W3P84-2967, Revised Final Rept on Significant Const Deficiency 105 Re Electrical Separation.Walkdowns & Surveillances Conducted. Restructuring of Walkdown Program Warranted.Minor Mod to Raceways & Installation of Cable Tray Covers Completed

Revised Final Rept on Significant Const Deficiency 105 Re Electrical Separation.Walkdowns & Surveillances Conducted. Restructuring of Walkdown Program Warranted.Minor Mod to Raceways & Installation of Cable Tray Covers Completed

ML20107M182
Person / Time
Site:	Waterford
Issue date:	10/31/1984
From:	Cook K LOUISIANA POWER & LIGHT CO.
To:	Jay Collins NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
105, W3P84-2967, NUDOCS 8411140055
Download: ML20107M182 (6)

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30WER & LIGHT NEW OALEANS LOUISIANA 70174-8000 . (504) 38.-a345 ena a m lu October 31, 1984 W3P84-2967 Q-3-A35.07.105 3-A1.01.04 Mr. John T. Collins Regional Administrator, Region IV U.S. Nuclear Regulatory Commission

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611 Ryan Plaza Drive, Suite 1000 7 Arlington, Texas 76011 \; 7/ - l l984

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Dear Mr. Collins:

Sdbject: Waterford 3 SES Docket No. 50-382 SIGNIFICANT CONSTRUCTION DEFICIENCY NO. 105

" Electrical Separation Deficiencies (Reg. Guide 1.75)"

Final Report

Reference:

LF&L letter W3P84-2669 dated September 21, 1984 The referenced letter revised the schedule for submittal of the final report on SCD-105. In accordance with 10CFR50.55(e)(3), enclosed are two copies of the LP&L final report on SCD-105 with the Justification for Interim Operation.

Very truly yours, b

K.W. Cook Nuclear Support & Licensing Manager KWC:GEW:sms Enclosure cc: NRC, Director, Office of I&E (15 copies)

NRC, Director, Office of Management G.W. Knighton, NRC-NRR E.L. Blake W.M. Stevenson W.A. Cross INPO Records Center (D.L. Gillispie) hD S

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W3P84-2967.

FINAL- REPORT OF

~SIGNIFICANT CONSTRUCTION DEFICIENCY NO. 105 R1

" ELECTRICAL SEPARATION DEFICIENCIES" -(REGULATORY GUIDE 1.75)

= INTRODUCTION Thisl report is submitted pursuant 'to 10CFR50.55(e) ~ It describes a Construction Deficiency and Quality Assurance Program breakdown that resultedLin deviations from the FSAR commitment'to IEEE-384-1974, " Criteria for Separation of Class IE.

Equipmentland' Circuits"; as endorsed by Regulatory Guide 1.75, "P'ysical-Independence of Electric-Systems".

To the best of our knowledge, this deficiency had not been reported to the USNRC pursuant to.10CFR21.

DESCRIPTION Design drawings. detail the requirements'for physical separation between redundant class IE raceways and between class.IE and non-class IE raceways in order to implement the commitments of the FSAR. FSAR Section 8.3.1.2.19 sets forth the Waterford-3 :ommitment to IEEE 384-1974 as endorsed by Regulatory-Guide 1.75.:.It states that separation of one foot horizontal and three feet.

vertical in the cable vault, and three feet horizontal and five feet vertical in general plant areas should be maintained. When these separation distances cannot be maintained, the raceways should be enclosed and separated by a minimum of one inch. When one inch separation cannot be maintained, a flame retardant material shall be placed between the raceways to provide the equivalent of one inch separation in air. During the CAT Audit, inspectors noted instances where neither cable tray covers nor fire barriers were pravided when the separation  :

distances outlined above could not be maintained.

Investigation into the deficiencies cited in the CAT-Audit revealed a lack of adherence to the specified' separation requirements throughout the plant. A review of contractor's installation documents and procedures' revealed that verification of separation was required for safety related installations.

Non-safety installation procedures did not require inspection for separation from safety related installations. It was determined that a Significant Construction Deficiency existed in Construction for not installing per the design drawings and in the Quality Assurance Program for not adequately implementing the Inspection Program.

SAFETY IMPLICATIONS l A walkdown of cable raceways to determine those installations which require '

interposing barriers in accordance with the design criteria was envisioned prior to the time of the audit. However, procedures did not require inspection of non-safety related conduit for separation from safety-related installations, and they would not, therefore, have fully ensured that the FSAR commitments to physical and electrical separation would be met.

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,W3P84-2967 Final Report ,SCD' 105 R1-Page 2 i

~ ENGINEERING EVALUATION Essentially the criteria used in.the walkdowns was extracted from B-288 Sheets 8,9,9A and 10 which contain' details specifying separation distances as follows:

(1)' Enclosed Raceway 1" Horizontal.or Vertical (2) Open Raceway. 3'-0 Horizontal /5'-0 Vertical-(General Plant Area) . .

I'-0 Horizontal /3'O Vertical- (Cable Spread Room)

Several of these details provide for barrier installation-including cable tray covers which reduce separation requirements to that of enclosed raceways.

The deviations recorded and submitted for evaluation were. basically divided into the following categories:

(A) Available separation distance was greater than.onc inch but:less than required.

(B)-Available separation was less than one inch.

For Group A, the violation was brought in line with the installation design criteria by introducing a barrier between the affacted components of the-raceway. In each instance, the barrier was installed even if analysis could demonstrate that it was not required. For Group B, a more detailed

subclassification was required which included

I. None of the raceway contained power cables.

II. At least one of the affected raceway contained a power cable.

Under each of these headings, the following relationships were considered:

l' A. conduit to conduit j B. conduit to tray l C. conduit to equipment D. tray to tray l E. tray to equipment i-l' In deciding if a modification was required, the following features affected the decision making process:

. (1) Specifications require that cable utilized at Waterford-3 meets the requirements of IEEE 383-1974. Therefore, the cable insulation and

'. Jacketing material will not support combustion once the flame source has been removed. For cables installed in enclosed raceway, the only source of i ignition is due to cable overloads or short circuiting. The cables may be l broken into the two basic categories of power cable and control /

instrumentation cable. In the latter case, there is insufficient energy i available from the source to create a high temperature condition in the raceway. In both cases, the cabling is provided with protective devices which ensure isolation of the faulted circuit within cycles of inception.

• W3P84-2967 Final Report - SCD 105 R1 Page 3 (2) Certain areas of the plant, specifically the cable spreading room, contain a dedicated cable tray water sprinkler system. (Reference FSAR Amendment 35.)

(3) In order for the contents of a raceway to affect the contents of another raceway it must introduce a heat transfer large enough and long enough to cause loss of function in the other cable. This temperature would have to be upwards of 250*C on a short time basis. The mean probability that a large energy release will occur in the raceway is 3E-8*. This probability is taken from NUREG/CR-2815 entitled " National Reliability Evaluation Program Procedures Guide" dated 9/9/82.

NOTE:

• This number is inherently conservative since it does not consider the probability of the simultaneous occurrence of an accident.

If items (1) and (3) are coupled together, it is obvious that for control / instrumentation circuits in one enclosed raceway which are within one inch (including touching) of another enclosed raceway containing control / instrumentation circuits, a modification to the design is not justified since there is neither sufficient energy nor high enough probability that the event would ever occur. This position is independent of the safety affiliation of the cables involved.

As a result, the criteria for those situations which involve a lack of minimum separation between enclosed raceways containing control /

instrumentation cables, was to accept as is.

(4) Where one or more of the enclosed raceways'is a covered cable tray and~the minimum separation distance does not exist, a fire rated barrier was/is being placed between the raceways. If there was insufficient space to add this barrier, an analysis of the possible energy release is made to ascertain if the adjacent circuits could lose function. If the results are negative (insufficient energy) no modification is made. If the results of the heat transfer analysis is positive (there is an adequate heat source) a Failure Modes and Effects Analysis (FMEA) is performed. If the FMEA shows that loss of function is acceptable, no modification is made. If the loss of function cannot be justified, the raceway is modified to an acceptable level.

(5) If any of the circuits involved contained non-class IE power circuits, the only options are installation of a fire rated barrier, successful FMEA or a raceway modification to achieve the required separation.

In accordance with the criteria detailed above corrective action was determined by ESSE engineering as follows:

(1) If the condition could be corrected by installation of cable tray covers, this was accomplished and documented. In a large number of the cases, the requirement for cable tray covers to be installed already existed.

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"(2) 'If the condition'could'be corrected'by minor modification to the raceway such as installation of minera11ac straps to provide 1" separation between' conduits (usually flexible conduits) the-modification was made by'the craft personnel, inspected by QA/QC and _

documented on_the punch list generated.

-(3) If.the_ condition involvad clearances of~1ess than 1" between raceways,

• either fire barrier material was identified as the corrective action -

or disposition.to accept as is was determined by ESSE engineering in 3 accordance with the above established criteria.

It should be noted that a large number of'the deviations recorded were the result.of installation of non-safety related conduits where procedures did not require inspection for separation-from safety related installations.

CORRECTIVE ACTION. ,

Several walkdowns and surveillances were conducted to identify all of the '

discrepancies. In the initial effort, an engineering walkdown proved insufficient during the surveillance program. A series of follow-up walkdowns and surveillances were conducted and it was detersined that a restructuring of the walkdown program was warranted. This program was formulated and controlled-by LP&L QA.

The QA walkdown, which identified raceway separation discrepancies has now been  ;

completed. An independent walkdown was also conducted by NUS. Results of the NUS walkdown were compared with the final results of the QA walkdown and all differences found were resolved. The evaluation process to provide disposition

. for all deviations has been completed.

Conditions which could be_ corrected by minor modification to the raceways were ~

completed by craft personnel, inspected by QA/QC and documented on the punch lists.

Cable trays requiring covers were identified and CIWA's generated. Installation of all cable tray covers has been completed.

Installation of fire barrier material as an alternate to metal tray covers, at conduit entrance points to the tray and as a separation barrier on selected conduits were also identified in the dispositions and CIWA's. generated. All I rework which has not been completed is being tracked under the LP&L Program via.

CIWA's. ,

l i In addition it should be noted that ESSE engineering also reviewed all l conditions involving multiple raceways being installed within the some Appendix

!- R-fire wrap for electrical separation requirements internal to the wrap. All-

! such conditions had been previously identified on EIRs generated by B&B, l ' installer of the Appendix R wraps. The above established criteria was applied

to each EIR to determine if a potential for rework existed within the Appendix y l- R wrap. All modifications resulting from this review were identified on a CIWA l and rework has been completed. "

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Final Report _- SCD 105 R1

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'Ebasco procedure CP-764 has been reviewed to require a Q.C. inspection of non-safety related conduit installations to identify discrepancies in separation requirements. Engineering and Quality control personnel shall be trained in

-separation requirements. Construction supervision will be retrained in these requirements.

Corrective action le scheduled to be complete by 10/31/84.

This is submitted as a revised final report.

5 JUSTIFICATION FOR INTERIM OPERATION The small amount of corrective action remaining is scheduled to be completed by 10/31/84. All work in the Reactor Containment Building (RCB) will support this schedule. The items remaining in the Balance of Plant (BOP) will be completed on or shortly thereafter with a completion not exceeding initial criticality.

These reworks are not considered a constraint to fuel load for the following reasons:

(1) Any remaining work outside the RCB will be very limited. THus the probability of a loss of redundant safety-related electrical circuits due to lack of RG 1.75 separation is extremely low.

(2) Even in the event of a fault affecting redundant circuits, the lack of fission products prior to Mode 2 provides assurance that the health and safety of the public will not be adversely affected.

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