Information Notice 1999-07, Failed Fire Protection Deluge Valves & Potential Testing Deficiencies in Preaction Sprinkler Systems

Failed Fire Protection Deluge Valves & Potential Testing Deficiencies in Preaction Sprinkler Systems

ML031040487
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
Issue date:	03/22/1999
From:	Matthews D Division of Regulatory Improvement Programs
To:
References
IN-99-007, NUDOCS 9903180104
Download: ML031040487 (7)

UNITED STATES NUCLEAR REGULATORY

COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555-0001 March 22, 1999 NRC INFORMATION

NOTICE 99-07: FAILED FIRE PROTECTION

DELUGE VALVES AND POTENTIAL

TESTING DEFICIENCIES

IN PREACTION SPRINKLER

SYSTEMS

Addressees

All NRC licensees.

Purvose The U.S. Nuclear Regulatory

Commission (NRC) is issuing this information

notice (IN) to alert addressees

to test methodologies

for fire protection

deluge valves that may not adequately

demonstrate

valve operability.

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.Backaround

Valves for sprinkler

system automatic

control (SSAC) are used In fire protection

systems that protect areas housing both safety-related

and non-safety-related

equipment

used for fire safe shutdown (FSSD). Many of these systems are used to provide primary fire protection

and to meet the requirements

of 10 CFR Part 50, Appendix R, Section III.G. Poor design, deficient maintenance, or inadequate

testing of SSAC valves and associated

solenoid valves can lead to a common-mode

failure of the valves to perform their design function of providing

adequate and reliable fire protection.

This, in turn, can result In fire damage to safe shutdown equipment

in the event of a fire.The Model A-4 Multimatic

Valve manufactured

by Grinnell Is a deluge valve designed specifically

for use In fire protection

systems. It Is used as a system control valve in deluge, preaction, and special types of fire protection

systems and may also provide for actuation

of fire alarms when the systems operate.Preaction

valves contain connections

for monitoring

pressure In the diaphragm

chamber and in the main water supply, for providing

valve drainage and for supplying

water to the diaphragm chamber. All required components

for these connections

are typically

supplied by the valve manufacturer

as "trim packages'

and are included as part of the Underwriters

Laboratories, Inc., (UL) and Factory Mutual, Inc., (FM) certifications

of the valves.plt ec' dor i w q9.qojOX 5p03;L ,A/ark Tok 1 K>~K-)IN 99-07 March 22, 1999 Description

of Circumstances

In the week of March 4, 1996, during surveillance

testing of preaction

sprinkler

systems in the Farley Unit I fire protection

system, 5 of 11 SSAC valves (Grinnell

Model A4 deluge valves)failed to trip open when water pressure was vented out of the diaphragm

chamber. Upon additional

testing, the licensee found that several other SSAC valves failed. The licensee's

root-cause

team, formed after the Initial valve failures, concluded

that the diaphragm

was sticking to its retainer and push rod disk, that the push rod assembly showed wear (pits and eroded plating), and that the associated

solenoid valves were not properly bleeding water pressure out of the diaphragm

area.The licensee's

root-cause

team found that plant personnel

were using an abrasive cleaning pad to clean the chrome-plated

push rod and the push rod guide in the diaphragm

retainers.

The team theorized

that this activity may have created rust particles

that caused the sticking.

In like manner, abrasives

used to clean the solenoid valves could cause the plunger assembly to stick.Grinnell does not recommend

using any abrasives, lubricants, or solvents because they may damage metallic surfaces such as valve seats, and may also damage elastomeric

seals.Grinnell recommends

cleaning the push rods, guides, and solenoid valves with only soap, water, and clean cloths.The root-cause

team also found that the solenoid valves were designed for operating

pressures of approximately

150 psig (UL maximum rated pressure Is 175 psig), whereas the actual operating

pressures

often exceeded 150 psig (the licensee determined

that fire protection

system pressures

sometimes

went as high as 225 psig). The NRC staff theorizes

that the valves may not be able to open against this pressure.Although the root-cause

team did not conclusively

determine

the root cause of the valve failures, the team recommended

(1) replacing

the diaphragms

and solenoid valves, (2) Installing

new solenoid valves with a design pressure of 200 psi (and factory tested to 300 psi), (3) flushing the solenoid valve piping and diaphragm

chamber when cleaning the solenoids, (4) requiring

the use of only soap, water, and a clean cloth when cleaning the solenoid valves, (5) cleaning the solenoid and SSAC valves more frequently, and (6) testing the valves more often -every 12 months Instead of 18 months (in the short term, the licensee Increased

testing to every 2, 6, and 12 months after resetting

the valves to improve reliability).

In subsequent

walkdowns, the team found that the piping for the deluge valve control drain lines had a 318-inch diameter In lieu of the %-Inch diameter line typically

supplied by the manufacturer

as part of the trim package listed by the independent

testing laboratory (i.e., UL or FM). The use of the smaller drain line could potentially

inhibit the bleedoff of water from the diaphragm

chamber, resulting

In Increased

pressure In the chamber. The staff notes that this restriction, in turn, could prevent the valve from opening.In mid-February

1998, the licensee performed

a scheduled

surveillance

test on several deluge valves In preaction

sprinkler

systems. One valve failed to trip, and its push rod had to be forced back manually after completely

isolating

and draining the diaphragm

chamber, closing the main Isolation

valve, opening the main drain, and opening the valve faceplate.

Inspection

of the rubber diaphragm

showed a "dimple* near the diaphragm

chamber supply inlet. The valve had been left in the tripped condition

for about 22 days in May 1997, then It was reset to the

IN 99-07 March 22, 1999 operable, ready position until this surveillance (for about 9 months). As a result of this failure, the licensee tested a sample of six additional

valves that had been left In a tripped condition

for long periods.One of these valves failed to trip electrically.

Inspection

of this valve Indicated

that the push rod appeared to be misaligned

in the retainer ring slot and some corrosion

had formed where the rod slides through the ring. Also, the diaphragm

was stuck to the face of the push rod. In total, five of the six sample valves and one other valve failed to operate properly.In June 1998, as part of the ongoing testing program, one of the deluge valves was manually actuated from its pull station; It failed to operate. An Investigation

Indicated

that the pull station housing had rotated and was preventing

complete travel (i.e., fully open) of the valve handle.After adjusting

the pull station housing, the handle was actuated again and the deluge valve successfully

tripped.The team commissioned

by the licensee to study the problems with the Grinnell A-4 valves concluded

that, although the cause and effect are not known, It appears that the failure occurred within a tripped open valve exposed to pressure over time. This exposure appears to cause the valve to fail after being reset. The team noted that the manufacturer

does not recommend

leaving the tripped-open

valves pressurized

for a significant

length of time. The root-cause

team is also exploring

other potential

failure mechanisms

of the Grinnell A-4 valve.The staff is continuing

to monitor the licensee's

investigation

into the valve failures.Discussion

The staff noted several potential

problems as a result of this event. First, as discussed

above, when deluge valves are left in the tripped condition

for long periods, the rubber diaphragm

is forced against the Inlet side of the diaphragm

chamber. When the valves are reset, the diaphragm

may then bond to the push rod flange, or pinch between the push rod flange and retainer ring, thus keeping the valve from operating

properly.

In the set condition, the rubber diaphragm

Is held by water pressure against the flange and retainer and bonding may possibly occur then. Bonding may be more probable In systems using well water or raw river water rather than potable water supplies.The staff also notes that it is a common practice for many plants to keep their preaction sprinkler

system deluge valves in a tripped condition

for long periods, usually during outages when welding or other activities

are taking place, which Increases

the likelihood

of spurious system actuation.

Grinnell recommends

that the valve be reset within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of any valve operation

and that the Internal components

of valves be cleaned and inspected

after any valve operation.

Second, the use of plant-supplied

or plant-designed

trim packages Instead of the UL- or FM-certified

packages and designs supplied by the valve manufacturer

may result In Issues such as undersized

drain lines, which may restrict the bleedoff from the diaphragm

chamber and further Inhibit valve actuation.

IN 9907 March 22, 1999 Third, an evaluation

by Grinnell concluded

that the valve release mechanism

may be jamming from the high pressure and surging conditions

In the fire protection

water supply system. The jamming may be related to deep indentations

on the valve latch. Cleaning and Inspection

of the valves' internal components

should reveal these potential

problems.While reviewing

this event, the staff noted that the licensee performs full-flow

testing. It is the staff's understanding

that many plants isolate the deluge valves from the main fire protection

water supply during individual

system valve testing. This practice is a potential

testing weakness and may mask the actuation

problems discussed

herein. With the deluge valve isolated, a limited volume of water is trapped in both the main line and the diaphragm

chamber supply line. The water In the diaphragm

chamber is slowly bled off until the valve opens. If the diaphragm

has bonded to the flange, the inlet to the diaphragm

chamber could be partially blocked, Inhibiting (but not preventing)

valve actuation.

However, during normal operation

with full flow from the diaphragm

chamber supply line, the primary flow path would follow the supply line to the drain, thus trapping water In the diaphragm

chamber and preventing

valve actuation.

Note the following

statement

in National Fire Protection

Association (NFPA) Standard 25 ("Standard

for the Inspection, Testing, and Maintenance

of Water-Based

Fire Protection

Systems," 1995 edition, section 94.3.2.2):

lEach deluge or preaction

valve shall be trip tested annually at full flow [emphasis

added] In warm weather and In accordance

with the manufacturer's

Instructions.'

The valve manufacturer

may also have special requirements

for inservice

testing. The A-4 valve manufacturer

recommends

partial flow testing where full-flow testing is undesirable.

Another event involving

the failure of automatic

deluge valves took place at Grand Gulf in 1983, and is discussed

in IN 84-16, "Failure of Automatic

Sprinkler

System Valves to Operate." While the licensee was performing

an operational

test of the emergency

diesel generator (EDG), a fire occurred in the diesel. The automatic

deluge valve (6-inch Model C valve manufactured

by the Automatic

Sprinkler

Company of America (ASCO)) failed to open. Approximately

3 months later, a Model C valve In a preaction

sprinkler

system for the EDG room at Grand Gulf failed to operate during a test. In both cases, scoring was found in the actuation

weight upper guide collar and in the box that encloses the weight guide bushing.Another Instance of repeated failures of a preaction

deluge valve occurred In 1997 at Limerick Unit 1. A Model AD 6-inch deluge valve manufactured

by Star Sprinkler, Inc., did not actuate during a surveillance

test. The frequency

of testing had been increased

because of earlier failures caused by suspected

mechanical

problems.

Continued

troubleshooting

of the valve failures uncovered

a potential

voltage mismatch between the deluge valve and the Chemetron release control panel, resulting

in marginal power available

to operate the valve. The Model AD valves were subsequently

replaced with Model AGO valves, also manufactured

by Star Sprinkler.

IN 99-07 March 22, 1999 Related Generic Communications

• IN 84-16, OFailure of Automatic

Sprinkler

System Valves to Operate," Issued March 2, 1984.* IN 92-28, 'inadequate

Fire Suppression

System Testing,'

Issued April 8, 1992.* IN 97-22, 'Potential

for Failure of the OMEGA Series Sprinkler

Heads," issued September

22, 1997.This information

notice requires no specific action or written response.

However, addressees

are reminded that they are required to consider Industry-wide

operating

experience (including

NRC information

notices) where practical, when setting goals and performing

periodic evaluations

under 10 CFR 50.65, 'Requirement

for Monitoring

the Effectiveness

of Maintenance

at Nuclear Power Plants.! 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.David B. Matthews, Director Division of Regulatory

Improvement

Programs Office of Nuclear Reactor Regulation

Technical

contacts:

Mark H. Salley, NRR Robert Caldwell, RII 301-415-2840

334-899-3386 E-mail: mxs36-nrc.aov

E-mail: rkcl(&nrc.ciov

William F. Burton, NRR 301-415-2853 E-mail: wfbS-nrc.aov

Attachment:

Ust of Recently Issued NRC Information

Notices I

IN 99-07 March 22, 1999 Related Generic Communications

• IN 84-16, "Failure of Automatic

Sprinkler

System Valves to Operate," issued March 2, 1984.* IN 92-28, "Inadequate

Fire Suppression

System Testing," issued April 8, 1992.* IN 97-22, "Potential

for Failure of the OMEGA Series Sprinkler

Heads," issued September

22, 1997.This information

notice requires no specific action or written response.

However, addressees

are reminded that they are required to consider industry-wide

operating

experience (including

NRC information

notices) where practical, when setting goals and performing

periodic evaluations

under 10 CFR 50.65, "Requirement

for Monitoring

the Effectiveness

of Maintenance

at Nuclear Power Plants." 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.Original signed by S.F. Newberry FOR David B. Matthews, Director Division of Regulatory

Improvement

Programs Office of Nuclear Reactor Regulation

Technical

contacts: Mark H. Salley, NRR 301-415-2840

E-mail: mxs3(&nrc.aov

Robert Caldwell, RII 334-899-3386 E-mail: rkc1a)nrc.aov

William F. Burton, NRR 301-415-2853 E-mail: wfbtfinrc.oov

Attachment:

List of Recently Issued NRC Information

Notices DOCUMENT NAME: S:MDRPMSEC%9907.IN

To receive a copv of this document.

Indicate In the box C=Copy wlo attachment/enclosure

E=Copy with attachmentlenclosure

N = No copy OFFICE PECB I j TECHEDITOR

l SPLB II uSPLB lI NAME -WFBurton* .RSanders*

MHSalley*

I KSWest*DATE I I1QIQQ 1114 /99 3/9/99 319l99-".- I ....--__I__ _-__-_ -... 11 --J OFFICE IC:SPLIB I D:DSSA l (A)C:PECB

I D:DRI II 1 NAME LMarsh* GHolahan*

RDennig* DMatdhlwsr

DATE 3/8/99 3/11/99 j 3/15/99 al 1V99 ]OFFICIAL RECORD COPY

IN 99-xx March xx, 1999 Related Generic Communications

• IN 84-16, "Failure of Automatic

Sprinkler

System Valves to Operate," issued March 2, 1984.* IN 92-28, "Inadequate

Fire Suppression

System Testing," issued April 8, 1992.* IN 97-22, "Potential

for Failure of the OMEGA Series Sprinkler

Heads," issued September

22, 1997.This information

notice requires no specific action or written response.

However, addressees

are reminded that they are required to consider industry-wide

operating

experience (including

NRC information

notices) where practical, when setting goals and performing

periodic evaluations

under 10 CFR 50.65, 'Requirement

for Monitoring

the Effectiveness

of Maintenance

at Nuclear Power Plants." 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.David B. Matthews, Director Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical

contacts: Mark H. Salley, NRR 301-415-2840

E-mail: mxs3(&'nrc.gov

Robert Caldwell, RII 334-899-3386 E-mail: rkcl (&nrc.gov William F. Burton, NRR 301-415-2853 E-mail: wfb(nrc.aov

Attachment:

List of Recently Issued NRC Information

Notices DOCUMENT NAME: G:\WFB\INDELUG

To receive a coDY of this document.

indicate in the box C=Conv wio attachment/enclosure

E=Coov with attachment/endosure

N = No codv OFFICE IPECB I T EDITOR lII SPLB I I I IISPLB I NAME WFBurton HA RSanders*MHSalley 41,/7 Kswest it ), L-:D:A:TE ll , 4 1/14 /99 1 Iq199 -Ax" go./99 DAT .i .& i~ .1/49 1 I IA E.....................

l l OFFICE C:SPLB lI[ D:DSSA (A)C D:DRPM I NAME f IMarsh W 1W GHolahan .j RDeigA -' l DMatthews DATE _ _1_99 ?I /L199 J13/ 99 1 / /99 OFFICIAL RECORD COPY