ML20214V344
| ML20214V344 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 11/07/1986 |
| From: | Lagergren W, Shepherd P TENNESSEE VALLEY AUTHORITY |
| To: | |
| Shared Package | |
| ML20214T770 | List: |
| References | |
| 304.03-SQN, 304.03-SQN-R02, 304.03-SQN-R2, NUDOCS 8612090643 | |
| Download: ML20214V344 (8) | |
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l TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT EMPLOYEE CONCERNS TASK GROUP OPERATIONS
- CEG Subcategory: Cable and Conduit
- Element: Cable Problems in Manholes l
Report Number: 304.03 - SQN, Revision 2 IN-85-945-001 BNP-QCP-10.35-8-13 i
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l Evaluator: P. L. Shepherd // ~/-8[
! P. L. S pher Date Reviewed by: . Y d#2 Y }/-7-fd OPS pber Date Approved by: * . -e /l ')- N W. R. Lahfgren Date 1722T 8612090643 861120 PDR ADOCK 05000327 r
P PDR
l I. CABLE PROBLEM IN MANHOLES This report evaluates the concern that electrical manholes (MH) are in a disorganized state and have water in them.
II. SPECIFIC EVALUATION METHODOLOGY This element consists of two concerns identified at Watts Bar Nuclear (WBN) and Bellefonte Nuclear (BLN) and determined to be generic to Sequoyah (SQN). These concerns were expanded at SQN to include water in the manholes by the Category Evaluation Group Head (CEG-H) from a discussion with SQN QA.
IN-85-945-001 " Electrical manholes are in a very disorganized state.
Cables are laying out of trays with several feet of slack due to cables being spliced and not laced down properly. Examples may be found in the manhole next to the " Fab" shop or manholes in front of the Turbine Building and Auxiliary Building entrance. CI has no additional information. No follow-up required."
BNP QCP-10.35-8-13 "CI expressed concern about condition of manholes in electrical cable trench to IPS."
The K-forms were reviewed to determine the specific areas of concern.
Referenced documents were researched to determine the requirements, and other historical documents including an NSRS report were reviewed.
Cognizant engineers and craft in electrical maintenance were interviewed and a sample of six manholes was inspected.
! This report was completed in accordance with the " Evaluation Plan for the Operations Category Evaluation Group" (CEG).
III. FINDINGS EVALUATION RESULTS I
l NSRS Report I-85-362-WBN, " Electrical Manholes," (Reference 1) documents the results of the investigation of concern IN-85-945-001 at W8N.
The SQN procedure that covers the installation of cables is M&AI-4 (Reference 2). No specific documents were found that control the !
housekeeping state in slectrical manholes.
Cognizant DNE managers and engineers in the Electrical Engineering Branch I and in the Sequoyah Engineering Project Electrical Unit E2 were l
- interviewed with the following results. There do not appear to be any I specific engineering requirements that prohibit electrical cables from IR1 l being continuously submerged in water. DNE said that manholes that I
! contain Class IE cables, especially Voltage Level V (6900 volt), should l have operational sump pumps. This " requirement" is indicated by sump l
- j. pumps showing on design drawings. As experienced at BFN, Voltage Level V l Page 1 of 5 l
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III. Findings (continued) cable with cross-linked polyethelene insulation (as installed at SQN) I have increased potential for failure after being subjected to excessive l moisture for several years due to " water treeing" (reference 3). Voltage IR1 Level V, Class 1E cables at SQN that are run through the manholes that l were found to have water are Diesel Generator. Emergency Raw Cooling l Water and the Fire Pumps. l The following seven manholes were inspected by the evaluator:
MH # DRAWING REVISION DETAIL USE MH 9B 15W810- 5 37 D5 to Diesel Gen. Building.
(DGB)
MH10A 15N810- 5 37 D5 to DGB MH 12 15N810-12 16 A12 to Condenser Cooling Water Intake Pumping Station (IPS)
MH 22 15N810-14 12 B14 to Cooling Tower Pumping Station MH 44 15N810-40 5 A40 to Office and Power Stores (OLPS)
MH 43 15N810-40 5 A40 to Const. Whse. & O&PS HH 81 15N810-41 5 C41 to 5th DGB The results of these inspections are as follows:
MH9B - The cover was about a foot below the surrounding grade and had gravel washed across part of one cover. This manhole was not opened for internal inspection.
MH10A - This is a double manhole with a common sump and pump, which was in the north section. There was about a foot of water standing in the bottom of both sections which was apparently as low as the sump pump would clear the water. This pump appeared to be functional. There were no cable trays under water. Cables in the south section were relatively neat and orderly.
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! The cables in the north section were loose in some trays and the ends of several abandoned cables were evident in this section.
MH12 - There are four independent manholes side by side that have this number. Two are in a roadway and two are in the adjacent grass. The manhole in the roadway closest to the curb was inspected. The manhole floor was dry and there was a small amount of water delpping out of a conduit into a small sump. There was no sump pump installed. Individual 3, said during an interview, that at least one of these manholes had recently been pumped out. The cable arrangement in this manhole was neat and the manhole was clean.
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III. Findings (continued)
MH22 - The top of this manhole was below the surrounding grade level and water had been draining under the cover into the
. manhole. There was only about a foot of water in this manhole so the water must have been draining down to the net manhole. There was no permanent access ladder and no sump pump. The cables were neat and the bottom tray was just above the water. There was scaffolding and ropes in the floor of the manhole.
MH43 - The top of the manhole was initially found under about three inches of water. After this water was removed and the manhole was opened the water inside was about six feet deep (about three feet below the MH cover). After removing the water inside the manhole the cable arrangement was inspected. None of the cables appeared to be tied down in the cable trays and there were scaffold boards laying across the track. This was a non-CSSC manhole.
MH44 - This manhole is adjacent to MH43, but it only had about two feet of water in it. No further inspections were made in i this manhole.
HH81 - This manhole was about six feet square and about five feet deep. It had about two feet of water in it with a sump pump that was out of service. Not only did the sump pump not run but the discharge piping had been disconnected. There were only a couple of cables running through this manhole. This manhole also had some debris lying on the floor.
I The cables in all manholes are coated with mud / dirt. There are several locations where sump pump controls / junction boxes are located below sump level. These controls have been flooded due to power failures or, sump pump failures. If the controls flooded during a power failure, the sump pump would fail to restart when the power was restored. Examples of these are the electrical manholes / sumps in the Essential Raw Cooling Water (ERCW) Pumping Station; and the valve vault at the Cooling Tower Pumping Station. The controls for the sump pumps in the second example have been relocated above the flood area according to cognizant craft personnel.
l There is no preventative maintenance (PM) or housekeeping program at SQN on electrical manholes and their associated sump pumps.
( Craft personnel interviewed, were asked why someone had not initiated corrective action on the water problems in electrical manholes. The amount of paperwork (i.e. DCRs/FCRs etc.) involved and the length of l
time required to effect a change was given as discouragement from taking j the initiative to request corrective actions.
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CONCLUSIONS Only six manholes and one ERCW pumping station electrical sump were inspected. Based on the findings from these sample inspections and interviews with cognizant Electrical Maintenance personnel, there is a
. wide-spread problem at SQN with water in electrical manholes and cable sumps.
Cable arrangement in manholes inspected was generally good with isolated areas that could be improved. Several manholes need to be cleaned and debris removed.
Based on the findings, these concerns were determined to be valid at SQN and requires corrective actions. Raising selected manhole covers above ground level and establishing a PM and housekeeping program for electrical manholes and sump pumps should resolve this concern. This concern has potential safety-related implications at SQN.
IV. ROOT CAUSE The lack of procedures governing housekeeping and preventative maintenance on sump pumps in electrical manholes has led to the validity of this concern.
Corporate and site procedures failed to incorporate requirements to specify and maintain the environment for Class 1E cables in aanholes.
Management inattentiveness to trends of having to pump water out of manholes prior to performing work has prevented these conditions from being reported earlier.
V. GENERIC APPLICABILITY
! This concern was specific to WBN and could apply to other nuclear plants. These concerns were substantiated at SQN and WBN. Both concerns have generic applicability to all TVA plants.
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VI. References
- 1. NSRS Report I-85-362-WBN
- 2. N&AI-4, Installation of Control, Power, and Signal Cable. Revision 9.
August 13, 1986.
- 3. Memorandum from J. A. Teague to H. B. Bounds, subject: Class IE l Cables Susceptible to Electro Chemical Treeing, July 26, 1982 lR1 (L23 820727 829). l VII. INNEDIATE OR LONG-TERM CORRECTIVE ACTION Corrective Action Tracking Document (CATD) 30403-SQN-02 response: lR2 Electrical Naintenance will assign an engineer to: l l
(1) Identify manholes to be PM ed. lR1 (2) Prioritize manhole list, CSSC first, l (3) Develop a PN program to address problems, and l (4) Schedule and perform PNs (initiate corrective action as necessary). l Corrective Action Tracking Document (CATD) 30403-SQN-01: lR2 SQN should consider additional corrective actions regarding voltage l 1evel V cables that would involve the design organization and consider lR2 issuing a CAQ document. CATD 30403-SQN-01 was issued to track this l additional requested response. l i
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I RI r i Hi tJC t~. - ECPS120J-ECPS121C TENNESSEE VALLEY AUTHORITY PAIE -
I REQUtflCY - REQUEST OFFICE OF NUCLEAR PDHER RUN TIME - 113 EMPLOYEE CONCERN PROGRAM SYSTEM (ECPS) RUN DATE - 10/,
() ONP - 1555 - RHM LIST OF EMPLOYEE CONCERN INFORMATION CATEGORY: OP PLANT OPER. SUPPORT SUBCATEGORY: 30403 CABLE PROBLEM IN MANNOLES GENERIC KEYWORD A g S H APPL GTC/MSR$ . P KEYNORD B SUB R PLT BBSN INVESTIGATION 5 CONCERN KEYNORD C CONCERN KEYNORD D NUMBER CAT CAT D LOC FL45 REPORT R - DESCRIPTION IN 945-001 OP 30403 N NBN YYYY I-85-362-MSN NS ELECTRICAL MANNOLES ARE IN A VERY DI 'NONCONFORMANCE REPORT SDRGANIZED STATE. CABLES ARE LAYING CONST PROCESS T50100 DUT OF TRAYS HITH SEVERAL FEET OF S ELECTRICAL LACK.DUE TO CABLES BEING SPLICED AN CABLE 1
g B NOT LACED DONN PROPERLY. EXAMPLES i MAY BE FOUND IN THE MANHOLE NEXT TO THE" FAB" SHOP OR MANHOLES IN FRONT 0F HE TURBINE BUILDING AND AUX. BUI g LDING ENTRANCE. CI HAS NO ADDITIONA L INFORMATION. NO FOLLON UP REQUIRE D.
QCP10.35-8-13 OP 30403 N BLN YYYY CI EXPRESSED CONCERN ABOUT CONDITION REPORT OF MANHOLES IN ELECTRICAL CABLE TRE NCH TO IPS.
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2 CONCERNS FOR CATEGORY OP SUBCATEGORY 30403 D
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TVA EMPLOYEE CONCERNS REPORT NUMBER: 304.03-SQN SPECIAL PROGRAM REPORT TYPE: Sequoyah Nuclear Plant - Element REVISION NUMBER: 2
- TITLE: Cable Problems in Manholes i
REASON FOR REVISION:
To incorporate SRP comments and TAS coranents Revision 1 To incorporate SQN Corrective Action Plan Response to Revision 2 CATD 30403-SQN-02 and incorporate SQN CATD 30403-SQN-01, open items PREPARED BY:
P. L. Shepard //-7-Td SIGNATURE DATE "1
I REVIEWS PEER: '
WW ~
J/-7"$4
// SIGNATURE DATE st SIGNATURE n/fff(f DATE h
g CONCURRENCES i
CEG-H: . mv fl-1-86 SRP: amaA S' U~lS
- No SIGNATURE DATE SIGNATURE
- DATE APPROVED BY-
{ $4 lf*/h"Y N/A r ECSP' MAN $ ER DATE MANAGER OF NUCLEAR POWER DATE h CONCURRENCE (FINAL REPORT ONLY)
- SRP Secretary's signature denotes SRP concurrences are in files, i 1722T 5
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