Information Notice 1988-94, Potentially Undersized Valve Actuators
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
WASHINGTON, D.C.
20555
December 2, 1988
NRC INFORMATION NOTICE NO. 88-94: POTENTIALLY UNDERSIZED VALVE ACTUATORS
Addressees
All holders of operating licenses or construction permits for nuclear power
reactors.
Purpose
This information notice is being provided to alert addressees to potential
problems concerning valves that may be equipped with undersized actuators
incapable of providing sufficient thrust to seat, unseat or properly operate
valves during some design conditions.
It is expected that recipients will
review the information for applicability to their facilities and consider
actions, as appropriate, to avoid similar problems. However, suggestions
contained In this information notice do not constitute NRC requirements;
therefore, no specific action or written response is required.
Description of Circumstances
In November 1987, the William B. McGuire Nuclear Station, Unit 1 (McGuire or
licensee), experienced problems with feedwater bypass control valve 1CF-107 for
steam generator 1D. During the startup of the unit, the level on steam genera- tor 1D decreased to approximately 15 percent on the narrow range level instru- mentation when flow through valve 1CF-107 failed to increase as demanded upon
increase of reactor power to above 3 percent.
During the licensee's investi- gation, it was noticed that the valve was not responding as demanded and that
in some cases the valve stroke time was slower than required for the control
signal.
Valve 1CF-107 is a Fisher Controls (Fisher) valve, Model Number
667-ET, that was delivered to McGuire in 1975.
During subsequent investigations by the licensee and Fisher, it was determined
by Fisher that the actuator for valve 1CF-107 had been sized using a calcula- tion that did not explicitly account for any valve packing friction forces.
The licensee identified additional valves supplied by Fisher and requested that
Fisher recalculate the actuator sizes to include allowances for valve packing
friction forces. These evaluations showed that although some valve actuators
were appropriately sized, some undersized actuators existed.
The licensee's immediate corrective actions for these undersized actuators
included spring adjustments wherever possible. In those cases in which com- plete closure against design loads could not be assured, the valves were
8811290538
'
'_ .----'
IN 88-94 December 2, 1988 declared inoperable and were deactivated in their safe positions. Permanent
corrective actions being considered by the licensee include changing control
air operating limits, installing different springs, and installing larger
actuators. The licensee is also considering methods that could be used to
measure actual packing frictional forces for use during actuator resizing
calculations.
Discussion:
Fisher Controls contacted the NRC regarding the potential undersized actuator
issue, and an NRC inspection was subsequently conducted at Fisher to determine
the extent of the problem.
On the basis of a review of Fisher documents and
discussions with Fisher personnel, the NRC determined that actuators for valves
supplied by Fisher may be undersized and incapable of seating, unseating or
properly operating their valves during some design conditions.
Fisher indicated that until the mid-1970s it had supplied sliding stem valves
with Fisher's standard single arrangement teflon packing, as its actuator sizing
technology was principally based on teflon packing.
During the sizing of
actuators for teflon-packed valves, Fisher did not account for the teflon
packing friction forces as, based on their experience, the friction forces were
calculated to be small compared to the actuator air pressure forces, actuator
spring forces, valve differential pressure forces, and valve seating forces.
Around 1975, Fisher began supplying a number of valves with graphite laminate
packing as a result of nuclear power industry requests to eliminate teflon
matertaT from radi to
invironmentMand general ersonml-health and sdfety
concerns resulting in the replacement of asbestos packing material.
In April
1976, Fisher began to explicitly account for packing friction forces in sizing
all valve actuators when it became apparent that graphite packing friction
forces and other non-teflon packing materials contributed significantly to the
overall friction forces. The change was fully implemented for all Fisher orders
shipped after January 1, 1977.
During the NRC inspection, Fisher also stated that some nuclear power plant
licensees may have installed packing different from that provided in the
original valve.
Such a change would be of concern if the new packing creates
higher friction forces than the original packing.
For example, data provided
by Fisher indicates that increased friction forces can result if teflon packing
is replaced with graphite packing or graphite laminate packing is replaced with
graphite ribbon packing.
If the size of the installed actuator cannot overcome
the increased friction forces associated with the packing change, then the
valve may be incapable of performing some of its intended functions.
In addition, Fisher informed the NRC of the potential for undersized actuators
on Fisher 9200 series butterfly valves.
These particular valves employ rotary
shafts rather than sliding stems and are not subject to the same packing
friction concerns previously discussed; however, some of these butterfly valves
may be equipped with undersized actuators for a different reason.
Fisher sized
butterfly valve actuators ordered before March 1, 1982, using a method that
under some circumstances underestimated the torque required to seat or unseat
the butterfly disk in the 9200 series valves.
Butterfly valves ordered after
IN 88-94 December 2, 1988 March 1, 1982, are not subject to this concern because they are equipped with
actuators sized by the current Fisher method that more accurately predicts
valve seat/disk frictional forces.
Conclusion:
The NRC has determined, on the basis of the McGuire event and the inspection at
Fisher Controls, that the following types of valves may be equipped with
undersized actuators-that may not provide sufficient thrust to seat, unseat
or properly operate their valves during some design conditions:
1. Sliding stem valves supplied by any manufacturer that were repacked using
materials or procedures that increased the packing friction forces beyond
those accounted for in sizing the actuators.
2.
Fisher Controls sliding stem valves shipped before January 1, 1977, supplied with graphite and other non-teflon packing. The actuators for
these valves were sized by Fisher without accounting for packing friction
forces. Actuators for sliding stem valves supplied by other manufacturers
may also be undersized, depending on the actuator sizing methods used by
these manufacturers.
3.
Fisher Controls 9200 series butterfly valves ordered before March 1, 1982.
The method used to size the actuators for these valves may have underes- timated the torque needed to seat or unseat the butterfly disk.
Licensees who identify valves with potentially undersized actuators may wish to
contact the appropriate valve manufacturer to obtain additional information.
No specific action or written response is required by this information notice.
If you have any questions regarding this matter, please contact one of the
technical contacts listed below or the Regional Administrator of the appropri- ate regional office.
Charles E. Ross
Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical Contacts:
Joseph J. Petrosino, NRR
(301) 492-0979
Jaime Guillen, NRR
(301) 492-1170
Attachment:
List of Recently Issued NRC Information Notices
"" mnt
December 2, 1988 LIST OF RECENTLY ISSUED
NRC INFORMATION NOTICES
Date of
Informati on
Notice No.
88-93
88-92
88-91
88-90
88-89
88-88
88-87 Subljecti
Teletherapy Events
Potential for Spent Fuel
Pool Draindown
Improper Administration
and Control of
Psychological Tests
Unauthorized Removal of
Industrial Nuclear Gauges
Degradation of Kapton
Electrical Insulation
Degradation of Westinghouse
ARD Relays
Pump Wear and Foreign
Objects In Plant Piping
Systems
Issuance
Issued to
12/2/88
All NRC medical
licensees.
11/22/88
All holders of OLs
or CPs for nuclear
power reactors.
11/22/88
All holders of OLs
or CPs for nuclear
power reactors and
all fuel cycle facility
licensees who possess, use, Import, export, or transport formula
quantities of strategic
11/22/88
All NRC licensees
authorized to possess, use, manufacture, or
distribute industrial
nuclear gauges.
11/21/88
All holders of OLs
or CPs for nuclear
power reactors.
11/16/88
All holders of OLs
or CPs for nuclear
power reactors.
11/16/88
All holders of OLs
or CPs for nuclear
power reactors.-- 86-10S
-- Feedwater Lirr Break
Supp. 3
--
1- t/10/58-
-
All-holders-'o-O tS-----
---
or CPs for nuclear
power reactors.
OL a Operating License
CP a Construction Permit
UNITED STATES
NUCLEAR REGULATORY COMMISSION
WASHINGTON, D.C. 20555
OFFICIAL BUSINESS
PENALTY FOR PRIVATE USE, $300
FIRST CLASS MAIL
POSTAGE & FEES PAID
PERMIT No.
j47
IN 88-94 December 2, 1988 March 1, 1982, are not subject to this concern because they are equipped with
actuators sized by the current Fisher method that more accurately predicts
valve seat/disk frictional forces.
Conclusion:
The NRC has determined, on the basis of the McGuire event and the inspection at
Fisher Controls, that the following types of valves may be equipped with
undersized actuators that may not provide sufficient thrust to seat, unseat
or properly operate their valves during some design conditions:
1. Sliding stem valves supplied by any manufacturer that were repacked using
materials or procedures that increased the packing friction forces beyond
those accounted for in sizing the actuators.
2.
Fisher Controls sliding stem valves shipped before January 1, 1977, supplied with graphite and other non-teflon packing. The actuators for
these valves were sized by Fisher without accounting for packing friction
forces.
Actuators for sliding stem valves supplied by other manufacturers
may also be undersized, depending on the actuator sizing methods used by
these manufacturers.
3.
Fisher Controls 9200 series butterfly valves ordered before March 1, 1982.
The method used to size the actuators for these valves may have underes- timated the torque needed to seat or unseat the butterfly disk.
Licensees who identify valves with potentially undersized actuators may wish to
contact the appropriate valve manufacturer to obtain additional information.
No specific action or written response is required by this information notice.
If you have any questions regarding this matter, please contact one of the
technical contacts listed below or the Regional Administrator of the appropri- ate regional office.
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical Contacts: Joseph J. Petrosino, NRR
(301) 492-0979 B6 Jaime Guillen, NRR
r>D c°
S
(301) 492-1170
,
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Attachment: List of Recently Issued NRC Information Notices
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- SEE PREVIOUS CONCURRENCES
- C/OGCB:DOEA:NRR
CHBerlinger
11/Z>'
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11/28/88
- OGCB:DOEA:NRR *PPMB:ARM *VIB:DRIS:NRR
- C/VfB:DRIS:NRR *D/DRIS:NRR
JGuillen
TechEd
JPetrosino
WBrach
BKGrimes
10/31/88
10/31/88
11/02/88
11/04/88
11/04/88
IN 88-xx
November xx, 1988 March 1, 1982, are not subject to this concern because they are equipped with
actuators sized by the current Fisher method that more accurately predicts
valve seat/disk frictional forces.
Conclusion:
The NRC has determined, on the basis of the McGuire event and the inspection at
Fisher Controls, that the following types of valves may be equipped with
undersized actuators that may not provide sufficient thrust to seat or unseat
their valves during some design conditions:
1. Sliding stem valves supplied by any manufacturer that were repacked using
materials or procedures that increased the packing friction forces beyond
those accounted for in sizing the actuator.
2.
Fisher Controls sliding stem valves shipped before January 1, 1977, supplied with graphite and other non-teflon packing. The actuators for
these valves were sized by Fisher without accounting for packing friction
forces. Actuators for sliding stem valves supplied by other manufacturers
may also be undersized, depending on the actuator sizing methods used by
these manufacturers.
3. Fisher Controls 9200 series butterfly valves ordered before March 1, 1982.
The method used to size the actuators for these valves may have underes- timated the torque needed to seat or unseat the butterfly disk.
Licensees who identify valves with potentially undersized actuators may wish to
contact the appropriate valve manufacturer to obtain additional information.
No specific action or written response is required by this information notice.
If you have any questions regarding this matter, please contact one of the
technical contacts listed below or the Regional Administrator of the appropri- ate regional office.
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical Contacts: Joseph J. Petrosino, NRR
(301) 492-0979
Jaime Guillen, NRR
(301) 492-1170
Attachment: List of Recently Issued NRC Information Notices
a
@
- SEE PREVIOUS CONCURRENCES
D/DOEA:NRR
C/OGCB:DOEA:NRR
CERossi
CHBerlinger
11/
/88
11A2R7/88
- OGCB:DOEA:NRR *PPMB:ARM *VIB:DRIS:NRR
- C/VIB:DRIS:NRR *D/DRIS:NRR
JGuillen
TechEd
JPetrosino
WBrach
BKGrimes
10/31/88
10/31/88
11/02/88
11/04/88
11/04/88
IN 88-xx
November xx, 1988 seat or unseat the butterfly disk in the 9200 series valves.
Butterfly valves
ordered after March 1, 1982, are not subject to this concern because they are
equipped with actuators sized by the current Fisher method that more accurately
predicts valve seat/disk frictional forces.
Conclusion:
The NRC has determined, on the basis of-the McGuire event and the inspection
at Fisher Controls, that the following types of valves may be equipped with
undersized actuators that may not provide sufficient thrust to seat or unseat
their valves during some design conditions:
1. Sliding stem valves supplied by any manufacturer that were repacked
using materials or proceidures that.increased the packing friction
forces beyond those accounted for in sizing the actuator.
2.
Fisher Controls sliding stem valves shipped before January 1, 1977, supplied with graphite and other non-teflon packing.
The actuators
for these valves were sized by Fisher without accounting for packing S2zL
friction forces.
Attuat
stem
alves
nan~ufacturers may also be under kd, depending on the actuato, ;;zin
meithuds used by these manufacturers.
3.
Fisher Controls 9200 series butterfly valves ordered before March 1, 1982.
The method used to size the actuators for these valves may have under- estimated the torque needed to seat or unseat the butterfly disk.
Licensees who identify valves with potentially undersized actuators may wish
to contact the appropriate valve manufacturer to obtain additional information.
No specific action or written response is required by this information notice.
If you have any questions regarding this matter, please contact one of the
technical contacts listed below or the Regional Administrator of the appropriate
regional office.
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical Contacts: Joe Petrosino, NRR
(301) 492-0979
Jaime Guillen, NRR
(301) 492-1170
Attachment:
List f Recently Is ed
RC Information Notices
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