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{{#Wiki_filter:Attachment to PLA-506 FINAL REPORT  ON PGCC/ACR PANEL CONNECTORS DESCRIPTION While implementing FDDR-KR1-506 (rework of termination cabinets), damaged insulation (cuts, knicks, shield solder connections, etc.) was discovered on the jumper wires connecting the field wiring terminal board to the cable connector in GE's T-Mods. This was reported in NCR-3030.
Subsequently, similar insulation damage and      deficient pin crimps  were discovered in the PGCC/ACR panel connectozs.      This  was reported in NCR-3403.
A sample  inspection program was implemented to determine the extent of insulation damage and defici.ent pin crimps. A visual inspection (extracting all pins) and pull test of all conductors and pins was performed within each of 250 sample panel connectors.        125 connectors in the ACR inner zing panels and 125 connectors in the relay and back row panels of Unit 1 were randomly selected for the sample.
The sample  sizes identifi.ed were based on  MZL-STD-105DE 29  April 1963, Table  I  General Inspection Level ZI and Table    ZZA  Single Sampling Plans for Normal  Inspection. The sample  plan was based on a 0.65 percent AQL acceptance  rate.
The sample  inspection determined that the Unit    1 ACR  inner ring/relay/back row panel connectors did not meet a 0.65 percent QAL      for insulation  damage and deficient crimps.
CAUSE The causes  of the problems could not be posi.tively identified. However, it is  believed that the damage to the insulation,.consisting of nicks, cuts and abrasions, was caused during the pin inse tion process.        The edge of the insertion tool can impact the conductor insulation and cause damage under the high forces required to insert pins into the connector dielectric.
The  deficient pin crimps could have been caused by a combination of manfuactur'ng personnel ezror and crimping tool malfunction. General Electric said that their QA program at the time did not provide for verifying the adequacy of the crimping tool prior to use each day.
ANALYSIS OF SAFETY IMPLICATIONS The PGCC/ACR panel connectors    do have safety-related control and instrumen-tation circuits. Zt is conceivable that improperly crimped pins could prevent circuits from performing their design safety-related functions.
Also, damaged insulation,    if uncorrected, could permit shorting oz intro-duction of external voltage sources into safety-related circuits which could prevent the circuits from performing the designed safety function.
Attachment to PLA-506 (cont'd)
Since damaged panel connectors are a random occurrence and could occur          in any safety-related circuit,      the  possibility  of a  failure  exists. The simultaneous degradation and loss'of safety-related circuits could result in a safety hazard to the operation of the plant.
Project Engineering has determined the        PGCC/ACR panel  connector deficiencies to be reportable under 10        CFR 50.55(e).
CORRECTIVE ACTION GE  issued FDI WJIQ, Rev. 0 to initiate a 100 percent visual inspection and pull test of all Unit    1  inner ring/relay/back row panel connectors with No.
20  AWG  wire. FDI  WJIQ, Rev. 1 was    later issued  and expanded the 100 percent inspection to    all  Unit  1  inner ring/relay/back row panel connectors.
The  inspection, repair/rework    and testing for Unit 1 are 95 percent complete. The remaining  five percent will be completed and tracked      by NCR-3403.
Unit 2,  will utilize  a  sampling plan similar to that used      for Unit 1.
CONCLUSIONS Upon  completion of the inspection program, the Unit 1 inner ring/relay/back row panel connectors    will have been subjected to inspection, repair/reworks and testing to assure their functionability and the detection and repair of defects.
Project Engineering has authorized a sampling plan for Unit 2, and Bechtel Construction and QC will document results and generate an NCR for any discrepancies.}}

Latest revision as of 00:46, 22 October 2019

Final Deficiency Rept Re Insulation Damage & Deficient Pin Crimps in Power Generation Control Complex/Advanced Control Room Panel Connectors.Cause Unidentified.Visual Insp & Pull Test Initiated on Unit 1
ML18030A128
Person / Time
Site: Susquehanna  Talen Energy icon.png
Issue date: 07/08/1980
From:
PENNSYLVANIA POWER & LIGHT CO.
To:
Shared Package
ML18030A127 List:
References
PLA-506, NUDOCS 8007140179
Download: ML18030A128 (2)
v • d • e


Text

Attachment to PLA-506 FINAL REPORT ON PGCC/ACR PANEL CONNECTORS DESCRIPTION While implementing FDDR-KR1-506 (rework of termination cabinets), damaged insulation (cuts, knicks, shield solder connections, etc.) was discovered on the jumper wires connecting the field wiring terminal board to the cable connector in GE's T-Mods. This was reported in NCR-3030.

Subsequently, similar insulation damage and deficient pin crimps were discovered in the PGCC/ACR panel connectozs. This was reported in NCR-3403.

A sample inspection program was implemented to determine the extent of insulation damage and defici.ent pin crimps. A visual inspection (extracting all pins) and pull test of all conductors and pins was performed within each of 250 sample panel connectors. 125 connectors in the ACR inner zing panels and 125 connectors in the relay and back row panels of Unit 1 were randomly selected for the sample.

The sample sizes identifi.ed were based on MZL-STD-105DE 29 April 1963, Table I General Inspection Level ZI and Table ZZA Single Sampling Plans for Normal Inspection. The sample plan was based on a 0.65 percent AQL acceptance rate.

The sample inspection determined that the Unit 1 ACR inner ring/relay/back row panel connectors did not meet a 0.65 percent QAL for insulation damage and deficient crimps.

CAUSE The causes of the problems could not be posi.tively identified. However, it is believed that the damage to the insulation,.consisting of nicks, cuts and abrasions, was caused during the pin inse tion process. The edge of the insertion tool can impact the conductor insulation and cause damage under the high forces required to insert pins into the connector dielectric.

The deficient pin crimps could have been caused by a combination of manfuactur'ng personnel ezror and crimping tool malfunction. General Electric said that their QA program at the time did not provide for verifying the adequacy of the crimping tool prior to use each day.

ANALYSIS OF SAFETY IMPLICATIONS The PGCC/ACR panel connectors do have safety-related control and instrumen-tation circuits. Zt is conceivable that improperly crimped pins could prevent circuits from performing their design safety-related functions.

Also, damaged insulation, if uncorrected, could permit shorting oz intro-duction of external voltage sources into safety-related circuits which could prevent the circuits from performing the designed safety function.

Attachment to PLA-506 (cont'd)

Since damaged panel connectors are a random occurrence and could occur in any safety-related circuit, the possibility of a failure exists. The simultaneous degradation and loss'of safety-related circuits could result in a safety hazard to the operation of the plant.

Project Engineering has determined the PGCC/ACR panel connector deficiencies to be reportable under 10 CFR 50.55(e).

CORRECTIVE ACTION GE issued FDI WJIQ, Rev. 0 to initiate a 100 percent visual inspection and pull test of all Unit 1 inner ring/relay/back row panel connectors with No.

20 AWG wire. FDI WJIQ, Rev. 1 was later issued and expanded the 100 percent inspection to all Unit 1 inner ring/relay/back row panel connectors.

The inspection, repair/rework and testing for Unit 1 are 95 percent complete. The remaining five percent will be completed and tracked by NCR-3403.

Unit 2, will utilize a sampling plan similar to that used for Unit 1.

CONCLUSIONS Upon completion of the inspection program, the Unit 1 inner ring/relay/back row panel connectors will have been subjected to inspection, repair/reworks and testing to assure their functionability and the detection and repair of defects.

Project Engineering has authorized a sampling plan for Unit 2, and Bechtel Construction and QC will document results and generate an NCR for any discrepancies.

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