ML20003A585
| ML20003A585 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 01/28/1981 |
| From: | Nichols T SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8102040335 | |
| Download: ML20003A585 (4) | |
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O Mr. Harold R. Denton, Director Office of-Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C. 20555 l
Subject:
Virgil C. Summer Nuclear Station Docket No. 50/395 Electrical Separation Audit
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Dear Mr. Denton:
In response to verbal questions raised by the Staff regarding the electrical separation audit report submitted on 1/6/81, we offer the
~following clarification:
The audit was performed by individuals who had not previously been involved with the design or construction of' V. C. Summer _ Nuclear Station to ensure the independence of the audit. 'For this reason SCE&G engineer-ing was not intimately involved _with the audit.
The audit report has been reviewed by SCESG. The majority of the discrepancies reported that are described as having documentation prior to the audit are the result of construction' decisions based'on work-schedule.
For example, SCE&G construction elected to complete cable -
installation before installing barriers and tray _ covers that' would interfere with cable installation. These discrepancies vere documented j
and tracked by the SCESC/QC department.
The majority of the marking discrepancies fell into the category of no color coding on the equipment to which the cable was terminated. The reason for this is the low priority placed on color coding the equipment-
~
by construction. This item of work is ongoing and will be completed -
prior to fuel load.-
The_ discrepancies that were covered by WCAP-8892-A have been reviewed with Westinghouse and' arc acceptable..'A report'on this item was' submitted-by letter to Mr. O'Reilly dated 1/16/81.
A total of 564 circuits 'and pieces of-equipment-were field audited,
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and a total of 347. discrepancies were discovered. An item was listed as a:
discrepancy before any-review was made to see if there was documentation "to cover it.
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8102040j37
Mr. 1.arold R. Denton January 28, 1981 Page Two The discrepancies were broken down into the following four categories:
A.
Separation problems 99 B.
Wrong circuit or equipment ID or color code 11 C.
No ID on equipment or circuit end 47 D.
No color code on equipment or circuit end 190 TOTAL 347 Following is a breakdown of the separation probicas in item A:
Ouantity Explanstion 13 Items identified as needing a barrier were identified on NCN-923 as barrier to be installed later.
18 Items identified as needing a barrier and listed in the audit report is not being documented. These items in-volved a condurc uleve a stack of trays, and were docu-mented between the cm.duit and the nearest tray. The cable that was audited was in a lower tray and therefore was thought not to bi documented.
9 Items identified as needing a barrier in the main control btard (MCB) were identified on NCN-731.
24 Items identified not meeting separation requirements inside cabinets are justified by Westinghouse WCAP-8892A.
19 ftems identified as requiring separation but were installed per the separation criteria and are acceptable.
For Instance separation is not required between associated and non-safety instrument cables.
4 Items identified as requiring barriers but the drawings call for tray covers to be installed which will meet the requirements.
2 Iten.s identified as requiring barriers but there are barriers called for on the drawings to be installed later.
3 Items identified as discrepancies were previously documented on SFR-3180, NCN-1005 and DN-5710.
1 Item identified as a discrepancy was approved and installed per FCR-A-241.
1 Itcu identified as a discrepancy had been wrapped with a batrier material in accordance with the criteria and should not have been listed.
Mr. Harold R. Denton January 28, 1981 Page Three Quantity Explanation 1
Item identified as a discrepancy was documented as a turnover exception.
1 Item nas listed twica as a discrepancy.
3 Items were identified as discrepancies and had no documentatica.
Two of these items were conduit that had been bent possibly by someone stepping on it and one involved a flex cenduit that had been pushed against a solenoid of the opposite train.
This leaves a total of 3 discrepancies described in the last item above, that were not documented as opposed to the 28 reported in the audit report.
The un-documented discrepancies do not indicate a breakdown of the QA program, but are items that most likely occurred after the inspection was complete. The separation discrepancies were not considered significant violations of the separation criteria, because they involved spatial separation between conduits. The conduits provide a double metallic barrier between the circuits.
Of the 11 items in category B, 4 were found to lack color coding and should be-in category D, 4 were found to be correct (could have been corrected since the audit),
1 was previously documented and 2 were associated circuits which are not verified for termination by QC, Categories C and D can be grouped together. Most of these fall in the category of work not yet completed as explained previously.
Cable ends that were not narked were those in which the cable was tagged when pulled, but the tag was not replaced when the end was cut for terminating. Also in many cases a color coded tag was not used because the cable itself was color coded every 5 feet and this was cicarly visible. Other cases involved small instruments in which there was no ~ room to place the tag, and the conduit was tagged with the cable number.
We do not consider the tagging discrepancies as significant, because as pointed out in the audit report, none resulted in an: errant pull of the cable. Also there are backup means of identifying the equipnent and circuits, such as sequential numbering of the cable every 2 feet, color. coding of the cable every 5 feet, marking the conduit with the circuit number.(multiple circuit conduits seceive a special number, but the circuits can be obtained from computerized listings) and color. code and location drawings.
Based on this review, SCE&G concurs with the conclusion of the audit.that the separation criteria are being met in' the construction of V. C. - Summer Nuclear Station and-no further auditing is required.
Very truly yours,
/
T. C. Nichols, Jr.-
JAW:TCN:gib cc: Page Four 1
c Mr. H.arold R. Denton January 28, 1981 Page Four cc:
V. C. Summer G. H. Fischer T. C. Nichols, Jr.
E. H. Crews, Jr.
O. W. Dixon, Jr.
W. A. Williams, Jr.
O. S. Bradham D. A. Nauman R. B. Clary A. A. Smith A. R. Koon J. B. Knotts, Jr.
J. L. Skolds B. A. Bursey H. N. Cyrus C. H. Price Om Chepra Hulbert Li Bill Belke
..PCF/Whitaker File
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