ML19338C706

Final Deficiency Rept:On 800228,132 Cables Damaged Under Reactor Pressure Vessel During Installation of Control Rod Drive Assembly.Caused by Inadequate Protection of Previously Installed Cables.Cables Repaired & Replaced

ML19338C706
Person / Time
Site:	Grand Gulf
Issue date:	08/11/1980
From:	Mcgaughy J MISSISSIPPI POWER & LIGHT CO.
To:
References
AECM-80-185, NUDOCS 8008180516
Download: ML19338C706 (2)

Text

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N I MISSISSIPPI POWER & LIGHT COMPANY i

A 3]m i EssasidananE Helping Build Mississippi P. O . 8 0 X 16 4 O. J A C K S O N MlS SIS SIP PI 39205 NUCLEA A PACDUCTICN CEPARTVENT August 11, 1980 Office of Inspection & Enforcement U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, N.W.

Suite 3100 Atlanta, Georgia 30303 Attention: Mr. J. P. O'Reilly, Director

SUBJECT:

Grand Gulf Nuclear Station Units 1 and 2 Docket Nos. 50-416/417 File 0260/15525/15526 PRD-80/03, Final Report, Damaged Instrumentation Cables Under Reactor Pressure Vessel AECM-80/185

References:

1) AECM-80/60, 3/31/80

2) AECM-80/125, 6/9/80 On February 28, 1980, Mississippi Power & Light Company notified Mr. M. J. Gouge of your office of a Potentially Reportable Defi-ciency (PRD) at the Grand Gulf Nuclear Station (CGNS) construction site. The deficiency concerns damaged instrumentation cables under the Reactor Pressure Vessel (RPV).

As reported to you in our reference 2 letter we have determined this deficiency to be reportable under 10CFR50.55(e). Details are described in the attached final report. This deficiency is not reportable under 10CFR21 because the cables do not meet the criteria of a delivered basic component.

Yours truly,

&y f r J. P. McGaughy, Jr.

Assistant Vice President, Nuclear Production 3

ATA:st Attach =ent

/7 cc: Mr. N. L. Stampley Mr. Victor Stello, Directoh ' '

Mr. R. B. McGehee Divisien of Inspection & Enforcement Mr. T. B. Ccnner U. S. Nuclear Regulatory Commission Washincton, D.C. J0555 Member Middle South Utilities system S008160 W b

. Attachment to AECM-80/185 Page 1 of 1 FINAL REPORT FOR PRD-80/03 I. Background and Description of Deficiencv On February 28, 1980, Mississippi Power & Light Company notified Mr. M. J. Gouge of your office of a deficiency concerning damaged instrumentation cables under the Reactor Pressure Vessel (RPV).

Mr. Gouge was notified at that time of our determination that this matter was not reportable within the meaning of 10CFR50.55(e).

This notification was made for information purposes only. On March 6,1980, Mr. Gouge informed Mississippi Power & Light Company that this deficiency should be considered and processed as a reportable condition.

Some 132 cables located under the Unit 1 Reactor Pressure Vessel were damaged during the installation of control rod drive assembly housings. Damaged cables pertain to the Control Rod Drive Hydrau-lic System and Neutron Monitoring System. The damage ranges from pinched insulation to insulation cut through to the con-ductor. This is documented in several Bechtel Nonconformance Reports (NCR) and Condition Reports (CR) and filed under Bechtel MCAR-GCNS No. 62.

Several factors contributed to the occurrence of this deficiency.

Primarily the working area under the RPV is quite restricted.

Because of this aspect instrumentation cables were installed prior to the installatica of the control rod drive housings.

We have determined that during the CRD housing installations, adequate measures were not taken to protect the previously installed cables.

II. Safety Implications Some of the damaged instrumentation cables are associated with safety related equipment, and as such, could have adversely affected the safety of plant operations at Unit 1. This de-ficiency is thus reportable under 10CFR50.55(e).

III. Corrective Actions The repair or replacement of damaged cables has been completed for Unit 1.

The Constructor is issuing a Work Plan / Procedure to address the deficiency and to prevent recurrence of the deficiency in Unit 2.

Details of corrective action are documented in Bechtel Manage-ment Corrective Action Report (MCAR) Number 62.

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