ML20094P389
| ML20094P389 | |
| Person / Time | |
|---|---|
| Site: | Midland |
| Issue date: | 05/14/1982 |
| From: | CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | |
| Shared Package | |
| ML19258A087 | List:
|
| References | |
| CON-BX19-014, CON-BX19-14, FOIA-84-96 NUDOCS 8408170195 | |
| Download: ML20094P389 (111) | |
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REPORT ON CAB',E INSTALLATION MIDLAND PLA:C UNITS 1 AND 2 May 14, 1982 l
8408170195 040718 PDR FOIA PDR RICE 84-96 1
REPORT ON CABLE INSTALLATION MIDLAND PLANT UNITS 1 AND 2 CONTEITS
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INTRODUCTION I-l II.
POTETIIAL GENERIC CONCERNS II-1 III. THE"P.AL ANALYSIS POTENTIAL CONCERNS III-1 IV.
ACTION PLANS IV-1 V.
CONCLUSION V-1 A W ACE'CITS 1
Results of the Special Electrical Overinspection 2
CPCo Nenconfor=ance Reports M01-9-2-013 M01-9-2-016 M01-9-2-021 3echtel Ncnconfor=ance Report 3996 3
Potential Generic Concerns Table and Backup Information
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INTRODUCTION PURPOSE This report describes the evaluation of the results of a major "overinspection" (ie, an inspection by Midland Project Quality Assurance Department (MPQAD) personnel of work previously inspected by Quality Control (QC) personnel) of electrical cable at the Midland jobsite. It also provides infor=ation regarding actions acco=plished; addresses the methodology for consideration of undetected misinstalla-tions in the rest of Class lE cables not overinspected; identifies potential safety concerns; and identifies actions to be taken.
BACKGROUND The NRC Region III Inspectors (R Gardner and R Love) conducted a special team inspection at the Midland plant May 18 through 22, 1981. One result of this inspection was a question concerning adequacy of the qualification of electrical QC inspectors and the process by which these QC inspectors were certified.
Personnel qualification and training records of these QC inspectors were reviewed and cc= pared to the requirements of Regulatory Guide 1.58 and ANSI Nh5.2.6.
The NRC Region III Inspectors considered the acceptability of the inspections performed by these inspectors to be indeter=inate. The NRC Region III Inspectors then requested that MPQAD perform an audit of QC I-1 i
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l to verify the adequacy of training, qualifications, and examinations of the personnel prior to certifying them as Level I or Level II QC inspectors. This =atter was left unresolved (NRC Item Nu=bers 50-329/81-12-08; 50-330/81-12-09).
NRC Inspection Reports. 50-329/82-06 and 50-330/82-06 have subsequently closed these ite=s by determining that training, qualification, and certification meet applicable requirements.
Conclusions of a subsequent inspection by the NEC Region III Inspectors revealed that the Consu=ers Power Cc=pany's June 1981 audit on training and certification resulted in " inconclusiveness." MPQAD agreed to perform another audit prior to December 31, 1981, which was accomplished on Nove=ber 2 through 6, 1981.
In addition to performing the second audit, the NRC Region III Inspectors required MPQAD to perform overinspections of selected installations.
OVERINSFECTION RESULTS Attach =ent 1 su=narizes the results of the overinspections of 1,08h cable installations. Misinstallations identified during that overinspection vere documented on nonconformance reports, which are included as.
NONCONFORMANCE REPORT DISPOSITIONS The reports identified 55 cables as not conforming to criteria.
Project Engineering was requested to evaluate these =isinsta11ations. All 55 I-2
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cables were evaluated by Project Engineering based on the specifics of the situation and the appropriate design criteria. All cases were determined to have no impact on safety. Fifty-two cables were disposi-tiened "use as is" and the remaining three cables were determined to require rework. Subsequent review and verification of the disposition actions will be made by MPQAD prior.to closure. One Consumers Power Company nonconfor=ance report has been closed.
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II. POTENTIAL GE'iERIC CONCERNS The previous section discusses how the 55 specific nonconforming cables were dispositioned. This section addresses the potential safety impact of the undetected occurrences of cable misinstallations of the type identified by the overinspection (ie, what if a situation similar to one of the specific 55 cases occurs at another location in the plant).
The potential concern is one of accountability (ie, not knowing the location of a given cable in a specific tray section) because unidentified misinsta11ations could potentially violate design criteria. The approach to this concern was to have Project Engineering evaluate each. case from a generic standpoint to determine whether any identified type of misinstalla-tion could have an adverse affect if it were to occur elsewhere and remain undetected.
8 includes a table, definition of ter=inology, and the specific cases, and identifies each case as belonging to one of two categories--
"No Concerns" or " Potential Concerns." This permitted determination of the types of misinsta11ations potentially duplicated elsewhere.
None of the misinstalled cables were evaluated to be a source of potential concern relative to 10CFR, Appendix R (fire protection) because of the wrapping design of the trays. Whenever any two Class 1E trays (of different channels) are within 20 feet of each other, one tray will be vrapped.
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i Therefore, a misinstalled cable vould be located in another 1E tray of the sa=e channel already evaluated for fire protection and it vould be wrapped if required.
Channel separation in accordance with Regulatory Guide 1 75 was dee=ed not to be a potential concern because the design is based on cable tray spacing. When trays from different channels are determined to be less than the required distance apart, one tray will be wrapped to provide an adequate barrier. Therefore, a misinstalled cable located in another tray of the sa=e channel vill be adequately separated (or protected) from trays of other channels.
It should be noted that of the 1,08h cables subject to overinspection, no cases of channel mixing due to misinstalled cables were detected.
This is because lE cables are color-coded, which makes this type of error apparent and thus vould be detected and corrected by the crafts or QC.
Results of the table are su==arized as follows.
DETEF3fINATION OF POTENTIAL CONCEF38 1.
Five cables were found to enter or leave tray in locations other than as specified in Drawing 7220-E-37. These cable installations did not use all designed tray vias (raceway sections) but also did not use any additional trays. These vere dispositioned as no potential problem because the absence of a cable in a tray via II-2
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ould make the resulting thermal analysis more conservative. These n
cables are identified in Attachment 3.as No Concern, Covered by Analysis."
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Six cables were installed into incorrect trays at transition points.
If repeated elsewhere, this could result in a voltage violation, T=
mixing power and instrument cable. As a result of this investigation, Quality Control vill add to the area valkdown procedure, PQCI T220-E-3.0, a requirement to inspect all cable transitions from raceways to assure that no voltage violations occur. Therefore, this type of misinstalla-tion poses no concern tecause deviations will be corrected or subject to Engineering evaluation for acceptability on a case-by-case basis.
These cables are identified in Attachment 3 as "No Concern, QC Area Walkdown."
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3 Five cables had discrepancies in that installation to turn from one racevay section into another resulted in a small length of the cable protruding into the adjacent raceway section. These cables were deter =ined to constitute no potential concern because Engineering's method for deter =ining which trays are to be wrapped vill include j
the requirement for wrapping a portion of the adjacent trays. These cables are listed in Attachment 3 as "No Concern, Wrapping Criteria."
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- h.. Eight cables involved airlining (limited routing of cable without using raceway) at the motor control center (MCC). Although these cables did not confor= to the detailed routing in 7220-E-37, they 4
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i did conform to the design criteria in 7220-E h2, Sheet 5, which
'gives notes and defines proper use of 7220-E-37 Because 7220-E h2 takes precedence over 7220-E-37, these cables were determined to constitute no potential safety concern. These cables are listed in Attachment 3 as "No Concern, Airlining at MCC."
5 Four cables were determined to constitute no potential concern because, W
although the cable was pulled, additional construction processes and y
inspections already planned at the time of the overinspection would l
have identified these conditions. These cables are listed in Attach-ment 3 as "No Concern, When All Field Work Is Done This Problem Will Be Corrected."
Two of the four cases were related to cables which had r
not been final trained in accordance with Procedure FPE h.000 nor inspected in accordance with PQCI E-3.0.
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terminated. One cable entered the wrong compartment of a control panel and the other was pulled to a wrong penetration.
I In each of the four cases, above, the subsequent construction activities could not have been acecm-plished and Construction Supervision and Field Engineering would have corrected the conditions.
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Sixteen cables had nonconformances directly related to extensive successive rework. This was determined to be a unique case and L
not repeatable; thus, it is not a potential generic concern. For l
l more details on this rework, refer to Sketch 25 of Attachment 3.
These cables are listed in Attachment 3 as "No Concern, Unique Case."
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7 The remaining 11 of the 55 cables represented a potential safety concern if the condition were repeated and remained undetected.
L Such a condition might result in nonconservative thermal analysis h
l' for trays that are subject to wrapping (for fire protection accord-ing to 10CFR, Appendix R, or channel separation according to Regulatory Guide 1.75) or have cable fill greater than 30% (by volu=e).
We believe that no previously planned work could have-prevented or corrected these conditions. Therefore, additional cable verifica-tion is required. The next section provides = ore detail on this subject.
For details on each of the 55 cables, see Attach =ent 3 b
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