Information Notice 1986-02, Failure of Valve Operator Motor During Environmental Qualification Testing

Failure of Valve Operator Motor During Environmental Qualification Testing

ML031220475
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:	01/06/1986
From:	Jordan E NRC/IE
To:
References
IN-86-002, NUDOCS 8512310466
Download: ML031220475 (3)

SSINS No.: 6835 IN 86-02 UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF INSPECTION AND ENFORCEMENT

WASHINGTON, D.C.' 20555 January 6, 1986 IE INFORMATION NOTICE NO.,86-02: FAILURE OF VALVE OPERATOR MOTOR DURING

ENVIRONMENTAL QUALIFICATIONTESTING

Addressees

(OL) or a

All nuclear power reactor facilities holding an operating'license

construction permit (CP).

Purpose

involv- This notice is to alert recipients of a potentially significant-problemenviron- during

ing the failure of Reliance Motor Corporation magnesium motors for River Bend

mental qualification (EQ) testing of Limitorque valve operators

recipients

and Nine Mile Point 2 nuclear power stations. It is expected that and consider

will review this information for applicability to their facilities

at their, actions, if appropriate, to preclude a similar problem occurring constitute

facilities. However, suggestions contained in thisinotice do-not

is required.

NRC requirements; therefore, no specific action or written response

Description of Circumstances

to theNRC that

On August 30, 1985, the General Electric Company (GE) reported ac motors during

they had experienced test anomalies of the Reliance, class RH,

EQ testing of a Limitorque fast-acting SMB-3-150 valve motorMile operator for its

Point 2) BWR

Gulf States Utilities (River Bend) and Niagara Mohawk (Nine motors have

customers. These motors have magnesium rotors. Magnesium rotor - Project

previously undergone EQ testing by Limitorque (PWR Qualification three motors

600456A) without failures. However,-during the current testing, motor had

'failed during the 100-day design-basis-event (DBE) test. The first thermal, been subjected to the 40-year qualification series of radiation, (LOCA)

mechanical, and dynamic aging before the loss-of-coolant-accident

testing. This motor had been exposed for 7 days to a steam environment with

the end

temperatures-as high as 355 F when the-rotor bar at the interface with

0

conducting bars.

ring had corroded, causing separation of the end ring from the

A second (unaged) motor was then substituted into the test; after 14 days in

0 the

the steam environment, with a maximum-temperature of 245 F, it experienced the same

same failure as the first motor., A third (unaged) motor experienced

0

failure following 43 days with a maximum temperature of 223 F.

8512310466

Ii

IN 86-02 January 6, 1986 Discussion:

Limitorque Corporation has used Reliance medium and large (180 frame and larger)

ac motors, with magnesium alloy as-a standard rotor material, in its operators, for many years. Although all specific applications and affected power plants

could not be identified, Limitorque has concluded that all domestic nuclear

power facilities, using Limitorque actuators, would have several motors in

180-frame size and larger containing magnesium alloy rotors. The magnesium

alloy rotors have been primarily used where high-torque, high horsepower, fast-acting motors are required. Reliance Motor Corporation has stated that, while they are reviewing possible design changes to prevent corrosion of the

rotor in high temperature steam environments, there are no existing rotors

available to replace the magnesium alloy components and retain the same motor

characteristics.

General Electric has reviewed the BWR applications and has provided recommended

action via Service Information Letter No. 425 (July 17, 1985). In summary, GE

recommends that licensees determine the plant-specific applications of magnesi- um motors subject to harsh environment, the adequacy of long-term cooling could

be evaluated assuming failure of the magnesium rotor MOVs a few days after the

DBE. Some systems may allow for the operator to position the valve to its safety

position immediately following the DBE instead of waiting for automatic actuation, while other systems may require realignment to a standby mode after initial core

cooling. In addition to operator training, it may be prudent to disconnect some

.-of_the_valve-actuation logic followingsafety positioning to prevent valve _

realignment without operator initiation. Other corrective actions may be

appropriate for specific applications.

PWR owners may wish to review their Limitorque MOV qualification packages in

light of this new information. If the review determines that the equipment may

not be qualified for its intended use then they may wish to consider taking

action, as recommended by GE for BWRs and as described above, to mitigate the

potential for long-term core cooling problems caused by motor-operated valve

(MOV) failures in the days following a DBE.

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.

ward L. Jar an, Director

ivision of mergency Preparedness

and Engineering Response

Office of Inspection and Enforcement

James E. Stewart, IE

(301) 492-9061 Attachment:

List of Recently Issued IE Information Notices

K> vK)

Attachment 1 IN 86-02 January 6, 1986 LIST OF RECENTLY ISSUED

IE INFORMATION NOTICES

Information - Date of

Notice No.. Subject Issue -Issued to

86-01 Failure Of Main Feedwater 1/3/86 All power reactor

Check Valve Causes Loss Of facilities holding

Feedwater System Integrity an OL or CP

And Water-Hammer Damage

85-101 Applicability of 10 CFR 21 12/31/85 All power reactor

.1 To Consulting Firms Providing facilities holding

Training an OL or CP

85-100 Rosemount Differential 12/31/85 All power reactor

Pressure Transmitter Zero facilities holding

Point Shift an OL or CP

85-99 Cracking In Boiling-Water- 12/31/85 All BWR facilities

Reactor Mark I And Mark II having a Mark I or

I,

Containments Caused By Failure Mark II containment

Of The Inerting System

85-98 Missing Jumpers From Westing- 12/26/85 All Westinghouse

-house-Reactor Protection- designed PWR

System Cards For The Over- facilities holding

Power Delta Temperature Trip an OL or CP

Function

85-97 Jail Term For Former 12/26/85 All power reactor

Contractor Employee Who facilities holding

Intent

ionally Falsified an OL or CP

Welding Inspection Records

85-96 Temporary Strainers Left 12/23/85 All power reactor

Installed In Pump Suction facilities holding

Piping an OL or CP

85-95 Leak Of Reactor Water To 12/23/85 All BWR facilities

Reactor Building Caused By holding an OL or CP

Scram Solenoid Valve Problem

85-94 Potential For Loss Of Minimum 12/13/85 All power reactor

Flow Paths Leading To ECCS facilities holding

Pump Damage During A LOCA an OL or CP

OL = Operating License

CP = Construction Permit