Information Notice 1988-13, Water Hammer & Possible Piping Damage Caused by Misapplication of Kerotest Packless Metal Diaphragm Globe Valves

Water Hammer & Possible Piping Damage Caused by Misapplication of Kerotest Packless Metal Diaphragm Globe Valves
	ML031150503
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, 05000000, Zimmer, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant
Issue date:	04/18/1988
From:	Rossi C; Office of Nuclear Reactor Regulation
To:	;
References
	IN-88-013, NUDOCS 8804110007
	Download: ML031150503 (6)
	v • d • e

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON D.C. 20555 April 18, 1988 NRC INFORMATION NOTICE NO. 88-13: WATER HAMMER AND POSSIBLE PIPING DAMAGE

CAUSED BY MISAPPLICATION OF KEROTEST

PACKLESS METAL'DIAPHRAGM GLOBE VALVES

Addressees

All holders of operating licenses or construction permits for nuclear power

reactors.

Purpose

This information notice is being provided to alert-addressees to potential

problems resulting from the-improper application of packless metal diaphragm

valves supplied by the Kerotest Manufacturing Corp. It isexpected 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 do not constitute NRC

requirements; therefore, no specific action or written response is required.

Description of Circumstances

Kerotest Y-pattern packless metal diaphragm globe valves are used in a variety

of applications innuclear power plant reactor systems. These valves are de- signed to meet each owner's equipment specifications. However, incidents have

occurred involving flow throttling and reverse flow as a result of the misap- plication of these valves.

On August 6, 1984, McGuire Unit 2 operators discovered a broken weld on the let- down line of the residual heat removal system. The system was inuse at.the time

and contaminated water was spraying from the broken pipe and from the stem of a

valve. A subsequent inspection revealed a number of damaged supports/restraints

and a broken socket weld that had completely separated. On April 5, 1985, seven

socket welds with crack indications were discovered on additional piping in this

system, although no welds had failed as they had inthe August 1984 event. The

root cause of these problems was attributed to excessive piping vibration induced

by "'chugging" during reverse flow through Kerotest Y-pattern packless metal

diaphragm globe valves.

On May 12, 1987, while Trojan operators were transferring water from the "All ac- cumulator via backflow through the fill line to the I'D" accumulator, the fill

line ruptured at the "A"accumulator nozzle-to-pipe weld. On May ?3, 1987, after

the broken line Ifad been repaired, operators again attempted to transfer water, and the fill line ruptured at the same location. The cause of the event was

attributed to backflow through the Kerotest Y-patter'n packless metal diaphragm

globe valve in the "A"l accumulator fill line. This backflow created a cyclic

8804110007

IN 88-13 April 18, 1988 Page ? of 2 vibration of the valve disk. This vibration induced high enough stresses in

the fill line to cause the pipe rupture.

On February 22, 1988, while Braidwood Unit 1 was draining the "D" accumulator, the fill line ruptured at a location similar to the location of a break pre- viously reported at Byron, which was not analyzed by the licensee. The break

location was also similar to that at Trojan. This line has a Kerotest Y-pattern

packless metal diaphragm globe valve installed. Analysis of the break determined

that it was caused by high cycle fatigue. The licensee has not been able to rule

out valve "chugging" as the cause of the high cycle fatigue.

Discussion:

Reverse flow through Kerotest Y-pattern packless metal diaphragm globe valves

has caused broken piping welds at two nuclear plants and may be responsible for

other broken welds where the root cause has not been identified. Because of

the stem and disk design used in Kerotest Y-pattern packless metal diaphragm

globe valves, these valves are not intended for applications that require flow

throttling or that subject the valves to reverse flow. Reverse flow in these

valves can result in "chugging" that induces flow vibrations and water hammer.

It may not be clear to plant operating personnel that violating these appli- cation criteria can result in serious consequences such as weld cracks and

pipe ruptures that breach the primary coolant pressure boundary.

The manufacturer's product literature did not clearly state that certain valve

types;s-hould notbe subjected to reverse flow or used for flow throttling. Older

issues of Kerotest instruction and engineernfgq manuals do not-worn usrs of-thei- valves' unidirectional flow properties. More recent editions have corrected this

deficiency; however, licensees may not have the corrected manual.

Purchase specifications may have been written without regard to flow direc- tionality because the manufacturer's literature did not note its importance.

This may have caused the improper use of these valves in applications where

bi-directional flow is anticipated either in normal operation or in coping

with emergency situations that require other-than-normal plant lineups.

No specific action or written response is required by this information notice.

If you have any questions about this matter, please contact the technical

contact listed below or the Regional Administrator of the appropriate regional

office.

Charles . Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

Technical Contact:

Rudy 0. Karsch, NRR

(301) 492-1178 Attachment: List of Recently Issued NRC Information Notices

K)

Attachment

IN 88-13 April.18e , 1988

.. f. . .

tIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Information Date of

Notice No. Subject Issuance Issued to

88-12 Overgreasing of Electric 4/12/88 All holders of ULs

Motor Bearings or CPs for nuclear

power reactors.

88-11 Potential Loss of Motor 4/7/88 All holders of OLs

Control Center and/or or CPs for nuclear

Switchboard Function Due power reactors..

to Faulty Tie Bolts

88-10 Materials Licensees: Lack 3/28/88 All NRC licensees

of Management Controls Over authorized to use

Licensed Programs byproduct material.

87-44, Thimble Tube Thinning in 3/28/88 All holders of OLs

Supp. 1 Westinghouse Reactors or CPs for nuclear

power reactors that

employ a Westinghouse

NSSS.

88-09 Reduced Reliability of 3/18/88 All holders of OLs

Steam-Driven Auxiliary or CPs for nuclear

Feedwater Pumps Caused power reactors.

by Instability of Woodward

PG-PL Governors

88-08 Chemical Reactions with 3/14/88 All NRC licensees

Radioactive Waste generating or pro- Solidification Agents cessing low level

radioactive waste.

88-07 Inadvertent Transfer of 3/7/88 All NRC broad licensees

Licensed Material to and licensees authorized

Uincontrolled Locations to possess byproduct

material as sealed

sources in teletherapy

units or "self-contained"

irradiators.

88-06 Foreign Objects in Steam 2/29/88 All holders of OLs

Generators or CPs for PV!Rs.

OL = Operating License

CP = Construction Permit

IN 88-13 April 18, 1988 vibration of the valve disk. This vibration induced high enough stresses in