ML20137R637
| ML20137R637 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 01/29/1986 |
| From: | Gridley R TENNESSEE VALLEY AUTHORITY |
| To: | Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| REF-PT21-86, REF-PT21-86-060-000 NCR-4430, PT21-86-060-000, PT21-86-60, NUDOCS 8602130344 | |
| Download: ML20137R637 (3) | |
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TENNESSEE VALLEY AUTHORITY CHATTANOOGA. TENNESSEE 374ot s.
J SN 157B Lookout Place January 29, 1986 y
C BLRD-50-438/85-23 r,
BLRD-50-439/85'-21
.e-U.S. Nuclear Regulatory Consnission
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Region II.
Attention:
Dr. J. Nelson Grace, Regional Administrator U
101 Marietta Street, NW, Suite 2900
' Atlanta, Georgia 30323 N --
Dear Dr. Grace:
BELLEFONTE NUCLEAR PLANT UNITS 1'AND 2 - SOLID STATE CONTROL SYSTEM CABINET WIRING WAS DAMAGED DUE TO TARGET ROCK SOLENOID WIRING AND DRAWING ERRORS -
BLRD-50-438/85-23, BLRD-50-439/85 FINAL REPORT The subject deficiency was initially reported to NRC-0IE Inspector Al Ignatonis on August 1, 1985 in accordance with.10 CFR 50.55(e) as NCR 4430. This was followed by our first interim report dated September 3,1985.
Enclosed is our final report. We consider 10 CFR Part 21 applicable to this deficiency.
If there are any questions, please get in touch with R. H. Shell at FTS 858-2688.
Very truly yours, TENNESSEE VAL Y AUTHORITY R. L. Gridley Manager of Licensing Enclosure cc:
Mr. James Taylor, Director (Enclosure)
Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C.
20555 Records Center (Enclosure)
Institute of Nuclear Power Operations
.1100 circle 75 Parkway, Suite 1500 d
Atlanta, Georgia 30339 B602130344 860129 PDR ADOCK 05000430 S
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An Equal Opportunity Employer M
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.J3 ENCLOSURE BELLEFONTE NUCLEAR PLANTS UNITS 1 AND 2 SOLID STATE CONTROL SYSTEN CABINET WIRING WAS DAMACED DUE TO TARGET ROCK SOLENOID WIRING AND DRAWING ERRORS BLRD-50-438/85-23 BLRD-50-439/85-21 NCR 4430 10 CFR 50.55(e)
FINAL REPORT Description of Deficiency Internal wiring in solid state control system (SSCS) cabinet IIX-IR-017A was damaged when a 120V ac potential was applied to at least two different field input points of the cabinet. The SSCS was designed for a 48V de input. The inputs involved were from Target Rock Incorporated (East Farmington, New York) solenoid valves that are controlled by the SSCS.
An internal jumper in the Target Rock valves supplied one side of the 120V ac signal (used to energize the solenoid) to the valve position limit switch terminals. On some valves, the 120V ac signal is used to energize local indicating lamps that require the use of an internal jumper; but when the position switches are connected as SSCS inputs, the internal jumper must be omitted.
The root causes of this deficiency were (1) Target Rock supplied a solenoid valve with an internal jumper that was not depicted on their drawings, and (2) TVA failed to specify the removal of one internal jumper that was shown on Target Rock's valve drawings (documentation error).
This deficiency is generic to unit 2 of BLN.
Similar wiring errors existed for train B solenoid valves and other Target Rock valves controlled by other train A SSCS cabinets. This condition is not applicable to other TVA plants.
Safety Implications The damaged SSCS circuitry controls a portion of the reactor coolant vent and drain system (NK).
If the identified deficiency was to remain uncorrected, any SSCS-controlled NK component or combination of components could be rendered inoperative, or operated when it should not be-operated. This could possibly lead to the inadvertent opening of a NK system drain valve or vent.
valve and a loss of coolant accident (LOCA). This condition could have adversely affected the safe operation of the plant.
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i' Corrective Action The Target Rock drawings and TVA schematics for all Target Rock solenoid valves controlled by SSCS have been reviewed. The one documentation discrepancy found,-system CA (auxiliary feedwater), has already been corrected
- by Field Change Request (FCR) E-4110, and the required drawing,has been issued. ~This completes all required documentation changes.
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.The condition of solenoid valves having jumpers between the coil and'11mit switches that are not shown on the drawing requires physical inspection of all i
Target Rock SSCS controlled solenoid valves (whether installed or still in-storage) and removal of those jumpers when found.
l The remainder of the SSCS will be inspected, and any damage discovered will be
-repaired.
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The completion of corrective action is scheduled to be complete six months l-before fuel load of the applicable units.
To prevent recurrence, the following actions will be taken:
1.
The vendor, Target Rock Incorporated, will be informed of the non-conforming condition and will be formally requested to initiate procedures to ensure that this condition does not recur. This' request will be forwarded to Target Rock by April 1, 1986.
In addition, TVA's source inspectors have been instructed to more closely compare Target Rock's provided equipment to approved drawings.
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Only one documentation problem was found, system CA, whD!. has been corrected..This is considered an isolated occurrence, and no further action to prevent recurrence is required.
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