Text

Insp Repts 50-295/87-24 & 50-304/87-25 on 870914-18.One Open Item Noted.Major Areas Inspected:Check Valve Testing Program,Check Valve Location,Check Valve Maint & Failure History & Response to INPO Event Rept 86-3
	ML20150C328
Person / Time
Site:	Zion File:ZionSolutions icon.png
Issue date:	02/09/1988
From:	Baker E; Office of Nuclear Reactor Regulation
To:	;
Shared Package
ML20150C327	List: ML20150C323; ML20150C328;
References
	50-295-87-24, 50-304-87-25, GL-87-06, GL-87-6, NUDOCS 8803180121
	Download: ML20150C328 (11)
	v • d • e

-

__

'

. .

,

.

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

Report Nos.: 50-295/8/024; 50-304/87025'

Docket Nos.: 50-295; 50-304

Licensee Nos.: DPR-39; DPR-48

Licensee: Comonwealth Edison Company

P. O. Box 769

Chicago, Illinois 60690

Facility: Zion Nuclear Power Station, Units 1 and 2

Inspection At: Zion, Illinois

Dates: September 14-18, 1987

Inspectors:

E. T. Baker, Team Leader Program Develo Fient Date

and Reactive Inspection Section (PDRIS)

R. N. Moist, PDRIS

A. S. Hasciantonio, Mechanical Engineering Branch

l J. H. Goodale, Consultant

Approved By.- b

E. J. Baker, Acting Chief, PDRIS, Vendor

N

Date"

P#

Inspection Branch

Inspection Sumary: Inspection on September 14-18,1987(ReportNos.50-295/

87024;50-304/87025)

l Areas Inspe'cted: Special, announced inspection of the check valve testing pro-

l gram, check valve location, check valve maintenance and failure history, and the

l response to the Institute of Nuclear Power Operations' (INPO) Significant Opera-

l ting Event Report (SOER) 86-3.

l Results: The findings of this inspection were that (1) pressure isolation

valves are not being tested individually as required by an NRC confirmatory

order issued February 29,1980;(2) valve testing does not ensure that all

safety functions will be fulfilled; (3) test procedures do not result in

I valid tests of all valves listed as being tested; and (4) valves failing leak

l

1

l

l $$8 *$8$$k $$0$h9y5

o

i _. _ . _ . . _ _ _ _ _ . . , _ _ _ _ . _ _ _ . . _ , _

_._. -

_ _ _ _ . _ __

'

. .

.

rate testing are not being repaired before restart contrary to connitments

made in a June 11, 1987 response to Generic Letter 87-06. The reason given for

not repairing the valves before restart was that spare parts were not available.

In addition, it was noted that the majority of valves inspected for location

were located close to sources of turbulence and that the vast majority of the

maintenance performed was corrective, as opposed to preventive.

With regard to your response to SOER 86-3, the inspectors considered it the

furthest along in terms of implementation and consideration of design aspects

of the four programs reviewed. It was apparent that Commonwealth Edison is

aggressively developing a program to address the issues raised in SOER 86-3.

No response is required to this inspection report. Unresolved Items 295/87032-

01 and 304/87033-01, issued under Region III inspection reports 50-295/87032 and

50-304/87033, cover findings 1, 3, and 4. Finding 2 (0 pen Items 50-295/87024-01

and50-304/87025-01) is considered open and will be referred to the Mechanical

Engineering Branch for followup during review of your latest Inservice Testing

Program submittal. Although the procedures and valves reviewed by the team

were specific to Unit 2, the findings are considered programmatic and based on

discussions with your staff are considered applicable to Unit 1.

1

l

1

l

.

l

-2-

_ _ _ _ _ _

_

i

-

. . l

.

-

DETAILS

1. PERSONS CONTACTED

E. Fuerst, Superintendent, Production -

T. Rieck, Superintendent, Service

W. Kurth, Assistant Station Superintendent, Operations

R. Budowle, Assistant Station Superintendent, Technical Services

J. Gilmore, Assistant Station Superintendent, Planning

C. Schultz, Regulatory Assurance Administrator l

L. Holden, Regulatory Assurance, Engineer

T. Printz, Assistant Technical Staff Supervisor

L. Laspisa, Assistant Technical Staff Supervisor l

J. Reiss, PWRE Field Engineering Supervisor '

,

R. Cole, PWR Engineer

S. Petrowski, Maintenance i

J. Tiennann, Primary Group Leader, Technical Staff

M. Madigan, Inservice Testing Coordinator

B. Soares, Inservice Testing Coordinator

G. Olson, Quality Assurance

M. Holzmer Senior Resident Inspector, NRC

P. Eng, Resident Inspector, NRC

The inspectors also spoke with other licensee personnel during the inspection.

Indicates those persons not present at the exit interview conducted on

September 18, 1987.

2. SCOPE

The inspection included valves in the auxiliary feedwater, component cooling,

chemical and volume control, diesel airstart, diesel cooling, feedwater, main

steam, residual heat removal, safety injection, and service water systems.

Review of maintenance and failure history was limited to maintenance and fail-

ure data that existed in the computerized data base; that data base contained

data for ab,out the last three years.

3. REVIEW 0F CHECK VALVES

3.1 Auxiliary Feedwater Turbine Steam Supply

Check valves 2MS-0006 and 2MS-0007 are located in the redundant auxiliary feedwater

(AFW) pump turbine steam supply headers. The valves are presently tested for

passing flow during the pump test under test procedure PT-7. The valves are

not tested for closure, although it appears that the valves' primary safety func-

tion is to isolate the redundant steam supply headers in the event of a steam

line break. Otherwise, failure of the valves to close could result in the loss

of the turbine-driven pump (0 pen Items 295/87924-01and304/87025-01). These

valves are included in the SOER response and may receive additional attention.

-3-

I

B

E

.

The maintenance history in the computerized data base did not contain any records

on these valves. Additionally, these valves were not inspected for location.

3.2 Auxiliary Feedwater System

Check valves 2FW-0031, 2FW-0032, and 2FW-0033 are the AFW pump discharge check

valves and valves 2FW-0066, 2FW-0067, 2FW-0068, and 2FW-0069 are the AFW header

to feedwater isolation valves. These valves are not included in the existing

valve testing program, but are tested for passing flow during the pump tests

performed using pump functional test procedure PT-7 (0 pen Items 295/87024-01

and 304/87025-01). Valves 2FW-0031, 2FW-0032, and 2FW-0033 do prevent reverse

flow or short-circuit flow when any pump is idle and as such should be tested

for closure. The forward flow ' testing of valves 2FW-0066, 2FW-0067, 2FW-0068,

and 2FW-0069 provides no indication of valve condition. If one of these valves

were to stick open, there would be no indication of it unless 2FW-0031, 2FW-0032,

or 2FW-0033 were also defective. These valves are included in the scope of the

SOER response and may receive additional attention in the future.

A review of the maintenance history in the computerized data base indicates

that valves 2FW-0033, 2FW-0066, 2FW-0067, and 2FW-0069 were removed, rebuilt,

and reinstalled between 1985 and the present as corrective maintenance.

Valves 2FW-0031, 2FW-0032, and 2FW-0033 were inspected for location and were

installed imediately downstream of the AFW pump discharge.

3.3 Component Cooling System

3.3.1 Valves 2CC-9463A, 2CC-9463B, and OCC-9464 are the component cooling

pump discharge check valves. These valves are tested for passing flow under

procedure TSS 15.6.106; however, there are no provisions for testing if the

valves close or not. These valves were inspected for location and were instal-

led imediately downstream of a 90-degree elbow and an isolation valve. There

was no history of any maintenance on these valves in the computerized data base.

3.3.2 Valves 20C-9500 and 200-9486 appear to be containment isolation valves;

however, neither valve is included in any test program. The valves are normally

open and are shown to pass flow during normal operations; however, there is no

test to show,the valves close on cessation or reversal of flow (0 pen Items

295/87024-01 and 304/87025-01). The function of these valves is being re-

evaluated to determine if they should be included in the IST program. These

valves were not inspected for location and no history of any maintenance on

these valves was found in the computerized data base.

3.4 Chemical and Volume Control System

3.4.1 Check valves 2VC-8401, 2VC-8481A, and 2VC-8481B are the charging pump

discharge check valves. The check valve on the positive displacement pump (PDP)

is imediately downstream of the pump discharge and a tee. The check valves on

the centrifugal pumps are located imediately downstream of the pump discharge

and two 90-degree elbows and immediately upstream of another 90-degree elbow.

-4-

. .

.

, ,

-

.

'

Valves 2VC-8481A and 2VC-8481B are forward flow tested under pump test procedure

PT-21. No test is perfonned to ensure that these normally open valves close

on cessation or reversal of flow (0 pen Items 295/87024-01and304/87025-01).

The PDP is not being run; therefore, discharge check valve 2VC8401 is not

included in the IST Program and is not being te,sted. A review of the mainten-

ance history in the computerized data base indicated that no maintenance has

been performed on these valves.

3.4.2 Check valves 2VC-8542A and 2VC-8542B are located in the pump minimum flow

lines. These valves are tested for partial disk lift under procedure TSS 15.6.89.

There is no current testing to show that the valves return to their seats on

cessation or reversal of flow (.0 pen Items 295/87024-01and304/82025-01). A

review of the maintenance history in the computerized data base indicated that

no work has been performed on these valves. The valves were not inspected for

location. These valves are being reviewed under the 50ER response.

3.5 DIESEL AIR SYSTEM

'

Check valves ODG-0025, ODG-0026, 2DG-0033, 2DG-0034, 2DG-0035, and 2DG-0036 are

located between the air receiver tanks and the diesel air starters. Two tir

receiver tanks for each diesel feed into a commcn header. The valves are

located 2 feet downstream of 90-degree elbows and 1 foot upstream of a tee.

The valves isolate the air receiver tanks from one another in the event of e.

rupture. One valve on each diesel is disassembled and inspected each refueling

outage under procedure TSS 15.6.20V-4. A review of the maintenance history in

the computerized data base indicated that the internals of check valve 2DG-0035

were replaced because the valve leaked.

3.6 DIESEL COOLING SYSTEM

Check valves ODG-0002, 1DG-0003, IDG-0004, 2DG-0003, and 2DG-0004 are located

downstream of the diesel engine's jacket water circulating pump and check valves

00G-0004, IDG-0007, IDG-0008, 20G-0007, and 20G-0008 are located downstream of

the engine-driven jacket water pump. None of the valves are included in any

testing program. Zion's technical staff stated that if any of the valves were

seriously degraded, the operators would detect a rise in the diesel engine's

operating temperature. The fact that the diesel engines do not overheat i

indicates that the valves are not restricting flow, but does not indicate

valve integ'rity (0 pen Items 295/87024-01and304/87025-01). There was no

record in the computerized data base that any maintenance had been performed

on these valves. Valves 1DG-0003 and 1DG-0007 were inspected for location.

Valve 1DG-0003 is located between two 90-degree elbows. Valve 1DG-0007 is

located immediately downstream of a 90-degree elbow. The inspectors were told

that the locations of these valves are representative of location of the other

valves.

4

-5-

.

. .

.

. 3.7 FEEDWATER SYSTEM

3.7.1 Check valves 2FW-0023, 2FW-0025, and 2FW-0027 are the feedwater pump discharge

check valves. The valves are located immediately downstream of the pump discharge

and immediately upstream of the isolation shutoff valves. These valves are not

included in any test program; however, one of the valves is scheduled to be in-

spected internally using fiberoptic techniques once every five years. Check

valve 2FW-0023 was inspected in July 1987, but without the benefit of a procedure

or acceptance criteria. In addition, no record of the examination existed.

Zion staff personnel indicated that in the future, a VT-1 inspection will be

conducted by an inspector qualified to perform the inspection, and the results

will be recorded and maintained by the system engineer.

3.7.2 Check valves 2FW-0005, 2FW-0006, and 2FW-0007 are the normally open feed-

water header isolation valves. These valves are the boundary between the

safety-related portion of the feedwater piping and the piping that is not

safety-related. These valves are not included under any testing program, but

are shown to be open during nonnal operation (0 pen Items 295/87024-01 and 304/

87025-01). These valves would prevent blowdown of the steam generator if the

feedwater pipe ruptured. They also prevent water supplied by the AFW system

from flowing back into the feedwater piping and thereby reducing flow to the

steam generator. These valves are included in the SOER response and may

receive additional attention. These valves were not inspected for location

and no records of maintenance activity were found in the computerized data base.

3.8 MAIN STEAM SYSTEM

Check valves 2MS-0008, 2MS-0009, 2MS-0010, and 2MS-0011 are the main steam isolation

check valves. These valves are currently tested using forward flow during normal

operation as an indicator that the valve is open and leak testing in the reverse

l direction as an indication of valve closure and degradation. A review of the

computerized, maintenance data base indicates that on May 8, 1986, check valve

IMS-0004 was found degraded. As a result, the licensee comitted to a compre-

hensive testing program and developed a procedure for testing the valves, TSS

15.6.107. Testing under this procedure detected degradation of a Unit 2 main

steam isolation check valve. All of Unit 2's main steam isolation check valves

were refurbished during the July 1987 outage. These valves were inspected for

location and.were found to be imediately downstream of the main steam isolation

valves. -

3.9 RESIDUAL HEAT REMOVAL

3.9.1 Check valves 2RH-8730A and 2RH-87308 are the residual heat removal (RHR)

pump discharge check valves. The licensee stated that these check valves are

only required to be exercised in the open, fomard flow direction. Full open

position is verified by measuring the flow through the valves per procedure

TSS 15.6.85.

-6-

. _ _ _ .

..

. .

,

.

1

-

Presently no tests are being performed to assure that the valves close. The

valves must close to prevent back flow through an idle RHR pump. The utility

responded to this concern by stating that test procedures for all valves that i

communicate through a common header will be reevaluated. These valves were not !

inspected for location and no records of maintenance activity were found in the l

computerized data base.

'

-

,

3.9.2 Check valves 2RH-8949A, 2RH-89498, 2RH-8736A, and 2RH-8736B are the

l

pressure isolation valves between the reactor coolant system (RCS) and the

lower pressure RHR system for the hot-leg injection lines. These valves were l

,

'

not inspected for location and no records of maintenance activity were found ,

in the computerized data base , l

Reaching the fully open position is presently verified using TSS 15.6.85 by

measuring flow through the connon supply line upstream of these valves. Indi-

vidual flow through these valves cannot be measured; only total flow can be

determined. The utility stated that the IST Program will be revised to measure

l the individual flow in each line. l

1

l

l Valve closure is presently verified by measuring backflow leakage per procedure

l

PT-2P. The backflow leakage through 2RH-8736A and 2RH-8736B is measured individu-

ally under Section III of PT-2P using the safety injection (SI) pumps to create

the backflow. The SI pumps generally develop 1500-1550 psig. In tests performed

on July 30, 1987, test pressure was measured as 1900 psig, with a leak rate of

4.8 gallons per minute (gpm). In tests perfonned on July 29, 1987, test pressure I

was measured as 2235 psig, with a leak rate of 9.5 gpm. In tests perfomed on )

,

March 29, 1987, test pressure was measured as 1800 psig, with a leak rate of I

1

4.7 gpm. In tests perfomed on July 17, 1986, test pressure was measured as !

1840 psig, with a leak rate of 4.7 gpm. In tests performed on June 27, 1986, 1

test pressure measured 1500 psig, but leakage was not measured because it was I

not required to be measured unless there was a pressure buildup after a five- l

minute waiting period. Pressure did not rise above 1500 psig after the waiting

i

period, so no leakage was measured. However, the pressure gauge was reading SI

i pump discharge pressure. Therefore, either 2RH-8736A or 2RH-87268 or both were

l 1eaking. But the test procedure, as written, did not require measuring the leak

l rate because the valves leaked badly enough that pressure had built up to the

capacity of the SI pump in less than five minutes.

InthecaseilistedabovewheretestpressureexceededthecapacityoftheSI

pump (1500 psig), valves 2RH-8949A and 2RH-8949B, which are downstream of 2RH-

8736A and 2RH-8736B, must have been leaking reactor coolant at least as much

as the leakage measured through 2RH-8736A and 2RH-8736B in order for the higher

pressures to be maintained during testing.

I Leakage through valves 2RH-8949A and 2RH-8949B is measured in combination with

leakage from other valves under Sections I and II of PT-2P. Only when the col-

l 1ective leakage exceeds 5 gpm are these valves individually tested. If the

l 5-gpm criterion is exceeded during testing under Section I, the valves are indi-

! vidua11y tested under procedure PT-2M. If the 5-gpm criterion is exceeded dur-

ing testing under Section II, the valves are individually tested under procedure

l PT-2N. Because of time constraints, neither of these procedures was reviewed

l in detail.

l

1

-7-

i

I

.

. .

.

-

3.9.3 Check valves 2SI-8957A, 2SI-89578, 2SI-9002A, 2SI-9002B, 2SI-9002C, and

251-90020 are the pressure isolation valves between the SI system and RHR system

and beueen the RCS and RHR system for the cold-leg injection lines. These

valves were not inspected for location and no records of maintenance activity

were found in the computerized data base. ,

Valves 2SI-8957A and 2SI-8957B are exercised to the fully open position using

TSS 15.6.85, with individual flow measurements as the acceptance criteria. The

valves are not tested for closure.

Valves 2SI-9002A, 2SI-9002B, 2SI-9002C, and 251-90020 are exercised to the fully

open position using TSS 15.6.85., with flow through the common supply line upstream

of each pair of valves being the acceptance criteria. The acceptance values are

presented in a graph included in the procedure. This method of determining flow

through each valve is presently unoer review. These valves are leak tested in

combination with other valves under Section II of PT-2P and are tested in pairs

under Section IV of PT-2P. The testing performed under Section II of PT-2P is

not considered valid because pressure is equalized on both sides of the valve.

The testing perfonned under Section IV of PT-2P, testing valves in parallel, is

being reviewed during the current IST Program review.

Under Section IV of PT-2P, the SI pumps supply the flow that causes the valves

to seat. The discharge pressure of the SI pumps ranges from 1500-1550 psig.

In tests perfonned on July 30, 1987 on valves 2SI-9002A and 2SI-9002B, test

pressure was measured as 2150 psig, with a leak rate of 4.8 gpm and valves 2SI-

9002C and 2SI-9002B experienced a pressure of 1700 psig, with a leak rate of 4.9

gpm. In tests performed on July 29, 1987, valves 2SI-9002A and 2SI-9002B

experienced a pressure of 2235 psig, with a leak rate of 9.5 gpm and valves

251-9002C and 2SI-9002D experienced a pressure of 1550 psig, with a leak rate

l of 9.5 gpm. In tests perfonned on March 28, 1987, valves 2SI-9002A and 2SI-

9002B experienced a pressure of 1650, with a leak rate of 5.5 a m, and valves

l

2SI-9002C and 2SI-9002D experienced a pressure of 1560 psig, with a leak rate

'

of 5.5 gpm. In tests perfonned on July 13, 1986, valves 2SI-9002A and 2SI-9002B

experienced a pressure of 1800 psig, with a leak rate of 5 gpm, and valves 2SI-

9002C and 2SI-9002D experienced a pressure of 1500 psig, with a leak rate of

4.8 gpm. In tests perfonned on June 27, 1986, it is not possible to tell what

,

occurred because the pressure and flow rate blocks are marked "NA No Buildup."

l As occurred with valves 2RH-8726A and 2RH-8736B tested on this same day, it

appears thal; the valves leaked badly enough that the pressure reached the maxi-

mum capacity of the SI pumps before exceeding the 5-minute waiting period and

no pressure buildup occurred thereafter, so no measurements were taken.

l 3.10 SAFETY INJECTION

3.10.1 Check valves 2SI-8922A and 2SI-8922B are the SI pump discharge check

valves. These valves are forward flow tested under TSS 15.6.85, but are .

not tested for closure. Water flows from the pump discharge through a reducer

and a 90-degree elbow, through the check valve, into isolation valves and a

second set of 90-degree elbows.

-8-

- -_ . _ - - . _ -.

. ,

~.

. 3.10.2 Valves 2SI-9032, 2SI-8900A, 2SI-89008, 2SI-8900C, and 251-89000 are in

the boron injection tank cold-leg injection flow path, between the charging pumps

and the RCS. The valves are forward flow tested under TSS 15.6.84 and are

not reverse flow leak tested. Valves 2SI-8900B and 2SI-8900C were determined

to be leaking backwards and work requests were issued on July 28, 1987 and

July 2,1987, respectively, to repair the valves. No other maintenance

l activities were recorded in the computerized data base. These valves were not

inspected for location.

'

3.10.3 Valves 2SI-8905A and 2SI-8905B are located in the hot-leg SI flow path

for RCS loops A and D. These valves are exercised using forward flow under

TSS 15.6.84 and are leak tested in combination with other valves under Section I

of PT-2P. However, the tests i'n Section I result in pressure being equalized

on both sides of the valves and, therefore, those are not valid tests. These

check valves would have to perform the pressure isolation function, if valve

2SI-9011A were opened inadvertently. These valves were not inspected for

location and no records of maintenance activity were found in the computerized

data base.

3.10.4 Valves 2SI-9004C, 2SI-9004D, 2SI-8949C, and 2SI-8949D are located in the

hot-leg SI flow path for RCS loops B and C. These valves are exercised using

forward flow under TSS 15.6.84 and are leak tested under Section I of PT-2P,

in combination with other valves. Because of the testing configuration,

pressure is equalized on both sides of valves 2SI-9004C and 2SI-9004D and the

! leak test is not considered a valid test. These valves were not inspected for

'

location and no records of maintenance were found in the computerized data base.

3.10.5 Check valves 2SI-9001A, 2SI-9001B, 251-9001C, 2SI-9001D, 2SI-9012A,

2SI-9012B, 2S1-9012C, and 2SI-9012D are the pressure isolation valves between

the RCS and SI system. The 9012 series valves are exercised using forward flow

i under TSS 15.6.85 and are leak tested under Section I of PT-2P, in combination

l with other Valves. However, because of the test configuration, pressure is

'

equalized on both sides of the valves and, therefore, the leak test is not

considered valid. The 9001 series valves are exercised using forward flow under

TSS 15.6.84 and leak tested under Sections I and II of PT-2P. These valves were

not inspected for location and no records of maintenance activity were found in

the computerized data base.

3.11SERVICIWATERSYSTEM

3.11.1 Check valves 2SW-0001, 2SW-0004, and 25W-0007 are the service water pump

discharge check valves. According to procedure TSS 15.6.108, proper disk lift

i

of the discharge valves is verified by ensuring that the pump discharge pressures

of the three punips are within 4 psig of each other. A discharge pressure differ-

ence of approximately 4 psig indicates that one of the valves may not be fully

open and is acting as a flow restriction. Proper clasure is indicated by an

-g-

-___- _ __ - _ _

.' .

.

. . audible closing of the valve when the pump is secured and by a zero pressure

reading on the local pump discharge pressure gauge.

The criteria used to determine disk lift and valve closure are not adequate.

The valves could be equally degraded and the discharge pressure for the indiv-

idual pumps would still be within the 4-psig requirement. Proper closure can-

not be assured simply by an audible signal from the disk impacting the valve

seat. Also, the physical arrangement of the check valve, in relation to the

pump discharge, would require extremely large backflow leakage through the

valve in order to measure any pressure at the pump discharge. The acceptabil-

ity of this test method will be reviewed during the IST Prognm review (0 pen

items 295/87024-01and304/87025-01).

These valves were located close to sources of turbulence. No records of main-

tenance activity were found in the computerized data base.

3.11.2 Check valves 2SW-0010 and 2SW-0011 are the service water header dis-

charge check valves to all the diesel generator heat exchanges (i.e., inter-

cooler, jacket water, lubricating oil, and af tercooler). The acceptance

criterion for required disk lift is defined in procedure TSS 15.6.97 as the

discharge water temperature being less than 180 F. This acceptance criterion

only indicates that adequate system cooling is available and does not verify

that each valve has opened fully. This acceptance criterion will be reviewed

during the IST Program review (0 pen Items 295/87024-01 and 304/87025-01).

Individual valve closure is verified by measuring the leakage through each

valve at least once every five years.

These valves are located close to sources of turbulence. The computerized

data base contained a record that valve 2SW-0010 had been opened for inspec-

tion and the "disk holder hanger" had been replaced.

3.12 SOER RESPONSE

Comonwealth Edison (CECO) corporate staff had developed an internal program

in response to SOER 86-3. The program required that a list of check valves be

developed for the systems listed in the SOER; maintenance history files for the

valves be generated and reviewed; valve locations be determined; check valve

design and application be reviewed, including valve size, valve type, flow

velocities, operating temperatures and pressures; and, finally, that recommenda-

tions be developed for increased maintenance, inspection, or design changes,

as necessary. The program appears to include all the aspects discussed in the

SOER. At the time of the inspection, this program had been implemented at Zion

to the extent that the affected valves had been identified (281 valves at Zion

Units 1 and 2), 40 valves in Unit 2 had been inspected for location, and the

licensee had started to collect data on critical, minimum, and maximum flow

velocities. A format and data base for storing and analyzing the information

had also been developed. CECO intends to compare the results of its analyses

with the recomendations contained in the application guidelines being developed

by the Electric Power Research Institute. Based on the results of the analyses

and the review on the failure histories, recomendations will be made to make

design changes, revise inspection and test procedures, and perform preventive

maintenance, as necessary.

Based on these observations, it was apparent that Comonwealth Edison is aggres-

sively developing a program to address the issues raised in SOER 86-3. However,

-10-

_ ._

.

,

.

- .,

.-

'

because of the problems discovered in current testing procedures implementing

the inservice testing program at Zion, the staff is concerned about the ability

of the technical staff at individual' plants to develop adequate and effective

procedures to implement enhanced mainter.ance, testing or inspection resulting

from the 50ER work. ,

.

h

e

-11-

- - , _ . - - - - . - - , _ - . - . - . . . .. . _ - . -__ -._. . . . - _ _ .. _ _ _ _ - _ _ . _ _ _ - ,

ML20150C328

Text

Navigation menu

Search