Information Notice 1986-61, Failure of Auxiliary Feedwater Manual Isolation Valve

Failure of Auxiliary Feedwater Manual Isolation Valve

ML031250047
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, Skagit, Marble Hill
Issue date:	07/28/1986
From:	Jordan E NRC/IE
To:
References
IN-86-061, NUDOCS 8607240026
Download: ML031250047 (4)

SSINS No.: 6835 n IN 86-61 UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF INSPECTION AND ENFORCEMENT

WASHINGTON, D.C. 20555 July 28, 1986 IE INFORMATION NOTICE NO. 86-61: FAILURE OF AUXILIARY FEEDWATER MANUAL

ISOLATION VALVE

Addressees

All licensees of nuclear power plants and holders of construction permits.

Purpose

This notice is provided to alert licensees to a failure of a manual isolation

valve as the result of a lack of maintenance on the valve during the operational

life of the plant.

It is suggested that recipients review this information for applicability and

consider actions, as appropriate, to preclude this and similar problems from

occurring at their facilities. However, suggestions contained in this notice

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

response is required.

Description of Circumstances

Following the loss of integrated control system (ICS) power at the Rancho Seco

plant on December 26, 1985, the plant tripped and an overcooling transient

occurred. Details of this event are documented in the NRC incident investiga- tion team's report, "Loss of Integrated Control System Power and Overcooling

Transient at Rancho Seco on December 26, 1985," NUREG-1195, February 1986.

When power was lost to the ICS, the plant responded as designed; the auxiliary

feedwater (AFW) ICS flow control valves, as well as other valves, went to the

50-percent open position. The auxiliary feedwater flow was excessive. When

the local manual attempt to close the flow control valve to the "A" once-through

steam generator (OTSG) was unsuccessful, the operator attempted to close the

manual isolation valve. This isolation valve could not be moved, even when a

valve wrench was used.

The NRC incident investigation team (IIT) found that the failure of the

auxiliary feedwater manual isolation valve was the result of a lack of any

maintenance on this valve during the operational life of the plant, about 10-12 years. The lack of a preventive maintenance program resulted in the valve

being inadequately lubricated, which caused the valve to seize.

8607240026

. 'IN 86-61 July 28, 1986 Discussion:

The AFW manual isolation valve is a locked-open valve located in the AFW

discharge header to the "A" OTSG. The licensee, Sacramento Muncipal Utility

District (SMUD), considers that the entire AFW system, which would include this

manual isolation valve, is safety-related. However, it appears that this valve

was only intended to be used to isolate the AFW (ICS) flow control valve for

maintenance. The valve is a 6-inch, ANSI Class 900-lb, pressure seal gate manu- factured by Velan Engineering. It is categorized as an ASME "Category E" valve

(i.e., it is normally locked open to fulfill its function).Section XI of the

ASME Boiler and Pressure Vessel Code (1974 Edition) requires no regular testing

of Category E valves. The positions of the valves are merely recorded to verify

that each valve is locked or sealed in its correct position. The ASME Code no

longer includes a Category E.

The Velan instruction manual provides the following guidance regarding

maintenance and operation of the valve:

° Lubrication of the stem threads and other working components should be

performed frequently and at least every 6 months. A lubrication schedule

recommends stem thread lubrication whenever the threads appear dry and

greasing of the yoke sleeve bearings concurrently with stem thread

I ubri cation.

o Valves that are not operated frequently and may remain open or closed for ....

long periods of time should be worked, even if only partially, about once

a month.

o Proper lubrication of the stem and sleeve can reduce required operating

torque by 7 to 30 percent.

o A caution also is provided not to use valve wrenches on the handwheels.

A review of the maintenance history of the "A" manual isolation valve indicated

that no maintenance (preventive or corrective) had been performed on the valve

during the operational life of the plant (i.e., since 1974). The licensee had

no program for preventive maintenance of manual isolation valves in the plant.

Two similar valves had failed previously, which prevented movement of the valve

• from the open position. The discharge isolation valve from the "A" AFW pump

failed on November 20, 1979 and the AFW manual isolation valve to the "B" OTSG

failed on February 20, 1980. In both cases, the yoke bearings were found seized

and had to be replaced.

During the December 26, 1985 incident, it was necessary to isolate AFW flow

to the OTSG to terminate the overcooling. When the flow control valve could

not be closed, the operator tried to close the manual isolation valve.

Because of the lack of maintenance, the isolation valve could not be closed

when it was needed. To address this problem, the SMUD has identified about _ ,-

100 manual isolation valves with functions similar to the AFW manual isolatios,'

valve, that will now be included in their preventive maintenance program.

IN 86-61 Julu 28, 1986 Additional discussion on the AFW manual isolation valve is included in

Section 5.3 of NUREG-1195.

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

If you have any questions regarding this matter, please contact the Regional

Administrator of the appropriate NRC regional office or this office.

Jordan, Director

Divisi of Emergency Preparedness

and Engineering Response

Office of Inspection and Enforcement

R. Wright, NRR

(301) 492-8900

H. Bailey, IE

(301) 492-9006 Attachment: List of Recently Issued IE Information Notices

Attachment 1 IN 86-60

July 28, 1986 LIST OF RECENTLY ISSUED

IE INFORMATION NOTICES

Information Date of

Notice No. Subject Issue Issued to

86-60 Unanalyzed Post-LOCA Release 7/28/86 All power reactor

Paths facilities holding

an OL or CP

86-31 Unauthorized Transfer And 7/14/86 All NRC general

Sup. 1 Loss Of Control Of Industrial licensees that possess

Nuclear Gauges and use industrial

nuclear gauges

86-59 Increased Monitoring Of 7/14/86 All NRC licensees

Certain Patients With authorized to use

Implanted Coratomic, Inc. nuclear-powered

Model C-100 and C-101 cardiac pacemakers

Nuclear-Powered Cardiac

Pacemakers

86-58 Dropped Fuel Assembly 7/11/86 All power reactor

facilities holding

an OL or CP

86-57 Operating Problems With 7/11/86 All power reactor

Solenoid Operated Valves At facilities holding

Nuclear Power Plants an OL or CP

86-56 Reliability Of Main Steam 7/10/86 All PWR facilities

Safety Valves holding an OL or CP

86-55 Delayed Access To Safety- 7/10/86 All power reactor

Related Areas And Equipment facilities holding

During Plant Emergencies an OL or CP

86-54 Criminal Prosecution Of A 6/27/86 All holders of NRC

Former Radiation Safety license authorizing

Officer Who Willfully Directed the possession of

An Unqualified Individual To byproduct, source, Perform Radiography or special nuclear

material

86-53 Improper Installation Of Heat 6/26/86 All power reactor

Shrinkable Tubing facilities holding

an OL or CP

OL = Operating License

CP = Construction Permit