ML17290A173

Paul Narbut, Assistant

Team Leader,

Region

V

Christopher Nyers,

Region

V

David Pereira,

Region

V

Steven

Jones,

Ann Dummer,

Prepared

by:

Jeffr

. J

obson,

Team Leader

Date

Team

nspe

ion Section

A

Special

Inspection

Branch

Division of Reactor Inspection

and

Licensee

Performance

Office of Nuclear Reactor Regulation

Reviewed

by:

Don ld

. Norki

,

ec ion Chief

Team Inspection Section

A

Special

Inspection

Branch

Division of Reactor Inspection

and

Licensee

Performance

Office of Nuclear Reactor Regulation

Date

a

Approved by:

Eugene

V. Imbro,

hie

Special

Inspection

Branch

Division of Reactor Inspection

and

Licensee

Performance

Office of Nuclear Reactor Regulation

Date

9304090307

950401

PDR

ADOCK 05000397

8

PDR

E

EXECUTIVE SUMMARY

The Special

Inspection

Branch of the U.S. Nuclear Regulatory

Commission

performed

a pilot service water system operational

performance

inspection at

Washington Nuclear Plant, Unit 2 from February

1 through

11,

1993.

The

service water system at the station comprises

both the high pressure

core

spray service water

system

and the standby service water system.

The inspec-

tion team focused

on the mechanical

design,

operational

control, maintenance,

and surveillance of the service water system

and evaluated

implementation of

the quality assurance

and corrective action programs.

The team also addressed

the licensee's

implementation of actions in response

to Generic Letter 89-13,

"Service Water System

Problems Affecting Safety-Related

Equipment."

The team found the design of the service water system to contain

adequate

margin to account for some calculational

uncertainties

and system degradation.

General

implementation of the licensee's

actions in response

to Generic Letter 89-13 appeared

to be adequate.

However, the team identified four deficiencies

with regard to corrective action program implementation

and procedural

adherence.

The team found that the licensee

did not correct

a "hammering" problem

associated

with service water loop isolation valves

SW-V-12A/B.

Although this

problem had

been

documented,

its extent or its possible ramifications

had not

been adequately

evaluated.

The licensee

had not resolved

a concern that was

identified by an internal review of the service water

system related to the

cathodic protection

system.

The operability of this system

had not been

confirmed even though the system status

had

been questioned

by the internal

review team.

Additionally, a problem evaluation request

was not generated

when spray

pond sulfur concentration limits were exceeded

due to biocide

chemical additions.

The team also identified mistakes

made in verifying the

position of spray

pond siphon line vent valves.

Significant observations

included:

~

lack of procedures

to cope with spray

pond icing

a biofouling program that

had not been proceduralized

or adequately

controlled

some degradation

(piping corrosion)

in the physical co'ndition of the

service water system

an improperly stored

crane in the service water pumphouse

potential for the freezing of some spray tree

arms

failure to include instr ument accuracies

in valve position verification

procedures

lack of a procedure for performing inspections of the spray

pond intake

structure

scaffolding in the residual

heat

removal

pump rooms that had

been

installed since plant start-up

The team identified strengths

in the licensee's

programs for performing heat

exchanger

performance testing

and in the internal audit that was performed

on

the service water

system in 1990.

TABLE OF

CONTENTS

1.0

INSPECTION

SCOPE

AND OBJECTIVES

2.0

GENERAL SYSTEM DESCRIPTION

.

3.0

SERVICE

WATER SYSTEM LEVEL REVIEW

~ae

3. 1

System Heat

Removal

Capacity

3.2

Design Function Verification

3.3

Seismic gualification

3.4

Instrumentation

3.5

Freeze

Protection

4.0

HECHANICAL COMPONENTS

REVIEW

.

4.1

SSW and

SW Pumps

4.2

SSW System Piping

4.3

Heat Exchanger

Evaluations

.

~

and Single Failure Analysi s ~

~

6

7

8

9

10

11

12

4.3. 1

Diesel Cooling Mater Heat Exchanger

4.3.2

RHR Heat Exchanger

.

4.3.3

Various

Room Coolers

.

5.0

SERVICE WATER SYSTEM MODIFICATION REVIEW .

5.1

Service

Water System

(SWS) Cross-Connect

Hodi

5.2

Replacement

of SW-V-2A/B .

.

6.0

SERVICE MATER SYSTEH SURVEILLANCE AND TESTING

fication

~

12

13

14.

14

15

6. 1

Technical Specification Surveill

6.2

Preoperational

Test

Review

6.3

Inservice Testing

6.4

System Unavailability Review

.

6.5

Heat Exchanger

Performance

Test

7.0

BIOFOULING CONTROL AND TESTING

.

8.0

MAINTENANCE

9.0

OPERATIONS

.

9. 1

Operations

procedures

9.2

Valve line-up program

9.3

Conduct of Operations

9.4

Operator training

ance Testing

~

Review

~

15

16

17

18

20

21

22

23

24

10.0

SYSTEM WALK-DOWN

11. 0

CORRECTIVE ACTIONS

APPENDIX A SUMMARY OF

INSPECTION FINDINGS

APPENDIX B - LIST OF OBSERVATIONS

APPENDIX

C - EXIT MEETING ATTENDEES

~

25

27

. A-1

. B-1

. C-1

~%

1.0

INSPECTION

SCOPE

AND OBJECTIVES

From February

1 through February

11,

1993, the U.S. Nuclear Regulatory

Commission

(NRC) staff performed

a pilot service water system

(SWS) opera-

tional performance

inspection

(SWSOPI) at Washington Nuclear Plant Unit 2.

The service water system at the station is comprised of both the high pressure

core spray service water

(HPCS

SW)

and the standby service water

(SSW)

systems.

The

SWSOPI focused

on the mechanical

design,

operational

control,

maintenance,

testing

and surveillance of the

and evaluated

implementation

of the quality assurance

and corrective action programs.

The primary objec-

tives of this inspection

were to:

~

assess

the performance of the

SWS through

an in-depth review of mechani-

cal

systems

functional design

and thermal-hydraulic performance;

operating,

maintenance,

and surveillance

procedures

and their implemen-

tation;

and operator training on the

Generic Letter (GL) 89-13,

assess

the functional design

and operational

controls of the

SWS based

upon the thermal

and hydraulic performance

requirements,

and determine

whether

SWS components

are operated

in a manner consistent with their

design

bases

assess

the licensee's

planned

and completed actions in response

to

"Service Water System

Problems Affecting

Safety-Related

Equipment," July 18,

1989

assess

the unavailability of the

SWS resulting from planned

maintenance,

surveillance,

and component failures

The team has characterized its findings as deficiencies

and observations.

Deficiencies

are either the apparent failure of the licensee

(1) to comply

with a requirement or (2) to satisfy

a written commitment or to conform to the

provisions of applicable

codes,

standards,

guides,

or other accepted

industry

practices that have not been

made legally binding requirements.

For items

that

may require enforcement

actions,

the

NRC regional office will issue the

Notice of Violation and/or Deviation.

Observations

are items considered

appropriate

to call to licensee

management

attention although they have

no

apparent direct regulatory basis.

2.0

GENERAL SYSTEM DESCRIPTION

During normal operating

and emergency conditions,

the

SSW and

SW systems

transfer heat from various safety-related

systems

and components

to the

ultimate heat sink (See Figure 1).

The

SSW system

and the

SW system,

combined,

are designed

to perform their cooling function following a design

basis

accident

assuming

a loss of offsite power and

a single active failure.

The

SSW system is designed to remove reactor

decay heat from the residual

heat

removal

(RHR) system during

a normal

shutdown,

including periods

when offsite

power is unavailable.

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0

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PPC KX

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PMPIRM COOLER

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SW PH

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OGIRM

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COOLER

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The ultimate heat sink consists of two square

concrete

ponds,

each with an

associated

pump house

and spray ring.

Loop A of the

SSW system

draws water

from pond A, cools safety-related

equipment

associated

with electrical

Division I, and discharges

to the spray ring over pond

B to dissipate

heat.

Similarly, loop

B draws water from pond B, cools safety-related

equipment

associated

with electrical Division II, and discharges

to the spray ring over

pond A.

The

SW system

draws water from pond A, cools equipment

as-

sociated with the

HPCS system (electrical Division III), and discharges

directly to pond A.

A siphon line between

the two ponds allows for water flow

from one pond to the other.

The ultimate heat sink provides sufficient

cooling capacity to support

a normal

cooldown or an emergency

cooldown

following a loss of coolant accident for a period of thirty days,

coincident

with a loss of offsite power and

a failure of one loop of the

SSW system.

The spray

ponds

are provided with makeup water from the tower makeup

(THU)

system.

The

TNU system supplies river or cooling tower basin water to the

spray

ponds to replace water lost during spray ring operation

due to evapora-

tion and drift.

In addition, the

THU system is designed to replace water lost

from the spay

ponds during

a tornado.

To ensure

system availability for this

mode of operation,

the

THU system is designed to operate following a design

basis tornado coincident with a loss of offsite power.

The

SSW and

SW pumps take suction

on the associated

spray

pond through

the

pump sump.

The bottom of the

pump

sump is depressed

below the bottom of

the spray

pond ensuring that adequate

pump submergence

is maintained at the

lowest design

pond water level.

A sloping pond bottom and

a weir wall around

the

pump

sump form a sand trap to prevent

heavy debris

from entering the

pump

suction.

A fixed screen is also provided to prevent floating debris from

entering the

pump suction

and to collect debris entrained

in the water flowing

toward the

pump suction.

Each

pump is located within a separate

pump bay and

is provided with a separate

sand trap

and intake screen.

The piping of the

SSW and

SW systems is constructed of carbon steel to

seismic Category I and American Society of Mechanical

Engineers Boiler and

Pressure

Vessel

Code

(ASME Code),

Section III, Class

3 requirements,

with the

exception of that portion of system piping to and from the plant cooling tower

basin,

which is constructed

to American National

Standards

Institute Standard

(ANSI) B31. 1 and seismic Category II requirements,

and portions of the keep

full subsystem

located in the

pump house,

which is constructed

to ANSI B31.1

and supported to seismic Category I requirements.

The piping was designed for

operating

pressures

of 150 psig or 309 psig,

depending

on location,

and

an

operating temperature

of 150 F.

The piping schedule

selected for the

reactor core isolation cooling

system includes

a corrosion allowance of 0.080 inches.

For each

SSW loop, the water flows from the

pump discharge

through

a discharge

check valve (SW-V-IA/B) and

a butterfly-type motor operated

discharge

valve

(SW-V-2A/B) to the loads serviced

by the system.

The

RHR heat exchanger

and

the diesel

cooling water

(DCW) heat exchangers

are the dominant loads

on the

SSW system.

The combined flow to these

heat exchangers

is in excess of 80X of

the respective

SSW loop total flow.

Other loads

on the

SSW system include

emergency

core cooling system

(ECCS)

component

and

pump room coolers,

the

(RCIC)

pump room cooler,

service water

pump

Jg

house cooler,

containment

atmospheric

control

(CAC) equipment,

diesel

gener-

ator room coolers,

switchgear

room coolers,

and control

room coolers or

chiller condensers.

The

SSW system also serves

as the backup supply of

cooling water to the spent fuel pool

(SFP)

heat exchanger

and

pump room

cooler.

The

B loop of the

SSW system is capable of performing

a beyond design

basis function of core or containment flooding through

a crosstie to the

RHR

system.

Flow to each

component is balanced

using

a combination of orifice

plates

and throttle valves.

The return flow from all components

in each loop

combines

in a single return header.

The return header is provided with a

locked open air operated

valve

(SW-PCV-38A/B), formerly used

as

a pressure

control valve,

and

a motor operated

gate-type isolation valve (SW-V-12A/B).

The keep full subsystem

is attached

to the return header

and is intended to

makeup for leakage

from the

SSW system past

SW-V-2A/B and SW-V-12A/B when the

SSW system is idle.

Flow from the return header is manually directed through

the spray ring isolation valve

(SW-V-170A/B) to the associated

spray ring when

cooling of the return water is required,

or directly into the pond through the

spray ring bypass

valve

(SW-V-165A/B) when pond temperature

is sufficiently

low.

Sor the

SW loop, the water flows from the

pump discharge

through

a

discharge

check valve

(HPCS-V-28)

and

a butterfly-type motor operated dis-

charge valve

(SW-V-29) to the loads serviced

by the system.

The

HPCS diesel

generator

DCW heat exchanger

receives

in excess of 75K of system flow.

The

other loads serviced

by the

SW system

are the diesel

generator

room

cooler,

switchgear

room cooler,

and the

pump room cooler.

The return

flow combines into a single return header

and is returned directly to spray

pond

A without spray.

The

SSW pumps are

AC motor driven, three stage, vertically mounted,

axial flow

pumps with a rated capacity of 10,500

gpm at

a total developed

head of 500 ft.

The design

minimum submergence

of the

SSW pumps is 4.0 ft.

The

SSW pumps are

provided with electrical

power from their associated

safety-related electrical

division.

Each loop of the

SSW system

may be started

manually, or aligned to

start automatically

when

an

ECCS

pump associated

with the loop or the diesel

generator

associated

with the loop starts.

On

a start signal with SW-V-2A/B

closed,

SW-V-12A/B begins to open.

When SW-V-12A/B has partially opened,

a

limit switch actuates

to start the

SSW pump.

At a

pump discharge

pressure

of

50 psig,

a pressure

switch actuates

causing

SW-V-2A/B to open partially and

stop, limiting the rate of system fill. Following a time delay of 50 seconds,

SW-V-2A/B continues

opening to its full open position.

The 'SSW pump will trip

on overcurrent,

undervoltage,

and closure of SW-V-12A/B.

The

SW pump is an

AC motor driven, vertically mounted,

two stage,

axial

flow pump with a rated capacity of 1200

gpm at

a total developed

head of 123

ft.

Minimum pump submergence

at rated conditions is 2.0 ft.

The

SW pump

is provided with electrical

power from safety-related

electrical Division III.

The

SW system

may be started

manually or aligned to start automatically

on

a

HPCS diesel

generator start.

On

a start signal, the

SW pump starts.

At a

pump discharge

pressure

of 50 psig,

a pressure

switch actuates

causing

SW-V-29 to open fully.

The

SW pump will trip on overcurrent

and under-

voltage.

i

The pumps,

discharge

valves,

and return header isolation valves for each

system loop are located within the

pump house associated

with the respective

loop.

The

SW pump, discharge

check valve,

and discharge

isolation valve

are located within pump house

A.

The

pump houses

are constructed

to seismic

Category I requirements

and protect

components

in the

SSW and

SW systems

from the effects of postulated

external missiles.

The

pump houses

are heated

by electric blast heaters.

The

pump houses

are cooled

by a fan which draws in

outside air, or,

when the associated

pump is running,

an air handling unit

cooled

by SSW.

To prevent freezing, all

SSW piping and components

are either located in

heated structures,

buried below the frost line, heat traced,

or maintained

by

procedure

in a drained condition during cold weather

when the system is not in

operation.

The structural integrity of the

SSW and

SW piping is also

protected,

in part,

by a cathodic protection

system which applies

an elec-

trical potential to sections of piping in order to reduce the rate of galvanic

corrosion.

3.0

SERVICE WATER SYSTEM LEVEL REVIEW

3. 1

System

Heat

Removal

Capacity

The Service Water System

(SWS)

was designed

to provide sufficient cooling

without additional

makeup water for at least

30 days of operation during

accident or abnormal conditions.

The design

assumed

the worst combination of

controlling parameters

such

as

dew point, wind speed,

and solar radiation,

including appropriate diurnal variations.

This results

in maximum evaporation.

and drift losses

during the worst 30 day average

combination of the control-

ling parameters

pertaining to a recent period of record at least

30 years in

length.

Sufficient conservatism

was provided to ensure that

a 30 day cooling

supply is available

and that the design basis

temperatures

of safety related

equipment

are not exceeded.

The team reviewed the thermal

performance

requirements

of the

SWS during

accident or abnormal conditions,

including the appropriateness

of the design

assumptions,

boundary conditions,

and models.

Calculation HE-02-92-41

provided the room temperatures

during Design Basis Accidents

such

as ashfall

or a loss of coolant accident

(LOCA).

This calculation provides

a maximum

water consumption profile for the spray ponds,

which assumes

that the spray

drift covers

as little of the ponds

as possible,

and maximizes evaporation

losses.

Additionally, the meteorology

was selected

to maximize the evapora-

tion from the spray trees.

Calculation ME-02-92-41 indicated that the

SWS has

adequate

total water

inventory at the end of 30 days of 2,490,000 gallons,

390,000 gallons

more

than the minimum for siphon operation.

The team verified by independent

checking

and by verifying assumptions,

calculations,

and initial boundary

conditions that the results

and conclusions

were accurate

and correct.

The

calculation

had

a starting inventory of 11.92 million gallons which is based '.

on the minimum FSAR pond level of 432'-9".

The Calculation incorporated

several

water consumption

conservatisms.

The most notable

are the following:

I '>

T'l~

%4 (

1

I)

l

I) the meteorology

used for the first three

days of the accident is the worst

single day meteorology of record,

2) zero cloud cover over the entire event,

and 3) wind direction which maximizes spray losses.

The team's

review of Calculation E/I-02-92-14 determined that the heat load

calculation of electrical

equipment

and cables

was appropriate

and presented

the maximum heat load into the various

rooms located in the plant buildings.

The most notable

assumptions

were that

a ground fault occurs in each safety

related division during the operating

modes, all components

(such

as relays,

switches,

and transmitters)

are continuously energized,

and the heat load for

the inverters

and chargers

is calculated

assuming

they are fully loaded to

their rated capacity.

With the maximum heat loads generated

by the electrical

equipment

and cables,

the

SWS thermal capacity performance

requirement

was

still adequate

and the maximum safety equipment

temperatures

were within

design requirements.

The team determined that the

SWS has

adequate

heat

removal capacity

based

on

the worst mass loss analysis for a period of 30 days without outside

makeup.

The

SWS is capable of accomplishing its safety function for a normal

cooldown

or emergency

cooldown following a

LOCA without the availability of off-site

power.

The team had

no concerns

regarding the

SWS thermal capacity performance

requirement.

3.2

Design Function Verification and Single Failure Analysis.

The Service Water System

(SWS) is designed to perform its required cooling

water function following a Loss of Coolant Accident

(LOCA), assuming

a single

.

active failure.

The

SWS has

two main loops:

Loop A (electrical division I)

and

Loop

B (electrical division 2).

They are physically separate

and indepen-

dent of each other.

Each loop has its own cooling pond with spray trees,

but

the ponds

are connected

with a siphon line since only the combined water

volume of the spray

ponds is adequate

to provide the cooling water for 30 days

without makeup.

By design,

Pump

A discharges

into Pond

B,

and

Pump

B dis-

charges

into Pond A.

In addition to Loop A and

Loop B,

a small auxiliary loop

(Loop C, electrical division 3) exists,

which is dedicated exclusively to the

cooling requirements

of the High Pressure

Core Spray

(HPCS)

system.

System

failure mode

and effects analysis of passive

and active components of the

are detailed in the Final Safety Analysis Report

(FSAR).

In addition,

any of

the

assumed

failures of the

SWS can

be detected

in the main control

room by

indication and/or alarms

from the various

system instruments'.

The team reviewed the

SWS for single active failure vulnerabilities

as stated

in the

FSAR and in Calculation NE-02-89-46, "Fault Tree Calculation."

As

described

above,

the three

SWS loops operate

independently,

i.e,

redundancy of

the service water system heat

removal function is achieved

by having multiple

cooling loops available

as

opposed to having redundancy

embedded within each

loop itself.

A single

SWS loop can fail by failure of any single

one of its

essential

components.

The team's

review of Calculation NE-02-89-46

and of the

FSAR addressed

four

principal single failure modes of the

SWS loop.

The first failure mode

was

insufficient coolant flow at the

pump suctions.

This failure can occur if

any debris in the spray

pond gets too close to the

pump house,

so that it gets

drawn onto the

pump intake screen

where it could cause

clogging.

Research

by

the

NRC team of this failure mode determined that with a

pump

sump bottom

elevation of 408'-3"

and

a normal

pond elevation of 433'-6", there is in

excess of 25'f water above the

pump suction,

and the

pump intake screen is

2-3'rom the bottom of the

pump

sump to the wet wall separating

the spray

pond from the

pump sump.

This mode of failure is very unlikely.

The second failure mode

was the failure of the

pump to produce

adequate

head.

This failure mode can

be caused

by failure of the

pump motor to start

due to electrical or mechanical

'causes,

failure of the

pump motor to keep

running for the required mission time,

and mechanical failure of the

pump

itself during the mission time.

The

SWS pumps

have backup electrical

supplies

via the emergency diesel

generators

in case of loss of off-site power.

In

addition, the

pumps consist of two independent

100X capacity

pumps

each

supplying normal

and emergency

shutdown cooling equipment.

A single active

failure of either the

pump or its respective

motor would inactivate that

loop's function.

However, the other

SWS loop is capable of performing the

cooldown function following the

LOCA.

The third failure mode is insufficient coolant flow from the

pump dis-

charge,

which can

be caused

by failure of the check-valve

SW-V-1A/B, the loop

isolation valve SW-V-12A/B, or the discharge

valve SW-V-2A/B.

Appendix A of

Calculation NE-02-89-46 indicated failure unavailabilities of 5.83E-04,

and

6.65E-04, respectively, for the check-valve

and the discharge

valve.

However,

the calculation did not address

failure of the loop isolation valve.

The team

was concerned that uncertainties

with this valve's operation could cause

a

loss of redundant

SW trains.

(See

paragraph

11.0 and Deficiency 93-201-04 in

Appendix A of report).

The fourth failure mode is

a maintenance

error rendering

an essential

component unavailable.

The maintenance

error can interfere with system

operation if a valve,

pump, or pump motor had

been disassembled

and then

incorrectly reassembled.

The licensee

performs

an operating test after

completion of maintenance

work which should reveal

any maintenance

errors.

3.3

Seismic gualification

The Service

Water System

(SWS)

has to accomplish its safety function despite

the occurrence of the most severe site related natural

events

including

earthquake,

ashfall, tornado,

flood, or drought.

The ultimate heat sink spray

ponds

and the pumphouses

were designated

as Seismic Category I.

These

components

provide cooling capability for a period of 30 days without outside

makeup.

The basis for this requirement is General

Design Criterion

2 of

Appendix A,

10 CFR 50,

"Design Bases for Protection Against Natural

Phenomena."

The team conducted

a walkdown of the

SWS to ensure that the safety-related

portions are seismically qualified.

The team noted that the

pump house

"A"

crane

HR-CRA-6A was not stored

against

the southwest wall as required

by Plant

Procedures

Manual

(PPN) 10.2.53,

"Seismic Requirements

for Scaffolding,

Ladders,

Tool

Gang Boxes, Hoists,

and Metal Storage

Cabinets".

In addition,

<<+,c

'II lv

e

attachment

8.4 specifically illustrates the acceptable

locations for storage

of hoists,

but does not indicate the

pump house

"B" crane

HR-CRA-6B (Observa-

tion f93-201-01).

The improperly stored

crane

prompted initiation of Problem

Evaluation Request

(PER) 293-125

on February 3,

1993 by the licensee.

PER

293-125 initiated Procedure

Deviation

Forms

(PDFs) which detailed the storage

requirements for cranes

HR-CRA-6A and

6B upon completion of lifts or mainte-

nance.

The

NRC team determined that both cranes

MR-CRA-6A and

6B were Seismic

Category I as were the dual rails upon which the cranes

are positioned.

No Seismic Category I structures

or components

appeared

to be in danger

by a

Seismic Category II structure.

The team

had

no concerns with the seismic

qualification of the

SWS.

3.4

Instrumentation

The Service

Water System

(SWS) spray

ponds

have two Technical Specification

(TS) requirements

which ensure

a minimum water level at elevation 432'"

Mean

Sea

Level

(HSL), and

a water temperature

of less than or equal to 77 F.

The

requirements for minimum water level

and

maximum water temperature

assure

availability of the ultimate heat sink (spray pond) under all weather condi-

tions,

and allow the operators

to take appropriate

action in case of an alarm

condition in either parameter.

The team verified that the minimum water level requirement of elevation

432'"HSL

provides sufficient water for 30 days of cooling without makeup capabil-

ity.

The team reviewed setpoint Calculation

CHR-90-319 for the high and low

trip points of 434'3"

and 433'0" respectively,

and found adequate

margin to

allow operators

to respond to each

alarm condition.

The low setpoint trip

condition of 433'0"MSL would provide 3" of water level before reaching the

TS

required level of 432'9"HSL which provides

ample time for operator action to

refill the spray

pond or determine

leakage

sources.

The high trip setpoint of

434'3"HSL is sufficiently below the top of the wall (435'HSL) to allow

operator action to stop makeup flow.

The bulk average

temperature

of the

SWS spray

ponds is recorded daily using

surveillance

procedure

PPH 7.0.0 to ensure that the temperature

is below the

77'F

TS requirement of Section 3.7. 1.3.

There is no requirement for a minimum

pond temperature.

The surveillance

procedure

requires four temperature

element readings

which are spaced

at different elevations in each

pond.

The

element readings

are

used in an algorithm developed

in calculation HE-02-84-55

to find the bulk temperature.

In addition, in each of the

pump house pits

are two temperature

elements

which are also

use'd.

The team reviewed the processes

and calculations

in determining the setpoints

of each of the temperature

elements.

A low setpoint of 35

F provides

an alarm

to alert operators

of potential

spray

pond freezing,

and allows operator

action to warm the ponds via system operation in a recirculation

mode.

The

high setpoint of 72'F ensures

that the

TS limit of 77'F is not .attained,

and

allows operator action to commence

spraying to lower pond temperature.

While performing surveillance

PPM 7.0.0 the licensee

discovered that two spray

t

'g

pond temperature

elements,

SW-TE-2A and 2E, were destroyed

by ice falling upon

them in early January

1993.

Problem Evaluation Request

(PER)

293-036 reported

the failed temperature

elements

on January

13,

1993.

The licensee

recommended

actions

were to repair the temperature

elements

when ice is off the pond,

and

continue operation until the temperature

elements

can

be repaired

using the

control

room temperature

indications for SWS

pump suction temperatures,

i.e.,

SW-TI-1A, 1B,

1C,

and

1D.

Those elements

are located in the

pump pits as

mentioned previously

and would not be damaged

by surface ice.

The team

reviewed the corrective actions of PER 293-036

and determined that the

SWS was

still operable

due to operable

pump suction temperature

indications.

The

NRC team reviewed several

concerns

over flow orifices supplied

by the

licensee

and installed in several

flow elements

in the

SWS cooling flow path

to several

components.

The concerns

were whether the flow orifice diameters

had

been determined correctly, whether the orifices were accurately

manufac-

tured in accordance

with standard

practices,

and whether

any measurements

or

testing

had

been

performed to ensure

accurate

flow determination for the

components.

The

NRC team reviewed flow orifice sizing calculations

as

conducted

by the Architect and Engineer

(ARE) Burns

and

Roe, Inc.

and deter-

mined that the calculations

appeared

to be accurate

and correct.

The

NRC

inspector verified the calculation's

design

parameters

to be accurate for the

SWS temperature

and pressure

operating

design basis.

The

NRC inspector reviewed the manufacturing specifications of the orifice

plates

per Project Engineering Directive (PED)W215-I-3727

and

PEDW215-I221

which required the orifice plates to be manufactured

in accordance

with the

Instrument Society of America (ISA) recommended

practice 3.2,

"Recommended

Practice for Orifice Plate Fabrication."

Orifices manufactured

to this

standard

would exhibit an accuracy of within +g-

1 X of the actual rate of

flow.

The

NRC walkdown of the

SWS indicated that the flow orifices were

installed properly and that the orifice plates

have the stamped orifice base

diameter

and instrument

number

on the paddle.

The orifice accuracies

were included in the

SWS loop instrument

accuracy

determinations for temperature

and level instruments.

However, the

NRC

inspector determined that the loop instrument

accuracy calculations for the

SWS flow instrument

had not been

updated to include the flow orifice accuracy

determinations

(see report section 6.1).

The licensee

had planned reviewing

and revising loop instrument calculations for the flow instruments later in

the year.

The team identified that the calculations for the flow instruments

appeared

to contain

adequate

margin to account for the instrument uncertain-

ties.

3.5

Freeze

Protection

The

SWS was designed

to be protected

against freezing

by allowing bypass

operation

and draining of spray header piping, inclusion of heat tracing for

above ground piping,

and by locating equipment within heated

enclosures.

Since the spray

ponds

and the above ground piping are usually exposed to

ambient winter weather conditions,

freeze protection

was designed

into the

system operations.

I,

~ '

1

~jr".

ih-

bf

9'

Paragraph

5.6 of procedure

number 2.4.5,

"Standby Service Water System"

provides for controlling spr ay pond temperature

and ring header

ice formation

by bypassing

the spray rings

and draining the rings

and risers

whenever

spray

pond temperature

decreases

below 60'F or the outside

ambient temperature

can

fall below 32'F.

The

SWS operation in cold weather simply bypasses

the spray

header

and

dumps the return water into the spray ponds.

This circulating mode

breaks

up any ice formation on the ponds,

and warms

up the ponds

due to excess

heat from the buildings being cooled.

The team identified that the horizontal piping runs for several

of the

spray trees

were sloped slightly down towards the nozzles,

in which case

the

horizontal piping would not be completely drained

back to the vertical risers.

The standing water in the horizontal

runs could freeze

and partially restrict

or completely block the flow of SWS water out the nozzle.

The team found no

more than ten horizontal piping (nozzles)

runs per pond which could freeze

solid, with several

others which would only partially freeze

along the bottom

of the pipe (Observation

93-201-02).The

licensee

issued

PER 293-140 to

evaluate this problem.

The

PER evaluation indicated that

up to four vertical

trees

may be removed

from each

pond

(28 nozzles) without affecting its post-

cccident design function.

4.0

MECHANICAL COMPONENTS

REVIEW

4.1

SSW and

SW Pumps

The team reviewed the operating characteristics

of the

SSW and

SW pumps

with respect

to the capability to perform their design functions.

Specifical-.

ly, the team examined

the adequacy of pump submergence

and the capability both

to provide adequate

flow and to prevent excessive

flow rates

and associated

cavitation

(pump runout)

under all anticipated operating configurations.

The team reviewed vendor supplied test data

and

pump curves,

pump installation

arrangement

drawings,

system pressure

drop and flow rate calculations,

and

preoperational

test results.

Vendor testing

and preoperational

testing

adequately

demonstrated

that the installed configuration of the

SSW and

SW pumps will ensure sufficient submergence

to prevent

pump cavitation or

vortex formation for the design basis

minimum spray

pond inventory.

The

and

SW systems

are flow balanced

such that the associated

pumps typically

operate

near their optimum design conditions.

With the exception of heat

exchangers

and the makeup line associated

with the spent fuel pool,

and, for

SSW loop B, the crosstie to the

RHR system,

the

SSW and

SW systems

normally operate with full flow to each

component.

The team determined that

supplying the heat exchangers

associated

with the spent fuel pool from the

system results in a minimal change

in system flow conditions.

The team did

not identify any system configurations

where

pump runout would be of concern.

The team concluded that the

SSW and

SW pumps

are appropriately sized for

their intended function.

In addition, the team has not identified any

operational

or design features of the

SSW or HPCS

SW systems

which would be

likely to result in premature failure of the associated

pumps.

10

rP~-~

4.2

SSW System Piping

The team reviewed the design of the

SSW and

SW system piping with regard

to the performance capability of the

SSW system

and its conformance with the

design

bases

and engineering

analyses

associated

with the

SSW and

SW

systems.

The team examined

SSW and

SW system flow balance test data,

and

SW system flow velocity and pressure

drop calculations,

and system

design criteria.

Piping size

was adequate

to supply the necessary

flow to each

component.

Flow

restricting orifice plates

and throttle valves were

used to establish

accept-

able

SSW and

SW flow to each

component,

while limiting the pressure

drop

through individual heat exchangers.

The

SSW system return header flow

velocity was most limiting with respect

to pipe wall erosion.

However,

calculated flow velocities were within acceptable

ranges to limit system

erosion for all sections of piping.

The calculated

flow velocity values

were

based

on flow rates

measured

during flow balance testing,

ensuring consistency

between

assumed

system

parameters

and actual

system flow characteristics.

The

functional capability of the siphon line demonstrated

during preoperational

-testing is consistent

with the performance

assumed

in the determination of

available spray

pond inventory.

The

SSW and

SW system piping was constructed

to acceptable

standards

in

accordance

with Section III of the

ASHE Code.

An appropriate

corrosion

allowance

was specified,

recognizing the susceptibility of carbon steel

piping

to general

corrosion.

Calculated piping stresses

are such that postulation of

through-wall cracks in

SSW system

ASME Code Class

3 piping is beyond the

design basis for flooding.

However, separation

of the two

SSW loops provides

a'dded

assurance

that flooding will 'not result in

a common

mode failure of

both

SSW system loops.

The keep full subsystem

is not constructed

to ASHE

Code Class

3 requirements,

but

a check valve in the

keep full subsystem,

which

is regularly tested

under the

WNP-2 inservice test plan, is constructed

to

ASNE Code Class

3 requirements

and blocks this potential flooding path.

The team concluded that the

SSW and

SW system piping design is adequate

for the

SSW and

SW systems to satisfy their performance

requirements,

and

is constructed

to standards

which are in accordance

with the design

bases

of

the systems.

4.3

Heat Exchanger Evaluations

4.3. 1

Diesel

Cooling Water Heat Exchanger

The diesel

generators

were supplied with

OCW heat exchangers

mounted

on the

diesel skid.

The vendor specified the required cooling water flow rate

based

on 95'F service water.

SSW and

SW flow rates

provided to the

DCW heat

exchangers

during flow balancing

are consistent with the vendor

recommended

values.

The Division I and Division II diesel

generators

are

tandem mounted diesels

driving a single generator,

and the flow balancing

procedure

establishes

the

combined outlet throttle valve position based

on total flow to the two

DCW

heat exchangers

associated

with each diesel

generator.

The piping configura-

tion results

in one

DCW heat exchanger receiving greater flow than the other.

Calculation

number HE-02-92-14,

evaluated

the capability of the heat exchanger

receiving the lower

SSW flow to cool the diesel

engine

under the greater

load.

The calculation

assumed

the second

DCW heat exchanger,

which is receiving the

greater flow, cools the diesel

engine operating at the lower load.

Adequate

cooling is provided to the Division I and Division II diesel

generators

under

these

non-uniform

SSW flow conditions.

There is little margin between the calculated

DCW temperature

under the

assumed

non-uniform flow and load conditions,

and the high

DCW temperature

alarm setpoint.

The licensee

indicated that

a modification to equalize the

SSW flow to the two

DCW heat

exchangers

of each

tandem diesel

generator is

under evaluation.

4.3.2

RHR Heat Exchanger

The

RHR heat exchangers

were designed for a

SSW flow rate of 7400

gpm at

an

inlet temperature

of 95 F.

The acceptable

flow range for SSW to the

RHR heat

axchangers,

established

during

SSW system flow balancing in accordance

with

procedures

PPH 7.4.7. l.l. 1 and

PPH 7.4.7. 1. 1.2, is 6900

gpm to 7600 gpm.

Calculation

number HE-02-92-245,

determined that

a

SSW flow of 6900

gpm at an

inlet temperature

of 90'F is capable of removing heat from the

RHR heat

exchanger

at the limiting design rate of 121.7 million BTU/hr.

The calcula-

tion adequately justified the capability of the

RHR heat exchanger

to perform

its design

heat

removal function at the established

SSW system

minimum flow

rate of 6900 gpm.

4.3.3

Various

Room Coolers

Calculations

HE-02-92-40

and HE-02-92-43,

determined

the maximum expected

temperatures

under design basis accident conditions for rooms cooled

by

and

SW.

Internal

heat loads resulting from operation of various elec-

trical equipment

were correctly evaluated

and accounted for in the calcula-

tions.

The heat loads resulting from infiltration, conduction

and convection

were generally correctly evaluated.

For the diesel

generator building and the

SSW pump houses,

the heat load resulting from solar radiation

was omitted, but

the effect of this omission is negligible.

The calculations correctly used

vendor data to determine cooling coil performance

under other than design

conditions.

Overall, the calculational

methodology is accep'table for deter-

mining maximum expected

room temperatures

under design basis accident condi-

tions.

5.0

SERVICE WATER SYSTEH MODIFICATION REVIEW

5. 1

Service Water System

(SWS) Cross-Connect

Hodification

The licensee

determined that in order to allow for periodic maintenance

of

submerged

steel structural

supports

and piping in the ultimate heat sink

(UHS)

spray ponds, it was necessary

to drain the ponds

one at

a time during

a

refueling outage.

The present

system design results

in the service water

(SW)

pumps taking suction

on one pond, providing cooling water to plant room

12

5

coolers

and essential

equipment,

returning cooling water to the other pond for

spray cooling,

and returning water to the

pump suction in the first pond via a

30 inch siphon.

This mode of operation precludes

draining of a pond for

maintenance.

A cross-connect

design

change will allow the return of water to

the pond from which it was drawn.

The change

involves the cross connection of

the return piping via

a removable

spool piece,

which will be installed

between

two permanently

located butterfly valves,

and the blockage of the siphon with

a plug.

By this change,

one

pond can

be drained with this cross connection

capability in place.

The

SWS cross-connect

modification was accomplished

via two Basic Design

Changes

(BDCs).

The first BDC;

No 84-1724-0D,

provides

a design for the first

stage

which installs flanges

on

SW return piping.

The second

BDC;

No 89-0103-

OA, provides the design of the connecting valves

(SW-V-933A and 933B)

and the

piping between

the flanges

and the siphon plug design.

Both

BDCs use ASHf

Section III, Code Class

3 fittings and piping to connect to the Class

3

piping.

The

BDC packages

were of excellent quality; the

SWS piping and instrumentation

xliagrams

(P&IDs) were updated to include the two valves

SW-V-933A and 933B.

The final safety analysis report

(FSAR) was modified to discuss this modifica-

tion and the added ability to drain one spray

pond during certain

modes of

shutdown operation.

The licensee

conducted

a Design Safety Analysis on the

SWS cross-connect

modification with focus in four areas:

1) redundancy

requirements,

2) ultimate heat sink

(UHS) water inventory, 3)

UHS cooling

water temperature limitations,

and 4) severe natural

phenomena.

The Design

Safety Analysis assumptions,

analysis,

and conclusions

were determined to be

complete

and thorough.

The team concluded that the

SW cross-connection

modification appeared

to be installed in accordance

with the modification's

design

packages.

5.2

Replacement

of SW-V-2A/B

In 1986, the

SSW system experienced

a water hammer while placing the supply

line to the spent fuel pool cooling water heat exchanger

in service.

This

event

damaged

piping and pipe supports.

Valve SW-V-2A/B had also required

substantial

maintenance

due to the severe throttling duty of the valve during

system startup since the valve was not designed for this function.

Hodifications were performed

under Plant Hodification Record 02-86-0324-1 to

reduce the potential for hydraulic transients

during system startup

and

decrease

required maintenance

of valve SW-V-2A/B.

The modifications included

replacement of pump discharge

valve SW-V-2A/B, deactivation of SW-PCV-38A/B,

activation of SW-V-12A/B for system discharge isolation,

and installation of

the

"keep full" subsystem.

Following the modification,

no further damage

due to hydraulic transients

has

been observed.

The more robust valve design

used for SW-V-2A/B has decreased

required maintenance.

Therefore,

the team concludes that the modification has.

improved the reliability of the

SSW system.

13

4"

1

I

The team reviewed relevant design

change

packages

and determined that the

modifications to the system were performed in accordance

with the requirements

of 10 CFR 50.59.

Each package

included

a safety evaluation of the proposed

modification, revised drawings, test requirements,

and field work procedures

necessary

to implement the change.

Procedure

numbers

TP 8.3.65

and

TP 8.3.73

addressed

testing following imple-

mentation of PHR 02-86-0324-1 for SSW loop

A and

B, respectively.

Testing of

the

SSW system controls

and interlocks

was performed satisfactorily.

However,

post-modification testing of the system

was performed in a partially, rather

than completely drained condition.

Since valves

SW-V-2A/B and SW-V-12A/B are

not required to be leak tight to perform their function,

and since the keep

full system is not safety grade,

the team concluded that testing from a

completely drained condition would be necessary

to ascertain

that damaging

hydraulic transients

would not occur under the most limiting conditions.

Operational

experience

and

a system startup

observed

by the team from a nearly

completely drained condition (without water hammer) indicate that the proba-

bility of hydraulic transients

has

been substantially

reduced

by the modifica-

tion.

Therefore,

the team concluded that the modification has likely elimi-

nated the potential for water

hammer

and

made the intended

improvement in

system reliability.

6.0

SERVICE

WATER SYSTEN SURVEILLANCE AND TESTING

6.1

Technical Specification Surveillance Testing

The

WNP-2 Technical Specifications

(TS) require that the Standby Service Water.

System

be demonstrated

operable

at least

once every 31 days

by verifying

proper valve position

and at least

once every

18 months

by verifying that each

automatic valve actuates

to its correct position

on

a service water actuation

test signal.

In response

to Generic Letter 89-13,

WNP-2 committed to continue

performing periodic flow balancing of each of the service water loops for TS

operability verifications.

TS-related

procedures

PPH 7.4.7. 1.1. 1 "Standby Service Water Loop A Valve

Position Verification," PPH 7.4.7.1.1.2

"Standby Service Mater Loop

B Valve

Position Verification," and

PPH 7.4.7.1.1.3

"HPCS Service

Water Valve Position

Verification" demonstrate

the operability of the

SSW system.

Valve lineups

are performed monthly to verify flow path valve positions.

Automatic valve

function is verified annually during the train operability demonstration.

Flow balancing is performed annually to adjust flows to the heat exchangers

and

room coolers.

The required flow values specified in the

SSW system valve position verifica-

tion procedures

did not include

an allowance for instrument error (Observation

93-201-03).

Based

on

a review of the documents

forming the bases for the

required flow values,

the team determined that sufficient margin exists to

compensate

for the effect on heat

exchanger

performance of a small reduction

in

SSW flow rate resulting from instrument inaccuracy.

However,

a formal

evaluation of the acceptability of the potentially reduced

SSW flow rate to

each

component

had not been performed.

14

6.2

Preoperational

Test Review

In 1983,

WNP-2 performed

a series of tests

on the Standby Service Water System

to verify its readiness

to perform its required functions.

Preoperational

Test Procedure

PT-58.0-A "Standby Service Water," tested

the system's inter-

locks and the operation of pumps

and valves.

Preoperational

Test SLT-S58.0-3

"SW Flow Balance,

" the original flow balance

procedure for the system,

measured

flow for each load

on the permanent

flow meter for each

component.

All flows matched

the required flows listed in the

FSAR except for the

RHR

pump seal

cooler.

The original design specification for the seal

cooler was

12 gallons per minute

(gpm) of service water flow at 105'F.

However, in the

test procedure,

the flow to the seal

cooler was reduced

from 12

gpm to 9 gpm.

The licensee

does not have documentation

to support the adequacy of the

reduced flow, but stated that the basis for the

9 gpm would be determined.

The design temperature

of the standby service water system is 85'F, which

would provide more cooling at

9 gpm than

12 gpm at 105'F service water.

In

addition, the licensee

stated that the installed cooler is

a different model

than

shown in the original design drawing and requires less flow.

Therefore,

the team concluded that the reduced flow to the

RHR pump seal

cooler was not

significant.

6.3

Inservice Testing

The inservice test

(IST) program implementation

and surveillance

procedures

were reviewed to verify conformance with Section

XI of ASME Boiler and

Pressure

Vessel

Code

and Generic Letter 89-04.

The team reviewed the follow-

ing inservice test program procedures:

PPM 7.4.0.5. 16 "Standby Service

Water

.

Loop A Operability Demonstration,"

PPM 7.4.0.5. 17 "Standby Service Water Loop

B Operability Demonstration,"

and

PPM 7.4.0.5. 18

"HPCS Service

Water Operabil-

ity Demonstration."

These

procedures

describe quarterly measurements

of valve

stroke times,

pump vibration velocity,

pump discharge

pressure

and flow, and

pond water temperature

and level.

The IST program for SSW pumps

and valves is consistent with Section XI, of the

ASME Boiler and Pressure

Vessel

Code.

IST results indicated that no pumps or

valves in the

SSW system

have

been in the Action Range in the last two years.

There is

a relief request

pending

on WNP-2's

pump test method.

The

SSW system

does not have

a means of setting constant

pressure

or flow for the purpose of

IST pump performance testing.

WNP-2 has developed

a reference

curve based

on

varying pressure

and flow.

Trending of pump performance is based

on normal-

ized data obtained

by dividing the measured

discharge

pressure

by the refer-

ence discharge

pressure

for,a given flow.

The instruments

used in IST

pressure

and flow measurements,

PI-32A/B and FI-8A/B, are accurate

to within

2X, as specified

by ASME Section XI.

6.4

System Unavailability Review

The licensee

developed

a system notebook for use in the Individual Plant

Evaluation

( IPE) that includes the system's

safety functions

and dependencies

on support

systems.

The unavailability used in the

IPE for the

SSW system

was

based

on assumptions

made in the development of the system notebook.

15

Actual system unavailability for the last two years

was determined

based

on

LCO logs

and Problem Evaluation Reports.

Unavailability of the

SSW from

planned

maintenance

and testing for the last two years

was less than

assumed

for the IPE.

HPCS Service Mater was

assumed

to have

no unavailability for

test

and maintenance

in the

IPE because all planned

maintenance

is performed

during outages.

Based

on the review of actual

system unavailability, the team

determined that the assumptions

made

by the licensee for the

IPE are valid.

6.5

Heat Exchanger

Performance

Test Review

WNP-2 committed to heat exchanger

performance testing in its response

to

GL 89-13.

WNP-2 also committed to inspect,

clean,

and eddy-current test the

service water side of the heat exchangers

on

a 5-year interval

as preventive

maintenance.

The licensee

also indicated they would perform annual

preventive

maintenance

inspections

on the air side of all air-to-water cooling coils in

the

SSW system.

The licensee

has developed

procedures

for data collection.

The results

are

trended to indicate

changes

in heat exchanger

performance.

The heat exchanger

performance testing includes

measurement

of cooling water flow and inlet and

outlet temperatures.

Flow measurements

are taken at the local flow meter for

each load

and

by ultrasonic test equipment.

Temperature

measurements

are

made

using six thermocouples

installed

around the outside of the pipe.

The

differential pressure

across

each

heat

exchanger is trended to detect tube

fouling.

Differential pressure

testing is performed

on the fan coolers

and

on

the

RHR pump seal

coolers.

Fan differential pressures

are trended

as

an

indicator of air flow.

WNP-2 is planning to install permanent

instrumentation.

(RTD thermowell

and permanent

flow element)

in the diesel

generator jacket

water cooler line in an upcoming outage.

WNP-2 began collecting data

on

heat exchanger

performance

in 1988.

In 1992,

a decreasing

trend

was noted in

the overall heat transfer coefficient for the

RHR heat exchanger.

The

licensee

concluded that the heat exchanger fouling had not reduced

the heat

removal capability of the heat

exchanger to an unacceptable

level.

However,

all

SSW heat exchangers

were cleaned

during the

1992 refueling outage.

After

cleaning,

baseline

heat exchanger

performance

data

was collected

and trended

during 1992.

Performance tests

conducted

under procedures

8.4.42, 8.4.54, 8.4.62,

and

8.4.63

measure

the overall heat transfer coefficient of the

RHR and

DCW heat

exchangers.

The licensee

evaluated

the acceptability of heat exchanger

performance

based

on

an assumption

that any degradation

in performance

from

design conditions calculated

from test results

was due to fouling of the heat

exchanger.

The licensee

explained that much of the observed

reduction in the

overall heat transfer coefficient indicated

by the test data resulted

from

decreased

shell side flow when low temperature

SSW is provided to the compo-

nent.

The licensee

has not identified

a correlation to determine the expected

shell

side film coefficient under reduced flow conditions,

such

as experienced

during heat

exchanger

performance testing.

Such

a correlation would permit

a

determination of the deviation from expected

performance

at reduced flow

conditions.

The present

method of evaluating

heat exchanger

performance test

16

Ci~-

I

data is conservative

in predicting the ability of the heat

exchanger to

perform its design function, but does not provide

an indication of the degree

of heat

exchanger fouling.

Test data is being collected

under various flow conditions,

and that by

comparing the results of tests

performed

under similar flow and temperature

conditions, it may be possible to determine

the degree of fouling which

occurred in the period

between tests.

This approach is acceptable

due to the

absence

of other more direct methods of determining the degree of heat

exchanger fouling.

The team determined that the licensee's

heat exchanger

performance testing and-

preventive maintenance

programs

meet the commitments

made in the Generic

Letter response.

The program is adequate

to determine

acceptable

performance

of the

SWS and trending of system performance will result in a more accurate

estimate of heat exchanger fouling.

7.0

BIOFOULING CONTROL AND TESTING

4RC Generic Letter 89-13, Action I, requested

that licensees

implement

and

maintain

an ongoing program of surveillance

and control techniques

to signifi=

cantly reduce the incidence of flow blockage

problems

as

a result of biofoul-

ing.

The actions

requested

included intake structure

inspections,

chemical

treatment of service water systems,

and periodic service water system flush-

ing/flow testing.

Prior to the issuance

of the generic letter, the

SWS spray

pond contained

significant concentrations

of algae

and water insects.

The choice of treat-

ment chemicals for use in the

SSW system

was limited by two factors.

First,

the

RHR heat exchangers

contain stainless

steel

components

which are subject

to intergranular stress

corrosion cracking

(IGSCC)

when the metal

comes in

contact with halogen

based

treatment

chemicals.

Second,

the water inventory

of the

SSW system

remains relatively static.

Continually treating the system

with a chemical that does not breakdown

may result in pond water of increasing

toxicity as well as anion concentrations

high enough to induce

IGSCC.

Buckman Laboratories

proposed

a program using Bulab 6003, that could meet the

above

two constraints

and eliminate fouling caused

by microorganisms,

elimi-

nate microbiologically induced corrosion potential, eliminate potential

fouling caused

by clams

and improve the

SSW system reliabili'ty.

Bulab 6003 is

a 35K-active solution of two different active ingredients.

It does not

contain

PCBs or priority pollutants which would violate the

WNP-2 National

Pollutant Discharge Elimination System

(NPDES) permit and it has the capabil-

ity of breaking

down quickly without building up toxins in the system.

The licensee

requested

and received the Energy Facility Site Evaluation

Council

(EFSEC)

approval of Bulab 6003 for a one year period.

EFSEC is the

Washington state

agency that oversees

environmental

regulation.

The licensee

needed

approval for the

SSW spray

ponds since the treated water would

subsequently

be released

to the Columbia river.

The Council set

a condition

that discharge

into the plant blowdown line can not occur before

30 days

have

elapsed after application

and chemical

analyses

shows

no detectable

active

ingredients.

17

In September

1991, the licensee

commenced

treatment of the

SSW spray

ponds

with Bulab 6003, at

a concentration of 15-30

ppm on

a monthly basis.

The

Bulab was fed from a tank adjacent to "B" Pumphouse

via flexible tubing and

discharged

immediately

above the

pump suction.

Plate counting

and the

turbidity of the bulk water were measured

from samples to monitor the effect

of the treatment relative to these

parameters.

Algae was

a predominant

problem prior to the Bulab addition.

After the Bulab addition, the algae

content

was noticeably diminished.

However, the aerobic bacteria

counts

showed

a sharp

increase

due to the dead algae.

This disturbance

in the

ecological

balance of the spray

ponds

had not been foreseen

by the licensee.

During plant shutdown

on April 19,

1992,

degraded

heat transfer performance

was observed for the

RHR "A" heat exchanger while in the shutdown cooling

mode.

The heat exchanger

was found to be coated with a layer of silt trapped

within a slime matrix.

The slime was believed to have originated

from a slime

forming bacteria within the

SSW spray

pond water.

The licensee

determined

the

root cause of the event

was insufficient monitoring of the

SSW system in

predicting fouling magnitude

and rates.

The inside surfaces of all of the

tubes in the

RHR "A" heat exchanger

were mechanically cleaned of the biologi-

cal fouling.

Due to the biofouling problems which existed in the

summer of 1992,

an

extensive

amount of Bulab 6003,

which contains sulfur,

was

added to the spray

ponds.

Consequently,

the sulfur concentration

went above the licensee's

control limit of 150

ppm in the

SSW system which was set to prevent

IGSCC on

the

RHR heat

exchanger tubing.

The licensee

did not issue

a Problem Evalua-

tion Request

(PER) to evaluate

exceeding

the sulfur limit.

This is identified.

as Deficiency 93-201-01 in Appendix A.

After the growth in the

summer of 1992, the licensee

developed

techniques

to

more effectively monitor biological growth in the spray ponds.

The biocide

additions

were based

on pond visual indications.

For example,

a brilliant

Kelly green

was indicative of a thriving, growing algae population.

A drab

olive or beige tinted green

was indicative of a biostatically suppressed

pond.

Two slime box units are

now operating in a side stream flow to monitor algae

(transparent

box)

and bacterial

(dark box) growth.

The growths observed

in

these

boxes closely parallel the pond growth and are useful

when

SSW pumps

are

not available to keep the pond agitated.

Also, the slime boxes

are easily

interpreted

backups to the subjective

methods of reading

pond health

by visual

observation of color and clarity.

The licensee

purchased

a Deposit Accumula-

tion Testing System

(DATS) biofouling monitor and is planning to install it in

the near future in the

SSW "A" pump house.

This unit will measure

changes

in

heat flux across

a stainless

steel

heat exchanger

tube

and changes

in flow

through the tube

as the tube

becomes

fouled with biological growth.

The tube

is easily removed for periodic inspection,

cleaning or replacement,

thus

allowing close correlation

between

changes

in operating

parameters

and

physical evaluation of the rate

and magnitude of biological growth.

The licensee

indicated they had inspected

the spray

ponds

once per refueling

outage,

and

no fouling accumulation

had

been

found in the safety-related

18

system.

However, this inspection

had not been proceduralized

(Observation

93-

201-04).

The licensee

agreed to implement

an

SMS card which is

a tracking

system to verify that the inspections

are completed.

The licensee

believes that Bulab 6003 has

been successful

in controlling algae

to reduce the incidence of flow blockage

problems

as

a result of biofouling,

although they are still in a trial period.

The team found there is

a need to

better proceduralize

the biofouling program

as is evidenced

by several

of the

teams

concerns

as well as

by WNP's

own gA audit of this program.

(See section

11.0 of the report).

The licensee

agreed to implement

a document to clearly

outline the program,

which will include the necessary

steps for each of the

departments

involved for the monitoring of biofouling at WNP-2.

8.0

MAINTENANCE

Action III of Generic Letter 89-13

recommended

that

a routine inspection

and

maintenance

program

be established

to ensure that corrosion,

erosion,

protec-

tive coating failure, silting and biofouling cannot

degrade

the performance of

the safety related

systems

supplied

by the service water system.

Action V

.further recommended

that maintenance

practices

be adequate

to reduce

human

errors in the repair

and maintenance

of the service water system.

In their February

5,

1990 response

to

GL 89-13, the licensee

committed to

perform

a) regularly scheduled

inspection,

cleaning,

and eddy current testing of

all service water heat exchangers

with accessible

tubing,

b) annual

inspection of the air side of air-to-water cooling coils,

and

c) monitoring of corrosion

coupons.

The licensee identified that in-service inspection

under

ASME Section XI and

periodic flow balancing for technical specification surveillance of the

service water system would also detect

system degradation

due to fouling.

The

licensee's

response

stated that the technical

accuracy

and completeness

of all

maintenance

procedures

was assured

through routine biennial

procedure

reviews.

The team reviewed maintenance

procedures

and completed

maintenance activities

performed during the past year

and found them adequate.

The results of eddy

current inspections of the residual

heat

removal

heat

exchan'gers

were reviewed

and found to be adequate.

8.1

Erosion Monitoring

The service water system

was not routinely monitored for pipe wall thinning

due to the low pressure

and temperature

operating conditions for the system.

The licensee

had observed cavitation erosion of a piping elbow downstream of

the service water

pump discharge

valve SW-V-2B.

The discharge

valve throttles

flow initially during system startup.

The degradation

had

been

obser'ved

visually during replacement

of the discharge

valve when the piping system

was

open.

The elbow was weld repaired to restore

the pipe wall thickness

in the

affected areas.

Following repair,

the area

was ultrasonically tested

(UT) to

19

establish

baseline

data for trending of future wall thinning.

No further

erosion

had

been detected

in subsequent

UT monitoring.

The licensee's

actions

were appropriate.

9. 0

OPERATIONS

9. 1

Operations

procedures

The team reviewed operations

procedures for normal,

abnormal,

and emergency

conditions,

procedures

for operating logs,

and examined

completed log records.

The

SSW procedures

are in the plant procedures

manual

(PPM).

Volume

1

contains administrative

procedures

including the operating

data

and logs

procedure;

volume

2 contains

normal operating

procedures

such

as procedures

to

make the

SSW system available;

volume

3 contains general

operating

procedures

such

as startup

and shutdown procedures;

volume

4 contains

annunciator

response

procedures

and abnormal

operations

procedures

such

as the loss of

SSW;

and volume

5 contains

the emergency

response

procedures.

Volume 7

contains surveillance

procedures

including shift and daily instrument checks.

.The licensee's

procedures

generally described

system operation

adequately,

except

as described

below:

None of the licensee's

operating

procedures

provided guidance to the operators

on pond icing (Observation

93-201-05).

During January

1993, the spray

ponds

iced over heavily.

Approximately SOX of the pond surfaces

were frozen with

thicknesses

estimated to be

up to

5 inches thick.

The inspectors

requested

the licensee

to consider the need for clear operator guidance

on what degree

of icing was acceptable,

and what actions

should

be taken if that icing limit

was approached.

As a result of the team's

questions,

the licensee

issued

Problem Evaluation

Request

(PER)

293-140

on February

5,

1993.

The licensee

concluded that pond

icing up to 5 inches in thickness

was acceptable

based

on the successful

operation of the system

on January ll, 1993 when the pond had

a solid covering

of ice up to 5 inches.

The return flow broke through the ice within 20

seconds.

The licensee corrective actions described

in the

PER include

revising the plant procedures

to provide operator guidance for icing and to

evaluate the effects of ice on operability, including the effect of the ice on

the seismic qualification of the steel

support structures for the spray nozzle

rings.

The evaluations

are scheduled

to be completed

by November

1,

1993,

preceding

the next expected

cold weather period.

The licensee

issued

a procedure

change,

Procedure

Deviation Form

(PDF)93-167

to

PPM 2.4.5,

on February

10,

1993 for the

operating procedure,

instruct-

ing the operator to monitor ice build up and contact the system engineer if

the pond freezes

over.

9.2

Valve line-up program

The team examined

the licensee's

valve lineup program including independent

verification, the locked valve program,

and the throttled valve program.

The

examination consisted of a review of the licensee's

valve line up procedures;

20

4'i

f*

~ f

I f

1

a review of records;

discussions

with operations

managers,

licensed

operators

and non-licensed

operators;

and

a walk down of portions of the system with an

operator verifying valve positions.

The licensee's

programs

were generally

sound

and met technical specification requirements.

The team observed

two areas

which were of concern.

There were insufficient instructions for setting the throttle valves for the

control

room ventilation cooling coils.

For a January

7,

1993

SSW valve line-

up specified

by

PPH 7.4.7. 1. l. 1,

"Standby Service Mater Loop A Valve Position

Verification", Section 7.2 of the procedure

requires

the flow to the control

room ventilation cooling coils be set to 120-125

gpm.

However, this flow is

established

by setting

two parallel throttle valves,

SW-V-104D and SW-V-106D,

which throttle flow to two parallel cooling coils.

The flow is read

by a

single flow meter,

SW-FI-35A, which is in a common return line from two branch

lines from the two throttle valves.

A similar condition exists for the

Loop

B

procedure

and valves.

The procedures

did not describe

how the flow split

should

be established.

Discussions

with operations

managers

and shift

personnel

showed that several different opinions existed

as to how the two

.valves should

be positioned to provide equal flow to the two coils.

The team

concluded the instructions

were insufficient.

The licensee

subsequently

issued

procedure

changes,

Procedure

Deviation Forms93-175

and 93-176,

on February 8,

1993, to revise the instructions to open

both valves

an equal

number of turns.

Additionally, the licensee

issued

an

interoffice memorandum

dated

February

11,

1993, to the Plant Technical

Services

Nanager which evaluated

the as-found condition of the control

room

cooling coils.

The estimated

flow imbalance

involved 80 gpm in one coil and

40 gpm in the other coil.

The licensee's

analysis

found the effects of this

imbalance

on control

room cooling to be small

and well within design limits.

The effect of the imbalance resulted in a 0.3'F increase

in the temperature

of

the air leaving the coils.

The team noted errors

made in the valve line up completed

on June

17, 1992 for

the

SSW system.

The errors all involved valves

SW-V-168B and

SW-V-169B which

are small vent valves

on the

B pond side of the large

A pond to

B pond siphon

line.

The errors consisted of:

The valve positioner initialed the valve line up sheet verifying that

the valves were shut.

However,

the valves were inaccessible

under water

at the time of the valve line up.

The valve position verifier annotated

the valve line up sheet with a

note that stated

"Valves removed

and line is capped".

The valves were,

in fact, not removed at the time of the valve lineup.

The shift manager

accepted

the valve line up and,

on June

17,

1992,

signed the system line up deviation sheet

which stated

"Valve removed,

line capped,

need

H524/1 print correction".

The shift manager did not

initiate

a drawing change

request for the

assumed error indicated

by his

21

note nor did he initiate a procedure revision request for the checklist

discrepancies

as required

by the plant startup

procedure

PPH 3. 1. 1

"Haster Startup Checklist".

The failure to perform the valve lineup verification of valves

SW-V-168B and

SW-V-169B is identified as Deficiency 93-201-02 in Appendix A to the report.

The team did not consider this

an immediate operability concern

as the

licensee

was able to provide evidence that the valves were closed

as required.

(See Deficiency 93-201-02 for details).

PPH 2.4.5,

"Standby Service Water System",

Attachment 6. 1 provided the normal

valve line up for the system

and required valves

SW-V-171A and SW-V-171B,the

spray header drain valves to be open.

The cold weather procedure,

Section 5.6

of PPH 2.4.5,

ends with the valves in a closed position.

This potential

confusion

was identified to the licensee.

The licensee

subsequently

issued

a procedure

change,

Procedure

Deviation

Form

93-167,

dated

February 8,

1993,

which changed

the normal position of the drain

valves to closed in normal weather

and open in cold weather.

The team

.identified the change to require additional operator actions not required

by

the original procedure.

Previously the header

was maintained

in a drained

condition in normal weather.

With the change,

the header will be maintained

full.

The full header will require operators

to be more alert to cold weather

conditions,

and to drain the header

when the temperature

drops.

The previous

normally drained condition was, therefore,

less susceptible

to operator error.

In addition, the full header

may introduce

new corrosion or nozzle plugging

problems.

The licensee

stated

they were considering

a change to remove the

valves or provide

a drainage

hole in the spray header.

9.3

Conduct of Operations

The team walked through selected

portions of procedures,

observed

a

SSW system

start,

and examined

pond level control

and makeup.

The team found that the

conduct of operations

was generally

sound.

The walk through

was conducted with an equipment operator,

a non-licensed

position.

The equipment operator

performs rounds,

performs valve

and breaker

lineups,

and operates

equipment.

The inspector

examined portions of PPH

7.4.7. 1. 1. 1,

"Standby Service

Water Loop A Valve Position Verification", and

PPH 2.4.5,

"Standby Service Mater System",

Section 5.2,

"Haimtaining Spray

Pond Level."

The equipment operator

demonstrated

familiarity with the

component locations,

was able to go directly to the applicable

components

selected

by the inspector

and was familiar with the procedures

and drawings

involved.

The team observed

a

SSW system start.

The control

room staff conducted

the

start at the request of the team to demonstrate

that the problem of system

water

hammer

had

been eliminated.

The team members

were stationed

at several

locations for the test.

The locations included the control

room, the higher

elevations of the reactor building near the residual

heat

removal

heat

exchangers,

and in the

pump house.

The operators

started

the system in

accordance

with their procedures.

Command,

control

and communications

22

I

'lg,j~ ~

,$4

appeared

to be good.

The system start resulted in a large

number of distract-

ing alarms.

The alarms

were expected

by the operators

and were considered

nuisance

alarms.

Operators

properly assessed

each

alarm both

on the front and

back panels

and acknowledged

them.

The results of the test were that water

hammer

was not observed.

The operators

properly secured

the system in

accordance their procedures.

Discussions

with several

operators

and equipment

operators

indicated that water

hammer

had not been

a problem for several

years

since the valve opening

sequence

had

been modified.

The team examined the cause

and status of the system startup nuisance

alarms;

The alarms

were due to the long time required for the

SSW system to achieve

operating pressure

due to the valve opening

sequence

and the large size of the

system.

The alarms

show up at components

served

by the

SSW system,

such

as

the diesel generators.

The alarms are, for instance,

"Loss of SSW flow".

The

problem of the nuisance

alarms

had

been identified by the licensee

in 1989 in

PER 289-0785.

The licensee

had prepared

a plant modification to install time

delays in the alarm circuits to eliminate the nuisance

alarms.

The modifica-

tion was

on the licensee's

schedule for accomplishment

in fiscal year

1994.

The team

had

no further questions

regarding the alarms.

The pond level control procedures

and methods

were discussed

with plant

personnel.

The makeup

system to the ponds is tapped off the Tower Hake

Up

(THU) system

which is the makeup

system for the non-safety circulating water

system for the main condensers.

This feature provides certain operating

strengths

in that the

THU is run constantly

and is not

a standby

system.

Therefore,

problems

such

as intake blockage would be noted

as they occurred

and would not be

a dormant problem revealed

only on system

demand.

9.4

Operator training

The team examined the licensee's

training program

as it applied to the

system.

The training for licensed

and non-licensed

operators

was examined

through discussion with a licensee training specialist,

review of training

manuals,

lesson

plans,

and training schedules.

The inspector also examined

the licensee's

training for plant modifications.

The team generally found the

training program adequately

addressed

the

SSW system.

Documentation

examined

included:

I

the

SSW chapter of the general training manual,

82-RSY-1404-T3,

October

1989

the "License Training System Descriptions,"

82-RSY-1405-T3,

January

1992

the lesson

guide for licensed operator

and Shift Technical Advisor (STA)

training, 82-RSY-1404-L3,

February

27

1992

the lesson

plan for non-licensed

operators,

82-EOS-0402-LP,

July 28,

1992

other lesson

plans applicable to equipment operators

from earlier years

23

I)

\\

II

In general,

the licensee's

program for SSW training met regulatory require-

ments.

The licensee

had regular simulator training,

about six times per year

per crew,

and regular post-outage

training on modifications, including service

water modifications.

10.0

SYSTEH WALK-DOWN

The team conducted

an in-depth walkdown of large portions of the

SSW system

and the spray ponds.

The walkdown was conducted with non-licensed

operators,

with a shift support supervisor,

and by unaccompanied

NRC inspectors.

The

inspectors

observed

valve positions, electrical

breaker positions,

the

presence

of locks

on locked valves,

the presence

of lead seals

on sealed

throttle valves, material condition of the system

and machinery spaces,

heat

trace operation,

valve labeling, flow rates to components,

control

room switch

positions,

alarms

and annunciators,

and

system

components

in operation.

The

inspectors

made the following observations:

A room cooler was located in the overhead

and

was difficult (required

a

ladder

and climbing) to access.

Nonetheless,

the cooling coils were

clean.

~

Temporary thermocouples

were installed at several

heat exchanger

locations to improve the performance

assessment

capability of the heat

exchangers.

~

Each of the many large

and small

SSW heat exchangers

was provided with a

flow indication device,

a valuable

system feature

from an operations

standpoint.

The majority of piping runs in the reactor building were unpainted

and

had experienced light corrosion.

The corrosion at flange fasteners

was

more severe

but had not yet produced significant stud wastage.

Without

attention,

the condition could eventually

become significant (Observa-

tion 93-201-06).

On the other hand the piping in the diesel

generator

rooms

had

been painted

and appeared

to be in much better condition.

During

SSW system operation,

the spray

pond return flow header valve

SW-

V-165B was properly shut with the spray nozzles

in operation,

but was

leaking at about 50-100

gpm.

This is

a large butterfly valve that is

used to bypass

the spray nozzles in cold weather.

Excess

bypass flow,

in warm weather could be

a problem.

The inspector inquired whether

a

maintenance

work request

(HWR) had

been submitted.

The licensee

determined that

an

HWR had not been submitted,

and consequently

generat-

ed HWR-AP-2337 describing the leak.

The leakage

was assessed

by

engineering

as described

in an interoffice memorandum

dated

February

11,

1993, to the manager of plant technical

services.

The assessment

concluded

the leakage

was not significant from an operability standpoint

I

yJ

and would result in an increase of maximum pond temperature of only

0.2'F.

The team considered this action to be adequate.

The team's

examination of the

HWR database

showed that the plant staff had not been

reluctant to write HWR's on the valve in the past.

~

Scaffolding was installed in both

RHR heat exchanger

rooms

on an

apparently

permanent

basis

(Observation

93-201-07).

Scaffolding is

ordinarily a temporary installation for a short duration job.

Per

discussion with the operator,

the scaffolding had

been installed since

startup

and

was used in a monthly surveillance

procedure.

The proce-

dure,

PPH 7.4.5. 1. 1,

"LPCS,

HPCS,

and

LPCI Fill Verification," requires

monthly venting from the top of the

RHR heat exchangers

to verify that

the system is full.

The scaffolding is necessary

to reach the high

point vent valves.

The team noted that the need for continuing operator

access

usually is met by providing permanent

ladders

and platforms

through

a design

change.

~

The spray

pond return header piping in spray

pond

B was heavily corroded

at the location where it exits the

B pumphouse

and transits

the spray

pond.

The piping at this location is horizontal

and is partially

submerged

in the pond water.

The heavy corrosion occurred at the

waterline which is subjected

to wetting and drying cycles.

The corro-

sion scale

was visually estimated

to be I/O inch.

The team

was con-

cerned that minimum wall thickness

might be affected

and discussed

the

observation with plant management.

The licensee

wrote

PER 293-150 to

address

the concern.

The

PER resolution stated that the corrosion

was

acceptable

based

on the observations

of the engineer in the opposite

pond when it was drained in 1992.

The observations

of heavy scale

on

structural

members at the waterline

showed very little thickness

reduction

when cleaned.

In addition, the

PER stated that the piping

design

allowed for a generous

corrosion allowance.

The

PER also stated

that the piping would be inspected

when the pond was drained during the

upcoming outage

in the spring of 1993.

The team considered

the

PER

evaluation to be adequate.

The

18 inch diameter

handwheel for Limitorque actuator

SW-MO-70B

appeared

to be oversized.

Since this valve could only be manually

operated,

the team

was concerned that excessive

torque could be applied

with the larger

handwheel

which could damage

the actuator.

Vendor

information from the actuator manufacturer

(Limitorque') specifically

prohibits the use of cheaters

to increase

handwheel

torque.

The

licensee initiated

PER 293-145 which determined that the oversized

handwheel

was acceptable

and

had apparently existed since construction.

The licensee initiated

a drawing change to identify the as-built

configuration.

The team found the licensee

actions

adequate.

11.0

CORRECTIVE ACTIONS

In their February

5,

1990 response

to Action III of GL 89-13, the licensee

identified that corrective actions

would be taken for indications of fouling

25

't

k)

t5

in the heat exchangers

of the service water system.

Routine corrective

maintenance

would be accomplished

through the use of maintenance

work requests

(MWRs).

The inspector

reviewed the licensee's

corrective actions for

deficiencies

identified in MWRs for the service water system for the past

two years,

and

the findings from the licensee's

Safety

Systems

Functional

Inspection

(SSFI)

of the service water system conducted

in December,

1990.

Recent audits

conducted

by the guality Assurance

department

and minutes of the onsite

and

offsite safety review groups

were also reviewed.

The purpose of this review

was to assess

the timeliness

and technical

adequacy of the licensee's

resolu-

tion of the deficiencies.

The licensee

s self-assessments

were corn'prehensive.

Substantive

findings were identified during their SSFI

and

gA audits.

Identified deficiencies

were generally adequately

resolved except for three

specific instances

of inadequate

corrective action which were noted

by the

inspection

team.

The licensee

had not resolved deficiencies previously identified in the

cathodic protection for the service water system.

The operational

status of

.the active cathodic protection

system

had

been identified as indeterminate

during the SSFI.

In the licensee's

disposition of the SSFI finding, the

existing system

was considered

unnecessary,

and

no corrective action was taken

pending engineering

evaluation.

During the

NRC inspection,

as

a result of the

team's questioning,

the licensee

determined that the installed cathodic

protection

system

was necessary

for the protection of buried piping from

corrosive attack.

The licensee initiated Problem Evaluation Request

PER-293-

152 to establish

corrective actions to restore

and maintain the system's

functional capability.

The non-conservative initial disposition

and untimely

engineering

evaluation of the SSFI finding was considered

a deficiency

and is

identified as Deficiency Number 93-201-03 in Appendix A to the report.

gA Audit 91-555,

dated

October

24,

1991,

was

an annual

audit of the licensee's

environmental

and effluent monitoring

performed

by the licensee's

Corporate

Licensing

and Assurance

group.

The audit identified that procedures

had not

been established

for the biofouling monitoring program.

The licensee

had

initiated

a guality Finding Report to address

the lack of procedures

for the

program.

At the time of the

NRC inspection,

procedures still had not been

established

for the licensee's

biofouling program.

The inspector

found the

lack of formal documentation

to be

a weakness

(Observation

93-201-08).

The licensee

had also not adequately

resolved

an apparent

common

mode defi-

ciency identified in the operation of motor operated

valves

(MOVs) in both

trains of the service water system.

The licensee

had identified that the loop

isolation valves

SW-V-12A/B repeatedly

hammered

when closing.

The control

logic for these

valves includes

a continuous

close

demand signal

which is

present

even after the valve has closed.

Due to apparent

relaxation of the

spring pack in the Limitorque actuator after closing, the torque switch (which

normally opens to stop motor operation at valve closure)

can again close.

Because of the ever-present

close

demand signal,

the actuator restarts

26

unexpectedly

and attempts to further close the already closed valve.

This

results in a short stroke

hammering of the valve disk into the seat.

The

licensee

had not determined

the cause of the repeated

relaxation of the spring

pack.

The licensee's

lack of corrective actions to preclude recurrence

of hammering

of SW-V-12A/B is identified as Deficiency Number 93-201-04 in Appendix A to

the report.

27

~

A

C

t

APPENDIX A

SUMMARY OF

INSPECTION FINDINGS

DEFICIENCY NUMBER 93-201-01

FINDING TITLE:

Inadequate

Evaluation of Spray

Pond Chemistry

(Section 7.0)

ESCRIPTION

OF CONDITION:

The

150

ppm sulfur limit in

PPM 1. 13. 1 was established

by Inter-Office Memo

SS2-PE-92-524

from materials

and welding dated

June

23,

1992 in order to

minimize the potential of stress

corrosion cracking in the stainless

steel

tubing of RHR heat exchangers

in the

SSW system.

The limit of 150

ppm of

sulfur was set at

a conservative

level

based

upon various research efforts.

Bulab 6003,

which is used to control the biofouling in the

SSW system,

contains sulfur.

Due to the biofouling problems

experienced this past

summer,

an extensive

amount of Bulab 6003

was

added to the spray ponds.

Water samples

were taken from the spray

ponds

by the Plant Support Chemistry Laboratory

after the addition of Bulab 6003 starting in September

1991.

The team found

that the sulfur concentration

in the Standby Service

Water

(SSW)

system

had

been at or above the

150

ppm control limit of sulfur since

September

1992

and

had reached

levels

as high as

183

ppm.

Although the sulfur limit was exceed-

ed, the licensee

could not discharge

into the plant blowdown line before

30

days elapsed

from the last Bulab application

due to the Energy Facility Site

Evaluation Council regulation.

The licensee failed to issue

a

PER when the

sulfur limit was exceeded

and only did so when this matter

was highlighted by

the team.

The

PER stated that even though the sulfur excursion

exceeds

the

current limit, there should

be

no detrimental effects to the heat exchanger

tubing based

upon

a review of the technical

basis for the limits.

C

DEFICIENCY NUMBER 93-201-02

~FEPIE

TITLE:

FIT

t

p

I

lt

pf

I

Ittp

dure (Section 9.2)

ESCRI PTION 0

CONDITION:

The following errors

made in the valve line up completed

on June

17, 1992 for

the

SSW system involved valves

SW-V-168B and SW-V-169B, which are small vent

valves

on the

B pond side of the large

A pond to

B pond siphon line.

~

The valve positioner initialed the valve line up sheet verifying that

the valves were shut.

However, the valves were inaccessible

under water

at the time of the valve line up.

The valve position verifier annotated

the valve line up sheet with a

note that stated

"Valves removed

and line is capped".

He did not

initial the sheet.

The valves were, in fact, not removed at the time of

the valve line up.

The shift manager

accepted

the valve line up and,

on June

17,

1992,

signed the system line up deviation sheet

which stated

"Valve removed,

line capped,

need

M524/1 print correction"

M524/1 is the piping and

instrumentation

diagram for the

SSW system.

The shift manager did not

initiate a drawing change

request for the

assumed

error indicate4

by his

note nor did he initiate

a procedure revision request for the checklist

discrepancies

as required

by the plant startup

procedure

PPM 3. 1.1

"Master Startup Checklist".

During the system walk down the team noted that the two vent valves were under

water and were very heavily rusted to the point of being probably inoperable.

The errors identified above represented

the last valve line up record.

The

team could not obtain

any valve line up verification that the valves were

properly positioned.

Licensee

management

indicated that the valves

had last

been positioned during startup,

around

1983, but that valve lineup records

were not kept for more than three years.

The team asked the licensee

to

verify that the safety function of the siphon line was not impaired.

The position of the vent valves is important in an accident

scenario

assuming

SSW design basis criteria.

The vent valves are

used to vent the air out of

the pond cross

connect

siphon line during pond filling. After pond filling,

the vent valve should

be shut to keep air out of the siphon line should

pond

level drop below the siphon line horizontal run.

The siphon line will not

work if it becomes air bound.

The accident

scenario

assumes

no makeup water

is available to the

pond for 30 days.

The inventory of both ponds is suffi-

cient to meet this criteria;

however,

the siphon must work to transfer

inventory from one

pond to the other.

Problem Evaluation

Request

(PER)

293-129

was written on February 4,

1993 to

address

the inspectors

concerns.

The licensee

concluded that the siphon line

was operable

based

on observations

made in the

summer of 1992 when the

A pond

was drained

and cleaned.

During that time, the siphon line was plugged

on the

A-2

~

A

l

r

water filled 8 pond side.

The

A pond was dry.

The system engineer stated

that

he observed that

no water was flowing from the siphon line on the

A pond

side.

If the vent line (underwater

on the

8 pond side)

was open, water would

be expected

to continuously flow into the dry A pond side.

The team consid-

ered this evaluation for siphon line operability to be adequate.

A-3

~

4

'V

DEFICIENCY NUMBER 93-201-03

KIIICICCTITLT:

I dd

PIT -dd

Ctddt

P t tt

ddt

C

(Section

11.0)

DESCRIPTION

OF CONDITION:

The operational

status of the active cathodic protection

system

had

been

identified as indeterminate

during the SSFI.

In the licensee's

disposition of

the SSFI finding, the existing system

was considered

unnecessary,

and

no

corrective action

was taken

pending engineering

evaluation.

During the

NRC

inspection,

the licensee

determined that the installed cathodic protection

system

was necessary

for the protection of buried piping from corrosive

attack.

The licensee initiated Problem Evaluation

Request

PER-293-152 to

establish

corrective actions to restore

and maintain the system's

functional

capability.

The inspector

found the licensee's

corrective actions to be technically

adequate.

The non-conservative initial disposition

and untimely engineering

>valuation of the

SSFI finding was considered

a deficiency.

k

C

~ 0

J

V

v

j

0

DEFICIENCY NUMBER 93-201-04

~IMOIN

T iLE:

F ii

t

h

i

9 f

1

EII-V-12A/B

(Section

11.0)

ESCRIPTION

OF CONDIT 0:

The inspector

found that the licensee

had not adequately

resolved

an apparent

common

mode deficiency identified in the operation of motor operated

valves

(MOVs) in both trains of the service water system.

In May of 1991, the

licensee

had identified in PER 291-359 that the loop isolation valves

SW-V-

12A/8 repeatedly

hammered

when closing.

The control logic for thes'e

valves

includes

a continuous

close

demand signal

which is present

even after the

valve has closed.

Due to apparent relaxation of the spring pack in the

Limitorque actuator after closing, the torque switch (which normally opens to

stop motor operation at valve closure)

can again close.

Because of the ever-

present

close

demand signal,

the actuator restarts

unexpectedly

and attempts

to further close the already closed valve.

This results in a short stroke

hammering of the valve disk into the seat.

The licensee

had not determined

-the cause of the repeated

relaxation of the spring pack.

However, the

licensee

considered

the hammering to be acceptable if not occurring more than-

six times per hour.

The licensee

based this limit on the duty cycle of the

motor.

The licensee's

disposition stated that no valve damage

would result

from continued

hammering

because

the torque switch limited the closing forces.

The inspector

found that the licensee

had not adequately

evaluated

the

potential overthrust condition resulting from the repeated

hammering.

Instances

of excessive

operational

loads

and valve damage

had

been identified

as the result of hammering in NRC Information Notice 85-20.

Vendor informa-

tion from the actuator manufacturer

(Limitorque) had also identified the

deficiency

and corrective actions.

In response

to the inspector's

concern,

the licensee initiated

a Problem Evaluation

Request to evaluate

the potential

damage to the valve.

During the inspection,

the licensee

reviewed data from

tests

conducted

in April, 1991,

which displayed

up to seven

hammering events.

The licensee

determined that

a

IOX increase

in closing thrust could be

attributed to the hammering.

The licensee

concluded the effects of hammering

could

be tolerated within the capability of the valve and actuator.

In

addition, at the request of the inspector,

the licensee

monitored motor

current for SW-V-12A/B to determine if hammering

were continuing undetected

after operation of the valve.

No hammering of either valve SW-V-12A/B was

observed

during the hour following closure.

Despite the fact that the valves did not exhibit hammering

when monitored,

the

inspector

was concerned that the potential for hammering

had not been elimi-

nated

and that the effects of continued

hammering

were not well known.

The

inspector noted that the

1991 diagnostic signature for the valves

showed that

the spring pack continued to relax after the valve stopped

hammering,

indicat-

ing

a potential

for spurious

hammering to occur.

In response

to the inspect-

or's concerns,

the licensee

indicated that both valves

SW-V-12A/B would be

disassembled

and inspected

during the next outage to determine the root cause

of the problem.

A-5

'\\

WO f

,J

The inspector

reviewed licensee

procedure

10.25. 132, Revision 3, "Thrust

Adjustment

and Diagnostic Analysis of Hotor Operated

Valves."

Paragraph

4.22

identified that hammering

may damage

the valve.

It further stated,

in part,

"Ensure that switches

and relays

are operated

and control logic has sufficient

contacts to open the circuit to prevent valve hammer... Inform Engineering if a

valve hammers."

In addition, the inspector

reviewed licensee

procedure

10.25.74,

Revision 8, "Testing Hotor Operated

Valve Hoto} s and Controls."

Paragraph

4.5 identified that hammering would eventually overthrust

and

damage

the valve.

It further stated,

in part,

"Contact the System Engineer to

address this condition if it exists."

Despite these

procedural

warnings,

the

licensee

had not taken corrective actions to preclude

recurrence of hammering

of SW-V-12A/B.

The inspector reviewed the design basis calculation NE-02-90-17 for the sizing

of the actuator

and found that the actuator did not appear to have adequate

capability under worst case

design basis conditions to perform its safety

function to open.

Under degraded

voltage conditions

and worst case

stem

lubrication conditions,

the rated pullout capability of the actuator

was

calculated to be 27232 lbs.

The force to unseat

valves

SW-V-12 A/B had

been

measured

under static test conditions to be 28701

and 31370 lbs.

The licensee

identified that the

maximum actuator torque

had not been

exceeded

during

pullout at the higher unseating

loads

because

of good stem lubrication.

The

licensee

concluded that the sizing of the actuator

was adequate

to assure

capability under design basis conditions

assuming

good stem lubrication.

However, since the pullout force also increases

due to hammering,

the inspec-

tor was concerned that the actuators

may not be able to unseat

the valve disk

to open the valve.

A-6

APPENDIX 8

LIST OF OBSERVATIONS

Observation

Number

93-201-01

93-201-02

93-201-03

93-201-04

93-201-05

e ort Para ra

h

3.3

3.5

6.1

7.0

9.1

~it~1

Improperly Stored

Crane in

Pumphouse.

Potential

Freezing of Spray

Tree Arms

Failure to Include Instrument

Accuracies

In Position

Verification Procedures.

Lack of Procedure for

Performing Intake Inspection

Inadequate

Spray

Pond Icing

Guidance

93-201-06

93-201-07

93-201-08

10.0

11.0

SWS Piping Corrosion

Permanently Installed

Scaffolding in

RHR Pump

Room

Inadequate

Procedures

for

Biofouling Program

APPENDIX

C

EXIT MEETING ATTENDEES

uclear

Re ulator

Commission

Paul Narbut

David Pereira

Vonna Ordaz

Eugene

V. Imbro

Jeffrey B. Jacobson

Christopher

Hyers

Lew Miller

R.

C. Barr

J.

W. Clifford

Ann. Dummer

Steven

Jones

WNP-2

.J.

D. Arbuckle

R. L. Koenigs

J.

V. Parrish

A. L. Oxsen

Phil Harness

Rod Webring

Jack Baker

James

C. Gearhart

Larry Harrold

Gregory 0 Smith

Alan Hosier

Ron Barbee

Stan Davison

Tom Hoyle

Carl Fies

J.

E.

Rhoads

LL Grumme

John

Dabney

William H. Sawyer

Clyde R. Noyes

Dennis

H. Hyers

Dan Becker

Curtis Moore

J.

S.

Flood

Paul

Inserra

Douglas

L. Williams

Inspector,

RV

Inspector,

RV

Reactor Engineer Intern,

Chief, Special

Inspection

Branch,

Team Leader,

Inspector,

Region

V

Chief, Reactor Safety,

Region

V

Senior Resident

Inspector,

RV

Senior Project Manager,

Mechanical

Engineer,

Mechanical

Engineer,