Bulletin 80-09: Hydramotor Actuator Deficiencies
SSINS No. 6820
NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
WASHINGTON, D.C. 20555
April 17, 1980
IE Bulletin No. 80-09
HYDRAMOTOR ACTUATOR DEFICIENCIES
ITT General Controls (ITT-GC) reported to the NRC two (2) problem areas
pertaining to their Models AH-90 and NH90 Series Hydramotor Actuators. The
NH 90 designators depicts nuclear class IE design. Either of the problems
reported could affect the operation of safety related equipment installed in
nuclear power facilities:
A. On December 7, 1979, ITT-GC reported the use of springs having
incorrect material installed in Models AH-90 and NH-90 Series
Hydramotor Actuators. Instead of 5160 steel, type 1060-1070 steel was
used for the No. 1 springs in the actuators. The incorrect spring
material does not meet the design strength and upon actuation of
greater than 3 inches stroke, a permanent set occurs resulting in a
decreased force output of up to 160 lbs, depending on spring
combinations used and specific adjustments made to the actuators. About
368 defective springs were used between September 1975 and January
B. On February 5, 1980, ITT-GC reported that the ITT-GC "Selection
Nomograph" for AH-90 and NH-90 series hydramotor actuators represent
the actual spring or hydraulic forces only and do not include the
effects of friction or residual hydraulic forces. It has been
determined that the actuators can have about 100 lbs. of friction and
an additional 40 lbs. of residual hydraulic pressure. Use of these
nomographs may result in selection of actuators undersized for the use
C. Action to be taken by licensees and construction permit holders
1. Each licensee and each holder of a construction permit should
determine whether any safety-related system or component in the
facility uses an AH90 or NH90 series Hydramotor Actuator
manufactured by ITT General Controls. (Note: To assist in this
determination a listing of customers that have purchased said
actuators and the number of actuators purchased is appended hereto
as Attachment No. 1. Since some of the Original Equipment
Manufacturers (OEM's) may delete the identity of components used
in their product, it may be necessary to consult with the OEM to
make the required determination.)
2. Operating facilities using said actuators in safety-related
IE Bulletin No. 80-09 April 17, 1980
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a. Review system functional testing to determining that
equipment using the subject actuators are periodically
b. Examine test records to determine whether the functional test
results conform to system requirements;
c. Verify that ample margin exists with respect to thrust
delivered to the load for long term operation considering
improper spring material and methods used to select the
actuator for a particular application.
d. Take any corrective actions required by the results of items
a., b. and c., above.
3. Facilities with construction permits using said actuators in
safety-related systems should:
a. Reevaluate actuator size selection in light of the
possibility of using actuators with defective springs or
which were sized by the "Selection Nomograph" without
accounting for internal friction and hydraulic resistance.
Said reevaluation should assure that the actuators will
perform their intended function.
b. Modify equipment qualification, preoperational and startup
test programs, as necessary, to demonstrate the functional
adequacy of the Hydramotor Actuator in light of the
aforementioned concerns. Particular attention should be given
to the possibility of defective springs taking a permanent
Note: ITT General Controls is presently performing
actuator testing on units supplied by one of their
customers (American Warming & Ventilating Co. Inc.)
and revising the methods used to select actuator
Each licensee or holder of a construction permit should report to the NRC
within 60 days of the results of actions taken, any corrective actions
required, and the date when corrective actions were or will be completed.
The report should be addressed to:
U. S. Nuclear Regulatory Commission
Director of Reactor Construction Inspection, O.I.E.
Washington, D.C. 20555
Approved by GAO, B180225 (ROO72); clearance expires 7/31/80. Approval was
given under a blanket clearance specifically for identified generic
Attachment No. 1
Cincinnati, OH 27
American Warming & Ventilating Co., Inc.
Maumee, OH 145
Copes Vulcan, Inc.
Lake City, PA 2
Fisher Controls Co., Inc.
Marshalltown, IA 38
Fisher Controls Co., Inc.
Corapolis, PA 4
General Signal Corporation
West Warwick, RI 2
Warwick, RI 4
New Philadelphia, OH 18
Masoneilan International, Inc.
Norwood, MA 10
Pacific Air Products
Santa Ana, CA 16
Posi Seal International, Inc.
No. Stonington, CT 14
Powers Regulator Co.
Portland, OR 1
Powers Regulator Co.
Skokie, IL 74
Ruskin Manufacturing Co.
Grandview, MO 4
Springville, UT 9
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