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.

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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 Itwas 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 Inthe 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 Inthe 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 Robert Caldwell, RII

301-415-2840 334-899-3386 E-mail: mxs3(&nrc.aov 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 jTECHEDITOR l SPLB II uSPLBlI

NAME -WFBurton* .RSanders* MHSalley* I KSWest*

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DATE 3/8/99 3/11/99 j 3/15/99 al1V99 ]

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 Robert Caldwell, RII

301-415-2840 334-899-3386 E-mail: mxs3(&'nrc.gov 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 IT EDITORlII SPLBIIISPLB

I I I

NAME WFBurton HA RSanders* MHSalley 41,/7 Kswest it), L-

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NAME f IMarsh W 1W GHolahan .j RDeigA-' l DMatthews

DATE _ _1_99 ?I /L199 OFFICIAL RECORD COPY

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