Information Notice 1990-11, Maintenance Deficiency Associated with Solenoid-Operated Valves

Maintenance Deficiency Associated with Solenoid-Operated Valves

ML031210595
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, 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, 05000000, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant, Crane
Issue date:	02/28/1990
From:	Rossi C Office of Nuclear Reactor Regulation
To:
References
IN-90-011, NUDOCS 9002230283
Download: ML031210595 (4)

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555

February 28, 1990

NRC INFORMATION NOTICE NO. 90-11:

MAINTENANCE DEFICIENCY ASSOCIATED

WITH SOLENOID-OPERATED VALVES

Addressees

All holders of operating licenses or construction permits for nuclear power

reactors.

Purpose

This Information notice is intended to alert addressees to a potential problem

resulting from improper maintenance that may affect the operability of main steam- line isolation valves (MSIVs), main steamline relief valves (MSRVs) or similarly

designed components.

The problem relates to solenoid-operated valves (SOts) that

may not have been properly maintained or tested after maintenance. It is expected

that recipients will review the information for applicability to their facilities

and consider actions, as appropriate, to avoid similar problems. However, sug- gestions contained in this information notice do not constitute NRC requirements;

therefore, no specific action or written response is required.

Description of Circumstances

During an inspection at Automatic Valve Corporation (AVC) in Novi, Michigan, the NRC staff learned that a nuclear power plant licensee may have performed

improper maintenance on SOVs, possibly by using an obsolete set of instructions.

AVC manufactures pneumatic control assemblies (PCAs) that are assembled on

actuators (manufactured by others) which in turn operate safety-related valves.

An evaluation of this situation led to the discovery of a failure mechanism for

SOVs that had not been considered previously. The NRC staff determined that

updated maintenance instructions consistent with current replacement parts

design were not provided to all users of these SOVs.

As a result, AVC sent a.

letter dated February 1, 1990, to utilities known to use SOVs supplied directly

by AVC, Atwood & Morrill and Target Rock (valve manufacturers that use solenoids

supplied by AVC), and General Electric (a nuclear steam system supplier that

supplied original equipment or subsequent parts for MSIVs and MSRVs). This

letter alerted organizations that received SOVs from AVC of the design change

and potential problem which could be caused by not using the proper tool; the

letter also provided a copy of the current maintenance instructions. AVC

obtains SOVs from a subtler supplier and may either incorporate them in an

AVC PCA, or provide only the SOVs.

9002230283

IN 90-11 February 28, 1990 Discussion:

The PCA directs air to the actuator to operate MSIVs and MSRVs. Multiple SOYs

in the PCA are arranged in a design such that with a single failure involving

one of the SOVs, the MSIVs and MSRVs are to go to or remain in the preferred

position following the single failure.

However, a single failure-was discovered

that could prevent an MSIV from achieving the preferred position; an MSRV would

remain closed, but would not be able to be opened. Even though the following

discussion is limited to MSIVs, it applies in an analogous manner to the MSRVs.

Therefore, the problem should not be considered to be limited to MSIVs.

In one design arrangement for an MSIV, the PCA has two SOVs controlling air

to and from a four-way air valve which in turn directs motive air under a

piston operator to open the MSIV or on top of the piston to drive the MSIV

closed.

Should one of the two SOVs mechanically bind in the energized

position, the four-way air valve cannot be moved; therefore, the MSIV would

fail to close when required, even though the other SOV was in the proper

(de-energized) position.

Mechanical binding was found to be a reasonable and potential possibility

because interchangeable parts with a different design were provided to

licensees without concurrent notification that a revised installation and

maintenance procedure should be followed. In the original design, "flats"

were used as a means of exerting a force to screw two metal pieces together.

The new design- required a- spanner- wrench. -Use-of--liers-or-v-ise-grips-tas __

designated in the earlier procedure) on a thin walled guide tube could deform

the tube and prevent a plunger actuated by the solenoid from moving freely.

inside the tube. It was reported that pliers or vise-grips may have been

used at one utility during either-disassembly or assembly of an SOY.

Sticking of the plunger within the guide tube (another binding mechanism) can

also occur without deformation of the tube if an improper lubricant is used.

Lubricants, as well as other materials, have been known to become sticky, cause

other problems and prevent proper operation of an SOV after extended time in a

high-temperature or excessive radiation environment. For example, Super 0 Lube, which is usually used by AYC in their valves, as well as by Ralph.A. Hiller in

their pneumatic/hydraulic operators, will begin to solidify after exposure to

a radiation dose of about 1.9 MegaRads. Another lubricant, Houghton 620, used

in qualification testing, has been subsequently identified by the manufacturer

as "Non-compatible" with unanodized aluminum, the material used in AVC PCAs.

There has been no unanimity as to which lubricant to use or its service life.

Lubricant and some of its effects are discussed in Information Notice 88-43,

"Solenoid Valve Problems," dated June 23, 1988.

IN 90-11 February 28, 1990 Gross damage or failures caused by the use of improper maintenance procedures

should be detected during post maintenance testing.

However, less than gross

damage might only cause the SOV to operate in a sporadic and unpredictable

manner. This is particularly true because not all PCAs are installed with the

same orientation (e.g., vertical versus horizontal) or in the same environment

(e.g., temperature, radiation field, and humidity). A review by the NRC staff

of plant equipment failure and maintenance records shows that not all licensees

adequately evaluate or compare actual service conditions with those intended or

used to qualify these components.

A review may be required of the-purchase documentation for MSIVs and MSRVs, along with any replacement parts, to establish whether licensees have the

potential for the above-described failure mechanism.

Because of the nature

of the control assembly used on MSIVs and MSRVs, several different vendors

and suppliers are involved in the manufacture, assembly, and procurement of

the PCA.

Therefore, licensees may not readily recognize the vendor mentioned

in this information notice as a supplier of a portion of one of their safety- related components.

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 NRR project

manager.

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

Technical Contacts: J. Carter, NRR

(301) 492-1194

H. Ornstein, AEOD

(301) 492-4439

K. Naidu, NRR

(301) 492-0980

Attachment:

List of Recently Issued NRC Information Notices

Attachment

IN 90-1l

Februsty 28, 1990 LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Date of

InTorAatron

Notice No.

90-10

90-09

88-30,

Supp. 1

90-08

88-23, Supp. 2

90-07

90-06

90-05

.

.

SubJect

Primary Water Stress

Corrosion Cracking (PWSCC)

of Inconel 600

Extended Interim Storage of

Low-Level Radioactive Waste

by Fuel Cycle and Materltls

Licensees

Target Rock Two-Stage SRY

Setpoint Drift Update

Kr-85 Hazards from Decayed

Fuel

Potential for Gas Binding

of High-Pressure Safety

Injection Pumps During a

Loss-of-Coolant Accident

New Information ReIarding

Insulation Material

Performance and Debris

Blockage of PMR Contain- ment Sumps

Potential for Loss of

Shutdown Coollng While

at Low Reactor Coolant

Levels

Inter-Syste- Di scharge -of

Reactor Coolant

Issuance

2/23/90

Issued to

All holders of OLE

or CPs for PWRs.

All holders of NRC

materials licenses.

215/90

2/2/90

All holders of OLs

or CPs for nuclear

power reactors.

2/1/90

All holdersof OLs

or CPs for nuclear

power reactors and

holders of licenses

for permanently shut- down facilities with

fuel on site.

1/31/90

All holders of OLs

or CPs for PWRs.

1/30/90

All holders of OLs

or CPs for nuclear

power reactors.

1/29/90

All holders of OLs

or CPs for nuclear

power reactors.

1I29190--

bATTI-lers of OLs

or CPs for nuclear

power reactors.

OL

• Operating License

CP

• Construction Permit

UNITED STATES

NUCLEAR REGULATORY COMMISSION

WASHINGTON, D.C. 20555

OFFICIAL BUSINESS

PENALTY FOR PRIVATE USE, S300

FIRST CLASS MAIL

POSTAGE

• FEES PAID

USNRC

PERMIT No. 0-67 DC

20555