HomeMy WebLinkAbout851172.tiff SSINS No. : 6835
IN 85-67
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UNITED STATES
NUCLEAR REGULATORY COMMISSION 0
OFFICE OF INSPECTION AND ENFORCEMENT AUG 2 01985_j,
WASHINGTON, D.C. 20555
August 8, 1985 CIREELEJ(r Col.q,
IE INFORMATION NOTICE NO. 85-67: VALVE-SHAFT-TO-ACTUATOR KEY MAY FALL OUT OF
PLACE WHEN MOUNTED BELOW HORIZONTAL AXIS
Addressees:
All nuclear power reactor facilities holding an operating license (OL) or a
construction permit (CP).
Purpose:
This information notice is provided to alert recipients of a potentially
significant problem pertaining to the renewed possibility of the
valve-shaft-to-actuator key falling out of place when the motor operator is
mounted below the horizontal axis. It is expected that recipients will review
the information for applicability to their facilities and consider actions, if
appropriate, to preclude a similar problem occurring at their facilities.
However, suggestions contained in this information notice do not constitute NRC
requirements; therefore, no specific action or written response is required.
Background:
On January 17, 1980 the Tennessee Valley Authority notified the NRC (NCR 19P)
of the failure of a containment isolation valve to operate properly at their
Sequoyah Nuclear Plant Units 1 and 2. The utility' s investigation indicated
that the failure was caused by the key, which locks the Bettis actuator to the
Henry Pratt valve shaft, falling out of place.
On May 1, 1980, the Henry Pratt Company notified the NRC of this condition.
The company indicated that they had alerted all of their nuclear customers of
the problem and that they had provided their customers with recommendations for
field modifications to correct the problem.
On the basis of the above notifications and a belief that other manufacturers
may be using a similar connection method, the NRC issued IE Circular No. 80-12,
"Valve-Shaft-to-Actuator Key May Fall Out of Place When Mounted Below Horizon-
tal Axis," on May 14, 1980.
Description of Circumstances:
On December 14, 1984 the Arizona Nuclear Power Project notified the NRC (DER
84-101) of the failure of a containment isolation system valve to operate
properly at their Palo Verde Nuclear Generating Station Units 1, 2, and 3. The
utility' s investigation indicated that the failure was caused by the key, which
locks the Limitorque actuator to the Henry Pratt valve, falling out of place.
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IN 85-67
August 8, 1985
Page 2 of 2
On May 23, 1985, the Henry Pratt Company notified (Part 21 Report No. 85-267)
the NRC of this condition and indicated that they had alerted all of their
nuclear customers of the problem. The company indicated that they had recom-
mended that their customers inspect the actuator to shaft connections and that
they had provided their customers with recommendations for changes to their
valve installation, repair, and replacement procedures. These procedure
changes recommended that ". . . Loctite 242 (formerly designated as CV) or 271
(formerly designated as AV) should be applied to all four sides of the key
prior to reassembly if valve/operator connection is broken for any reason.
Loctite Grade 277 is also acceptable although its higher shear strength may
make its disassembly more difficult. "
Henry Pratt also recommended that the NRC issue a supplement to IE Circular No.
80-12 to emphasize ". . . that when actuators of any type and manufacture are
removed from Pratt valves and reinstalled in the field . . ." Loctite should
be used. Because circulars are no longer issued, this recommendation is being
met by this information notice.
It must be noted that this type of problem can occur not just in valves manu-
factured by Henry Pratt, but in any valve that uses a key to attach the actua-
tor to the valve shaft when the actuator is mounted below the horizontal axis.
While the NRC cannot recommend the use of Loctite on valves manufactured by
companies other than Henry Pratt, it does suggest that each utility contact its
valve manufacturers to determine the appropriate method of preventing the keys
from falli-n . ..
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 oc'dan, Director
Divisijbn f Emergency Preparedness
andlEn ineering Response
Office of Inspection and Enforcement
Technical Contacts: Richard J. Kiessel , IE
(301) 492-8119
Edward R. Schweibinz, RIII
(312) 790-5542
Attachment: List of Recently Issued IE Information Notices
Attachment 1
IN 85-67
August 8, 1985
LIST OF RECENTLY ISSUED
IE INFORMATION NOTICES
Information Date of
Notice No. Subject Issue Issued to
85-66 Discrepancies Between 8/7/85 All power reactor
As-Built Construction facilities holding
Drawings And Equipment holding an OL or CP
Installations
85-65 Crack Growth In Steam 7/31/85 All PWR facilities
Generator Girth Welds holding an OL or CP
85-64 BBC Brown Boveri Low-Voltage 7/26/85 All power reactor
K-Line Circuit Breakers, With facilities holding
Deficient Overcurrent Trip an OL or CP
Devices Models OD-4 and 5
85-63 Potential for Common-Mode 7/25/85 All power reactor
Failure of Standby Gas Treat- facilities holding
ment System on Loss of Off- an OL or CP
Site Power
85-62 Backup Telephone Numbers to 7/23/85 All power ,reactor
the NRC Operations Center facilities holding
an OL and certain
fuel facilities
85-61 Misadministrations to Patients 7/22/85 All power reactor
Undergoing Thyroid Scans facilities holding
an OL and certain
fuel facilities
85-60 Defective Negative Pressure 7/17/85 All power reactor
Air-Purifying, Fuel Facepiece facilities holding
Respirators an OL or CP
85-59 Valve Stem Corrosion Failures 7/17/85 All power reactor
facilities holding
an OL or CP
85-58 Failure Of A General Electric 7/17/85 All power reactor
Type AK-2-25 Reactor Trip facilities designed
Breaker by B&W and CE holding
an OL or CP
OL = Operating License
CP = Construction Permit
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