ML17056C114

Insp Repts 50-220/92-24 & 50-410/92-28 on 920927-1031. Violation Noted.Major Areas Inspected:Plant Operations, Radiological Controls,Maint,Surveillance,Emergency Planning, Security & Safety Assessment

ML17056C114
Person / Time
Site:	Nine Mile Point
Issue date:	11/18/1992
From:	Larry Nicholson NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
Shared Package
ML17056C111	List: ML17056C110 ML17056C112 ML17056C114
References
50-220-92-24, 50-410-92-28, NUDOCS 9212010082
Download: ML17056C114 (30)

See also: IR 05000220/1992024

Text

Report Nos.:

Docket Nos.:

License Nos.:

U.S. NUCLEAR REGULATORY COMMISSION

REGION I

92-24; 92-28

50-220; 50-410

DPR-63; NPF-69

Licensee:

Facility:

Location;

Dates:

Niagara Mohawk Power Corporation

301 Plainfield Road

Syracuse, New York

13212

Nine Mile Point, Units 1 and 2

Scriba, New York

September 27 through October 31, 1992

Inspectors:

W. L. Schmidt, Senior Resident Inspector

W. F. Mattingly, Resident Inspector (in training)

R. K. Lorson, Reactor Engineer

J. T.

erokun, Project Engineer

Approved by:

g~ Larry E. Nicholson, Chief

Reactor Projects Section No. 1A

Division of Reactor Projects

Date

TM

1

'

d

'

'e 'pl

operations, radiological controls, maintenance,

surveillance, emergency planning, security, and

safety assessment/quality

verification activities.

gegiilg

See Executive Summary.

92120i0082 92ii23

PDR

ADOCK 05000220

9

PDR

EXECUTIVE

ARY

Nine MBe Point Units 1 and 2

NRC Region I Inspection Report Nos. 50-220/92-.24 R 50-410/92-28

September 27 - November 7, 1992

I n

NMPC operated Units 1 and 2 safely over the period. AtUnit 1 two instances occurred which

indicated that senior reactor operators did not fullyunderstand their responsibilities.

Specifically,

a station shift supervisor left the control room unattended by a senior reactor operator for about

five minutes.

This represented

an apparent violation. Also, a station shift supervisor failed to

stop a surveillance test when an unanticipated half scram signal occurred.

This represented

a

violation of NMPC procedure for the use of procedures.

i

1

i

1

nr I

The radiological controls observed over the period were good.

Chemistry department actions

following identification of a higher than expected

offgas release

rate were very good.

The

release rates indicated a small release of noble gases through the cladding of one or. more fuel

pins in the reactor core. The magnitude of the release rates remained at least 100 times less than

the technical specification limits for gross noble gas releases.

inten n e

nd

irveill nce

Personnel performed well during routine maintenance and surveillance observations.

nin

'

T

i

Review of Unit 1 emergency diesel generator testing showed that the refueling cycle test did not

demonstrate the design basis or the intent of technical specifications.

This issue was unresolved.

Unit 2 personnel took appropriate actions on an NRC information notice dealing with Potter

Brumfield relays.

$gg~ri

Routine tours indicated good performance by the on-site security force.

f

A

n

n li

Verif'

n

Several LERs were reviewed.

Review ofthe LERs documenting a recent reactor scram and loss

of one off-site power line showed that NMPC believed that previous corrective actions had been

too narrow. An unresolved item was opened pending inspector review ofother recent corrective

actions.

TABLE

F

1.0

SUMMARYOF FACILITYACTIVE'IES.......,...

1.1

Niagara Mohawk Power Corporation Activities....

1.2

NRC Activities .......................

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2

2

2

2.0

PLANT OPERATIONS

2.1

Plant Operations Review - Unit 1 ........................

2.1.1

Less than the Required Number ofSenior Reactor Operators in the

Control Room

2.1.2

High/Low Reactor Water Level Instrument Trip Channel Test ..

2.1.3

Instrument AirSystem Walkdown

2."2

Plant Operations Review - Unit2........................

2.2.1

Emergency Diesel Generator Fuel OilReceipt............

2

2

3

3

4

5

5

3.0

RADIOLOGICALAND CHEMISTRY CONTROLS

3.1

Routine Observations - Unit 1 and Unit2............ ~......

3.2

Fuel Failure - Unit 1

6

6

6

4.0

MAINTENANCE......................

4.1

Maintenance Observations Units

1 and 2....

4.2

Division II Emergency

Diesel

Generator

Troubleshooting

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Output

Breaker

Relay

5.0

SURVEILLANCE

o ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

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5.1

Observation of Surveillance Activities - Unit 1 ................

5.1.1

Containment Spray System Operability Test

5.1.2

High Drywell Pressure Instrument Trip Channel Test

5.2

Observation of Surveillance Activities - Unit2................

5.2.1

Low Pressure Coolant Injection Pumps B&CAutomatic Start Time

Delay Relays Functional

Test...........;..........'.2.2

Automatic Depressurization InitiationTime Delay Relay Functional

est

o

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T

8

8

8

8

8

6.0

SECURITY AND SAFEGUARDS

7.0

ENGINEERING AND TECHNICALSUPPORT..............

7..1

Unit 1

7.1.1

Review of Emergency Diesel Generator Testing......

7.1.2

(Closed) Unresolved Item 50-220/91-12-03:

Emergency

Generator Fuel Oil Filter Design Review..........

7.1.3

(Closed)

Unresolved

Item 50-220/91-17-02:

Improper

Related DC Breaker Setting ..................

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Diesel

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Safety

9

9

9

10

11

0

Table of Contents (Continued)

722

Untt2 .........................................

11

7.2.1

NRC Information Notice 92-04 Potter Brumfield MDR Rotary

Rclay Failures ................................

11

8.0

SAFETY ASSESSMENT AND QUALITYVEIGFICATION

8.1

Review of Licensee Event Reports (LERs) and Special Reports......

8..

~ 1o 1

Unl't 1

e

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8.2

(Closed) Unresolved Items 92-25-01: Review ofAugust 28, 1992 Reactor

Scram and 92-25-02, Review of Partial Loss of Off-Site Power......

12

12

12

~

12

9.0

MANAGEMENTMEETINGS...............................

12

~ The NRC inspection manual procedure or temporary instruction that was used as inspection

guidance is listed for each applicable report section.

DETAILS

1.0

SUMMARYOF FACILITYACTIVITIES

1.1

i

MhwkPwr

n A ivi

The Niagara Mohawk Power Corporation (NMPC) operated Nine Mile Point Unit 1 (Unit 1)

safely, essentially at full power, during the period.

On September 28, chemistry technicians

noticed an increase in the gross noble gas activity level at the discharge of the offgas system

hydrogen recombiner.

This indicated that there was a small (approximately 100 times less than

the technical specification limit) release of gaseous

activity from the reactor fuel.

NMPC

continued to monitor the release rates over the period. On October 9, the station shift supervisor

(SSS) on duty left the control room for about five minutes, without another senior reactor

operator

(SRO) being in the control room.

On October 23, while conducting calibration

surveillance testing on the reactor water level high/low instruments, operators and instrument and

control (1&C) technicians failed to stop the procedure when unexpected alarms were received.

NMPC operated Nine Mile Point Unit 2 (Unit 2) safely and at essentially full power over the

period.

1.2

A ivi i

Resident inspectors conducted inspection activities during normal, backshift, and weekend hours

over this period.

There were seven hours of backshift (evening shift) and six hours of deep

backshift (weekend, holiday, and midnight shift) inspection during this period.

I

During the weeks of October 19 and 26 a routine engineering inspection was conducted,

the

findings of which will be documented

in Combined Inspection Report 50-220/92-26 & 50-

410/92-30.

During the week of October

19 a routine security inspection was conducted,

the findings of

which willbe documented in Combined Inspection Report 50-220/92-20 & 50-410/92-22.

2.'0

PLANT OPERATIONS (71707, 71710, 93702)

2.1

Pl n

ti ns Revi w-

nit 1

Routine observations of control room activities indicated that control room operators

safely

monitored and controlled plant operations.

Regular tours of the plant were conducted to assess

equipment conditions, radiological conditions, fire protection, security, general housekeeping

practices,

and personnel safety. The inspectors observed a very high level of performance and

generally good conditions throughout the plant except as discussed below in section 2.1.1 and

2.1.2.

2.1.1

than R

uired

eni r R

r

tor in the

ntr l R

m

On October 9, the SSS, a licensed SRO, left the control room when the assistant station shift

supervisor (ASSS), the other SRO on-shift, was not in the control room.

This resulted in not

having the technical specification required SRO in the control room, for about five minutes.

While the ASSS was touring the plant, the SSS desired to discuss work planning with planning

'ersonnel

and left the control room to go to a meeting room approximately 40 feet from the

control room.

NMPC management

learned of this issue five days after it occurred and took adequate

actions

to review the situation.

A fact finding meeting with the individuals involved, conducted

on

October 14, indicated that the SSS did leave the control room without another SRO present.

However, because of poor communications and understanding of the process for identification

and reporting of technical specification violations, the issue was not documented on a deviation

event report at the time that it occurred.

NMPC quickly developed an investigation plan to review the incident, which included interviews

of the personnel involved and a review of control room security card reader printouts.

NMPC

discussed this issue with NRC management on several occasions.

NMPC presented their overall

conclusion of the investigation verbally on October 30.

Based on the investigation, NMPC

determined that this was an isolated event. NMPC decided that there were several corrective

actions which needed to be taken; one of which was to remove the SSS from licensed duties.

The SSS leaving the control room for five minutes was oflow safety significance, as the unit was

operating at steady state power.

However, the failure to properly document and communicate

the violation of technical specification to station management was more safety significant. This

issue was considered

an apparent violation of the technical specifications.

(220/92-24-01)

2.1.2

i h/Low Rea

r W

r

v 1In

m n Tri

h nn 1T

The inspector noted during a review of control room logs that the SSS terminated surveillance

test procedure N1-ISP-036-003 followingthree unanticipated half-scrams and prior to completion

of the procedure. The SSS stopped the test because low level half-scram signals, not identified

by the applicable procedural step 'or plant impact statement,

were actuated during performance

of attachments one, two and three.

The inspector interviewed the test and operations personnel

who performed this procedure and concluded that the operating personnel were unsure of the

expected test results and did not,terminate the test until the same unexpected half scram occurred

during performance of three procedure attachments.

The inspector also noted that the plant

impact statement in the proce'dure stated that a "turbine trip half-scram" and a "feedwater pump

high level trip half-scram signal" would be actuated during this test.

This was incorrect since

neither of these functions existed in the plant.

Inspector review of the procedure and electrical

logic diagrams showed that the low water level instrumentation operated as designed during the

testing.

The failure of the procedure to provide operating personnel with the expected plant

impact assessment

and the failure of operators to stop the procedure and assess

the reasons for

unexpected half-scram conditions were contrary to NMPC Nuclear Division Directive (NDD)-

PRO-01, and was considered a violation of Technical Specification 6.8.1 requirements for the

content and use of procedures.

(220/92-24-02)

The inspector discussed the operator procedural adherence issue with unit management who took

appropriate corrective action to resolve the problem.

The inspector discussed

the procedural

weaknesses

with instrument and control supervisory personnel who stated that this procedure

would be corrected prior to the next performance.

The inspector also reviewed Technical

Specification Table 4.6.2a which delineated the surveillance test requirements for the low reactor

water level instrumentation.

The inspector reviewed the applicable surveillance procedures and

the tracking system used to ensure that the technical specification requirements were met.

The

surveillance test schedule was tracked with the aid of a computerized data base which enabled

planning personnel

to generate

the correct work requirements

for the test'personnel.

The

surveillance

procedures

and

the tracking

system

satisfactorily

ensured

that the technical

specification requirements discussed

above were met.

2.1.3

n

m nt Air S stem W lk

wn

The inspector performed a comprehensive

walkdown of the accessible portions of the safety-

related instrument air system.

The inspector noted several discrepancies

between

the actual

system configuration and applicable drawings.

The inspector identified these items to the

cognizant system engineer who stated that the system drawings were being upgraded

as part of

the system design basis reconstitution; expected, to be completed by December,

1992,

The

inspector

also reviewed

the Service,

Instrument,

and Breathing Air Operating

Procedure

(Nl-OP-20, revision 19) and noted a procedural weakness in that none of the instrument air

valves inside the reactor building were included in the procedure valve line-up.

The inspector

discussed this issue with the operations support supervisor who stated that this procedure would

be upgraded to include these valves following completion of the drawing revisions discussed

above.

The inspector concluded that these drawing and procedural weaknesses

could lead to a

loss of air to a system load. The inspector noted that an adequate recovery procedure (N1-SOP-

6, revision 2) existed to enable the operators to mitigate this event, and maintain the plant in a

safe condition. Additionally, the inspector reviewed the loss ofinstrument air safety analysis in

the updated safety analysis report (USAR), and verified that the plant could be shutdown and

maintained in a safe condition with a complete loss of instrument air.

The inspector noted that the physical condition of the system was good. Pipe hangers

were

properly made up, system valves were properly aligned, support systems were operational, and

the instrumentation was properly installed.

However, some minor material deficiencies were

noted which were discussed with the cognizant system engineer, who promptly addressed

each

issue in an appropriate manner.

One deficiency, involving the labelling of valves inside the

reactor building, was discussed with the operations support supervisor, who stated that labelling

would be improv'ed following completion of the drawing upgrades mentioned above.

Review of selected pressure switch calibration records and outstanding corrective maintenance

items identified no deficiencies or significant issues.

The instrument air compressor preventive

maintenance'procedure

(N1-MPM-094-602, revision 0), and the results from the most recent

performance of this maintenance were reviewed.

The procedure contained a weakness in that

the piston end clearance specifications did not agree with the values listed in the compressor's

technical manual.

The clearance readings obtained during the most recent measurement

did

conform with the technical manual specifications.

This issue was discussed with a maintenance

supervisor and the system engineer who stated that the procedure would be enhanced to conform

with the vendor's recommendations.

In summary, the drawing and procedure controls for the instrument air system inside the reactor

building were weak.

Operators were provided with adequate procedural guidance to address the

effects of- loss of air conditions.

NMPC was planning actions to correct these and other minor

problems identified, as part of the ongoing design basis reconstitution.

2.2

I n

ti n Rviw-

ni 2

NMPC safely operated Unit 2 at near fullpower in conformance with approved procedures and

regulatory requirements.

Control room activities, including shift turnovers and crew briefings,

panel manipulations, emergency operating procedure use, and operator response to alarms, were

observed.

Regular tours ofthe plant were conducted to assess equipment conditions, radiological

,conditions, fire protection, security, general housekeeping

practices and personnel safety,

The

inspector observed a very high level of performance and generally good conditions throughout

the plant.

2.2.1

mer

n

Dieel

n

rF

l

ilR

i t

h

Unit 2 Technical Specification 4.8.1.1.2.c for emergency diesel generator (EDG) fuel oil and

chemistry procedures permit up to 31 days to perform a complete analysis of new fuel oil, after

an addition to the EDG fuel oil storage tanks.

Before adding new fuel oil to the storage tanks,

however, it is analyzed for five critical parameters:

API gravity, kinematic viscosity, flash

point, appearance,

and cloud point. During two previous inspections (50-410/92-15 and 92-17)

a concern was raised over the topping-off of all three EDG fuel tanks from a single tanker with

oil that might not meet the requirements of the 31 day analysis.

This potentially could allow the

three EDGs to run on oil that did not meet the required specifications and might lead to a

common mode failure of the EDGs.

Both inspection reports stated that NMPC would change

their procedure to include provisions for holding the fuel oil in the tanker until complete analysis

results were received.

NMPC subsequently notified the NRC that their EDG fuel oilprocedure would continue to allow

31 days to perform the complete analysis since this was'he technical specification requirement.

However, the corporate chemistry laboratory was providing analysis results within two weeks.

Also, NMPC's goal was to have these laboratory analysis results within two days of sampling,

before adding the new fuel to the storage tanks.

This goal has been successfully demonstrated

several times recently.

The inspector found the sampling procedure satisfactory based on the

above information.

3.0

RADIOLOGICALAND CHFMISTRY CONTROLS (71707)

3.1

rv'-n1

I 2

During routine tours ofboth units the inspectors observed generally good radiological conditions

and personnel adherence to radiological postings.

32

elFilur -

ni

1

During routine daily gross noble gas offgas system

sampling on September

28, chemistry

personnel identified an increased release rate downstream ofthe hydrogen recombiner, but before

the offgas system holdup volumes.

Offgas system release rates increased to a maximum of about

4700 pc/sec.

Steady

state release

rates prior to this had been less than 2000 pc/sec.

The

doubling of the release rate caused NMPC to enter their failed fuel action plan.

Isotopic analysis of offgas samples indicated a release of gases generated in the reactor's fuel.

Plotting of the sample data showed that the release rate peaked at approximately 4700 pc/sec.

Then the release rate decreased

to a new level, higher than the previous steady state level, but

lower than the peak.

Unit 1 Technical Specification Section 3.6.15c allows a noble gas release

rate of 0.5 c/sec and up to 1.0 c/sec ifthe offgas system is functioning.

NMPC continued to monitor the offgas activity daily over the period. Aggressive sampling was

undertaken during a control rod sequence

exchange to gather data which might be 'useable to

determine the general location of the leak in the core. The chemistry department performed well

in identifying and trending this fuel failure information.

4.0

MAINTENANCE(62703)

4.1

in

n

rv

ni

1

n

2

Maintenance activities were observed during this inspection period to ascertain that safety related

activities were being conducted according to approved procedures,

technical specifications, and

appropriate industrial codes and standards.-

Observation of activities and review of records

verified that: required administrative authorizations and tag outs were obtained, piocedures were

0

7

adequate,

certified parts and materials were used, test equipment was calibrated, radiological

requirements were implemented, system prints and wire removal documentation were used, and

quality control hold points were established.

Maintenance activities observed included:

WR 1-208393

WR 1-197020

WR 2-207308

WR 2-209091

WR 2-195186

WR 2-209425

WR 2-201901

Recirculation flow master controller troubleshooting

EDG 103 air start compressor motor replacement

Low pressure core spray keep fillpump replacement

Division II emergency diesel generator output breaker relay troubleshooting

Service water pump A impeller and shaft replacement

EDG

1 service water relief valve replacement

EDG

1 speed sensor troubleshooting

The above activities were effective with respect to meeting the safety objectives.

4.2

ivii nIIEmr

n

Di

1

n

r

Br krR1

Tr

h

in

During a field inspection to support electrical maintenance on DivisionIIsupply breaker 103-13,

the Division IIEDG became inoperable for approximately 20 minutes.

This occurred when one

of three 87G phase differential current relays for the Division II EDG output breaker actuated

due to the vibration of closing the breaker 103-13 cubicle, door.

Actuation of the 87G relay

tripped its associated

86 relay which provided a trip and lock-out signal to the EDG breaker and

caused

several control room annunciators

to actuate, indicating that the Division II EDG was

inoperable.

The EDG output breaker did not change position since it was already open, but it

was now unable to shut and the EDG was blocked from starting.

The operator's

initial

investigation found that the DivisionIIEDG problems coincided with shutting the breaker 103-13

cubicle door.

The operators subsequently

reset the 86 relay and declared the EDG operable.

A deviation/event report (DER) and subsequent work request were issued to troubleshoot the

problem..

The inspector was concerned

over the potential effects of a seismic event on the relay in

question.

The inspector monitored this maintenance activity by observing portions of the work

in progress,

reviewing the troubleshooting

and

maintenance

procedures,

and interviewing

personnel involved with conducting the maintenance.

The as found condition of the 87G relay

met all of the calibration and vendor installation requirements,

however, the relay continued to

trip when subjected to certain vibrations. The relay was replaced and all three 87G relays in the

cubicle were satisfactorily field tested for sensitivity to vibration. NMPC was conducting a root

cause analysis of the failed relay and planned to discuss this vulnerability to certain vibrations

with the vendor, in order to develop test methods to identify the failure mechanism on other

relays.

The inspector concluded that the troubleshooting and repairs to the Division EDG output breaker

relays were thorough, well planned, and properly executed to minimize any adverse plant impact.

8

5.0 'URVEILLANCE(61700; 61726, 61707)

5.1

rvati n f

rv ill n

A

vi

-

nit 1

5.1.1

n

inment

ili

T

The performance of the quarterly technical specification operability test for a containment spray

and a containment spray raw water pump was observed.

The inspector noted through direct

observation that the test was well supervised

and controlled.

Interviews of the test personnel

showed

a high level of knowledge regarding test requirements.

The inspector noted good

material condition of the containment spray system components.

The test data was promptly

reviewed by appropriate licensee personnel

who correctly determined

that both pumps was

acceptable.

The inspector

independently

verified calculations,

including the

method of

calculating the deep draft containment spray raw water pump suction pressure.

Additionally, the

test data

was compared

against the pump curves

and no problems were identified.

The

surveillance

test procedure

(N1-ST-Q6C,

revision 2) was

satisfactory

and

met technical

specification and IST requirements.

5.1.2

i hD

11P

I

m

T

nn 1T

The high drywell instrument trip channel test was required by Technical Specification 4.6.2.a

to verify the operability of the trip channels.

The inspector observed a selected portion of the

test and noted that the instrument trip channel functioned properly.

The test data and the

surveillance procedure were reviewed and no problems were identified.

5.2

erv i n f

rvilln

A ivii

-

ni 2

5.2.1

w Pressure

lan

In'

n P m

s B8c

Aut m tic

tart Time Dela

Rela

Th'e inspector observed this testing for the B and C low pressure coolant injection (LPCI) pumps

according to test procedure (N2-ESP-ENS-M731, revision 5).

The monthly functional test of

the LPCI automatic start time delay relays verified the operability of these relays under normal

and emergency power conditions.

A test switch simulated a loss of coolant accident (LOCA)

which caused the associated emergency core cooling system (ECCS) time delay relays to actuate.

The test was then repeated while simulating a loss ofoffsite power (LOOP) to verify operability

of the time delay relays with emergency power.

The inspector noted that the procedure was

correctly performed

and

that the personnel

involved were knowledgeable

about

the test

requirements.

The inspector confirmed that the test equipment was properly installed and that

measured

results

were within procedural

limits and

met Technical

Specification

3/4.3.3

requirements.

5.2.2

m

D

r

I'

nTim D

Rl

F

i nlT

The Division I automatic depressurization

system (ADS) initiation time delay relay test satisfied

Technical Specification 4.3.3.1-1.A.2.b.

The test was performed by tripping the master trip

units for the ADS logic while in the test mode and measuring the. time delay until the actuation

of the relay contacts.

During this test, the inspector observed that the test was properly executed

and that the relay contacts actuated within the technical specification limit.

6.0

SECURITY AND SAFEGUARDS (71707)

The inspectors routinely toured protected and vital areas at both units.

These tours included

night time walkdowns of the protected area and observation of security activities. No significant

issues were identified.

Further, the inspector observed good controls of temporary security

fences to allow demolition of a site building.

7.0

ENGINEERING AND TECHNICALSUPPORT (71707, 92703, 37700, 90700)

7.1

7.1.1

evi w fEm r en

Di

1

ne

r T

in

The inspector reviewed the outage surveillance test for EDGs and determined that the testing

being performed by NMPC did not match the design basis for the EDGs.

Specifically NMPC

has not been testing the start of the EDGs in conjunction with LOCA signal. The outage test ST-

R2 simulates a LOCA signal, which causes all ECCS pumps to start and all containment isolation

valves to close.

Then a simulated loss of emergency bus voltage signal is inserted to start each

of the emergency diesel generators separately.

This causes the emergency bus to strip loads and

isolate from the off-site power system and remain de-energized until its EDG starts, energizing

the ECCS loads on the bus in sequence.

This method did not appear to meet the intent of technical specifications or the system design

basis as described in the USAR, in that the LOCA and LOOP were not simultaneous.

The

inspector discussed this with the NMPC engineering and technical personnel.

NMPC was in the

process of reviewing the technical rational for the conduct of this testing.

This issue was

unresolved at the end of the period.

(220/92-24-03)

7.1.2

lo

nre

lv

Item

22

1-12-

Em r en

Die el

en rat r Fuel

il Fil r

D

i nR view

The inspector reviewed the actions taken by NMPC to an EDG fuel oil system concern.

The

fuel oil system was not designed with differential pressure indication (or alarms) for the fuel oil

filter. Ifthe filterwas to become clogged, the EDG could be starved of fuel and lose load prior

to operators becoming aware of the clogged filter. Further, the filter consists of two elements

in parallel with both elements continuously in service and cannot be replaced without shutting

10

down the EDG.

Two sight glasses

are provided on the filter: one shows that the engine is

receiving full fuel flow and the second shows that the filter is clogged when an inlet fuel oil

pressure of 60 psig is attamed. Atthis pressure, flow to the filteris diverted through the second

sight glass and back to the fuel oil tank.

However, ifthis happens,

the diesel engine would

already be starved of fuel and indication in the sight glass would be of no help to maintain the

EDG operating.

NMPC performed a review ofthe filterdesign. Their immediate corrective action was to revise

Operations Monthly Surveillance Test, N1-ST-M4, "Emergency Diesel Generator Manual Start

and One Hour Rated Load Test," to include recording the fuel oil pressure during testing to

ascertain that the fuel oil filters are not becoming clogged.

An acceptable pressure range of 15

to 50 psig is specified in the procedure., The vendor's recommended

replacement schedule for

the fuel oil filter is every two years.

The plant replaces

the filter every refueling outage as

specified in procedure N1-NMP-GEN-852, "EDG Engine and Associated Equipment Inspection

Diesel Generator

102 and Diesel Generator

103."

Additionally, NMPC has generated

a

modification package, Conceptual Modification¹ N1-91-016, to replace the 2-element filterwith

two separate spin-on filters and to install a differential pressure indicator across the filtersystem.

The inspector found that NMPC was taking adequate actions to assure the adequacy of the fuel

oil filtration design. This was based on: the routine preventive maintenance performed to ensure

that the filter remains unclogged;

the specifications for the fuel oil ensure that debris is not

introduced into the system; and the good results of the trend of the filterinlet pressure recorded

during the monthly diesel runs.

The pressure has remained at 25 psig, indicating that debris is

not being deposited on the filter. Additionally, the installation of a differential pressure gauge

during the next refueling outage would provide another method of monitoring pressure across

the filterto let the operators know ifthe filter is becoming clogged.

The inspector inspected the

filter on both diesel engines

and noted that the "adequate flow" sight glass was full on both

engines.

No discrepancies

were observed. This item was closed.

7.1.3

losed

Unres lvedItem

-22 / 1-17- 2 Im ro

r afet

RelatedD

Breaker

t in

NMPC corrected a previously identified condition that would have led, during certain accident

conditions, to the common DC output breaker from the battery charger and static inverter to

battery board

12 tripping on an overcurrent before supplying it designed 400 amps.

NMPC

identified this when the breaker tripped during an installation test of the static inverter.

Even

though the trip setpoint was 400 amps, the trip occurred at a load of approximately 274 amps.

Upon further review, NMPC determined that the breaker setpoint did not account for equipment

tolerances and thus would trip under anticipated loading conditions.

The breaker setpoint was

raised to 460 amps to account for accuracy tolerance.

11

The NRC electrical distribution safety system functional inspection (EDSFI) team reviewed this

issue in 1991. The team concluded that the licensee's actions were broad in scope and that they

were taken in a time.y manner.

The team also determined that'in addition to the actions taken

by the licensee to prevent recurrence,

the following,actions must be taken:

Revise applicable procedures to ensure that I&Csetpoint changes are reviewed for impact

on electrical equipment/system

design.

Review previous setpoint changes made under the I&C setpoint program for impact on

electrical equipment.

Issue a lessons learned transmittal to appropriate personnel

To accomplish

these

actions,

NMPC revised

three

Nuclear

Engineering

and

Licensing

procedures: NEP-DES-120, "NMP1 Design Change Control Program"; NEP-DES-310, "Design

Input"; and

NEP-DES-340,

"Design Calculations."

The licensee

also

revised

guideline

NEG-1E-001, "I&CSetpoint Change Process" to improve in this area.

The inspector reviewed

previous setpoint changes

made under the I&C setpoint program and no discrepancies

were

identified. Appropriate personnel have been briefed on the issue and the lessons learned.

Based

on these actions, the inspector concluded that adequate actions have been taken to address this

issue. This item was closed.

7.2

gni~2

7.2.1

NR

Inf rm tion Notice

2-

P tter Brumfield MDR R

Rela

F ilure

The inspector reviewed the actions taken by NMPC in response

to NRC Information Notice 92-04 which discussed recent experience regarding Potter &Brumfiield (P&B) MDRrotary relay

failures.

NMPC's computerized

data base

search

identified that 136 of these relays were

installed at Unit Two; in the reactor protection, main steam, standby liquid control and service

water systems.

NMPC verified that routine surveillance testing periodically exercised all but one ofthese relays.

Such periodic testing of the relay is important in identifying a relay failure. The relay that was

not tested is normally de-energized

and provides an input to a non-safety related system.

The

inspector independently

reviewed

selected

relays and found that the relays were tested

as

specified by the licensee.

To date, four slow relay response failures have occurred, which could be attributed to the failure

mechanism

described in NRC IN 92-04.

These failures were identified during the routine

surveillance testing discussed above and the licensee replaced each relay using a "like for like"

substitution.

NMPC plans to replace all of these relays (with relays not subject to the failure

mode described in NRC Information Notice 92-04) by the completion of refueling outage four.

The inspector found the licensee's

response to this issue comprehensive

and appropriate.

0

12

8.0

SAFETY ASSESSMENT AND QUALITYVERIFICATION(71707, 92700)

8.1

vi

fLi

n

Ev

R

ER

n

i 1R

8.1.1

+nit I

The inspector reviewed the following LERs and Special Reports and found them satisfactory:

'c

LER 92-10, dated October 5, 1992.

Inadvertent operation with less than the minimum required

average power range monitor channels per trip system due to personnel error.

8.2

I

nre

1v

It m

2-2 - 1'eview fAu

t28

1

2Rea t r

c

m

n

2-

2-2 Rview fP

1

f ff-i Pwr

The inspector

found

that

licensee

event

reports

submitted

by NMPC (92-17,

for the

August 28, 1992, reactor scram and 92-19 for the September

16, 1992, loss of off-site power

line 5) adequately addressed

the specific events.

Based on'his review the unresolved items were

closed.

However, each report stated that previous corrective actions could have been broader

in scope and may have prevented these instances.

The inspector reviewed the previous corrective

actions taken for the December 18, 1991 reactor scram due to feed water system problems and

the three other instances of losing off-site power in the last two years.

The inspector concluded

that the corrective actions taken for each, event were focused and did not address broad actions.

The inspector considered

this an unresolved issue (220/92-24-04 and 410/92-28-04) pending

review and evaluation of the adequacy of the corrective action breadth and depth on recent

issues.

9.0

MANAGEMI<NT MEETINGS

At periodic intervals and at the conclusion of the inspection, meetings were held with senior

station management

to discuss the scope and findings of this inspection.

Based on the NRC

Region I review ofthis report and discussions held with Niagara Mohawk representatives, it was

determined that this report does not contain safeguards or proprietary information.