ML20082C913

Amend 1 to Final Deficiency Rept,Item 102 Re Damaged Control Rod Blades.Initially Reported on 830927.Investigation Revealed Misalignment of Several Control Rod Blade Guides. Guides Realigned

ML20082C913
Person / Time
Site:	Fermi
Issue date:	11/10/1983
From:	Wells D DETROIT EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
102, 10CFR-050.55E, 10CFR-50.55E, EF2-65289-REV-1, NUDOCS 8311220245
Download: ML20082C913 (3)

Text

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Dmd Denald A. Wells Detroit MEMP ^"~ [

Edison =(m23m=h November 10, 1983 EF2-65289, Rev. 1 Mr. James G. Keppler, Regional Administrator Region III U. S. Nuclear Regulatory Commission 799 Roosevelt Road

! Glen Ellyn, Illinois 60137

Subject:

Amended Report of 10CFR50.55(e) Item on Damaged Control Rod Blades (#102)

Dear Mr. Keppler:

This is an amendment to Detroit Edison's final report, which was submitted to Region III on October 27, 1983, providing additional information concerning the damaged control rod blades at the Fermi 2 site. This item was originally reported on September 27, 1983, to Mr. J. Konklin of NRC Region III by Detroit Edison's Mr. W. R. Wingfield, Quality Engineer - Construction Quality Assurance.

On September 22, 1983, a problem was discovered following Preopera-tional Test E1100.001 ("Three RHR Pump Run"). While inserting the control rods, some operated sluggishly and others would not fully insert. Attempts to insert additional rods were stopped pending further investigation. The initial investigation revealed there was actual damage sustained to two (2) of the control rod blades and two (2) orifice fuel supports. This was later verified by an inspection performed by a General Electric, Wilmington representative. The damaged items have been returned to General Electric, Wilmington for repair.

Further investigation and a detailed inspection of core internals re-vealed a misalignment of several control rod blade guides. . A differ-ential pressure across the core plate during the previous "Three RHR Pump Run" had caused a lif t of the blade guides. Blade guides have been subsequently cleaned and re-used. A detailed plan to inspect i control rod blades, orifice fuel support castings, and blade guides has been developed and implemented. In addition, five (5) LPRM's were bowed approximately 1/4 to 1/2 inch over their total length, and one (1) LPRM was damaged (bent) while removing a fuel support casting l during inspection. The five (5) bowed and one (1) damaged LPRM will be electrically tested and repairs and/or replacements made as

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8311220245 831110 DR ADOCK 05000 g}

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NOV 1619Q3 l . -

Mr. James G. Keppler, Regional Administrator November 10, 1983 EF2-65289, Rev. 1 Page 2 necessary. Following inspection and reassembly of the core internals, PRET.C1150.001, Supplemental Test #13 was performed on the affected Control Rod Drives to verify proper rod motion. Results of this testing has verified that performance of rod motion has been acceptably accomplished.

An evaluation of safety implications has determined that there is no compromise of safety or reliability. The ability to insert control rods is a safety concern only when fuel is installed in the core.

Enrico Fermi 2 has not loaded fuel. Even if the occurrence had gone undetected, the ability to insert control rods with fuel in the core would not have been jeopardized. The blade guides which interfered with the control rod insertion are temporary, and will be replaced by fuel bundles at fuel load; removal of the temporary guides would have eliminated any interference, and all control rods could have been inserted when fuel was in the core.

The following precautions were taken to prevent blade guide lift during a subsequent RHR Pump Run on October 7,1983, (incorporation of a-g into PRET.E1100.001 by TCN 1166):

a. removal of the temporary 0* manway cover;

b. ' removal of all blade guides, except for four (4) single

! blade guides tied around each incore probe;

c. removal of all peripheral fuel support pieces;

d. assuring that the water level is over the blade guides prior to LPCI injection;

e. verify proper blade guide position subsequent to each three

(3) or four (4) pump RHR injection; j f. core plate P monitored to verify no. blade guide lif ting while remaining below the calculated limit that would cause blade guide lifting; and

g. verify all blade guides for proper blade guide positions af ter reinstallations in support of CRD operation.

Similar precautions will be taken during further RHR three (3) and four (4) pump vessel injections.

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Mr. James G. Keppler, Regional Administrator Novembe r 10, 1983 EF2-65289, Rev. 1 Page 3 If you have questions concerning this matter, please contact Mr. G. M. Trahey, Assistant Director - Project Quality Assurance.

Very truly yours, ,

jlf

@t[WL DAW /ERN/pn cc: Mr. Richard DeYoung, Director Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Mr. Paul Byron, Senior Resident Inspector U. S. Nuclear Regulatory Commission 6450 North Dixie Highway Newport , 111chigan 48166 l

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