ML20112C864
| ML20112C864 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 02/28/1985 |
| From: | Hall D ILLINOIS POWER CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| REF-PT21-85, REF-PT21-85-147-000 55-84-21, PT21-85-147, PT21-85-147-000, U-10252, NUDOCS 8503220164 | |
| Download: ML20112C864 (6) | |
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IA*IZO 1/LIN0/S POWER COMPANY CLINTON POWER STATION, P.O. BOX 678. CLINTON, ILLINOIS 61727 U-10252 February 28, 1985 Docket No. 50-461 Mr. James G. Keppler Regional Administrator Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137
SUBJECT:
Reportable 10CFR50.55(e) Deficiency 55-84-21:
Battery Charger Electrical Lug Crimps
Dear Mr. Keppler:
On October 17, 1984, Illinois Power Company notified Mr. F.
Jablonski, NRC Region III (Ref:
IP memorandum Y-25868 dated October 17, 3984) of a potentially reportable deficiency concerning the improper crimping of the 18-22 AWG wire lugs for the safety related battery chargers.
This initial notification 5.as followed by one (1) interim report (ref:
IP letter U-10223, D. P. Hall to J. G. Keppler, dated November 20, 1984).
Illinois Power's investigation of the above issue is complete and has determined that this issue represents a reportable deficiency under the provisions of 10CFR50.55(e).
This letter is submitted as a final report regarding this reportable deficiency.
Attachment A provides the details of our investigation.
We trust that this final report provides sufficient background information to perform a general assessment of this reportable deficiency and adequately describes our overall approach to resolve this issue.
Sincerely yours, D.
. Hall Vice-President RLC/lr(LCF)
Attachment cc:
NRC Resident Office Director, Office of I&E, US NRC, Washington, DC 20555 Illinois Department of Nuclear Safety INFO Records Center MAR 8 BBS 8503220164 850228 PDR ADOCK 05000461 S
PDR is TEA 7
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s ATTACHMENT A Illinois Power. Company Clinton Power Station Docket No. 50-461 Reportable 10CFR50.55(e) Deficiency 55-84-21:
Battery Charger Electrical Lug Crimps-Final Report Statement of Reportable Deficiency Improper crimping of.the battery chargers' 18-22 AWG. wire lugs may result in insufficient contact surface between the wire and lug, causing discontinuity of the circuits which are
. essential for proper operation of the battery chargers.
An investigation and evaluation of this issue was performed to determine the extent of this problem, root cause, effect on-
-installed hardware, and significance-to the safety of operation of Clinton Power Station (CPS).
Background
While performing Generic Test Procedure, GTP-46, on-Battery Charger 1B (Equipment ID No. IDC07E), the lug crimped to wire 43 came off.
Inspection of the lug which was crimped.to wire 43,
- revealed improper crimping by the vendor-(Power Conversion Products (PCP), Crystal Lake, IL).
Further investigation.of battery charger 1B revealed additional type 18-22.AWG wire lugs 1
being improperly crimped.
Identified discrepancies were i
i documented on Nonconforming Materials Report (NCMR) No. 1-0218.
Our preliminary. investigation determined that the improper crimping problem was evident.on all safety-related battery chargers.
Battery chargers No. 1DC06E, 1DC07E, and 1DC08E are installed and IDC011E is the spare battery charger which-is stored in the warehouse.
Investigation Results/ Corrective Action i-Illinois Power (IP) prepared and implemented an investigation. plan to determine the extent of this problem-at i
CPS.
The investigation plan included:
1.
A review was performed of receiving inspection reports for the safety-related battery chargers.
This review p
was extended to include applicable inspection procedures where appropriate.
i Page 1 of 5
ATTACHMENT ~A (continued) 2.-
A. review was performed _to identify corrective work which may have.been performed on the subject equipment, including the procedures used to perform such work after.the. receiving inspection procedure was completed
.for the battery chargers.
l 3.
Based on the information obtained from items #1 and #2, an evaluation was. performed to determine if the identified deficiencies occurred as a result of poor workmanship by the vendor or work performed at CPS.
4.
An evaluation was performed to determine the effect t
of this potential problem on similar equipment supplied by the same supplier / manufacturer.
4 The following discussion summarizes the results of our investigation:
. The battery chargers were procured'in accordance with the i
requirements of Sargent and Lundy (S&L) Specification:K2989, and were delivered to the Clinton Power Station (CPS) in 1979.
Baldwin Associates (BA) performed the receiving inspection associated with the battery chargers.
A. review of BA's Receiving Inspection Instructions determined that.the requirement of visual inspection for proper workmanship was included.
Emphasis of--the.
l receiving inspection was to identify damage which may have -
occurred during shipping.. Based on our review,.the BA Quality-Control Receiving Inspection Instructions were considered adequate for their intended purpose.
In addition, BA provided Quality Control Surveillance at the vendor facility.
Under the surveillance program, Baldwin Associates Quality Control (BAQC). reviewed'and accepted various i'
vendor quality procedures including one entitled, Use of Crimping r
Tools.
Supplier Quality Control Activity' Report No. C12128-1, specifically addressed QC inspection of crimped lug _ terminations associated with the Class 1E Battery Chargers.
The activity report states that all crimped lugs were found secure with the exception of cable insulation being cut short, therefore not meeting the K2989 Specification requirements.
However, the inspector subsequently accepted the terminations based on his judgement that the connections appeared secured in the lugs.
Based on the review of QC Surveillance Report No. C12128-2 l~
andJthe present findings associated with the lug crimp deficiencies, it appears that the QC Inspector did not inspect.
the lug crimps for the " tan) dot impression" which is the correct indication of a1 proper crimp.
This appeared to be an isolated case of inadequate inspector training.
Since the particular QC inspector is no longer employed at this project, no further action is considered necessary.
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ATTACHMENT A (continued)
Maintenance Work Request (MWR) Nos. A17000, B915 and B4761 were initiated to replace all the 18-22 AWG wire lugs on battery charger IDC07E.
This work was accomplished in accordance with approved _IP procedures utilizing a-QC inspection plan which identifies the steps taken for the independent verification of work performed.
The findings discussed above, lead to the following conclusions:
1.
BA Receiving Inspection Instructions are considered adequate.
2.
BA Supplier Quality Control Surveillance check plan provides adequate-guidance to perform vendor inspection.
3.
.IP QC_ inspection plan assures quality work performance by the IP Maintenance Department.
The' delayed' discovery of th'e lug crimp deficiencies is attributed to the fact that the battery chargers were stored in
- the warehouse prior to being installed.
During storage and following. installation,'there were no requirements to perform an inspection of the battery chargers' internal connections.
In
- July 1981,.a purchase order change was processed to contract the services of a PCP engineer during initial energization of battery chargers 1DC06E and 1DC07E in preparation for equipment turnover. 'Since the equipment checkout responsibility had been delegated to1the vendor, there was no need for BA or IP to perform further checks or inspections at that p'oint.
At the time of GTP-46 implement -ton, the IP Startup Organization was required to thorougl. 3 check the DC system including battery chargers and their internal connections, to assure that they met design requirements.
GTP-46 was performed g
' in: September 1984, prior to preoperational tests for Division 2 DC System, at which time the subject deficiencies were observed.
Relugging of the 18-22 AWG, wire connections in the four (4) safety-related battery chargers was performed by the IP Maintenance Staff utilizing approved procedures for Class lE termination work.
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Our investigation has determined corrective action is not required in either the IP Receiving or IP Vendor Surveillance
' Inspection Instructions, since these procedures adequately provide the necessary guidance.
Our investigation has determined Page 3 of 5 1
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ATTACHMENT A (continued) that the: subject deficiency is of vendor origin, therefore Power Conversion Products, Inc. has been advised of the details of our
. investigation and requested to address the identified deficiency under.the provisions of 10CFR, part 21 (ref:
IP letter KLP-1214-IPC, dated November _ 14, 1984).
Root Cause and Similar Concerns
. Subsequent to the installationlif the battery chargers, the only work performed on-them prior to GTP implementation _was the
- external' connections.
All the internal-wire connections were part,of the' original equipment as supplied by the Vendor.
Based cn1 the nature-of the deficiency, it'is concluded that the deficiency originated at the vendor production facility at the time of manufacturing.
Our investigation has determined that~the root cause was either the. improper use:of the crimping tool or the use of.an
-uncalibratedLcrimping tool.
From the investigation results, it can be concluded that the IP arocedures/ programs have not contributed to the cause of this deficiency.
In connection with the IP-10CFR 50.55(e)-. investigation of-
-this issue, on November 28, 1984, a-PCP. representative visited CPS to-insaect the Battery Chargers.
The-inspection concluded that a number of lug crimps for 18-22 AWG wire connectors made at the factory were inadequate.
Our investigation reviewed the other safety related battery-chargers for similar concerns.
Physical inspection of battery chargers IDC06E, IDC08E and spare unit IDCllE confirmed that the
-improper crimping was limited to'18-22 AWG wire lug connections.
-The Division ~3 battery charger, item tag i lE22-S001E, is supplied by Eltra Corporation (C&D Battery Division) and does not contain. improper crimping.
Safety Implications / Significance Our investigation committee conducted an evaluation of the charger circuitry where improper crimps were observed.
The results indicate that crimp; failure at the observed locations could cause:
a) loss:of control power to the-Silicon Controlled Rectifier (SCR) fi tbg circuitry Te amplifier circuit board thus b) loss of signels a
losing a num',c;.f ansor inputs ac) loss of certain annunciator functions, etc.
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A ATTACHMENT A (continued)
The general effect of any of the above failures would cause malfunction of the battery charger thus jeopardizing charger functional-availability as a backup DC source.
Since the subject crimping. deficiency is observed in Division 1, 2 and 4 safety frelated battery chargers, postulated failure mode would make the respective divisional DC backup source unavailable.
The'above
- potential condition is not-acceptable based on the plant design commitments.
Considering the above factors, the subject deficiency is determined to be reportable under the provisions of 10CFR50.55(e).
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