IEB 80-23 Failures of Solenoid Valves Manufactured by Valcor Engineering Corporation (Generic Letter 80-97)
GL80097
UNITED STATES
NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTA ST., N.W., SUITE 3100
ATLANTA, GEORGIA 30303
November 14, 1980
Duke Power Company
ATTN: W. O. Parker, Jr.
Vice President, Steam Production
P. O. Box 2178
Charlotte, NC 28242
Gentlemen:
Enclosed is IE Bulletin No. 80-23 which requires action by you with regard
to your nuclear power facility.
In order to assist the NRC in evaluating the value/impact of each bulletin
on licensees, it would be helpful if you would provide us an estimate of the
manpower expended in conduct of the review and preparation of the report(s)
required by the bulletin. Please estimate separately the manpower
associated with corrective actions necessary following identifaction of
problems through the bulletin.
Should you have any questions regarding this bulletin or the actions
required by you, please contact this office.
Sincerely,
James P. O'Reilly
Director
Enclosures:
1. IE Bulletin No. 80-23
2. List of Recently Issued IE Bulletins
cc w/encl:
J. T. Moore, Project Manager
.
SSINS NO.: 6820
Accession No. :
8008220257
UNITED STATES IEB 80-23
NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
WASHINGTON, D.C. 20555
IE Bulletin No. 80023: FAILURES OF SOLENOID VALVES MANUFACTURED BY VALCOR
ENGINEERING CORPORATION
Introduction:
Valcor Engineering Corporation (Valcor) has submitted 10 CFR 21 Reports
addressing failures of Valcor solenoid valves used at nuclear power
facilities. These failures have occurred at nuclear facilities owned by
Duke Power Company and Omaha Public District, and are purportedly limited to
solenoid valves having part numbers (P/N's) V70900-21-1 and V70900-21-3.
The information presented in this bulletin is intended to shed light on the
defective solenoid valves so that appropriate actions can be taken to
circumvent the degradation of any safety-related system using such solenoid
valves.
DISCUSSION;
The specific Valcor solenoid valves addressed herein were purportedly
designed as Class IE components. However, in light of the reported
failures, it appears that neither the design nor the qualification tests
were adequate for Class IE service. Valcor has attributed the failures to a
latent defect in the magnet wire. Valcor believes that this defect
manifests itself when the solenoid valves are continuously energized at
elevated temperatures by an incompatibility between the magnet wire's
polyvinyl varnish coating and the wire's polyimide insulation which causes a
dielectric breakdown leading to turn-to-turn shorts within the coil.
Valcor states that the above incompatibility is limited to solenoid valves
having P/N's V70900-21-1 and V70900-21-3, and that all customers affected by
the aforementioned defect have been notified. A listing of Valcor customers
so notified and valves purchased follows.
CUSTOMER P.O. NO. VALVE P/N QTY
Anchor-Darling P-827 V70900-21-1,3 24
Anchor-Darling N663 V70900-21-1 6
Casare Bonetti (Italy) 1535/79 V70900-21-3 10
Duke Power Company E95188-11 V70900-21-3 100
Duke (Mill Power) C-97733 V70900-21-1,3 335
Duke Power Company E97822-11 V70900-21-3 70
Ralph Hiller HA-187-0 V70900-21-3 14
Mill Power E52462-73 V70900-21-1,3 20
Omaha Public Pwr Dist. 43472 V70900-21-3 19
Stone and Webster L000 #43 V70900-21-3 8
Copes Vulcan 911,553 V70900-21-1 4
TOTAL 610
.
IEB 80-23
November 14, 1980
Page 2 of 4
Valcor's corrective actions include making arrangements for replacing
existing coils with a newly designed coil using a 997 silicone varnish
coating instead of the polyvinyl varnish. Sample coils of the new design
are scheduled to undergo qualification tests. We do not know the
particulars of these tests, but Valcor has scheduled the first phase of
these tests for completion by November 15, 1980, and has identified the
second phase as an on-going aging test.
Fort Calhoun has replaced twelve of its original solenoid valves with Valcor
type V70900-21-3 valves, ten of which are located inside containment and two
outside. This substitution was made because the original solenoid valves
did not meet the requirements of IE Bulletin No. 79-01. However, subsequent
to the replacement, Fort Calhoun has experienced five failures of these
Valcor solenoid valves. Each failure involved a solenoid valve located
inside containment and designed for operation in the normally energized
mode. These two factors (i.e., continuously energized mode of operation and
a somewhat elevated temperature inside containment) tend to support Valcor's
contention regarding the failure mechanism.
ACTIONS TO BE TAKEN BY HOLDER OF OPERATING LICENSES:
1. Determine whether Valcor solenoid valves having P/N's V70900-21-1 or -3
are used to perform any safety-related function at your facility. If
so, identify the safety-related systems using these solenoid valves,
the total number of such solenoid valves used, and evaluate
acceptability of continued operation with potentially defective
solenoid valves. A report of the results of the evaluation of
continued operation shall be submitted within ten (10) days of the date
of this bulletin and should include factors such as (a) operator's
ability to promptly identify a failing or failed solenoid valve, (b)
effect of solenoid valve failures on safety-related systems and
subsequent operator actions required, and (c) possible degradation of
the power supply serving a failed solenoid valve and the effects on
other components served by said power supply. If no such solenoid
valves are used, you need only submit a negative declaration to this
effect within thirty (30) days of the date of this bulletin and you
need not respond to the remaining items.
2. Licensees of operating plants using the aforementioned solenoid valves
in safety-related applications shall periodically test the coils for
potential turn-to-turn shorts in a manner that will not violate any LCO
or cause any undesirable transient. The tests should account for coil
resistance changes due to temperature effects attributed to the
environment and to I2R losses in the coil to provide accurate
indications of changes in resistance due to turn-to-turn shorts.
These tests are to be initiated within ten (10) days of the date of
this bulletin. The following schedule is recommended until the units
are replaced with qualified units:
.
IEB 80-23
November 14, 1980
Page 3 of 4
(a) Daily for solenoid valves operated in a normally energized mode;
(b) Weekly for solenoid valves operated in a normally deenergized
mode.
Whenever the tests indicate that ten percent or more of the coil turns
have been shorted, said solenoid valve, or its coil, shall be replaced
with a new unit.
3. Licensees of operating plants shall submit a report within forty-five
(45) days of the date of this bulletin describing their longer term
corrective action plan and the date by which the corrective actions
will be implemented. As a minimum, the longer term corrective measures
should include the replacement of the coils with fully qualified coils.
New solenoid valve assemblies (i.e., a repaired unit with a replacement
coil or a completely new unit) shall be demonstrated to be qualified
for its safety-related application per the applicable requirements of
IEEE 323-1974, IEEE 344-1975, IEEE 382-1982 and IE Bulletin No. 79-01B
and supplements thereto.
ACTIONS TO BE TAKEN BY HOLDERS OF CONSTRUCTION PERMITS:
1. Determine whether Valcor solenoid valves having P/N's V70900-21-1 or -3
are to be used to perform safety-related functions at your facility.
If so, a report addressing this matter shall be submitted by the
earlier of the two following dates: (a) within ninety (90) days of
the date of this bulletin; (b) two weeks prior to the date by which
you expect to receive an operating License.
The above report should indicate your plans to replace said valves
prior to commencing operation, if this is the case. Otherwise, if you
propose to commence operation prior to replacing said valves, the
report should indicate the safety-related systems where such valves are
to be used, and should include an evaluation of the acceptability of
operating with potentially defective valves. This evaluation should
address factors such as your proposed test plan, operator's ability to
promptly identify a failing or failed valve, effect of solenoid valve
failure on safety-related systems and subsequent operator actions
required, and the preventive measures you plan to implement to
circumvent the effects of failures of these valves.
If no such valves are to be used in your facility, submit a negative
declaration to this effect within forty-five (45) days of the date of
this bulletin but prior to the date by which you expect to receive an
operating license.
The above requested reports shall be submitted to the director of the
appropriate NRC region within time stipulated for each item in the this
bulletin. A copy of each report shall be forwarded to the Director,
Division of Resident and Regional Reactor Inspection, Office of Inspection
and Enforcement, United States Nuclear Regulatory Commission, Washington,
D.C. 20555.
IEB 80-23
November 14, 1980
Page 4 of 4
Approved by GAO, B180225(R0072); clearance expires November 30, 1980.
Approval was given under a blanket clearance specifically for identified
generic problems.
Page Last Reviewed/Updated Tuesday, March 09, 2021