctly, not only to prevent I fuel rod failure, but also to obtain reliable test data.

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Because of this event the orientation of all the other assemblies in the core were verified by both the number orientation and the spring clip location.

A note of assembly GEB 160a's number orientation was included in the core veri-fication records for reference in future fuel movements and verifications. All future core verifications will include verification of orientation by both num-ber orientation and spring clip location. The new fuel inspection procedure will be changed to contain a step to verify the identification number orientation as being correct.

Very truly yours, COMMONWEALTH EDISON COMPANY QUAD-CITIES l'UCLEAR POWER STATION

)f)< ll N. J. Kal t vianakis fr.

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"3 Station Suoerintendent NJK/EAS/vmm cc: Reg *on lit, Directorate of Regulatory Operations J. S. Abel

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