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Insp Repts 50-313/89-35 & 50-368/89-35 on 890918-22. Violations Noted.Major Areas Inspected:Safety Significance & Licensee Corrective Actions Re Control Wiring Configuration Discrepancies Identified by NRC During 890818-0915 Insp
	ML19327C142
Person / Time
Site:	Arkansas Nuclear
Issue date:	11/09/1989
From:	Chamberlain D; NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
To:	;
Shared Package
ML19327C141	List: ML19327C140; ML19327C142;
References
	50-313-89-35, 50-368-89-35, IEIN-88-075, IEIN-88-75, NUDOCS 8911200270
	Download: ML19327C142 (22)
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APPENDIX A-

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U.S. NUCLEAR REGULATORY COMISSION

REGION IV

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.NRC Inspection ~ Report: 50-313/89-35

Operating License:

DPR-51

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50-368/89-35

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50-368

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Docket:, 50-313

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Licensee: Arkansas Power & Light Company (AP&L)

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P.O. Box 551

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Little Rock, Arkansas 72203'

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facility: Arkansas Nuclear One (ANO), Units 1 and 2'

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Inspection At: Russellville, Arkansas

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Inspection Conducted:

September 18-22, 1989

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. Inspectors:

W. F. Smith, Senior Resident Inspector (Team Leader)

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Project Section A, Division of Reactor Projects

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J. E. Bess, Senior Resident Inspector

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Project Section D, Division of Reactor Projects

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R. A. Kendall

Inspector

Events Assessment Branch, Nuclear Reactor Regulation

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l Approved:

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D. D. Gnamberlain, Chief, Project Section A

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Inspection Summary

Inspection Conducted September 18-22,1989.(Report 50'-313/89-35; 50-368/89-35)

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Areas Inspected: Reactive, unannounced inspection to obtain an indepth

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uncerstanding of the extent, safety significance, and licensee's corrective

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actions pertaining to the control wiring configuration discrepancies identified

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by an NRC Diagnostic Evaluation Team during the inspection conducted between

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August'18 and September 15, 1989.

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first violation (pparent violations of NRC mgulations were identified.

Results: Three a

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identified in

Technical Specification 3.3.1.(paragraph 2) involved noncompliance with Unit 1

c). Since initial startup of Unit 1 in 1974,

the unit was operated with two of the three service water pumps not fully

operable. The controls for Pumps P4A and P4C contained an unidentified set of

contacts (that were supposed to have been removed during startup testing) which

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could have pmvented the pumps from restarting during certain accident

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conditions. As such, this issue was considered b

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The second violation (identified in paragraph 3) y the NRC as safety significant.

involved the failure to

maintain fiberglass sleeving for separation in accordance with the installation

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drawings.

The third violation (identified in paragraph 3) involved failure to take timely

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and appmpriate corrective action subsequent to the licensee's discovery of

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wiring errors in 4160 and 6900 VAC switchgear panels during Unit I and Unit 2

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outages in 1988.

Although the small nunter of potential operational problems

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were fomally documented and corrected, the large number of minor discrepancies

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and labeling errors were apparently not appropriately documented and acted upon

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by plant management until August / September 1989 when more such problems were

found in the Unit I control room by the NRC Diagnostic Team.

The team considered corrective actions taken as a result of this latest

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discovery to be appropriate, however, it was not established as of the issuance

of this report as to when the licensee intended to have all safety-mlated

parels in compliance with the design documentation (wiring diagrams and

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schematics).

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Upon observing a number of lifted leads in control room panels which were not

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clearly identified as " spares," the team reviewed the licensee's programs to

assure the proper temination of lifted leads. Weaknesses were found as

described in paragraph 4.a of this report. The licensee promptly implemented

interim measures to reduce the possibility of lifted lead problems and

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committed to mvisit the program in the near future. This action appeared

adequate.

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The team noted that the licensee had plant modification programs with excellent

controls over system design configuration and that compliance with the programs

would probably prevent future losses of configuration control.

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DETAILS

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. Persons Contacted

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N. S. Carns. Director, Nuclear Operations

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L. W. Humphrey, General Manager, Nuclear Quality.

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R. A. French, Plant Manager, Unit 2

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A. J. Wrape. III, Manager, EE/I&C Design

B. M. Durst, Project Engineering Superintendent

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G. A. Parks, Quality Control Supervisor

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J. J. Fisicam, Manager, Licensing

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J. H. Mueller, Manager, Central Support

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D. C. Mims. Plant Engineering Superintendent

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R. D. Lane, Manager, Engineering

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J. D. Jacks, Nuclear Safety &' Licensing Specialist

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B. E. Williams, Plant Engineering Supervisor

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D. N. McKenney, Plant Engineer

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C. W. Taylor, Nuclear Safety &' Licensing Specialist

K. L. Coates, Maintenance Manager, Unit 1

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L. A. Taylor, Licensing Specialist

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R. A. Sessoms Manager, Central Support

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G.:T. Jones Engineering' General Manager

J. ' G. Waxenfelter,- Maintenance Manager, Unit 2

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D. D.1 Gregory, Planning and Scheduling Supervisor

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Present at exit interview.

In addition to the above personnel, the NRC inspectors held discussions

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with various' operations, engineering, technical support, maintenance, and

administrative members of the licensee staff.

-2.

Service Water Pump Control Circuit Deficiencies

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On September 12, 1989, while performing a sampling inspection of as-built

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wiring connections in Unit 1 Control Room Panel C18, the NRC Diagnostic

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Evaluation Team identified discrepancies between the as-built wiring

configuration of the control circuits for Service Water Pump P4A

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(Breater A302) and the applicable wiring diagram.- Panel C18 is a

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Division 1 Engineered Safety Feature (ESF) cabinet. The specific types of

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deficiencies were as follows:

Wires were found terminated at locations where no connections were

~ hown to exist on the internal connection diagram.

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Wires shown on the internal connection diagram were found to be

missing.

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Labeling of termination points differed from that shown on the

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internal connection diagram; electrical connections were found at

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locations different than specified on the internal connection

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diagram.

Electrical jumpers were found to be installed but were not shown en

the internal connection diagram.

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Upon discovery of the wiring discrepancies, the licensee physically traced

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the affected circuits to detemine the actual installed circuit

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configuration. The installed configuration was then compared to the

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electrical schematic diagram drawing showing the control circuits for

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Bmaker A302. All differences were identified, and the effect of the

differences on circuit operation was analyzed. The schematic diagrams

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were considered by the licensee to be the top level documents that

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accurately reflected the plant design and installation. The licensee's

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review identified an extra set of relay contacts wired into the control

circuit for Breaker A302. The relay would have been energized on an ESF

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signal (high containment pressure or low reactor coolant system pressure).

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The contacts were not shown on the electrical schematic diagram and should

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not have been wired into the circuit. The licensee initiated Condition

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Report CR-1-89-481, describing the extra contacts. The condition-

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report operability assessment and the subsequent independent operability

evaluation concluded that the extra contacts had no effect on operation of

Service Water Pump P4A.

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On September 13, 1989, a review of the control circuits for the remaining

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service water pump motor feeder breakers revealed that an identical wiring

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. error existed in the contro1~ circuit for Service Water Pump P4C

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(Breaker A402). The licensee issued a second condition report

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(CR-1-89.-484 ) . ' The, operability assessment for this condition report was

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perforined by a-third engineer who identified a scenario in which the extra

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contactF would have prevented the Circuit from perfoming its intended

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safety function. Under plant conditions whem:

(1) an ESF signal would

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be generated (resulting in a reactor trip and turbine-generator trip);

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(2) offsite power remained available; and (3) it a fast transfer

(approximately 6 cycles or 1/10 of a second) of plant safety-related loads

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from the unit auxiliary transformer to the startup transformer failed to

occur, but a slow transfer (less than 2 seconds) did occur, the wiring

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error would have prevented the automatic restart of the affected service

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water pumps. The normally operating service water pumps would trip on

undervoltage at their respective 4160 VAC buses if a fast transfer did not

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take place. Pump restart would be prevented because the txtra contact in

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the breaker control circuits would have sealed in the circuit breaker

anti-pump circuit, which was designed to lock out the breaker in the

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tripped position.

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Power distribution to the service water pump motors and operation of the

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circuit breakers, including the anti-pump circuitry, are discussed in

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detail in Appendix B.

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Upon discovery that the extra contacts in the breaker control circuits

would prevent pump restart during the accident scenario described above,

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The third service

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the licensee declared Pumps P4A and P4C inoperable.

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water pump (P48) remained operable; its breaker control circuits did not

. contained a limiting condition for operation (LCO)pecifications (TS)

contain the extra contacts. The ANG-1 Technical S

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that required the

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reactor to be 'in the hot shutdown condition within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> if two out of

. the three service water pumps were not operable to provide redundant and

independent flow paths. On September 15, 1989, the licensee removed the

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extra contacts and exited the LCO.

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The' licensee determined that the extra contacts had existed in the breaker

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control circuits since plant construction in 1974. Although Service Water

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Pump P4B was unaffected by the wiring error, only Pumps P4A and P4C were

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o)erating in the normal system lineup. P4B was a standby " swing pump"'

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t1at could be powered from either electrical division and was used to

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replace Pumps P4A ano P4C when they were taken out of service.

If' pumps

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P4A and P4C were in service when an ESF signal and slow transfer to

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offsite power occurred, neither pump would restart. The standby pump

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(P4B)'would have to be manually started to reestablish service water

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flow.' Under these conditions, a single failure of P4B would result in the

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. loss.of all service water.

Restart of Pumps P4A and P4C could only be

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accomplished through nonroutine operator actions at the breaker cubicles

in their respective switchgear rooms since the anti-pump circuit bypassed-

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" both the remote and local control switches.

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'The licensee' attempted to reconstruct the series of revisions made to the

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schematic diagrams and wiring diagrams ap?11 cable to service water pump

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controls to determine the root cause of t11s problem.

Th'.: results were

complex and, in some instances, speculative.

It was the team's

' understanding that the unwanted contacts were originally intended to start

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the service water pumps automatically upon receipt of an ESF signal. .

Through the evolutionary process of preoperational testing and schematic

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diagram revisions, the contacts were supposed to have been disconnected

because the licensee considered that they were not needed to start already

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running pumps. The schematic was revised to show the contacts removed,

but because the wiring diagram did not accurately reflect the as-built

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(i.e.,thecontacts.forP4AandP4Cappeareddisconnected)',the

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electrician was probably misled to believe the contacts were already

removed from the control circuits for Service Water Pumps P4A and P40,

when in fact they were still installed.

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Since initial plant operation in 1974 Service Water Pumps P4A and P4C

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appeared to have been incapable of performing their intended safety

function given an ESF signal eccurring in conjunction with a slow transfer

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of safety-related loads to the startup transformer. Although this

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scenario has not occurred at ANO-1, successful completion of slow

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transfers following failures to fast transfer have been experienced. The

wiring' problems were not detected during periodic routine surveillance

testing because the test conditions did not include simulation of an ESF

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, signal in conjunction with a slow transfer. Consequently, two of the

three service water pumps were not fully operable as required by ANO-1

TS 3.3.1.(c) since initial startup. This is an apparent violation of

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NRC regulations and will be the subject of discussion at the enforcement

coaference referred to in the letter transmitting this inspection report.

NRC Information Notice 88-75, Supplement 1, " Disabling Diesel Generator

Output Circuit Breakers by Anti-Pump Circuitry," (dated April 17,1989)'

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discussed design problems where circuit breakers for safety-related

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equipment have been locked out in the tripped condition by unwanted

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actuation of anti-pump circuitry and the importance of carefully analyzing

all' differences between plant conditions during testing and conditions

that could exist when the equipment under test is required to perfom its

safety function in order to verify the acceptability of. the test. The

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analysis is necessary whenever complete system integrated testing cannot

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be performed under actual conditions.

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On September 16, 1989, a second error affecting Unit 1 service water

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. system wiring was identified in ESF Cabinet C-18. An unterminated wire

was found that resulted in inoperability of.a " Service Water Pump Trip"

annunciator in the control room. The loose wire disabled inputs to the

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- annunciator from Service Water Puinp P4A, and also from Service Water

Pump P4B, when it was aligned to receive power from 4160 VAC Bus A3.

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length of time.that the annunciator was inoperable was unknown. The

control room annunciators were not' designed as safety-related equipment.

The safety significance of the inoperable annunciator was that the

operators would not have been ,imediately informed of-changes in pum)

status that,. in the absence of operator actions, could have led to tie

overheating of safety-related equipment cooled by the service water

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system. However, other information was available in the control' room

providing indication of a service water pump trip (e.g., service water loop

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pressure indication, SPDS diagnostic screen for the service water system,

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equipment temperature alarms, and pump run lights).

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A' review of the schematic and wiring diagrams for the affected annunciator

revealed a discrepancy between the diagrams. One diagram identified the

unterminated wire as a spare; the other diagram showed the wire to be

terminated. The licensee initiated a " temporary modification" which

quickly reterminated the wire to restore the alarm functions,

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3.

Review of Wiring Errors and Corrective Actions

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Following the discovery of wiring errors, which reduced the ability of

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Service Water Pumps P4A and P4C to perform their safety function during

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certain accident scenarios, the licensee developed an inspection plan to

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determine the extent of wiring problems at ANO-1 and ANO-2. The

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inspection plan consisted of three phases.

Each phase involved comparison

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of as-built installed wiring to the corresponding schematic and wiring

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diagrams to identify errors in either the as-built plant wiring or the

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diagrams. The safety significance of the errors would then be evaluated.

Final long-term corrective actions were to be detemined based on the

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findings from each of the three phases.

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> Phase I of the inspection plan cunsisted of a review of the control

circuits for all 4160 VAC circuit breakers similar in design to the

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service water pump breakers that were affected by the wiring error. 'In

addition to the service water pumps for both ANO-1 and ANO-2, the licensee

i reviewed the breaker control circuits for the following automatically

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actuated safety-related equipment:

Reactor Building Spray Pumps (Unit 1) and Containment Spray

Pumps'(Unit 2)

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' Primary Hakeup Pumps -(Unit 1) and High Pressure Injection

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Pumps (Unit 2),

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Decay Heat Removal Pumps (Unit 1) and Low Pressure Injection Pumps .

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(Unit 2),

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Motor Driven Emergency Feedwater Pump (Unit 1).

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The Phase 'I review involved comparison of the as-built control circuits to

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the electrical schematic diagrams and the internal.and external connection

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diagrams. The schematic diagrams showed the electrical interconnections

between tne individual components used to make up the control circuit for

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a given breaker. During plant construction for Unit 1, the schematic

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diagrams were more carefully controlled, revised. and maintained than the'

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connection (wiring) diagrams. The schematic diagrams were considered the

most accurate electrical drawings at ANO. The schematic diagram for a

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given circuit was referred to'as a " scheme." For example, the control

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circuit for Breaker A302 is referred to as Scheme A302. The interface

connections between wiring internal to the divisional ESF cabinets'

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(located in the control room) and the external field wiring for a given

scheme was typically contained on' a single terminal strip mounted inside

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the ESF cabinet. - On Unit 1, the terminal strip was numbered the same as

the scheme

i.e., the wiring for Scheme A302 is found on Terminal

StripA302)(. The internal wiring (i.e., wiring inside the cabinet t..a

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was connected to individual components mounted within the cabinet such as

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relays, switches, annunciators, etc.) was terminated via crimped ring lug

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to screw connections to one side of the strip. The external wiring (i.e.,

wiring that left the cabinet going to other locations such as other

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control room' cabinets,. the breaker cubicles in the switchgear room, etc.)

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was similarly terminated to the other side of the strip. The internal

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' wiring was shown on " internal connection diagrams," also referred to as

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" vendor prints," because the diagrams were originally supplied by the

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cabinet vendor that wired the cabinet prior to its shipment onsite. The

vendor for the Unit 1 ESF cabinets was Magnetics, Inc. The vendor prints

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< were not well controlled during plant construction. The vendor prints

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were not always revised accurately or in a timely manner; the licensee

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relied almost exclusively on the schematic diagrams as the source of

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information for all activities involving plant circuit configurations.

The external wiring was shown on " external connection diagrams," which

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. were originally prepared by the plant architect engineer and constructor,

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Bechtel corporation. The external connection diagrams were considered to

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be more accurate than the vendor prints but not as accurate as the

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schematic diagrams,

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For'each scheme reviewed in Phase I, the internal wiring was traced 'r@

the' teminal strip to the individual components, lhe internal wiri n m

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all red in Cabinet C18 (Division 1) and all green in Cabinet C16

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(Division 2).

Internal wires were labeled at each end (i.e., at both the.

. teminal strip and the. device). The. labels designated the terminal strip '

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and temination point to which the wire was connected. The internal wires

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were individually reviewed'to detemine if the labeling at each end was

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cormet and if the wires were terminated at the proper locations. The

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' wires were pull-checked by hand where possible to ensure that corresponding

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11abels at each end were affixed to the same wire.

In a few cases, wires

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wem not pull-checked because their routing was difficult to. follow and

the' licensee was concerned that physically moving the wires could affect

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plant operation. The Phase I review was conducted with both units at'

power.

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All discrepancies between the actual (as-built) wiring t,nd the vendor

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prints or schematic diagrams were documented.

Similarly, the external

wiring was reviewed, and all discrepancies between the actual wiring and

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the external connection diagrams or schematic diagrams were also

documented. The external wiring left the cabinet via multi-conductor

cables. . Each conductor in a given cable was color coded. The external

wiring was inspected to detemine if the individual wires were terminated

at-the proper. locations, and properly color coded, and that the labeling

was correct.

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The sampling inspection of cabinet wiring for the schemes in Phase I were

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performed by two teams.

Each team included an instrumentation and

accompanied by Quality Control (ystem electrical engineer.

control (I&C) technician and a s

The teams were

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QC) personnel who independently monitored

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the walkdown activities. Technical support for evaluation of identified

discrepancies was provided by plant licensing and engineering groups. The

licensee indicated that over 20 people were involved in the Phase I

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review. During the circuit tracing process, the wiring diagrams were

-colored according to as-found conditions. The diagrams were marked with

yellow highlighter as the wiring was reviewed.

Red was.used to indicate

wires that were found installed but not shown on the diagrams; green was

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used to indicate wires shown on the diagrams that were found to have been

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deleted or not installed. Blue was used to indicate terminations that

were electrically correct, but the as-found termination point differed

from the termination point designated by the wiring diagram. All drawings

were signed as verified by the engineers performing the inspections.

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A total of 84 discrepancies were found betw.:en as-built wiring and the

corresponding electrical diagrams during the Phase I review (47 at Unit 1

and 37 at Unit 2). Discrepancies were found on schematic diagrams,

internal connection diagrams, and external connection diagrams. All

discrepancies were documented and subsequently reviewed to determine the

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impact on the operability of the circuit. No operational or functional

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problems were identified as a result of the 84 discrepancies. The

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of the disempancies were found during review of the vendor

majority (73 total; 37 at Unit I and 36 at Unit 2?. A total of four errors

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were found on the external connection diagrams (three at Unit 1), and

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'seven errors were found on the schematic diagrams (all.seven at Unit 1).

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Six of the seven ' schematic diagram errors involved conductors for a given

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cable not being listed in the proper sequence on the diagrams. The

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convention used at ANO listed the conductors in order based on their color

coding. No unanticipated circuit operations or " sneak circuits" were

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discovered,

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The licensee appeared satisfied that the Phase I results verified that the

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schematic diagrams were accurate. Approximately 40 percent of the errors

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identified during the vendor print inspections were wire labeling errors

(i.e., the destination notation shown on the label physically attached to

the wire was incorrect) or teminal strip temination point labeling

errors. The licensee's recommended corrective action was to retag the

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mislabeled wires and termination strips to show the correct cable-

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destinations and termination points. Approximately 60 percent of the

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errors 1dentified during the vendor print walkdowns were drawing errors.

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The licensee's recommended corrective action was to revise the vendor

prints as necessary to accurately reflect the as-built wiring

1;ista11ation. Typical drawing errors included items such as the'

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Jumpers correctly installed but not shown on the vendor prints.

Spare relay contacts incorrectly shown to be wired into the circuit.

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Different relay contacts shown on the drawings than are used in the

actual circuit.

The licensee provided the results of the completed Phase I review to the

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team. The team reviewed the Phase I results and conducted separate plant

walkdowns of the as-built wiring' for several schemes included in the

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licensee's Phase I review. The team found that drawings used by the

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~ licensee during their walkdowns accurately reflected the results. The

team did not findgany discrepancies that were not already documented by

the licensee during the Phase I review. Based on the above, the team

concluded that the licensee's Phase I inspections were as thorough and

carefully performed as could be expected while the plant was at power.

The team also' concluded that the 11censee's Phase I review wt.s reasonable

to provide an adequate level of assurance that breaker control circuit

wiring problems, such as affected service water pump operability at ANO-1,

would not exist in breaker control circ its of similar design used to

automatically actuate safety-related equipment at AN0-1 and ANO-2.

Phase II of the licensee's inspection plan consisted of an expanded scope

.of inspections of control circuits for safety-related equipment to

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identifyMiringerrorsanddrawingdiscrepancies. The same methodology

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used in the Phase I review was applied to.the Phase II. review. The

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licensce performed comparisons of the as-built wiring configuration using

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the associated wiring diagrams; the diagrams were marked and all errors

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were documented for, subsequent engineering evaluation, including

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/ comparison reviews'against the schematic diagrams. The circuits traced in

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the Phase II review were associated with 86 individual schemes between

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Units 1.and 2.. All circuits were located inside cabinets in the control

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rooms.' The schemes included circuitry used to actuate motor operated

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valves, solenoid operated valves, fans, coolers, and auxiliary relays.

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Circuits reviewed were associated with a number of different systems,

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' including the following:.

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Core Flood Tanks,

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Emergency Feedwater System,

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Emergency Power Distribution,

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Primary Makeup and Safety Injection Systems,

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Reactor Coolant Pump Seals,

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Steam. Generator Blowdown and Sampling,

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. Decay Heat Removal System,

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Control Rod Drive Cooling, and

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Service Water System.

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The results of the Phase II review were very similar to the results of

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Phase I.

Numerous discrepancies were' identified between the actual

circuit installation'and the corresponding diagrams. None of the

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discrepancies resulted in operability problems for safety-related

equipment. All installed wiring reviewed during Phase II was verified to

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be electrically correct; no new failure modes or " sneak circuits" were

identified. However, a total of 131 discrepancies were identified-(78 at

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Unit 1 and 53 at Unit 2). Again, discrepancies were found on the

schematic diagros, external connection diagrams, and internal connection

diagrams (vendorprints). Similar to Phase I, most of the Phase 11

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discrepancies were associated with vendor prints (102 out of 131; 56 at

'

Unit 1 and 46 at Unit 2), and consisted primarily of destination marking

errors on the drawings. As was the case in Phase I, a number of labeling

errors were found on installed wires and terminal blocks during' Phase II.

Labeling errors accounted for 35 out of 131 (or approximately 27 percent)

of the discrepancies.

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There were 17 errors identified during Phase II on schematic drawings (14

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at Unit 1).- TheLschematic drawings contained " cable block diagrams" that

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showed the cables routed between different locations containing components

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used in the circuit and listed the conductors (including spares)

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associated with the cables. The majority of the schematic drawing

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discrepancies were associated with these cable block diagrams. The cable

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' block diagrams were a secondary function of the schematics and, as such,

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the errors were considered minor. Several errors were found in the

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circuit arrangement portion of the schematic diagrams (e.g., misnumbered

handswitchcontacts). The licensee also considered these errors to be

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minor and concluded that the Phase II results restored confidence-in the

accuracy of the schematic diagrams.

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The 11censee's recomended corrective actions for Phase II were to correct

the labeling problems and'to revise the drawings as necessary to eliminate

the discrepancies between the drawings and the installed wiring. The team

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performed a review of Phase II, similar to Phase I, with similar results.

It appeared that the licensee's comparisons were thorough and precise.

Phase III of the licensee's inspection plan consisted of additional

inspections of wiring inside control room cabinets, and in local panels

throughout the plant for Unit 1 only.

Unit 2 was excluded because, within

a few days. Unit 2 was to be shut down for the seventh refueling outage,

after which more complete inspections could be conducted. The review

methodology used in Phase III was the same as that used during the Phase I

and Phase II reviews. The Phase III review had not been completed prior

to ccmpletion of the team's activities onsite and, thus, the results of

the. Phase III review were not available.

3

The team performed an independent walkdown comparison of as-built wiring

to the corresponding wiring diagrams for selected circuits, both inside

control room cabinets and at local panels that had not been reviewed by

-the licensee. The control room circuits reviewed included circuits inside

the reactor protection system cabinets for Unit 1.

No discrepancies were

identified between reactor protection system circuits and the associated

diagrams. However, discrepancies were identified during the review of

wiring internal, to. local panels and at the 480 VAC switchgear._ The

discrepancies were similar to those identified by the licensee during the

Phase I and Phase II reviews.

For example, in electrical equipment room

Chiller VCH4A Control Panel C198, the following discrepancies were

identified:

Color coding of installed conductors did not match that shown on the

wiring diagram,

,

The actual labeling of terminal strip teemination points differed

from that shown on the wiring diagram.

Three conductors were terminated to one termination point; there

should have been a maximum of two,

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Installed jumpers were not shown on the wiring diagram, and

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Two wi ms were connected to points where only one wire was shown on

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the drawing.

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It' appeared that several of the' discrepancies' in C198 were associated with'

the multiplication of termination points that resulted from " daisy

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chained"' power supply. returns for a number of control relays mounted

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inside the panel.

It did not appear that these discrepancies had any

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effect on circuit operation; however, a complete circuit evaluation using

the schematic diagrams was not performed.

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The. team randomly selected electrical drawings'of components which the

.

licensee had inspected. The following Unit 2 (Control Room Panel 2C17)

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components were checked by the licensee and verified by the inspectors.

.HPI? Pump "A"

Drawing M-2201-285-28

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LPI Pump "A"

Drawing M-2202-285-17

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ContainmentSprayDump(2P35A)

Drawing M-2201-285-19

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ServiceWaterPump(2P48).

Drawing M-2201-285 24

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ServiceWaterPump(2P4A)

Drawing M-2201-285-20

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The results of the verification of the licensee inspection by the team-

'

indicated that the discrepancies were correctly identified. The team did

not identify,any different- types of discrepancies than those already

identified by the licensee.

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In conjunction with the Unit 2 components mentioned above, the NRC

1

inspector also verified the wiring scheme for the Unit 1,(Control Room

Panel C16) components listed below:

Reactor Building Spray Pump. (P35A) .

Primary Makeup Pump (P36A)

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Primary Makeup Pump (P36B)

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DecayHeatRemovalPump(P34A)

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The results of this inspection did not identify any additional significant

wiring problems. Discrepancies s_uch as labeling errors, drawing errors,

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and terminal board mislabeling were evident. The discrepancies identified

were minor and did not appear to have any adverse effect on the operability

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of the1 components inspected.

Also, during the inspection of Control Room Panels C16 and C18, the team

noted housekeeping was poor. The following concerns were identified by

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the team and discussed with the licensee:

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ITerminali strip covers were found ' laying in the bottom of the cabinets

even though Bechtel . Drawing E-2054 Sheet 1 of 4, stated terminal

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strips should have covers.

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The fiberglass sleeving installed over s'everal non-Class IE cables

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was torn and ragged. Bechtel Drawing E-2059 stated that fiberglass '

'

sleeving may be used in lieu of metal raceways or steel barrier .

plates where the distance between non-Class IE and Class IE wiring is

less than 6 inches.. In some cases, the fiberglass sleeving was torn

,

to the. extent that its purpose (to provide protection for redundant

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. systems) was.not being fulfilled. The failure to maintein the

fiberglass sleeving-in accordance with Drawing E-2059 is.an apparent

violation of Criterion.V of Appendix B to 10 CFR Part 50.-

-

Tape, dust, trash, and lead flagging material (found attached to an

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Agastat Relay) were found inside the cabinets.

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Spare. cable ends were not capped or taped,

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Tenninal wires to Annunciator Panel C-07 were determinated with the

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lugs still on the terminals, thus making it difficult for anyone

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inspecting the cabinet to determine whether or not the determinated

wires were supposed to be in that condition.

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The. team randomly selected various electrical panels not inspected by the

'

. licensee to verify whether similar as-built conditions existed. This

sar;911ng included Motor Control Centers (MCCs), chiller and unit cooler

control panels, protection cabinets, and emergency diesel generator

panels.

J

The results of this inspection indicated that.

,

' Housekeeping was better than that found in the control room-panels.

Spare cables were taped or capped.

It was obvious that they were

spares.

As-built conditions of the cabinets were generally reflected in the

drawings being used. There were minor exceptions similar to those

'

found during the licensee's Phase I and Phase II inspections but

to a lesser degree.

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Prior to the licensee's implementation of Phase III inspections, the, team

questioned the licensee's focus on control room cabinets rather than

including cabinets outside the control room. In response, the licensee

indicated that while Phase III would be looking at such panels, detailed

walkdowns of the 6900 and .4160 VAC switchgear were performed during the

llast outage for Units 1 and 2.

Unit I was inspected in the September 1988

,

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timeframe, and Unit'2 was inspected in the March 1988 timeframe. The team

reviewed the results of those inspections and found that on Unit 160 cubicles

were inspected involving approximately 95 drawings. The same nature of

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discrepancies.(roughly 200)werefoundandweredocumentedonthedrawings

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as described above. Also, nine condition reports were issued for problems

such as deficient crimps, incorrect wiring, jumpers missing, and improper

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terminations. These deficiencies were corrected prior to startup-

following the outage. On September 19,.1988, one wiring error was

discovered in Unit 1 that could have prevented automatic start of High.

Pressure Injection Swing Pump P36B on an ESF actuation signal. The

"walkdown revealed that a wire in the as-built configuration was terminated

on' a different terminal' than specified on the drawings. Subsequent

.

' investigation determined that an. interlock between a pump power supply

' breaker-and the associated motor operated disconnect in the proper feeder'

-line was.miswired and could have defeated the autonatic start function ~ of -

'

'the pump. This was reported in LER 1-88-013.

In Unit'2, one wiring problem was identified and corrected before startup

.

following the outage. Fifty-eight cubicles vere ~ inspected involving about

.'

105 drawings, with roughly 250 discrepancies identified on the marked up

drawings.

The team noted'that the licensee did not formally document the many minor

discrepancies.found on both units such that proper management attention

would be focused on the timeliness and extent of corrective actions.

-

Consequently, the team was led to believe that roughly 450-documented

discrepancies in the. electrical plant were stored in an engineering file

,

cabinet and were receiving little or no attention until resources became

l'

available to correct the drawings. There was no apparent priority. The

results of the Phase I and II inspection illustrated that the problem was

widespread and should have been promptly expanded and corrected in 1988.

10 CFR 50, Appendix B, Criterion XVI, requires, in part, that neasures be

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established to ensure that such conditions adverse to quality be promptly

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' identified and corrected.

Failure of the licensee to meet this

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requirement.after identifying the high' number of minor deficiencies in the

4160 and 6900 VAC switchgear cabinets is an apparent violation of NRC

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regulations.

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Although the safety significance of each of the minor discrepancies in the

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panels may have been minimal, the large number appeared to increase the

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potential for errors that could affect safety system operability during

activities that rely on the accuracy of electrical diagrams (e.g.,

troubleshooting and repair or circuit modifications).

For example, on

,

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October 26, 1988, IAC technicians were working on a trend recorder in

Unit 1 Control Room Panel C14.

In order to deenergize the recorder, the

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technicians traced the power supply lead wires back to a fuse panel

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mounted in Control Room Panel C14 that contained two fuses. One fuse was

labeled as a spare, and the other fuse was unlabeled. Upon removing the

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unlabeled fuse (thought to be in the recorder circuit since the other fuse

was labeled as a spare), power was lost to the controllers for both decay

heat removal cooler outlet valves, causing the valves to close, resulting

'

in loss of the decay heat removal function. Subsequently, the fuse

labeled spare was pulled which deenergized the trend recorder. As

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corrective action for the event, the fuses were properly labeled, and an

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internal. memo was issued to craf t personnel at ANO that described the

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event and stressed that when improper labeling is found during a job, work

should be stopped and the appropriate supervisor informed.

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4.

Wiring Configuration Control Programs

- a.

Lifted Lead and Jumper Control

The team conducted a review to establish confidence that adequate

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controls'were in place to ensure that'11fted leads would be

,

. reconnected to the proper terminals. The licensee could not produce

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any specific procedural requirements implementing such controls,

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except that Maintenance Administrative Procedure 1025.003,

Revision 30, " Conduct of Maintenance," did address the subject,

though inadequately. Attachment 1. " Maintenance Reference Guides,"

-

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had Guideline 3.9'under " Electrical Systems Guide" which stated that

1

" Lifted leads should be marked to aid in re-termination.

Independent

verification of re-termination should be done.

(Rotation.ofmotors

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shouldbe.maintainedcorrect).* There were no guidelines in the. I&C

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Guide'which addressed lif ted leads. This was an area that appeared

'

most vulnerable' to lifted lead problems.

,

The team discussed Guideline 3.9 with maintenance personnel and

,

learned that in most detailed procedures, where a lead,is to be

pulled, there was a signoff and verification on re-termination, but

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that was only required on the initiative of the procedure writers or

reviewers because there was no procedural requirement that

independent verification of retennination be done. The team also

1

noted-that some licensee personnel considered a motor rotation test

sufficient verification that the motor leads were properly connected.

'The team expressed concern to the licensee that while postmaintenance

testing is essential to prove the success of the maintenance

activity, failure'to independently verify proper retermination could

lead to equipment damage and/or personnel injury. The team also

.

pointed out the increased importance of independent verification in

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view of so many labeling errors in the electrical panels. The

.

licensee committed to reconsider lifted lead controls and, as an

interim, committed to add instructions to Procedure 1025.003 that

would require validation of the applicable wiring drawing before

leads would be lifted, when specific lead lifting instructions were

not provided. The licensee also reported, during a conference call on

October 2,1989, that the "shoulds!' in Guideline 3.9 were changed to

"shall."' The NRC staff will follow up during a future inspection to

verify that acceptable lifted lead controls have been placed in

effect (Inspector Followup Item 313/8935-01;368/8935-01).

b.

Plant Modifications

The team reviewed the licensee's plant modification process to

determine if proper controls were in place to assure that plant

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configuration and documentation will;not be degraded as a result of

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temporary or permnent plant changes. The team reviewed the

following. documents:

' NP-20.JRevision 3. "AN0 Plant Modifications Manual"

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' 1000.103, Revisico 4, " Plant Modification Process"

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6030.003, Revision 2, " Installation Verification and AS-Built

Requirements"

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The team also reviewed many of the lower tier implementing . .

6000-series procedures. The team noted that'the licensee had-

.

'

developed and: implemented a wall-defined, carefully-controlled, )lant

modifications program.

In April 1984, the. licensee' formed a'tas <

force to develop a comprehensive list of deficiencies and concerns

'

' with the program in place at the time and then to provide

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alternatives for eliminating these problems. As a result, an 18-step-

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process was developed and implemented, and was in effect during this

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inspection. _ The'18 steps carried a given plant change from the -

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. identification of the need to the critique and completion report.

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Excellent controls were in place to ensure,that drawing and procedure

updates were made at the appropriate time in the process. After

reviewing the controlling documents and discussing the plant

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- modification process with cognizant licensee personnel, the team

concluded that the process should not cause any problems in plant

configuration documentation and controls.

'

No violations or' deviations were identified.

'

5.

Corrective Actions and Conclusions

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inspections and reviews conducted by the team, the team concluded that

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ANO. Units 1 and 2, both had a significant number of minor discrepancies

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between the as-built electrical panels in and out of the control room and

',

the design documents (wiring drawings).

Since the electrical schematics

appeared to' reflect the' as-built condition, the team considered it

unlikely that' additional errors affecting the operability of

safety-related equipment will be found.

As discussed above, the team was concerned that the licensee was aware of

the large number of discrepancies in the 4160 and 6900 VAC switchgear

L

panels; but failed.to take timely action to correct the specifics and to

look at other panels for similar problems. The concern was partly based

.on the increased probability of errors that could be caused by working in

,

panels with labeling and wiring errors. One such error was discussed

above when decay heat removal was lost due to pulling improperly labeled

,

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fuses. The concern was also based on the possibility that, had the

licensee inspected the control room and ot1er panels sooner, the service

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water pump " sneak circuit" may have been found by the licensee long before

the NRC Diagnostic Team evaluation.in August and September 1989.

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The team noted that the housekeeping problems identified in the'. control

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room cabinets:in Unit I were not typical:of other cabinets in Units 1 or 2.

'The licensee's Phase I and II inspections appeared adequate to provide

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confidence .that t5e control rooms for both units were not likely to have

,

. additiona1 ' operational problems. During a conference call conducted on

October 2,1989, the licensee reported that the Phase III inspection had

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' been completed.. Phase III was similar to Phase I and II.but was limited

_

-to Unit 1 only. This inspection included more circuits in the contro11

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room and some MCC panels outside the control room. The results were

'

similar.to those found by the team when they inspected panels outside the

-

control room.

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Having just commenced the' seventh refueling outage on Unit-2 (2R7), the

licensee comitted to conduct detailed walkdowns on the Unit 2 480 VAC

MCCs outside the control room and Control Room Panels 2C16, 2C17, 2C18,

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and 2C33. These, in addition to the 4160 and 6900 VAC switchgear panels

]..

previously inspected, were considered by the licensee to be the areas of

. greatest exposure for- safety problems. The licensee further comitted to

'

have all spare leads (not terminated) identifiable by a standard and

consistent method, such as cutting off the lug and covering the end with a

heat shrink insulator.

>

The licensee did not commit to a schedule for walkdown and correction of

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drawing and hardware deficiencies for all safety-related panels et the

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time of this< inspection. This will be the subject of further. discussion

with licensee management during the scheduled enforcement conference.

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'

6.

Exit Interview

The inspection scope and findings were sumarized on September 22, 1989,

,

with those persons indicated in paragraph 1 above. The licensee did not

. identify, as proprietary, any of the material provided to, or reviewed by,

the team during this inspection.

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APPENDIX B

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Se'rvice Water Pump Configuration _ and Pump Breaker Anti-Pump Circuit'

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Operation

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The service water system at ANO-1, contains three 100 percent capacity

0

. pumps that can provide service water flow to ESF equipment, including control

. room and switchgear room cooling units, the emergency feedwater pumps, and the

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emergency diesel generators. Only one pump is needed to satisfy shutdown

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,

cooling requirements under accident conditions.

Power distribution to the'

,

service water pumps is shown in Figure 1.

Power to the pump motors is provided

,

from independent and redundant Class 1E safety-related 4160 VAC buses A3 and

,

A4. These buses. can receive power from the main generator via the unit

. auxiliary transformer, from offsite vie either of two startup transformers, or

-

,

-

from the emergency diesel generators.

Power to Service Water Pump P4A is

supplied from Bus A3'and power to Service Weter Pump P4C is supplied from

Bus A4.

Service Water Pump P48 is a " swing pump" that is powered from 4160 VAC

.

Bus A6, which in turn can receive power from either Bus A3 or A4.

Bus A6 is'

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normally aligned to receive power from Bus A3 (A4) when Service Water Pump P4A

(P4C) is taken out of service.

During normal plant operation, two of the three service water pumps are

continuously running; powe'r to the pumps is provided from the main generator

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'

via the unit auxiliary transformer.

If the main generator trips, as would

occur on an ESF signal, power to 4160 VAC Buses A3 and A4 is designed to

,

'

- automatically fast transfer (approximately 1/10 of a second) from the unit

auxiliary transformer to one of the two startup transformers. The startup

transformer selected depends on the positioning of " preferred standby" selector

switches in the control room. Both startup transformers are powered from the

-

offsite power system.

If a fast transfer does not occur, a slow transfer

. i

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should occur within the next 2 seconds, assuming the standby source is

-

available (i.e., secondary ' voltage is normal, breaker control power is

'

available,etc.). If the fast transfer is successful,~ the service water pumps

'

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will continue to operate. . If the fast transfer is unsuccessful, the service

water pumps will trip because the voltage at the 4160 VAC buses will decay to

below the pump breaker undervoltage trip setpoint before the slow transfer

takes place. Therefore, on a slow transfer, it is necessary to restart the

>

pumps. The control circuit for service water pump Breakers A302, A303, A402,

..

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and.A403 are designed to automatically restart the pumps following a slow

L

transfer.

If a slow transfer does not occur within 2 seconds, feeder

Breakers 'A309 and A409 will open to isolate Bus A3 and A4 from the startup

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' transformers. Emergency Diesel Generators No. I and No. 2 will automatically

K

'

start, attain rated speed and voltage, and tie onto Buses A3 and A4 (via

closure of diesel generator output Breakers A308 and A408) within 15 seconds

after sensing loss of bus voltage. The service water pumps should sequence

onto the diesel generators in approximately an additional 15 seconds.

,

I'

A' simplified block diagram of the control circuit for Breaker A302 is shown in

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Figure 2.

The control circuits for Breakers A303, A402, and A403 are similar,

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The control circuit is designed to either:

(1) close the breaker by energizing

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>

,

(

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!

j

,

the closing coil in response to an automatic or manual pump start signal, or

'

(2) trip the breaker by energizing the trip coil in response to an automatic or

manual pump trip signal. Auxiliary contacts located on the circuit breaker

'

'itself will change status as the breaker opens and closes. The auxiliary

l

i

contacts are used in the control circuit to allow only the closing coil or the

trip coil to be energized at a given time. The auxiliary contacts also open .to

I

' deenergize the closing coil-(trip coil) when the breaker closes (opens)' to

prevent coil burnout. Although the closing coil and trip coil cannot be

-

energized simultaneously, under certain conditions both a close signal and a

,

trip signal could coexist (e.g., when a fault condition occurs after the

,

breaker has been signaled to close). The circuit breaker anti-pump circuit

l prevents the breaker from cycling repeatedly between the closed and tripped

positions whenever both close and trip signals coexist. The anti-purrn circuit

~

~i

,

is designed such that, following a breaker trip, one attempt to reclose the

'

' breaker is allowed; however, subsequent closure attempts are prevented.

~

,

'

Following a trip of Breaker A302 on Bus A3 undervoltage, four conditions

'

-(permissives) must be satisfied before the breaker will automatit, ally reclose

,

to restart Pump P4A. The pennissives are numbered 1 through 4 on Figure 2 and

are listed below:-

4

1.

TM pump,must be running when the undervoltage condition occurs (the

control switch contacts are closed in the "af ter start" position; a pump

not previously running will not automatically start).

2;

The voltage at Bus A3 must have returned to above the undervoltage trip

,

setpoint (i.e., bus voltage is acceptable for pump operation).

,

3.

Power to Bus A3 must-be supplied from upstream 4160 VAC Bus Al via Circuit

'

Breaker A309 within 2. seconds of the undervoltage condition or breaker

closure is prevented until 15 seconds after power is restored to Bus A3

from Emergency Diesel Generator No. I via circuit Breaker A308. The

15-second delay is provided to ensure proper diesel generator load

sequencing. The tripping of Feeder Breaker A309 on Bus A3 undervoltage is

.'

delayed for 2 seconds to allow time for a slow transfer to restore power

to the bus from offsite.

,

,

,

4.

The anti-pump circuit must be deenergized.

If a close signal exists when

the breaker trips, the closing coil will energize causing the breaker

closing springs to discharge. The breaker will attempt to close but will

i

open again if a trip signal still exists.

Limit switch conts.ts on the.

closing springs will close to energize the anti-pump circutt when the

s

springs discharge. The anti-pump circuit will seal in if the close signal

t

A

is still present and will remain sealed in as long as a close signal

'

. exists. The anti-pump circuit locks out the breaker in the tripped

position preventing subsequent closure attempts although the close signal

remains. This action is intended to prevent repeated attempts to close

the breaker against a fault condition. The anti-pump circuit must be

reset by removing the close signal before another attempt can be made to

'

,

reclose the breaker.

-

.

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a.s---

e.

.~w-..n.+,e,

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Mi

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F

-2-

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,

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'

Nonelof the above conditions for automatic restart of a service water pump?

j

L,

depend on the existence of an ESF signal. However, the~ extra. contacts from

i

,

engineered safeguards Relay 152X-302 that were found wired onto the breaker

>

close-circuit effectively bypass the control switch and Bus A3 voltage

,

c

cpermissives. The extra contacts are shown using a' dashed line in Figure 2.

< >

l.

-

The problem caused by the extra contacts is that on ar' ESF signal where atslow

"'

transfer from the unit auxiliary transformer to the startup transformer occurs,

!

,

the breaker will: trip on. bus undervoltage, but the existing breaker close

!

L

. signal will not clear'because the Bus A3 voltage permissive is bypassed by the

contact. .The slow transfer will restore power to Bus A3 within 2 seconds

,

(therefore, Bus Feeder Breaker A309 remains. closed), but not before the breaker

- has attempted.to reclose andithe anti-pump circuit has energized'and sealed in,

t

Since both' the remote and local' control switch contacts are bypassed by the

>

extra contact.' reset of the anti-pump circuit (hence, breaker closure to

i

,

restart the pump) is not' possible.without nonroutine operator action (e.g;.

"'

,

La

, -removing'the circuit: breaker 125 VDC control power fuses at the breaker

'

'cc

cubicle in.the switchgear room.

If the extra contact were not-in the circuit

2and a slow: transfer' occurred, the Bus A3 voltage permissive would clear the

'

.

close signalist the same time that the breaker trips on bus undervoltage.

Reclosure of the. breaker'does not' occur until bus voltage returns to an

-

' the breaker has successfully reclosed) pump circuit will not occur until after.

acceptable. level (seal in.of the anti-

' ' '

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D-1 POER DISTRIBUTION TO IlE SERVI & WATER FUPS

i

by ,

TO 500kV

SWITCHYARD

D

c1

,

]

MAIN

MM

FROM 500kV'

FROM 161kV

i

'

TRANSFORMER WW

SWITCHYARD

.'

UNIT AUXILIARY

STARTUP

.

'

TRA SFORMER

TRANSFORMER

I

M

MM

NO.1

MJJL)

NO.2

g

'

TY WY

WTWT

WT WT

-

4

. o

n

TO 6.9kV BUSES

TO 6. %V BUSES

TO 6.9kV BUSES

f

{

\\

l

MAIN

GENERATOR

l

1)

1 4160 Vac BUS A21

1 4160 Vac BUS A1 1

_

r

EMERGENCY DIESEL

GENERATOR NO. 1

GENERATOR No. 2

1) A308 1)A3091)A409 1)A408

_

4160 Vac Bus A4

4160 Vac BUS _ A3

T)A302 -T) A303

'

T)A403 T)A402

'

BUS.A6

O

P4A

P48

P4C

SERVICE WATER PUMPS

FIGUE 1

. .

.

. . - . - .

.--

-

.

- . ,

.

.-

. - . -

.

. - .

.-

m

q

,

I

.o

,,

.x , -

.

,

,'

SERVICE WATER PLPP P4A BEAKER A302 CONTROL CIRCUIT

,

( SIFPLIFIED BLOCK DIAGRAM )

'

,

l

i

l

125 Vdc

CONTROL POWER

~

SOURCE

]

,

T

'

I

r- -

l-

7

1. CONTROL'

MANUAL-

EXTRA

'

SWITCH

MANUAL

AUTOMATIC

-l

!

PERMISSIVE

TRIP

START

CONTACTS

'i

(CONTROL

l

FROM

l

(CONTROL

(BUS A3

ENGINEERED

SWITCH)

UNDER-

SWITCH)

l

SAFEGUARDS l

VOLTAGE,

l

I

PHASE

i

RELAY

I

152X-302 l

2. BUS A3

FAULT, OR

VOLTAGE

GROUND

L

I

_]

PERMISSIVE

FAULT)

l

1

L _ ._

--%

.

3. DIESEL

GENERATOR

SEQUENCING

'

PERMISSIVE

4. ANTI-

i

PUMP

PERMISSIVE

BREAKER

AUXILIARY

CONTACTS

LOSING

TRIP

COIL

FIGUE 2

.

%

+

-

---

- ,

,,,

---

- , - - .

.c,--.c..

-,-

- - - - , - -

ML19327C142

Text

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