IR 05000289/1975007
| ML19256D615 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 04/04/1975 |
| From: | Gage L, Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML19256D614 | List: |
| References | |
| 50-289-75-07, 50-289-75-7, NUDOCS 7910190574 | |
| Download: ML19256D615 (7) | |
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II:I Form 12
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U. S. NUCLEAR REGUIATORY Com!ISSION
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0FFICE OF INSPECTION AND EhTORCDIEh7
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REGION I
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IE Inspection Report No:
56-289/75-07 Docket No: 50-289 Licensee:
Metropolitan Edison Company L'icense No:
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P. O. Box 542 Priority:
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C Reading, Pennsylvania 19603 Category:
Safeguards s,
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Group:
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Location:
Middletown, Pennsylvania (Three Mile Island 1)
Type of Licensee:
S ecial, Announced P
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of Inspection:
March 21. 1975
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Dates of Previous Inspection:
March 12-14 1975 Reporting Inspector:
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L. W. Gage, Rea6Mnspecto'f DATE
Accompanying Inspectors:
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DATE
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DATE Other Accompanying Personnel:
Nona DATE Y/Q/7(
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Revicved By:
%N R.C.Haynes, Son'iorR)actorinspector DATE
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7010100 ( 7 9
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s SUMNARY OF FINDINGS
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Enforcement Action
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Items of Noncomoliance r
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Deviations
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None
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Licensee Action on Previously Identified Enforcement Items s,
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Not applicable J
Design Chances None-identified Unusual Occurrences (Reference:
Licensee Nonroutine,30-day Report No. 75-01)
The referenced report, transmitted by the licensee to OIE:I via le'tter No. GQL 0791, dated February 24, 1975, described a trip of the Westing-house DB-50 electrical feeder breaker.
The trip was attributed to a viring fault in the Emergency' Lighting Panel CT-1 Circuit of the I-T-E EE Imperial 1B Engineered Safeguards Motor Control Center.
The fault was traced to a wire (in the CT-1 circuit, between the DB-50 feeder and an MO 30 circuit breaker) that burned and opened.
Other Significant Findings A.
Current Findines Unresolved Item - Calibration of Critoing Tools
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The licensee is investigating the purchase of a crimping tool, for use with No. 10 AWG wire and smaller, which can be calibrated.
The licensee is also reviewing their present procedure for control of too'Is and test
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equipment to determine if crimping tools will be added to the list of controlled equipment.
This item is unresolved.
(Details, Paragraph 2.)
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B.
Status of Previousiv Reported Unresolved Items
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(Reference:
Inspection Report No. 50-289/75-05)
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Design and Construction of ES Motor Control Centers The licensee has' initiated corrective action to preclude a repeti-tion of the failure that occurred in the 1B Engineered Safeguards Motor Control Center.
They have completed their review of the
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arenitect-engineer's specification for the design of the cotor control centers, and they are presently inspecting the vendor's workmanship in the fabrication of the motor control centers.
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This' item is unresolved.
(Details, Paragraph 3.)
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Management Interview At the conclusion of the inspection, the inspector held a meeting at
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the site with the following personnel to discuss the inspection find-ings:
Metropolitan Edison Comoany Mr..J. Colitz, Unit 1 Superintendent tir. C. Hart =an, Unit 1 Lead Elcetrical Engineer
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'x. J. Herbein, Station Superintendent
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Mr. G. May, Senior Staff Engineer
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Mr. W. Potts, Supervisor of Quality Control
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The following items were discussed, and the inspector's findings were acknowledged by the licensee:
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Purpose of the Inspection The inspector stated that the purpose of this special, announced inspection was to examine the licensee's inspection efforts, to date, on the Engineered Safeguards Motor Control Centers.
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Current Findings - Unresolved Items
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The inspector stated that the following items were observed and are considered to be unresolved:
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1.
Calibration of Crimping Tools The licensee is investigating the purchase of a cri= ping tool,
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for use with No. 10 AUG wire and smaller, which can be cali-brated.
The licensee is also reviewing their present procedure fo.r control of tools and test equipment to determine if crimp-ing tools will be added to the list of controlled equipment.
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This item is unresolved.
(Details, Paragraph 2.)
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2.
Design and Construction of ES Motor Control Centers
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The licensee has initiated corrective action to preclude a repeti-tion of the failure that occurred in the 1B Engineered Safeguards Motor Control Center.
They have completed their' review of the
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architect-engineer's specification for the design of the mot.)r control centers, and they are presently inspecting the vendor's
workmanship in the fabrication of.the motor control centers.
This item is unresolved.
(Details, Paragraph 3.)
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DETAILS
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Persons Contacted Hetropolitan Edison Comenny
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Hr. C. Hartman, Unit 1 Lead Electrical Engineer Mr. G. May, Senior Staff Engineer Mr. H. Mitchell, Electrical Maintenance Supervisor 2.
Calibration of Crimping Tools
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The inspector examined the capability of the licensee for repairing wiring deficiencies in the MCCs.
He observed the crimping tools
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that the licensee has available for crimping lugs onto wire leads.
One -- a Thomas & Betts "Sta-Kon Tool", No. WT 100M -- is used for L
crimping lugs onto wire of No. 10 AWG and smaller.
This tool has no mechanical stops to limit jaw travel.
The depth of the crimp is dependent upon the manual pressure exerted by the user.
The licensee has attributed the failure of the CT-1 circuit wire
..._._.1 to an improperly crimped lug on No. 14 AWG wire. l(Refer to Details, paragraph 3.)
The licensee does not anticipate having to replace more than a few wires in the MCCs.
If, in replacing these wires, spare wires are unavailable and new wire terminations are required, the licensee stated he would (1) document the replacements, (2) exercise caution in using the crisping tool, and (3) carefully examine the completed crimps.
In the meantime, the licensee is investigating the purchase of a different crimping tool: one that has stops to limit its jaw travel.
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The licensee has two other crimping tools.
They are used for crimp-ing luga onto wire of No. 8 AWG and larger.
Both tools ~have mechani-cal stops which limit jaw travel.
The licensee is presently deter =i-ning the feasibility of including the cri= ping tools in his Admin-istrative Procedure No.1022 for " Control of Measuring and Test Equipment".
Thin item is considered to be unresolved, pending a subsequent review by an NRC inspector of the licensee's actions on purchasing and controlling crimping tools.
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3.
Design and Construction of ES Motor Control Centers
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The inspector reviewed the results of the licensee's inspection of the MCCs, to date.
The. inspection is being conducted and documented in accordance with procedure No. SOP-168, dated March 15, 1974, titled, "E.S.C.C. Breaker Inspection".
modules in the MCCs have been inspected.
Eleven workmanship-type
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deficiencies have been found and are being corrected.
(Approxi-mately half of these deficiencies are cases where a nut, anchor-ing a lug to a stud, can be torqued less than additicnal turn.)
The licensee has scheduled the completion of his inspection of all the engineered safeguards circuits (131 of them) in the seven I-T-E Imperial MCCs for April 18, 1975, with seven ex-
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ceptions*; he has scheduled the completion of his inspection of i
all the remaining circuits in the MCCs for June 30, 1975.
These inspections include the viring " upstream" of the MCC circuit
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breakers (between the 1000-ampere bus and the breakers) and the
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wiring " downstream" of the MCC * circuit breakers (between the breakers i.
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and the. terminals on the MCC frame).
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The licensee, af ter reviewing the architect-engineer's speci-fication for the MCC (Specification titled "Lov Voltage Motor and Feeder Distribution Equipment -- TMI Nuclear Station Unit'
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dor's design standard for wiring (Standard titled " Wire and Cable Sizing for Series 9600", dated January 20, 1966), now attributes the failure of the wire in the CT-1 circuit to an improperly crimped lug and not to an undersize wire.
The licensee feels that the defective crimp caused a point o,f high x
resistance in the wire at the lug.
The wire heated at this point, melted, opened, and then dropped towards a grounded surface.
There was resultant arcing, from the wire to the surface and also from the wire to the lug of an adjacent wire in the AHE-29B circuit.
This caused the ARE-29B wire to melt and open and simultaneously caused the DB-50 breaker to trip.
g This item is considered to be unresolved, pending a subsequent review by an NRC inspector at the co=pletion of the licensee 's inspection program.
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Note:
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The sr.ven exceptions; which require de-energization of the 1000-ampere bus, are as follows:
Circuit No.
Circuit Description AHE-1A React r Bldg. Vent Fan (lA)
ARE-1B Reactor Bldg. Vent Fan (1B)
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AHE-lc Reactor Bldg. Vent Fan (lC)
NRS-1B Nuclear Service River Water Pump 13 Strainer EG-P-1A.,
Diesel-Generator Air conpressor (lA)
EG-P-1B Diesel-Generator Air Compressor (lB)
EG-Y-1A Diesel-Generator Auxiliary Panel s.
The licensee has scheduled the inspection of these circuits for his next planned shutdown.
This information was transmitted by the licensee (J. Colitz) to OIE:I (R. Spessard) via telephone, on Ebrch 25, 1975.
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