Information Notice 1996-68, Incorrect Effective Diaphragm Area Values in Vendor Manual Result in Potential Failure of Pneumatic Diaphragm Actuators

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Incorrect Effective Diaphragm Area Values in Vendor Manual Result in Potential Failure of Pneumatic Diaphragm Actuators
ML031050477
Person / Time
Site: Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, Mcguire, Nine Mile Point, Palisades, Palo Verde, Perry, Indian Point, Fermi, Kewaunee, Catawba, Harris, Wolf Creek, Saint Lucie, Point Beach, Oyster Creek, Watts Bar, Hope Creek, Grand Gulf, Cooper, Sequoyah, Byron, Pilgrim, Arkansas Nuclear, Three Mile Island, Braidwood, Susquehanna, Summer, Prairie Island, Columbia, Seabrook, Brunswick, Surry, Limerick, North Anna, Turkey Point, River Bend, Vermont Yankee, Crystal River, Haddam Neck, Ginna, Diablo Canyon, Callaway, Vogtle, Waterford, Duane Arnold, Farley, Robinson, Clinton, South Texas, San Onofre, Cook, Comanche Peak, Yankee Rowe, Maine Yankee, Quad Cities, Humboldt Bay, La Crosse, Big Rock Point, Rancho Seco, Zion, Midland, Bellefonte, Fort Calhoun, FitzPatrick, McGuire, LaSalle, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant  Entergy icon.png
Issue date: 12/19/1995
From: Martin T
Office of Nuclear Reactor Regulation
To:
References
IN-96-068, NUDOCS 9612160116
Download: ML031050477 (8)


UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555-0001 December 19, 1996 NRC INFORMATION NOTICE 96-68: INCORRECT EFFECTIVE DIAPHRAGM AREA

VALUES IN VENDOR MANUAL RESULT IN

POTENTIAL FAILURE OF PNEUMATIC DIAPHRAGM

ACTUATORS

Addressees

All holders of operating licenses or construction permits for nuclear power reactors.

Purpose

The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice to alert

addressees to the fact that some vendors have published incorrect values for effective

diaphragm area for some spring-type pneumatic diaphragm actuators and that use of these

incorrect values may result in safety-related air-operated valves not fully closing under design

basis conditions. It is expected that recipients will review the information for applicability to

their facilities and consider actions, as appropriate, to avoid similar problems. However, suggestions contained in this information notice are not NRC requirements; therefore, no

specific action or written response is required.

Description of Circumstances

On October 4, 1996, Commonwealth Edison, licensee for the LaSalle County Station, issued

a notification puisuant to 10 CFR Part 21 (Accession No. 9610080102). The notification

identified the deficiency as incorrect values for the effective diaphragm areas, as published

by the original and current valve vendors, for certain models of pneumatic actuators.

The original valve vendor, Black, Sivalls, and Bryson (13S&B), was later purchased by

WKM Valve Division of ACF Industries, then by Muesco, and by Anchor/Darling Valve

Company. The affected model of actuator is the Model 70-13 pneumatic diaphragm actuator, sizes 35, 70, 140, and 280. The size refers to the published diaphragm area in square

inches. The affected actuators are either direct acting (extends the valve stem when air

pressure is applied) or reverse acting (retracts the stem when air is applied) spring return

actuators.

The Part 21 notification included an attachment providing a Nuclear Plant Reliability Data

System (NPRDS) listing of valves of the applicable model number by plant; however, the

listing may not include all of the applicable valves and may include valves that are not safety

related or that are not required to isolate as are the primary containment isolation

9612160116 `l

D _,_j A

IN 96-68 December 19, 1996 valves at the LaSalle County Station. Some of the valves listed are not diaphragm actuated

valves and the identification of some items is incomplete. The present manufacturer, Anchor/Darling Valve Company, was unable to compile a complete listing of the actuator

applications because purchase order records from the original vendor are unavailable.

Discussion

The licensee found discrepancies in the bench set values of the actuators during the LaSalle

County Station refueling outage that took place from February through April 1996. The

published bench set and the actual bench set values, indicated from testing by the plant

mechanics, were inconsistent. "Bench set" refers to the amount of preload and final

compression force placed on the actuator spring so that the applied spring force on loss of

air will achieve the required travel of the valve stem. Bench set adjustments are made by

applying air pressure to the actuator in accordance with the manufacturer's published values

and adjusting the spring compressive force by means of an adjusting screw to achieve the

desired relationship between air pressure and valve stem travel. When performing bench set

testing, incomplete valve stroke is typically indicative of a stiffer-than-expected spring.

However, testing by the licensee indicated that the springs were within manufacturer's

tolerances and additional testing with a known spring force, a known air supply pressure, and

a known load indicated that the actual effective diaphragm area, which relates to the force

opposing the spring as well as to the compression of the spring for proper preloading, was

less than the published values.

Anchor/Darling Valve Company was contacted by the licensee and performed a series of

tests to determine the actual effective diaphragm area. These tests indicated that the actual

diaphragm areas of the various sizes of the Model 70-13 actuators were approximately

90 percent of the published values. Further testing by the licensee uncovered a contributing

problem that further reduced the effective diaphram area. The diaphragm case consists of

two halves bolted together. Generally one half is deeper than the other. It was discovered

that reverse-acting actuators assembled with a deep upper half caused unintended stretching

of the diaphragm within the casing.

The licensee determined that the primary containment isolation valves would have closed at

the design-basis-accident containment pressure of 40 pounds per square inch; however, many of the valves may not have been properly set up to close against the normally higher

system pressure under some operating conditions. That is, the valves may not have closed

under the highest expected differential pressure of the contained system fluid. Further details

of the concern are in Licensee Event Report 50-373/96-011, dated October 28, 1996, (Accession No. 9611010277).

The licensee determined which valves at the LaSalle County Station were affected and was

able to properly adjust the actuators to account for the discrepancies between the published

values for the diaphragm area and the actual diaphragm area by (1) adjusting the bench set

on the spring to achieve the required closing force and (2) reversing the diaphragm casings

so that the deeper part of the casing was installed on the bottom with the shallower part of

the casing installed on top to prevent the diaphragm from stretching.

IN 96-68 December 19, 1996 The licensee has not identified similar problems on actuators made by other manufacturers, but licensees should be aware of the concern when testing and making adjustments to the

bench set of pneumatic actuators. The proper setup of these actuators is especially

important when the attached valve is used for isolation in a safety-related application.

Licensees may wish to review their valves and actuators for applicability of this information.

This information notice requires no specific action or written response. If you have any

questions about the information in this notice, please contact one of the technical contacts

listed below or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager.

Thomas T. Martin, Director

Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical contacts: Patricia Campbell, NRR

(301) 415-1311 E-mail: plcenrc.gov

David Skeen, NRR

(301) 415-1174 E-mail: dIsenrc.gov

Andrew Dunlop, Rill

(630) 829-9726 E-mail: axd7@nrc.gov

Attachment: List of Recently Issued NRC Information Notices

my b tC~ -I-h

Attachment

IN 96-68 December 19, 1996 LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Information Date of

Notice No. Subject Issuance Issued to

96-67 Vulnerability of Emergency 12/19/96 All holders of OLs

Diesel Generators to Fuel or CPs for nuclear

Oil/Lubricating Oil Incom- power reactors

patibility

96-66 Recent Misadministrations 12/13/96 All U.S. Nuclear

Caused by Incorrect Cali- Regulatory Commission

brations of Strontium-90 Medical Use Licensees

Eye Applicators authorized to use

strontium-90 (Sr-90)

eye applicators

96-65 Undetected Accumulation 12/11/96 All holders of OLs

of Gas in Reactor Coolant or CPs for nuclear

System and Inaccurate power reactors

Reactor Water Level

Indication During Shutdown

96-64 Modifications to Con- 12/10/96 All holders of OLs

tainment Blowout Panels or CPs for nuclear

Without Appropriate reactors

Design Controls

96-63 Potential Safety Issue 12/05/96 All U.S. Nuclear

Regarding the Shipment Regulatory Commission

of Fissile Material licensees authorized

to possess special

nuclear material in

unsealed quantities

greater than a critical

mass

96-62 Potential Failure of the 11/20/96 All holders of OLs

Instantaneous Trip Function and CPs for nuclear

of General Electric RMS-9 power plants

Programmers

OL = Operating License

CP = Construction Permit

IN 96-68 December 19, 1996 The licensee has not identified similar problems on actuators made by other manufacturers, but licensees should be aware of the concern when testing and making adjustments to the

bench set of pneumatic actuators. The proper setup of these actuators is especially

important when the attached valve is used for isolation in a safety-related application.

Licensees may wish to review their valves and actuators for applicability of this information.

This information notice requires no specific action or written response. If you have any

questions about the information in this notice, please contact one of the technical contacts

listed below or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager.

signed by

Thomas T. Martin, Director

Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical contacts: Patricia Campbell, NRR

(301) 415-1311 E-mail: plc@nrc.gov

David Skeen, NRR

(301) 415-1174 E-mail: dls@nrc.gov

Andrew Dunlop, Rill

(630) 829-9726 E-mail: axd7@nrc.gov

Attachment: List of Recently Issued NRC Information Notices

Tech Editor has reviewed and concurred on 11/08/96

  • SEE PREVIOUS CONCURRENCES

DOCUMENT NAME: 96-68.IN

To receive a copy of this document, indicate In the box: 'C' = Copy w/o

attachmentlenclosure 'E' = Copy w/attachment/enclosure 'N' = No copy

OFFICE TECH CONTS C/PECB:DRPM D/DRPM,,,----

NAME PCampbell* AChaffee TMa/n

DSkeen*

ADunlop*

DATE 12/05/96 12/12/96 12/II/96 OFFICIAL RECORD COPY

OFFICIAL RECORD COPY

IN 96-XX

December XX, 1996 The licensee has not identified similar problems on actuators made by other manufacturers, but licensees should be aware of the concern when testing and making adjustments to the

bench set of pneumatic actuators. The proper setup of these actuators is especially

important when the attached valve is used for isolation in a safety-related application.

Licensees may wish to review their valves and actuators for applicability of this information.

This information notice requires no specific action or written response. If you have any

questions about the information in this notice, please contact one of the technical contacts

listed below or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager.

Thomas T. Martin, Director

Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical contacts: Patricia Campbell, NRR

(301) 415-1311 E-mail: plc@nrc.gov

David Skeen, NRR

(301) 415-1174 E-mail: dls@nrc.gov

Andrew Dunlop, RIII

(630) 829-9726 E-mail: axd7@nrc.gov

Attachment: List of Recently Issued NRC Information Notices

OFC J PECB:DRPM Region IlIl EMEB:DE C/EMEB:DE C/PECB:DRPM

NAME DSkeen* ADunlop* PCampbell* RWessman* AChaffee &

DATE__ 12/05/96 J11/27/96 111/21/96 11/22/96 112/96 Ho~

-

OFC ID/DRPM I /44 NAME TMartin

DATE 112/ /96

[OFFICIAL RECORD COPY]

DOCUMENT NAME: G:XDLS\IN96-AOV.EDA

  • SEE PREVIOUS CONCURRENCE

IN 96-XX

December XX, 1996 The licensee has not identified similar problems on actuators made by other manufacturers, but licensees should be aware of the concern when testing and making adjustments to the

bench set of pneumatic actuators. The proper setup of these actuators is especially/

important when the attached valve is used for isolation in a safety-related application.

Licensees may wish to review their valves and actuators for applicability of this

information.

This information notice requires no specific action or written response. If you ye any

questions about the information in this notice, please contact one of the tec 6ical contacts

listed below or the appropriate Office of Nuclear Reactor Regulation (NRR) roject manager.

Thomas T. Martin, Dire or

Division of Reactor Pr gram Management

Office of Nuclear R ctor Regulation

Technical contacts: Patricia Campbell, NRR

(301) 415-1311 E-mail: plc@nrc.gov

David Skeen, NRR

(301) 415-1174 E-mail: dls@nrc.gov

Andrew Dunlop, Rill

(630) 829-9726 E-mail: axd7@nrc.g

Attachment: List of Recently Iss d NRC Information Notices

OFC PECB:DRPM 1 IIon II EMEB:DE C/EMEB:DE C/PECB:DRPM

NAME D. Ske P. Campbell R. Wessman A. Chaffee

DATE j/AI5196 ' / 1,4t96 Ii/I,21/96 1/tf C96 f / /96 OFC I D/DRPM/

NAME _T. rtin

DATE l //96

[OFFICIAL/RECORD COPY]

DOCUMNT NAME: IN96-AOV.EDA

IN 96-XX

November XX, 1996 The licensee has not identified similar problems on actuators made by other manufacturers, but licensees should be aware of the concern when testing and making adjustments to the

bench set of pneumatic actuators. The proper setup of these actuators is especially

important when the attached valve is used for isolation in a safety-related application.

Licensees may wish to review their valves and actuators for applicability of this

information.

This information notice requires no specific action or written response. If you have any

questions about the information in this notice, please contact one of the technical contacts

listed below or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager.

Thomas T. Martin, Director

Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical contacts: Patricia Campbell, NRR

(301) 415-1311 E-mail: plc@nrc.gov

David Skeen, NRR

(301) 415-1174 E-mail: dls@nrc.gov

Andrew Dunlop, Rill

(630) 829-9726 E-mail: axd7@nrc.gov

Attachment: List of Recently Issued NRC Information Notices

OFC PECB:DRPM Region III EMEB:Dt--, C/EMEB:DE C/PECB:DRPM

NAME D. Skee A.Dun14A IP. Campbell R. W A. Chaffee

DATE // a/296 i /A796 VI' II 0//96 I 7N96 / /96 OFC I D/DRPM

NAME T. Martin

DATE / /96

[OFFICIAL RECORD COPY]

DOCUMENT NAME: IN96-AOV.EDA