Bulletin 81-02: Failure of Gate Type Valves to Close Against Differential Pressure
SSINS No. 6820
Accession No.:
8011040283
IEB 81-02
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
WASHINGTON, D.C. 20555
April 9, 1981
IE Bulletin No. 81-02: FAILURE OF GATE TYPE VALVES TO CLOSE AGAINST
DIFFERENTIAL PRESSURE
Description of Circumstances:
As a part of its pressurized water reactor (PWR) Safety and Relief Valve
Testing Program, the Electric Power Research Institute (EPRI) conducted
limited testing of a number of valves used on PWRs as power-operated relief
valve (PORV) isolation or block valves. These tests indicate a number of
cases in which certain of these valves failed to fully close under
conditions that approximated those of their intended service (i.e.,
saturated steam at approximately 2,400 psi). The valves that failed to fully
close are gate type motor-operated valves that may be used in various
safety-related applications in addition to PORV block valves.
Background on EPRI Testing:
The proposed full-scale qualification testing of PORV block valves, with a
completion date of July 1, 1982, was first provided to the utilities in a
September 5, 1980, draft of NUREG-0737. The item was formally issued, with
Commission approval, in NUREG-0737 on October 31, 1980.
The block valve qualification testing was proposed in NUREG-0737 primarily
as an additional means of reducing the number of challenges to the emergency
core cooling system and the safety valves during plant operation.
In anticipating a request for PWR block valve testing, EPRI decided to make
provisions for the installation of block valves between the test steam
source and the test PORV in July 1980 at the Marshall test facility. The
Marshall test facility is a full-flow steam test facility owned by Duke
Power Company. Test PORVs had been carefully selected, with close
coordination between EPRI, its consultants and PWR utilities, to assure that
PORVs representative of those in service or intended for service would be
tested. However, for the block valves that have been tested concurrently,
this selection process was not followed because an NRC block valve test
program had not been formulated. Therefore, seven readily available valves
were obtained and tested by EPRI, primarily to obtain some general baseline
information on block valve closure capability.
For the block valves that were tested, EPRI had not established, at least at
the time of testing, the population of plants, either operating or under
construction, that might have a valve of the type needed for testing. In
addition, it should be noted that the test conditions used at Marshall to
date were only those that were determined to be applicable for steam testing
of PORVs.
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IEB 81-02
April 9, 1981
Page 2 of 4
These test conditions were selected after review by EPRI, utilities, and PWR
NSSS vendors. NRC staff also reviewed and concurred with the test
conditions. To date, there has been no similar specific determination by
EPRI or the NRC staff as to the relevance of the Marshall block valve test
conditions to the conditions in any specific PWR plant under which a block
valve should be able to close to isolate a stuck-open PORV.
To date, EPRI has tested a total of seven PORV block valves, all at the
Marshall facility. During these tests, the following valves failed to fully
close during the EPRI PORV block valve testing:
1. Westinghouse Electro-Mechanical Division (W-EMD) 3-inch Valves - These
valves, which are manufactured by W-EMD, can be identified by the
yokemounted nameplates that are stamped "WESTINGHOUSE" and include
"VALVE IDENT." and "VALVE I.D." numbers given in Table 1. Supplemental
analyses and water testing, performed by W-EMD, determined that a
4-inch valve also would not close fully and therefore is included in
this bulletin. The nameplate data on this valve are given in Table 1.
These analyses and tests also determined the threshold differential
pressure across the valves above which closure cannot be assured. These
values are given in Table 1. A list of power reactor facilities
believed to have the affected valves is given in Table 2. It is our
understanding that W-EMD has notified these facilities of the failure
of these valves to fully close.
2. Borg-Warner Nuclear Valve Division (BW-NVD) 3-inch 1500-pound Motor-
Operated Gate Valves - These valves can be identified by BW-NVD part
numbers 75460, 77910, and 79190. Supplemental testing to determine
threshold differential pressures for less severe service has yet to be
completed. A list of power reactor facilities believed to have the
affected valves is given in Table 3. BW-NVD has submitted a 10 CFR Part
21 report in which they indicated that they have notified these
facilities of the failure of these valves to fully close. (Note:
Similar valves with BW-NVD part numbers 74380 and 74380-1 have been
modified, retested, and demonstrated to close under test conditions. As
a result, they are not included in this bulletin.)
3. Anchor Darling 3-inch 1540-pound Double-Disc Valve - This valve, the
first of a series of specially designed valves, has been modified,
retested, and demonstrated to close under test conditions. The
remaining valves will be similarly modified during manufacture. As a
result, they are not included in this bulletin.
It must be cautioned that Tables 2 and 3 may not be complete. For example,
the staff is aware of one power reactor facility that obtained affected
valves from another inventory. For this reason, this bulletin is applicable
to all power reactor, facilities with an operating license or construction
permit.
The tests and analyses performed to date raise doubts as to the ability of
the affected valves to close under less severe service conditions. These
valves have also been supplied for utilization in a number of safety-related
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IEB 81-02
April 9, 1981
Page 3 of 4
applications. In the case of the W-EMD valves, they are also provided as
spares or replacements through direct sales from the manufacturer. For this
reason, this bulletin is applicable to the affected valves that are required
to close with a differential pressure across them in safety-related systems
or as PORV block valves.
The responsibility for notification and corrective actions based on adverse
test results continues to lie with the utilities and vendors in the
industry. NRC will continue to monitor the progress of the qualification
program. All adverse test data will continue to be evaluated on a
case-by-case basis. NRC staff will take appropriate action, if necessary,
to assure that the necessary corrective actions are made in a timely manner.
Actions to be Taken by Licensees:
1. Within 30 days of the issuance date of this bulletin, ascertain whether
any of the affected valves have been installed, or are maintained as
spares for installation, where they are required to close with a
differential pressure across them in safety-related systems or as PORV
block valves. The differential pressures of concern include the
following:
a. For the W-EMD manufactured valves, values in excess of the
threshold values in Table 1.
b. For the BW-NVD valves, any value.
2. If no affected valves are identified, report this to be the case and
ignore the items below.
3. If any affected valves are identified as being installed, take
corrective action and evaluate the effect that failure to close under
any condition requiring closure would have on system(s) operability
pursuant to the facility technical specifications for continued
operation.
4. If any affected valves are identified as spares, either modify the
valves so that they are qualified for the intended service or obtain
qualified replacements prior to installation.
5. Within 45 days of the issuance date of this bulletin, submit a report
to NRC listing the affected valves identified, their service or planned
service, the maximum differential pressure at which they would be
required to close, the safety consequences of the valve's failure to
close, the corrective action taken or planned, and the schedule for
completing the corrective action.
Actions to be Taken by Construction Permit Holders:
1. Ascertain whether any of the affected valves are or will be installed
or maintained as spares for installation where they are required to
close
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IEB 81-02
April 9, 1981
Page 4 of 4
with a differential pressure across them in safety-related systems or
as PORV block valves. The differential pressures of concern include the
following:
a. For the W-EMD manufactured valves, values in excess of the
threshold values in Table 1.
b. For the BW-NVD valves, any value.
2. If no affected valves are identified, report this to be the case and
ignore the items below.
3. If any affected valves are identified, either modify the valves so that
they are qualified for the intended service or obtain qualified
replacements prior to startup.
4. Within 90 days of the issuance date of this bulletin, submit a report
to NRC listing the affected valves identified, their planned service,
the maximum differential pressure at which they would be required to
close, the safety consequences of the valve's failure to close, the
corrective action taken or planned, and the schedule for completing the
corrective action.
For those cases in which reports have already been submitted in accordance
with the Technical Specification, 10 CFR Parts 21 and/or 50.55(e), this
information need not be resubmitted. Rather, licensees or construction
permit holders should reference this earlier report and submit only the
additional information requested above.
Reports, signed under oath or affirmation under the provisions of Section
182a of the Atomic Energy Act of 1954, shall be submitted to the Director of
the appropriate NRC Regional Office and a copy shall be forwarded to the
Director of the NRC Office of Inspection and Enforcement, Washington, D.C.
20555.
If you need additional information regarding this matter, please contact the
appropriate NRC Regional Office.
This request for information was approved by GAO under blanket clearance
number R0072 that expires November 30, 1983. Comments on burden and
duplication should be directed to Office of Management and Budget, Room
3201, New Executive Office Building, Washington, D.C. 20503.
Attachments:
1. Table 1 - Identification of W-EMD
Manufactured Valves and Differential
Pressure Limits for Operation
2. Table 2 - Partial List of Plants With
Affected Valves Manufactured by W-EMD
3. Table 3 - Partial List of Plants With
Affected Valves Manufactured by BW-NVD
4. Recently issued IE Bulletins
.
Attachment 1
April 9, 1981
IEB 81-02
TABLE 1. IDENTIFICATION OF W-EMD MANUFACTURED VALVES AND DIFFERENTIAL
PRESSURE LIMITS FOR VALVE OPERATION
Nominal W-EMD
Valve Model "VALVE ***
Size (in.) Reference IDENT."* "VALVE I.D."** (psid)
3 3GM88 03OOOGM88 3GM58 or 3GM78 or 3GM88 1500
3GM88 03002GM88 3GM58 or 3GM78 or 3GM88 1500
3GM99 03001GM99 3GM58 or 3GM78 or 3GM88 750
4 4GM88 04OOOGM88 4GM78 or 4GM88 750
4GM88 04002GM88 4GM78 or 4GM88 750
4 4GM87 04OOOGM87 4GM77 750
4GM87 04002GM87 4GM77 750
* This number is found on the yoke-mounted nameplate and occupies the
first nine positions of a 24-position number. It is used in evaluating
the functional P requirements.
** This number is found on the yoke-mounted nameplate and occupies the
first three positions of a six-position number. Valves sold as spares
or replacements may not contain this number.
*** Pressure below which valve will close (as shipped).
Notes: A "position" may contain more than one character. The
three-position "VALVE I.D." number consists of five digits in the
three positions; for example, 3 GM 78.
All nameplates have "VALVE IDENT." numbers, but those sold as
spares or replacements may not have "VALVE I.D." numbers. The
"VALVE IDENT. " number includes the manufacturer's model
reference, and the "VALVE I.D." number is a reference to the valve
system application. The "VALVE I.D." number also appears on
Westinghouse valve indexes and system flow diagrams. There is no
reference to the "VALVE IDENT. " number on these indexes or flow
diagrams.
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Attachment 2
April 9, 1981
IEB 81-02
TABLE 2. PARTIAL LIST OF PLANTS WITH
AFFECTED VALVES MANUFACTURED BY W-EMD
"VALVE IDENT." Number
04OOOGM88
04002GM88
03OOOGM88 04OOOGM87
03002GM88 03001GM99 04002GM87
Plant
Operating plants (supplied as spares or replacements except as noted):
Beaver Valley 1 X
Connecticut Yankee X
Farley 1, 2 X*
Indian Point 2 X
Kewaunee X
North Anna 1, 2 X
Oconee 1, 2, 3 X X
San Onofre 1 X
Surry 1, 2 X X X
Zion 1, 2 X
Nonoperating plants (supplied as original scope of supply except as noted):
Beaver Valley 2 X X
Braidwood 1, 2 X X
Byron 1, 2 X X
Callaway 1, 2 X X
Comanche Peak 1, 2 X X
Harris 1, 2, 3, 4 X X
Jamesport 1, 2 X X
Marble Hill 1, 2 X X
San Onofre 2, 3 X**
Seabrook 1, 2 X X
South Texas 1, 2 X
Summer X X
Vogtle 1, 2 X X
Watts Bar 1, 2 X X
Wolf Creek X X
* Transferred from inventory at another plant.
** Spares or replacements.
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Attachment 3
April 9, 1981
IEB 81-02
TABLE 3. PARTIAL LIST OF PLANTS WITH
AFFECTED VALVES MANUFACTURED BY BW-NVD
Plant NVD-P/N
Arkansas Nuclear One, Unit 2 75460
Bellefonte 79190
Palo Verde 77910
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Page Last Reviewed/Updated Tuesday, March 09, 2021