Information Notice 1986-50, Inadequate Testing to Detect Failures of Safety-Related Pneumatic Components or Systems

Inadequate Testing to Detect Failures of Safety-Related Pneumatic Components or Systems

ML031220684
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:	06/18/1986
From:	Jordan E NRC/IE
To:
References
IN-86-050, NUDOCS 8606160044
Download: ML031220684 (4)

ORIGINAL SSINS No.: 6835 IN 86-50

UNITED STATES.

NUCLEAR REGULATORY COMMISSION

OFFICE OF INSPECTION AND ENFORCEMENT

WASHINGTON,,D.C. 20555 June 18, 1986 IE INFORMATION NOTICE NO. 86-50: INADEQUATE TESTING TO-DETECT FAILURES OF

SAFETY-RELATED PNEUMATIC COMPONENTS OR

SYSTEMS

Addressees

All nuclear power reactor facilities holding an operating license (OL) or a

construction permit (CP).

Purpose

This notice is being provided to alert recipients to a potentially significant

problem pertaining to inadequate testing practice relating to air operated

valves. The NRC expects that recipients will review this notice for applica- bility to their facilities. However, suggestions contained in this notice do

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

response is required.

Past Related Correspondence:

IE Information Notice No. 82-25, "Failures of Hiller Actuators Upon

Gradual Loss of Air Pressure," July 20, 1982 IE Information Notice No. 85-35,- '.Failure of Air Check Valves to Seat,"

April 30, 1985 IE Information Notice No. 85-84, "Inadequate Inservice Testing of Main

Steam Isolation Valves," October 30, 1985 IE Information Notice No. 85-94, 'Potential for Loss of Minimum Flow

Paths Leading to ECCS Pump Damage During a LOCA," December 13, 1985

Description of Circumstances

The NRC has reported previously on instances where safety-related equipment

failed to operate as intended when non-safety-related pneumatic systems were

unavailable (IE INs 82-25 and 85-35). In these situations, main steam isola- tion valves and containment isolation valves failed to operate properly when

control air pressure decreased slowly rather than rapidly as would be expected

for an air line break. In the case of IN 85-35, the fault was exposed by a

loss of offsite power test, and in the case of IN 82-25, the fault was exposed

by a preoperational test designed .to simulate a slow air leak. In both cases,

8606160044

IN 86-50

June 18, 1986 the components in question--an accumulator isolation check valve (IN 85-35) and

pneumatic selector valves (IN 82-25)--were not tested adequately. Several

recent events have indicated continuing problems of similar nature. These

events are discussed below.

On February 13, 1986, the licensee at Turkey Point Unit 3 first reported to tht

NRC a concern that the component cooling water (CCW) system might fail to meet

its functional requirements for a design-basis accident. One part of the

concern involved the CCW heat exchanger outlet control valve. This valve

regulates flow of intake cooling water (ICW) to this heat exchanger. Loss of

control air, coincident with a loss of offsite power, a valid engineered

safeguards features (ESF) actuation signal, and a loss of an emergency diesel

generator (EDG) would cause this valve to fail closed. If this happened, the

CCW heat exchanger would not receive sufficient flow of ICW. This situation

was discovered during a design review of the ICW system. Earlier disclosure

might have been possible if ICW operation had been considered or tested with

non-safety-related control air secured, coincident with loss of electrical

power.

On January 7, 1986, the licensee at Robinson Unit 2 reported a concern with the

air-operated valves in the safety injection (SI) pump minimum-flow recircula- tion line from the pump discharge to the refueling water storage tank (RWST).

This concern evolved from review of IN 85-94. Two such valves had been insert- ed in series in this line and had been designed to fail closed on loss of

non-safety-related air or loss of electrical power to the valves. The purpose

of the valves is to protect the RWST (outside containment) from highly radioac- tive reactor coolant during the long-term circulation phase of accident recov- ery. In the event of SI initiation under small-break loss-of-coolant-accident

conditions concurrent with closure of either of these valves, the SI pumps

would be operating with no flow until reactor pressure decreased below their

shutoff head. This would damage the SI pumps after only a short time. The

licensee's remedy was to put mechanical blocks on the air operators so the

valves would fail as-is (open). Again, if SI operation had been considered or

tested with non-safety-related control air secured, the fault might have been

disclosed earlier.

On December 9, 1985, the licensee at Catawba Unit 2 reported finding that one

of the two valve closure springs was missing on one of the pressurizer

power-operated relief valves (PORVs). Thus, with loss of air the valve would

not have closed against system pressure. The other two PORVs had their normal

complement of springs. The valve with the missing spring had been found

satisfactory in preoperational tests. During the preoperational loss of air

test, the valve closed because system pressure was not present; during the hot

functional test, the valve closed because actuator air pressure was present.

This is clearly a case in which a fail safe valve was tested without all

actuator power secured (IN 85-84).

IN 86-50

June 18, 1986 No specific action or written response is required by this information notice.

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

Administrator of the appropriate regional office or this office.

d~waA tJordan, Director

Divisi of Emergency Preparedness

and E gineering Response

- ~ Office of Inspection and Enforcement

Vern Hodge, IE

(301) 492-7275 Attachment: List of Recently Issued IE Information Notices

Attachment 1 IN 86-50

June 18, 1986 LIST OF RECENTLY ISSUED

IE INFORMATION NOTICES

Information Date of

Notice No. Subject Issue Issued to

86-49 Age/Environment Induced 6/16/86 All power reactor

Electrical Cable Failues facilities holding

an OL or CP

86-48 Inadequate Testing Of Boron 6/13/86 All BWR facilities

Solution Concentration In The holding an OL or CP

Standby Liquid Control System

86-47 Feedwater Transient With 6/9/86 All BWRs and PWRs

Partial Failure Of The facilities holding

Reactor Scram System an OL or CP

86-46 Improper Cleaning And Decon- 6/12/86 All power reactor

tamination Of Respiratory facilities holding

Protection Equipment an OL or CP and

fuel fabrication

facilities

86-45 Potential Falsification Of 6/10/86 All power reactor

Test Reports On Flanges facilities holding

Manufactured By Golden Gate an OL or CP and

Forge And Flange, Inc. research and test

facilities

86-44 Failure To Follow Procedures 6/10/86 All power reactor

When Working In High Radiation facilities holding

Areas an OL or CP and

research and test

reactors

86-43 Problems With Silver Zeolite 6/10/86 All power reactor

Sampling Of Airborne Radio- facilities holding

iodine an OL or CP

86-42 Improper Maintenance Of 6/9/86 All power rector

Radiation Monitoring Systems facilities holding

an OL or CP

86-41 Evaluation Of Questionable 6/9/86 All byproduct

Exposure Readings Of Licensee material licensees

Personnel Dosimeters

OL = Operating License

CP = Construction Permit