Information Notice 1989-01, Valve Body Erosion

Valve Body Erosion

ML031180473
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:	01/04/1989
From:	Rossi C Office of Nuclear Reactor Regulation
To:
References
IN-89-001, NUDOCS 8812300119
Download: ML031180473 (4)

- s

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555 January 4, 1989 NRC INFORMATION NOTICE NO. 89-01: VALVE BODY EROSION

Addressees

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

Purpose

This information notice is provided to alert recipients to a potential generic

problem pertaining to erosion found in carbon steel valve bodies in safety- related systems. It is expected that recipients will review the information

for applicability to their facilities and consider actions, if appropriate, to

preclude a similar problem. However, suggestions contained in this notice do

not constitute NRC requirements; therefore, no specific action or written

response is required.

Description of Circumstances

During the Brunswick Steam Electric Plant, Unit 1 refueling outage, inspections

performed on December 13, 1988, indicated areas of significant but localized

erosion on the internal surfaces of several carbon steel valve bodies. The

affected safety-related globe valves were the 24-inch RHR/LPCI system injection

and 16-inch suppression pool isolation valves. Subsequent ultrasonic testing

of identical valves on Unit 2, which was operating at power, indicated similar

erosion. Additional valves used for throttling service (such as high pressure

coolant injection) have indicated less erosion possibly due to the fact that

they have seen less service.

Discussion:

The valve bodies that have been ultrasonically tested indicate that the minimum

measured wall thicknesses are approaching the minimum code allowable thicknesses.

Minimum Wall Thickness - inches

Valve Unit 1 Unit 2 Code Allowable Nominal

RHR/LPCI Train A 2.7 2.6 1.47 4 RHR/LPCI Train B 1.7 1.9 1.47 4 Suppression Pool Train A N/A 0.8 0.49 2 Suppression PmT ITrain B 0.7 0.6 0.49 2

7 881230119

IN 89-01 January 4, 1989 The obvious safety concern is that continued operation without weld repair or

replacement could lead to rupture of safety-related valve bodies.

The root cause assessment of this erosion phenomenon has not been finalized. The

licensee currently believes that the erosion may have resulted from throttling

the globe valves below their design flow range. Excessive throttling can promote

cavitation which enhances internal valve body erosion.

A similar problem appears to be occurring at Hatch Unit 1. On November 17, 1988, a severe banging noise was heard coming from the line which connects the "B" loop

of the RHR system to the Condensate Storage and Transfer System. At the time, the "B" loop of RHR was in the shutdown cooling mode. Further investigation

revealed that the cause of the banging was cavitation of the 24-inch RHR/LPCI

system injection globe valve. The Unit 1 shift supervisor took action to

alleviate the problem by repositioning the valve to increase the flow rate, thus reducing the cavitation. Examination of the valve body wall thickness

has not been reported to date.

Past Related Generic Communications:

NRC Information Notice No. 88-17, "Summary of Responses to NRC Bulletin 87-01,

'Thinning of Pipe Walls In Nuclear Power Plants'," dated April 22, 1988, provides

additional information on erosion downstream of turbine-driven reactor feedwater

pump minimum-flow control valves. LaSalle Unit 1 experienced through-wall

ero-sin in th-e-expa-fde-rdire-tly dt-ons-tream-of-the-cone-shaped1sc- in-the

minimum-flow control valve.

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.

bar1_

esE.,irector '

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

Frank J. Witt, NRR

(301) 492-0823 Attachment: List of Recently Issued NRC Information Notices

Attachment

IN 89-01 January 4, 1989 Page'1 of 1 LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Information Date of

Notice No. Subject Issuance Issued to

88-46, Licensee Report of Defective 12/30/88 All holders of OLs

Supp. 2 Refurbished Circuit Breakers or CPs for nuclear

power reactors.88-101 Shipment of Contaminated 12/28/88 All holders of OLs

Equipment between Nuclear or CPs for nuclear

Power Stations power reactors.88-100 Memorandum of Understanding 12/23/88 All major nuclear

between NRC and OSHA materials licensees

Relating to NRC-licensed and utilities holding

Facilities (53 FR 43950, CPs and OLs.

October 31, 1988)

88-99 Detection and Monitoring 12/20/88 All holders of OLs

of Sudden and/or Rapidly or CPs for PWRs.

Increasing Primary-to- Secondary Leakage

88-98 Electrical Relay Degradation 12/19/88 All holders of OLs

Caused by Oxidation of or CPs for nuclear

Contact Surfaces power reactors.

88-97 Potentially Substandard 12/16/88 All holders of OLs

Valve Replacement Parts or CPs for nuclear

power reactors.

88-96 Electrical Shock Fatalities 12/14/88 All holders of OLs

at Nuclear Power Plants or CPs for nuclear

power reactors.

88-95 Inadequate Procurement 12/8/88 All holders of OLs

Requirements Imposed by or CPs for nuclear

Licensees on Vendors power reactors.

88-94 Potentially Undersiled 12/2/88 All holders of OLs

Valve Actuators or CPs for nuclear

power reactors.

88-93 Teletherapy Events 12/2/88 All NRC medical

licensees.

OL = Operating License

CP = Construction Permit

IN 89-01 January 4, 1989 The obvious safety concern is that continued operation without weld repair or

replacement could lead to rupture of safety-related valve bodies.

The root cause assessment of this erosion phenomenon has not been finalized. The

licensee currently believes that the erosion may have resulted from throttling

the globe valves below their design flow range. Excessive throttling can promote

cavitation which enhances internal valve body erosion.

A similar problem appears to be occurring at Hatch Unit 1. On November 17, 1988, a severe banging noise was heard coming from the line which connects the "B" loop

of the RHR system to the Condensate Storage and Transfer System. At the time, the "B" loop of RHR was in the shutdown cooling mode. Further investigation

revealed that the cause of the banging was cavitation of the 24-inch RHR/LPCI

system injection globe valve. The Unit 1 shift supervisor took action to

alleviate the problem by repositioning the valve to increase the flow rate, thus reducing the cavitation. Examination of the valve body wall thickness

has not been reported to date.

Past Related Generic Communications:

NRC Information Notice No. 88-17, "Summary of Responses to NRC Bulletin 87-01,

'Thinning of Pipe Walls In Nuclear Power Plants'," dated April 22, 1988, provides

additional information on erosion downstream of turbine-driven reactor feedwater

pump minimum-flow control valves. LaSalle Unit 1 experienced through-wall

erosion in the expander directly downstream of the cone-shaped disc in the

minimum-flow control valve.

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 E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

Frank J. Witt, NRR

(301) 492-0823 Attachment: List of Recently Issued NRC Information Notices

ECEB:DEST:NRR D:DEST:NRR C:O CB:DOEA:NRR

FJWitt LShao CHBerlinger CERossi

12/ /88 12/ /88 12/3o/88 12Wg88

1~Z,

f A. 5