United States Nuclear Regulatory Commission - Protecting People and the Environment

ACCESSION #: 9509210131

Tennessee Valley Authority, 1101 Market Street,
Chattanooga, Tennessee  37402-2801

O. J. "Ike" Zeringue
Senior Vice President, Nuclear Operations

SEP 14 1995

CDR-50-390/95-05                                          10 CFR 50.55(e)
CDR-50-391/95-05

U.S. Nuclear Regulatory Commission
ATTN: Document Control Desk
Washington, D.C. 20555

Gentlemen:

In the Matter of the Application of     )              Docket Nos. 50-390
Tennessee Valley Authority              )                          50-391

WATTS BAR NUCLEAR PLANT (WBN) UNITS 1 AND 2 CONSTRUCTION DEFICIENCY
REPORT (CDR) 50-390, 391/95-05 - DEFICIENCY INVOLVING VENDOR WIRED
SAFETY-RELATED ELECTRICAL PANELS - FINAL REPORT

The purpose of this letter is to provide a final report for the subject
deficiency in accordance with 10 CFR 50.55(e).  The subject deficiency
was initially reported to the NRC Operations Center on August 18, 1995,
as Finding Identification Report WBFIR930012307.  The subject deficiency
was subsequently upgraded to Significant Corrective Action Report
WBSCA950014.

The Enclosure 1 contains a final report for the subject deficiency. 
Enclosure 2 contains a list of commitments made in this submittal.

If there are any questions, please telephone P. L. Pace at (615) 365-
1824.

Sincerely,


O. J. Zeringue

Enclosures
cc:  See page 2


U.S. Nuclear Regulatory Commission
Page 2

SEP 14 1995

cc (Enclosures):
     INPO Record Center
     700 Galleria Parkway
     Atlanta, Georgia 30339

     NRC Resident Inspector
     Watts Bar Nuclear Plant
     Rt. 2, Box 700
     Spring City, Tennessee 37381

     Mr. P. S. Tam, Senior Project Manager
     U.S. Nuclear Regulatory Commission
     One White Flint North
     11555 Rockville Pike
     Rockville, Maryland 20852

     U.S. Nuclear Regulatory Commission
     Region II
     101 Marietta Street, NW, Suite 2900
     Atlanta, Georgia 30323


                               ENCLOSURE 1

              WATTS BAR NUCLEAR PLANT (WBN) UNITS 1 AND 2 
             VENDOR WIRED SAFETY RELATED ELECTRICAL PANELS 
            SIGNIFICANT CORRECTIVE ACTION REPORT WBSCA950014
           10CFR50.55(e) CONSTRUCTION DEFICIENCY REPORT (CDR)
                          CDR 50-390, 391/95-05
                              FINAL REPORT

DESCRIPTION OF DEFICIENCY

Loose connections have been identified in vendor wired safety-related
electrical panels.  The loose connections involve both the termination of
incoming field cables as well as vendor terminations.

BACKGROUND

Deficiencies in vendor wired safety-related electrical panels had been
identified during a configuration control walkdown of 40 Unit 1 panels in
1984.  The deficiencies were documented in Nonconformance Report (NCR) W-
205-P.  The deficiencies can be categorized as: (1) labeling deficiencies
(primarily on vendor wiring); (2) wiring/configuration control
deficiencies (e.g., wires on different terminal than shown on drawings);
or (3) physical problems (e.g., nicks on insulation and loose terminal
connections).  The deficiencies which required correction were resolved
through rework or drawing changes.  The NCR was determined to not be
significant and was closed in 1985 without requiring a walkdown of any
additional panels.

In 1987 an Employee Concerns Special Project (ECSP) review team did not
recognize that the physical deficiencies associated with NCR W-205-P had
not been adequately dispositioned for the uninspected panels.  However,
in January 1993, WBN Site Quality Assurance personnel reviewed the ECSP
evaluation of NCR W-205-P during an audit (WBA93307).  In February 1993
the significance determination of the NCR was questioned and documented
in Finding Identification Report (FIR) WBFIR930012307.  An action was
initiated against that FIR to evaluate any deficiencies identified
through the walkdown inspection of the previously uninspected vendor
wired safety-related electrical panels required for Unit 1 operation and
determine whether they could have created a substantial safety hazard, if
left uncorrected.  That action has been completed.

SAFETY IMPLICATIONS

Based on a review of the work implementing documents associated with
deficiencies identified during the above walkdowns, four categories of
deficiencies were identified: (1) terminal blocks; (2) loose connections;
(3) cables/conductors; and (4) cable/conductor insulation gaps. 
Categories 1, 3, and 4 have been evaluated as not having an adverse
impact on plant safety.  However, Category 2 was determined to
potentially have an adverse impact on plant safety.

Although some of the identified loose connections could involve
nonsafety-related circuits fed from the safety-related panel, a
significant portion of


the loose connections have been confirmed to be associated with safety-
related circuits in various safety-related systems (e.g. Component
Cooling System, Safety Injection System, Ventilating System, Essential
Raw Cooling Water System, Residual Heat Removal System, etc.), and
involve redundant divisions of safety-related circuits.  Assurance cannot
be provided that the identified loose connections would maintain circuit
continuity during a seismic event.  Therefore, those loose connections
would be assumed to create an open circuit during a seismic event.  The
resulting condition may affect the capability to mitigate the
consequences of design basis events or safely shut down the reactor and
maintain it in a safe shutdown condition.

CAUSE OF THE DEFICIENCY

The cause for the deficiencies existing past closure of NCR W-205-P was
personnel error.

A configuration walkdown of vendor wired safety-related electrical panels
was conducted in 1984.  The walkdown was designed to identify and correct
electrical deficiencies.  After inspecting 40 vendor wired safety-related
electrical panels, numerous identified deficiencies were documented in
NCR W-205-P.  The responsible organization incorrectly determined that
the NCR was non-significant.  By the procedure in effect at the time,
non-significant NCRs were not required to be reviewed for Unit 2 generic
applicability, extent of condition, root cause, or recurrence controls. 
Therefore, the incorrect significance determination resulted in the
remaining vendor wired safety-related electrical panels not being
inspected.

CORRECTIVE ACTIONS


The cause for this construction deficiency was the subject of Notice of
Violation (NOV) 50-390, 391/93-24-01.  TVA initially replied to that NOV
on June 8, 1993.

The loose connections identified in previously uninspected vendor wired
safety-related electrical panels required for Unit 1 operation have been
corrected as part of the Unit 1 closure of WBFIR930012307.

Unit 2 vendor wired safety-related electrical panels not inspected by
NCR W-205-P or WBFIR930012307 will be dispositioned prior to Unit 2 fuel
load.


                               ENCLOSURE 2

                           LIST OF COMMITMENTS

Unit 2 vendor wired safety-related electrical panels not inspected by
NCR W-205-P or WBFIR930012307 will be dispositioned prior to Unit 2 fuel
load.


*** END OF DOCUMENT ***
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