Failures of Main Steam Isolation Check Valves Resulting in Disc SeparationML031130139 |
Person / Time |
---|
Site: |
Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, Mcguire, Nine Mile Point, Palisades, Palo Verde, Perry, Indian Point, Fermi, Kewaunee, Catawba, Harris, Wolf Creek, Saint Lucie, Point Beach, Oyster Creek, Watts Bar, Hope Creek, Grand Gulf, Cooper, Sequoyah, Byron, Pilgrim, Arkansas Nuclear, Three Mile Island, Braidwood, Susquehanna, Summer, Prairie Island, Columbia, Seabrook, Brunswick, Surry, Limerick, North Anna, Turkey Point, River Bend, Vermont Yankee, Crystal River, Haddam Neck, Ginna, Diablo Canyon, Callaway, Vogtle, Waterford, Duane Arnold, Farley, Robinson, Clinton, South Texas, San Onofre, Cook, Comanche Peak, Yankee Rowe, Maine Yankee, Quad Cities, Humboldt Bay, La Crosse, Big Rock Point, Rancho Seco, Zion, Midland, Bellefonte, Fort Calhoun, FitzPatrick, McGuire, LaSalle, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant ![Entergy icon.png](/w/images/7/79/Entergy_icon.png) |
---|
Issue date: |
12/20/1990 |
---|
From: |
Rossi C Office of Nuclear Reactor Regulation |
---|
To: |
|
---|
References |
---|
IN-90-079, NUDOCS 9012140086 |
Download: ML031130139 (10) |
|
Similar Documents at Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, Mcguire, Nine Mile Point, Palisades, Palo Verde, Perry, Indian Point, Fermi, Kewaunee, Catawba, Harris, Wolf Creek, Saint Lucie, Point Beach, Oyster Creek, Watts Bar, Hope Creek, Grand Gulf, Cooper, Sequoyah, Byron, Pilgrim, Arkansas Nuclear, Three Mile Island, Braidwood, Susquehanna, Summer, Prairie Island, Columbia, Seabrook, Brunswick, Surry, Limerick, North Anna, Turkey Point, River Bend, Vermont Yankee, Crystal River, Haddam Neck, Ginna, Diablo Canyon, Callaway, Vogtle, Waterford, Duane Arnold, Farley, Robinson, Clinton, South Texas, San Onofre, Cook, Comanche Peak, Yankee Rowe, Maine Yankee, Quad Cities, Humboldt Bay, La Crosse, Big Rock Point, Rancho Seco, Zion, Midland, Bellefonte, Fort Calhoun, FitzPatrick, McGuire, LaSalle, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant |
---|
Category:NRC Information Notice
MONTHYEARInformation Notice 2020-02, Flex Diesel Generator Operational Challenges2020-09-15015 September 2020 Flex Diesel Generator Operational Challenges ML20225A0322020-09-0303 September 2020 NRC Choice Letter to NAC International with Attached Safety Inspection Report, IR 0721015/2020201, February 24-27, 2020 and July 22, 2020, Inspection of NAC International in Norcross, Georgia Information Notice 2012-09, PWROG-16043-NP-A, Revision 2, PWROG Program to Address NRC Information Notice 2012-09: Irradiation Effects on Fuel Assembly Spacer Grid Crush Strength for Westinghouse and CE PWR Fuel Designs.2019-11-30030 November 2019 PWROG-16043-NP-A, Revision 2, PWROG Program to Address NRC Information Notice 2012-09: Irradiation Effects on Fuel Assembly Spacer Grid Crush Strength for Westinghouse and CE PWR Fuel Designs. Information Notice 2011-20, NRC060 - NRC Information Notice 2011-20: Concrete Degradation by Alkali-Silica Reaction (Nov. 18, 2011)2019-07-24024 July 2019 NRC060 - NRC Information Notice 2011-20: Concrete Degradation by Alkali-Silica Reaction (Nov. 18, 2011) ML19196A2452019-07-15015 July 2019 Public Notice - Sequoyah Nuclear Plant, Unit 2 - Exigent Amendment to Facility Operating License Information Notice 2019-01, Inadequate Evaluation of Temporary Alterations2019-03-12012 March 2019 Inadequate Evaluation of Temporary Alterations ML16028A3082016-04-27027 April 2016 NRC Information Notice; IN 2016-05: Operating Experience Regarding Complications From a Loss of Instrumentation Air Information Notice 2015-05, Inoperability of Auxiliary and Emergency Feedwater Auto Start Circuits on Loss of Main Feedwater Pumps2015-05-12012 May 2015 Inoperability of Auxiliary and Emergency Feedwater Auto Start Circuits on Loss of Main Feedwater Pumps Information Notice 2015-05, Inoperability Of Auxiliary And Emergency Feedwater Auto Start Circuits On Loss Of Main Feedwater Pumps2015-05-12012 May 2015 Inoperability Of Auxiliary And Emergency Feedwater Auto Start Circuits On Loss Of Main Feedwater Pumps Information Notice 2013-20, OFFICIAL EXHIBIT - NYS000538-00-BD01 - NRC Information Notice 2013-20: Steam Generator Channel Head and Tubesheet Degradation (October 3, 2013) (ML13204A143)2013-10-0303 October 2013 OFFICIAL EXHIBIT - NYS000538-00-BD01 - NRC Information Notice 2013-20: Steam Generator Channel Head and Tubesheet Degradation (October 3, 2013) (ML13204A143) Information Notice 2013-20, Official Exhibit - NYS000538-00-BD01 - NRC Information Notice 2013-20: Steam Generator Channel Head and Tubesheet Degradation (October 3, 2013) (ML13204A143)2013-10-0303 October 2013 Official Exhibit - NYS000538-00-BD01 - NRC Information Notice 2013-20: Steam Generator Channel Head and Tubesheet Degradation (October 3, 2013) (ML13204A143) Information Notice 2013-11, OFFICIAL EXHIBIT - NYS000551-00-BD01 - NRC Information Notice 2013-11: Crack-Like Indication at Dents/Dings and in the Freespan Region of Thermally Treated Alloy 600 Steam Generator Tubes (July 3, 2013)2013-07-0303 July 2013 OFFICIAL EXHIBIT - NYS000551-00-BD01 - NRC Information Notice 2013-11: Crack-Like Indication at Dents/Dings and in the Freespan Region of Thermally Treated Alloy 600 Steam Generator Tubes (July 3, 2013) Information Notice 2013-11, Official Exhibit - NYS000551-00-BD01 - NRC Information Notice 2013-11: Crack-Like Indication at Dents/Dings and in the Freespan Region of Thermally Treated Alloy 600 Steam Generator Tubes (July 3, 2013)2013-07-0303 July 2013 Official Exhibit - NYS000551-00-BD01 - NRC Information Notice 2013-11: Crack-Like Indication at Dents/Dings and in the Freespan Region of Thermally Treated Alloy 600 Steam Generator Tubes (July 3, 2013) Information Notice 2010-12, Intervenors' Fifth Motion to Amend and/or Supplement Proposed Contention No. 5 (Shield Building Cracking). Appendix VI: NRC FOIA Responses (B-51 Through B-53); Turkey Point Event Report; NRC Information Notice 2010-12: Contain2012-08-17017 August 2012 Intervenors' Fifth Motion to Amend and/or Supplement Proposed Contention No. 5 (Shield Building Cracking). Appendix VI: NRC FOIA Responses (B-51 Through B-53); Turkey Point Event Report; NRC Information Notice 2010-12: Containment Liner Cor Information Notice 2010-12, Intervenors' Fifth Motion to Amend and/or Supplement Proposed Contention No. 5 (Shield Building Cracking). Appendix VI: NRC FOIA Responses (B-51 Through B-53); Turkey Point Event Report; NRC Information Notice 2010-12: Con2012-08-17017 August 2012 Intervenors' Fifth Motion to Amend and/or Supplement Proposed Contention No. 5 (Shield Building Cracking). Appendix VI: NRC FOIA Responses (B-51 Through B-53); Turkey Point Event Report; NRC Information Notice 2010-12: Containment Liner Cor Information Notice 2010-12, Intervenors' Fifth Motion to Amend And/Or Supplement Proposed Contention No. 5 (Shield Building Cracking). Appendix VI: NRC FOIA Responses (B-51 Through B-53); Turkey Point Event Report; NRC Information Notic2012-08-17017 August 2012 Intervenors' Fifth Motion to Amend And/Or Supplement Proposed Contention No. 5 (Shield Building Cracking). Appendix VI: NRC FOIA Responses (B-51 Through B-53); Turkey Point Event Report; NRC Information Notice 2010-12: Containment Liner Cor Information Notice 2012-13, Boraflex Degradation Surveillance Programs and Corrective Actions in the Spent Fuel Pool2012-08-10010 August 2012 Boraflex Degradation Surveillance Programs and Corrective Actions in the Spent Fuel Pool Information Notice 2012-13, Boraflex Degradation Surveillance Programs And Corrective Actions In The Spent Fuel Pool2012-08-10010 August 2012 Boraflex Degradation Surveillance Programs And Corrective Actions In The Spent Fuel Pool Information Notice 2012-11, Age Related Capacitor Degradation2012-07-23023 July 2012 Age Related Capacitor Degradation ML12031A0132012-02-0606 February 2012 U.S. Nuclear Regulatory Commission Investigation Report No. 2-2010-058, Cpn International, Inc Information Notice 2011-19, Licensee Event Reports Containing Information Pertaining to Defects to Basic Components2011-09-26026 September 2011 Licensee Event Reports Containing Information Pertaining to Defects to Basic Components Information Notice 2011-15, Steel Containment Degradation and Associated License Renewal Aging Management Issues2011-08-0101 August 2011 Steel Containment Degradation and Associated License Renewal Aging Management Issues Information Notice 2011-17, Calculation Methodologies for Operability Determinations of Gas Voids in Nuclear Power Plant Piping2011-07-26026 July 2011 Calculation Methodologies for Operability Determinations of Gas Voids in Nuclear Power Plant Piping Information Notice 2011-13, Official Exhibit - NYS000329-00-BD01 - NRC Information Notice 2011-13, Control Rod Blade Cracking Resulting in Reduced Design Lifetime (Jun 29, 2011) (NRC in 2011-13)2011-06-29029 June 2011 Official Exhibit - NYS000329-00-BD01 - NRC Information Notice 2011-13, Control Rod Blade Cracking Resulting in Reduced Design Lifetime (Jun 29, 2011) (NRC in 2011-13) Information Notice 2011-13, Official Exhibit - Nys000329-00-Bd01 - NRC Information Notice 2011-13, Control Rod Blade Cracking Resulting in Reduced Design Lifetime (Jun 29, 2011) (Nrc in 2011-13)2011-06-29029 June 2011 Official Exhibit - Nys000329-00-Bd01 - NRC Information Notice 2011-13, Control Rod Blade Cracking Resulting in Reduced Design Lifetime (Jun 29, 2011) (Nrc in 2011-13) Information Notice 2011-13, OFFICIAL EXHIBIT - NYS000329-00-BD01 - NRC Information Notice 2011-13, Control Rod Blade Cracking Resulting in Reduced Design Lifetime (Jun 29, 2011) (NRC in 2011-13)2011-06-29029 June 2011 OFFICIAL EXHIBIT - NYS000329-00-BD01 - NRC Information Notice 2011-13, Control Rod Blade Cracking Resulting in Reduced Design Lifetime (Jun 29, 2011) (NRC in 2011-13) Information Notice 2011-04, IN: Contaminants and Stagnant Conditions Affecting Stress Corrosion Cracking in Stainless Steel Piping in Pressurized Water Reactors2011-02-23023 February 2011 IN: Contaminants and Stagnant Conditions Affecting Stress Corrosion Cracking in Stainless Steel Piping in Pressurized Water Reactors Information Notice 2011-04, In: Contaminants and Stagnant Conditions Affecting Stress Corrosion Cracking in Stainless Steel Piping in Pressurized Water Reactors2011-02-23023 February 2011 In: Contaminants and Stagnant Conditions Affecting Stress Corrosion Cracking in Stainless Steel Piping in Pressurized Water Reactors Information Notice 2011-04, in: Contaminants and Stagnant Conditions Affecting Stress Corrosion Cracking in Stainless Steel Piping in Pressurized Water Reactors2011-02-23023 February 2011 in: Contaminants and Stagnant Conditions Affecting Stress Corrosion Cracking in Stainless Steel Piping in Pressurized Water Reactors Information Notice 2010-26, New England Coalition'S Motion for Leave to Reply to NRC Staff'S Objection to Nec'S Notification of Information Notice 2010-26 and Entergy'S Response to the Supplement to Nec'S Petition for Commission Review of LBP-10-2010-12-30030 December 2010 New England Coalition'S Motion for Leave to Reply to NRC Staff'S Objection to Nec'S Notification of Information Notice 2010-26 and Entergy'S Response to the Supplement to Nec'S Petition for Commission Review of LBP-10-19 Information Notice 2010-26, New England Coalition'S Motion for Leave to Reply to NRC Staff'S Objection to Nec'S Notification of Information Notice 2010-26 and Entergy'S Response to the Supplement to Nec'S Petition for Commission Review2010-12-30030 December 2010 New England Coalition'S Motion for Leave to Reply to NRC Staff'S Objection to Nec'S Notification of Information Notice 2010-26 and Entergy'S Response to the Supplement to Nec'S Petition for Commission Review of LBP-10-19 Information Notice 2010-26, 2010/12/21-NRC Staff'S Objection to Nec'S Notification of Information Notice 2010-262010-12-21021 December 2010 2010/12/21-NRC Staff'S Objection to Nec'S Notification of Information Notice 2010-26 ML13066A1872009-12-16016 December 2009 Draft NRC Information Notice 2009-xx - Underestimate of Dam Failure Frequency Used in Probabilistic Risk Assessments ML1007804482009-11-23023 November 2009 Email from Peter Bamford, NRR to Pamela Cowan, Exelon on TMI Contamination Control Event Information Notice 2009-11, NSP000059-Revised Prefiled Testimony of Northard/Petersen/Peterson-NRC Information Notice 2009-112009-07-0707 July 2009 NSP000059-Revised Prefiled Testimony of Northard/Petersen/Peterson-NRC Information Notice 2009-11 Information Notice 2009-10, Official Exhibit - NYS000019-00-BD01- NRC Information Notice 2009-10, Transformers Failures - Recent Operating Experience (Jul. 7, 2009) (NRC in 2009-10)2009-07-0707 July 2009 Official Exhibit - NYS000019-00-BD01- NRC Information Notice 2009-10, Transformers Failures - Recent Operating Experience (Jul. 7, 2009) (NRC in 2009-10) Information Notice 2009-09, Improper Flow Controller Settings Renders Injection Systems Inoperable and Surveillance Did Not Identify2009-06-19019 June 2009 Improper Flow Controller Settings Renders Injection Systems Inoperable and Surveillance Did Not Identify Information Notice 2008-12, Reactor Trip Due to Off-Site Power Fluctuation2008-07-0707 July 2008 Reactor Trip Due to Off-Site Power Fluctuation Information Notice 2008-11, Service Water System Degradation at Brunswicksteam Electric Plant Unit 12008-06-18018 June 2008 Service Water System Degradation at Brunswicksteam Electric Plant Unit 1 Information Notice 2008-04, Counterfeit Parts Supplied to Nuclear Power Plants2008-04-0707 April 2008 Counterfeit Parts Supplied to Nuclear Power Plants Information Notice 1991-09, Counterfeiting of Crane Valves2007-09-25025 September 2007 Counterfeiting of Crane Valves Information Notice 2007-28, Potential Common Cause Vulnerabilities in Essential Service Water Systems Due to Inadequate Chemistry Controls2007-09-19019 September 2007 Potential Common Cause Vulnerabilities in Essential Service Water Systems Due to Inadequate Chemistry Controls Information Notice 2007-29, Temporary Scaffolding Affects Operability of Safety-Related Equipment2007-09-17017 September 2007 Temporary Scaffolding Affects Operability of Safety-Related Equipment Information Notice 2007-14, Loss of Offsite Power and Dual-Unit Trip at Catawba Nuclear Generating Station2007-03-30030 March 2007 Loss of Offsite Power and Dual-Unit Trip at Catawba Nuclear Generating Station Information Notice 2007-06, Potential Common Cause Vulnerabilities in Essential Service Water Systems2007-02-0909 February 2007 Potential Common Cause Vulnerabilities in Essential Service Water Systems Information Notice 2007-05, Vertical Deep Draft Pump Shaft and Coupling Failures2007-02-0909 February 2007 Vertical Deep Draft Pump Shaft and Coupling Failures Information Notice 2006-31, Inadequate Fault Interrupting Rating of Breakers2006-12-26026 December 2006 Inadequate Fault Interrupting Rating of Breakers Information Notice 2006-29, Potential Common Cause Failure of Motor-operated Valves as a Result of Stem Nut Wear2006-12-14014 December 2006 Potential Common Cause Failure of Motor-operated Valves as a Result of Stem Nut Wear Information Notice 2006-29, Potential Common Cause Failure of Motor-operated Valves As a Result of Stem Nut Wear2006-12-14014 December 2006 Potential Common Cause Failure of Motor-operated Valves As a Result of Stem Nut Wear Information Notice 2006-13, E-mail from M. Mclaughlin on NRC, Regarding NRC Information Notice 2006-13: Groundwater Contamination2006-07-13013 July 2006 E-mail from M. Mclaughlin on NRC, Regarding NRC Information Notice 2006-13: Groundwater Contamination 2020-09-03 The following query condition could not be considered due to this wiki's restrictions on query size or depth: <code> [[:Beaver Valley]] OR [[:Millstone]] OR [[:Hatch]] OR [[:Monticello]] OR [[:Calvert Cliffs]] OR [[:Dresden]] OR [[:Davis Besse]] OR [[:Peach Bottom]] OR [[:Browns Ferry]] OR [[:Salem]] OR [[:Oconee]] OR [[:Mcguire]] OR [[:Nine Mile Point]] OR [[:Palisades]] OR [[:Palo Verde]] OR [[:Perry]] OR [[:Indian Point]] OR [[:Fermi]] OR [[:Kewaunee]] OR [[:Catawba]] OR [[:Harris]] OR [[:Wolf Creek]] OR [[:Saint Lucie]] OR [[:Point Beach]] OR [[:Oyster Creek]] OR [[:Watts Bar]] OR [[:Hope Creek]] OR [[:Grand Gulf]] OR [[:Cooper]] OR [[:Sequoyah]] OR [[:Byron]] OR [[:Pilgrim]] OR [[:Arkansas Nuclear]] OR [[:Three Mile Island]] OR [[:Braidwood]] OR [[:Susquehanna]] OR [[:Summer]] OR [[:Prairie Island]] OR [[:Columbia]] OR [[:Seabrook]] OR [[:Brunswick]] OR [[:Surry]] OR [[:Limerick]] OR [[:North Anna]] OR [[:Turkey Point]] OR [[:River Bend]] OR [[:Vermont Yankee]] OR [[:Crystal River]] OR [[:Haddam Neck]] OR [[:Ginna]] OR [[:Diablo Canyon]] OR [[:Callaway]] OR [[:Vogtle]] OR [[:Waterford]] OR [[:Duane Arnold]] OR [[:Farley]] OR [[:Robinson]] OR [[:Clinton]] OR [[:South Texas]] OR [[:San Onofre]] OR [[:Cook]] OR [[:Comanche Peak]] OR [[:Yankee Rowe]] OR [[:Maine Yankee]] OR [[:Quad Cities]] OR [[:Humboldt Bay]] OR [[:La Crosse]] OR [[:Big Rock Point]] OR [[:Rancho Seco]] OR [[:Zion]] OR [[:Midland]] OR [[:Bellefonte]] OR [[:Fort Calhoun]] OR [[:FitzPatrick]] OR [[:McGuire]] OR [[:LaSalle]] OR [[:Fort Saint Vrain]] OR [[:Shoreham]] OR [[:Satsop]] OR [[:Trojan]] OR [[:Atlantic Nuclear Power Plant]] </code>.
[Table view]The following query condition could not be considered due to this wiki's restrictions on query size or depth: <code> [[:Beaver Valley]] OR [[:Millstone]] OR [[:Hatch]] OR [[:Monticello]] OR [[:Calvert Cliffs]] OR [[:Dresden]] OR [[:Davis Besse]] OR [[:Peach Bottom]] OR [[:Browns Ferry]] OR [[:Salem]] OR [[:Oconee]] OR [[:Mcguire]] OR [[:Nine Mile Point]] OR [[:Palisades]] OR [[:Palo Verde]] OR [[:Perry]] OR [[:Indian Point]] OR [[:Fermi]] OR [[:Kewaunee]] OR [[:Catawba]] OR [[:Harris]] OR [[:Wolf Creek]] OR [[:Saint Lucie]] OR [[:Point Beach]] OR [[:Oyster Creek]] OR [[:Watts Bar]] OR [[:Hope Creek]] OR [[:Grand Gulf]] OR [[:Cooper]] OR [[:Sequoyah]] OR [[:Byron]] OR [[:Pilgrim]] OR [[:Arkansas Nuclear]] OR [[:Three Mile Island]] OR [[:Braidwood]] OR [[:Susquehanna]] OR [[:Summer]] OR [[:Prairie Island]] OR [[:Columbia]] OR [[:Seabrook]] OR [[:Brunswick]] OR [[:Surry]] OR [[:Limerick]] OR [[:North Anna]] OR [[:Turkey Point]] OR [[:River Bend]] OR [[:Vermont Yankee]] OR [[:Crystal River]] OR [[:Haddam Neck]] OR [[:Ginna]] OR [[:Diablo Canyon]] OR [[:Callaway]] OR [[:Vogtle]] OR [[:Waterford]] OR [[:Duane Arnold]] OR [[:Farley]] OR [[:Robinson]] OR [[:Clinton]] OR [[:South Texas]] OR [[:San Onofre]] OR [[:Cook]] OR [[:Comanche Peak]] OR [[:Yankee Rowe]] OR [[:Maine Yankee]] OR [[:Quad Cities]] OR [[:Humboldt Bay]] OR [[:La Crosse]] OR [[:Big Rock Point]] OR [[:Rancho Seco]] OR [[:Zion]] OR [[:Midland]] OR [[:Bellefonte]] OR [[:Fort Calhoun]] OR [[:FitzPatrick]] OR [[:McGuire]] OR [[:LaSalle]] OR [[:Fort Saint Vrain]] OR [[:Shoreham]] OR [[:Satsop]] OR [[:Trojan]] OR [[:Atlantic Nuclear Power Plant]] </code>. |
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
WASHINGTON, D.C. 20555 December 20, 1990
NRC INFORMATION NOTICE NO. IN 90-79: FAILURES OF MAIN STEAM ISOLATION CHECK
VALVES RESULTING IN DISC SEPARATION
Addressees
All holders of operating licenses or construction permits for nuclear power
reactors.
Purpose
This information notice is intended to alert addressees to potential problems
involving the design and location of main steam isolation check valves (MSCVs)
that could result in disc separation as a consequence of fatigue failure of the
post (or stud). 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
On October 8, 1990, the Tennessee Valley Authority (the licensee) noted that
three of four MSCVs had failed at the Sequoyah Nuclear Power Plant, Unit 1. Each
failure involved the disc separating from the swing arm. In 1982, the disc on
one of the same Sequoyah MSCVs had become disconnected, and in 1983, the disc on
a main steam isolation valve (MSIV) at the Joseph M. Farley Nuclear Plant, Unit 2 (effectively the same design as the Sequoyah MSCVs) became disconnected, too.
(See 'Discussion' below.)
In March 1990, before the recent MSCV failures, the licensee inspected an MSCV at
Sequoyah Unit 1 in response to Electric Power Research Institute (EPRI) guidance
(see below). The licensee found that this MSCV was severely worn where the
surface of the swing arm collar met the surface of the disc. The valve post that
connects the disc to the swing arm was worn at the unthreaded portion that meets
the swing arm collar; and both washers, originally located where the threaded and
unthreaded portions of the post meet, were missing. As a result of these
findings, the licensee inspected the other three MSCVs and found that two of them
had similar levels of degradation. To correct the problem, the licensee, in
consultation with the valve manufacturer, modified the posts of all three
affected MSCVs by machining down the unthreaded portion of the posts, adding weld
buildup using high-hardness filler material, and remachining the posts to their
original diameter. They also redistributed the stresses at the post-to-disc
connections by reducing the thread torque preload on the post from 2800 to 2400
f t
~8
K-' V IN 90-79 December 20, 1990 In September and October 1990, personnel at Sequoyah Unit 1 heard loud noises
coming from the steam piping. A radiograph revealed that an MSCV disc had
separated from its swing arm. Further investigation revealed that the discs in
two other MSCVs had also separated from their respective arms. The licensee
found that the detached disc in one MSCV had lodged against its valve stop, and
the detached discs from the other MSCVs had traveled several hundred feet through
the piping and had lodged Just upstream of the turbine throttle valves. All '
valve posts had broken at a machined fillet where the portion threaded into the
disc joins the unthreaded portion that passes through the swing arm collar (see
Figure 1). In addition, an inspection of the MSCVs in Unit 2 revealed cracks
similar to those that led to the 1982 failure at Unit 1. The Unit 2 valves had
not received the weld buildup modification noted above.
Discussion:
The MSCVs at Sequoyah Unit 1 were manufactured by Atwood & Morrill Co., Inc.
These valves are 32-inch, articulated, swing check valves with a single-post
design and are located just downstream of the main steam isolation valves
(MSIVs). All of the MSCVs that experienced disc post failures are actually
welded to their corresponding MSIVs; the MSCV with the disc still intact was
located 2.5 pipe diameters downstream of its corresponding MSIV and was not
severely worn. The NRC staff believes that although the valve location may have
made the MSCVs susceptible to high-cycle, low-stress fatigue failure, the weld
buildup modification in 1990 appears to have so accelerated the rate of fatigue
wear that the posts failed within seven months.
EPRI studied the mechanisms that cause check valves to degrade and the methods to
prevent this degradation. The results of this study are documented in EPRI
NP-5479, Application Guidelines for Check Valves in Nuclear Power Plants,"
January 1988. The EPRI study indicates that placing check valves just downstream
of a source of turbulence could cause failure and is 'deserving of priority
attention." Flow disturbances Just upstream of a check valve can cause discs to
flutter and subject valve internals to cyclic loads and premature failure.
The backstop design may be another possible contributor to the MSCY failures at
Sequoyah Unit 1. The configuration'is such that a single backstop makes contact
with the disc edge. The swing arm is beveled where it contacts the disc, per- mitting oscillation of the disc that is further exaggerated by a 40-mil clear- ance between the post and swing arm collar. This arrangement allows a maximum
resultant disc oscillation of up to approximately 0.25 inch at the rim of the
disc. In the case of Sequoyah Unit 1, the effects of this design were magnified
by having the post built up with filler material'; this modification concentrated
the stresses on the post where it meets the disc and accelerated the failure of
the post. Atwood & Morrill recommended, as corrective action, modifying
Sequoyah's single-backstop MSCV design to a three-point backstop design that may
help limit lateral disc oscillation. The NRC staff has identified that other
Atwood & Morrill and Schutte A Koerting swing check valves with single posts may
be of this design and may, therefore, be susceptible to this mode of failure.
Other valves with a similar design may also be affected.
IN 90-79 December 20, 1990 In previous instances, MSCV discs have separated from their respective swing arms
when the post(s) failed before approaching its design fatigue life. For
instance, the previous Sequoyah Unit 1 failure occurred in 1982 when the post
came unscrewed from its disc when a tack'weld connecting the post to the disc
failed. At Farley Unit 2, in 1983, an Atwood & Morrill, 32-inch MSIV disc
separated when the posts failed. Although neither of these failures involved the
1990 weld buildup modification performed at Sequoyah Unit 1, both cases involved
the articulated check valve design that helps ensure proper disc-to-seat
alignment, but also allows flexure of the disc during flow conditions while the
valve is on the open'backstop. This flexure, caused by flow disturbances, exposed the posts of both the Sequoyah Unit 1 and Farley Unit 2 valves to cyclic
loads and, in the case of Farley Unit 2, resulted in excessive wear and eventual
fatigue failure of the posts.
It appears that any check valve with disc flexure is susceptible to cyclic
fatigue failure -f-the posts. Such features as single-post design, backstop
contact with the disc edge instead of the disc nut, and valve location near a
source of turbulence, increase the susceptibility of a check valve to cyclic
fatigue failure. The result may be that the post unscrews from the disc, unscrews from the nut, or simply fails; and the disc separates. An example of
such a failure is a main feedwater regulator check valve (manufactured by
Pacific Valve Company) disc separation at the San Onofre Nuclear Generating
Station, Unit 1, in 1985, when the post failed because of high flow velocity and
valve installation near a source of turbulence. (Other recent examples of
failures of check valve internals are discussed in Information Notice 90-03,
"Malfunction of Borg-Warner Bolted Bonnet Check Valves Caused by Failure of the
Swing Arm", dated January 23, 1990, Information Notice 89-62, Malfunction of
Borg-Warner Pressure Seal Bonnet Check Valves Caused by Vertical Misalignment of
Disk", dated August 31, 1989, NRC Bulletin No. 89-02, "Stress Corrosion Cracking
of High-Hardness Type 410 Stainless Steel Internal Preloaded Bolting in Anchor
Darling Model S350W Swing Check Valves or Valves of Similar Design", dated
July 19, 1989, and Information Notice 83-54, *Common Mode Failure of Main Steam
Isolation Nonreturn Check Valves", dated August 11, 1983.)
Among the corrective actions taken by the industry in response to these check
valve failures are: tack welding the post to the disc, better disc nut locking
devices, interference threads for the post, multiple-backstop designs, and
multiple-post designs. Despite these actions, check valves continue to fail
prematurely. Most recently, a potential problem was found at Sequoyah Unit 2 during their 1990 refueling outage, where an MSCV had cracks in its post and disc
near the post-to-disc weld similar to those that led to the 1982 post-to-disc
weld failure at Unit 1. These cracks occurred despite the corrective actions--
i.e., reweld of the disc and increased torque preload on the post--taken by the
licensee in response to the 1982 post failure.
Check valves are used widely in the nuclear industry and can play a key role in
the safe operation of the plant. -EPRI has taken steps to improve the longevity
of these valves by providing guidance for improving check valve reliability. The
NRC staff also has developed an action plan (NUREG-1352) aimed at improving check
valve reliability. An underlying concern with check valve reliability appears to
N-' - IN 90-79 December 20, 1990 be that certain features, such as valve installation location and backstop
design, may increase the susceptibility of check valve internals to premature
cyclic fatigue failure.
This information notice requires no specific action or written response. If
you have any questions about this matter, please contact one of the technical
contacts listed below or the appropriate NRR project manager.
Charles E. Ross , D rector
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical Contacts: Angie P. Young, NRR
(301) 492-1167 Yun-Seng Huang, NRR
(301) 492-1417 Edward Girard, RII
(404) 841-4186 Attachments:
1. Figure 1. Articulated, Swing Check Valve with Single Backstop
2. List of Recently Issued NRC Information Notices
Attachment 1 IN 90-79 December 20, 1990 Figure 1. Articulated, Swing Check Valve
with Single Backstop
'
Attachment 2 IN 90-79 December 20, 1990 ,
LIST OF RECENTLY ISSUED
NRC INFORMATION NOTICES
Information Date of
Notice No. Subject Issuance Issued to
90-78 Previously Unidentified 12/18/90 All holders of OLs or
Release Path from Boiling CPs for boiling water
Water Reactor Control Rod reactors (BWRs).
Hydraulic Units
90-77 Inadvertent Removal of Fuel 12/12/90 All holders of OLs or
Assemblies from the Reactor CPs for pressurized- Core water reactors (PWRS).
88-23, Potential for Gas Binding of 12/10/90 All holders of OLs or
Supp. 3 High-Pressure Safety Injection CPs for pressurized- Pumps During A Loss-Of-Coolant water reactors (PWRs).
Accident
90-76 Failure Of Turbine Overspeed 12/7/90 All holders of OLs or
Trip Mechanism Because Of CPs for nuclear power
Inadequate Spring Tension reactors.
90-75 Denial Of Access To Current 12/5/90 All Michigan holders
Low-Level Radioactive Waste of NRC licenses.
Disposal Facilities
90-74 Information on Precursors To 12/4/90 All holders of OLs or
Severe Accidents CPs for nuclear power
reactors.
90-73 Corrosion Of Valve-To- 11/29/90 All holders of OLs or
Torque Tube Keys In CPs for nuclear power
Spray Pond Cross Connect reactors.
Valves
90-72 Testing of Parallel Disc 11/28/90 All holders of OLs or
Gate Valves In Europe CPs for nuclear power
reactors.
90-71 Effective Use of Radi- 11/6/90 All NRC licensees
ation Safety Committees authorized to use by- to Exercise Control Over product material for
Medical Use Programs medical purposes.
90-70 Pump Explosions Involving 11/6/90 All uranium fuel
Ammonium Nitrate fabrication and
conversion facilities.
OL = Operating License
CP = Construction Permit
IN 90-79 December 20, 1990 be that certain features, such as valve installation location and backstop
design, may increase the susceptibility of check valve internals to premature
cyclic fatigue failure.
This information notice requires no specific action or written response. If
you have any questions about this matter, please contact one of the technical
contacts listed below or the appropriate NRR project manager.
KgInaM Signed by
Charles -. rNo, 5 °,stbirector
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical Contacts: Angie P. Young, NRR
(301) 492-1167 Yun-Seng Huang, NRR
(301) 492-1417 Edward Girard, RII
(404) 841-4186 Attachments:
1. Figure 1. Articulated, Swing Check Valve with Single Backstop
2. List of Recently Issued NRC Information Notices
OFC :OEAB:DOEA :EMEB:DET :OEAB:DOEA :RII :RPB:ADM :C:OEAB:DOEA :
NAME :APYOUNG* :YSHUANG* :DFISCHER* :EGIRARD* :TECH ED* :ACHAFFEE* :
DATE :11/02/90 :11/08/90 :11/14/90 :11/14/90 :12/07/90 : 11/16/90 :
OFC :D:DET :C:OGCB:DOEA :D:DOEA :
NAME :JERICHARDSON*:CHBERLINGER
:------------- :------------ ------------------ ------------ ------------:---
DATE :11/21/90 :12/11/90 :/J / /90 :
OFFICIAL RECORD COPY
Document Name: CHECKM *See previous concurrence
IN 90-
November XX, 1990 This information notice requires no specific action or written response. If you
have any questions about this matter, please contact one of the the technical
contacts listed below or the appropriate NRR project manager.
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical Contacts: Angie P. Young, NRR
(301) 492-1167 Yun-Seng Huang, NRR
(301) 492-1417 Edward Girard, RII
(404) 841-4186 Attachments: (1) Diagram of Articulated, Swing Check Valve with Single Backstop
(2) List of Recently Issued KRC Information Notices
OFC :OEAB:DOEA :EMEB:DET :RII
MOEAB;DEA :RPB:ADM :C:OEAB;DOEA :
---- z----- t ar---------r-^-------------}6tt--- ---
NAME :APYOUNG* : G :DF ER EGIRARD :CHAFFEE:
_ _ :------H D------------------------:
DATE :11/02/90 :(T /90 :/g/o/*S/9 :1I : (' /1'/90 :
.D.C:OGCB:DOEA
- E :D:DOEA
' NAM4E :JERICHA ON:CHBERLINGER :CEROSSI : : : :
DATE :11/i I/90 : / /90: / /90:
OFFICIAL RECORD COPY
Document Name: CHECK1
The previous Sequoyah Unit 1 failure occurred in 1982 and involved separation
of the disc from the post due to the failure of the post-to-disc weld. At
Farley in 1983, the disc separated when the bolts that attach the disc to the
swing anm failed in an MSCV of similar size and design as those at Sequoyah.
Neither of these failures involved the 1990 weld buildup modification performed
at Sequoyah 1.
During the current refueling outage, a Sequoyah Unit 2 MSCV was found to have
cracks in the its post and disc near the post-to-disc weld. This appears to be
the same potential failure mechanism which caused the MSCV failure at Sequoyah
Unit 1 in 1982.
This information notice requires no specific action or written response. If
you have any questions about this matter, please contact one of the the
technical contacts listed below or the appropriate NRR project manager.
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical Contacts: Angie P. Young, NRR
(301) 492-1167 Yun-Seng Huang, NRR
(301) 492-1417 Edward Girard, RII
(404) 841-4186 Attachments: (1) Diagram of Atwood and Morrill Co.,Inc. Check Valve
(2) List of Recently Issued NRC Information Notices
OFC :OEAB:DOEA :EMEB:DET :OEAB:DOEA :RX :RPB:ADM :C:OEAB:DOEA :
-- - - - - -.- K
NAWE :APYOUNG :YSHUANG :DFISCHER :EGIRARD :TECH EDJ 42; :ACHAFFEE :
DATE : II/ cg /90 : / /90 / /90 / /90 : I IS/g :/ / /90
OFC :D:DET :C:OGCB:DOEA :D:DOEA : : :
NAME :JERICHARDSON:CHBERLINGER :CEROSSI : : :
DATE : / /90: / /90: / /90: : :
OFFICIAL RECORD COPY
Document Name: (CHECK)
|
---|
|
list | - Information Notice 1997-01, Improper Electrical Grounding Results in Simultaneous Fires in the Control Room and the Safe-Shutdown Equipment Room (8 January 1997, Topic: Safe Shutdown, Emergency Lighting)
- Information Notice 1997-02, Cracks Found in Jet Pump Riser Assembly Elbows at Boiling Water Reactors (6 February 1997)
- Information Notice 1997-03, Defacing of Labels to Comply with 10 CFR 20.1904(b) (20 February 1997)
- Information Notice 1997-04, Implementation of a New Constraint on Radioactive Air Effluents (24 February 1997, Topic: Backfit)
- Information Notice 1997-05, Offsite Notification Capabilities (27 February 1997, Topic: Earthquake)
- Information Notice 1997-06, Weaknesses in Plant-Specific Emergency Operating Procedures for Refilling the Secondary Side of Dry Once-Through Steam Generators (4 March 1997)
- Information Notice 1997-07, Problems Identified During Generic Letter 89-10 Closeout Inspections (6 March 1997, Topic: Hot Short, Safe Shutdown, Weak link)
- Information Notice 1997-08, Potential Failures of General Electric Magne-Blast Circuit Breaker Subcomponents (12 March 1997, Topic: Coatings, Weak link)
- Information Notice 1997-09, Inadequate Main Steam Safety Valve (MSSV) Setpoints and Performance Issues Associated with Long MSSV Inlet Piping (12 March 1997)
- Information Notice 1997-10, Liner Plate Corrosion in Concrete Containments (13 March 1997)
- Information Notice 1997-11, Cement Erosion from Containment Subfoundations at Nuclear Power Plants (21 March 1997)
- Information Notice 1997-12, Potential Armature Binding in General Electric Type Hga Relays (24 March 1997)
- Information Notice 1997-13, Deficient Conditions Associated with Protective Coatings at Nuclear Power Plants (24 March 1997, Topic: Coatings)
- Information Notice 1997-14, Assessment of Spent Fuel Pool Cooling (28 March 1997, Topic: Time to boil, Coatings)
- Information Notice 1997-15, Reporting of Errors and Changes in Large-Break Loss-of-Coolant Accident Evaluation Models of Fuel Vendors and Compliance with 10 CFR 50. 46(a)(3) (4 April 1997, Topic: Coatings, Fuel cladding)
- Information Notice 1997-16, Preconditioning of Plant Structures, Systems, and Components Before ASME Code Inservice Testing or Technical Specification Surveillance Testing (4 April 1997, Topic: Stroke time, Coatings)
- Information Notice 1997-17, Cracking of Vertical Welds in the Core Shroud and Degraded Repair (4 April 1997, Topic: Coatings)
- Information Notice 1997-18, Problems Identified During Maintenance Rule Baseline Inspections (14 April 1997, Topic: Probabilistic Risk Assessment, Coatings, Emergency Lighting)
- Information Notice 1997-19, Safety Injection System Weld Flaw at Sequcyah Nuclear Power Plant, Unit 2 (18 April 1997, Topic: Boric Acid)
- Information Notice 1997-20, Identification of Certain Uranium Hexafluoride Cylinders That Do Not Comply with ANSI N14.1 Fabrication Standards (17 April 1997, Topic: Uranium Hexafluoride)
- Information Notice 1997-21, Availability of Alternate AC Power Source Designed for Station Blackout Event (18 April 1997, Topic: Main transformer failure)
- Information Notice 1997-22, Failure of Welded-Steel Moment Resisting Frames During Northridge Earthquake (25 April 1997, Topic: Earthquake)
- Information Notice 1997-23, Evaluation and Reporting of Fires and Unplanned Chemical Reaction Events at Fuel Cycle Facilities (7 May 1997, Topic: Earthquake, Uranium Hexafluoride)
- Information Notice 1997-24, Failure of Packing Nuts on One-Inch Uranium Hexafluoride Cylinder Valves (8 May 1997, Topic: Uranium Hexafluoride)
- Information Notice 1997-25, Dynamic Range Uncertainties in the Reactor Vessel Level Instrumentation (9 May 1997, Topic: Earthquake)
- Information Notice 1997-26, Degradation in Small-Radius U-Bend Regions of Steam Generator Tubes (19 May 1997, Topic: Eddy Current Testing, Earthquake)
- Information Notice 1997-27, Effect of Incorrect Strainer Pressure Drop on Available Net Positive Suction Head (16 May 1997, Topic: Earthquake)
- Information Notice 1997-28, Elimination of Instrument Response Time Testing Under the Requirements of 10 CFR 50.59 (30 May 1997, Topic: Enforcement Discretion)
- Information Notice 1997-29, Containment Inspection Rule (30 May 1997)
- Information Notice 1997-30, Control of Licensed Material During Reorganizations, Employee-Management Disagreements, and Financial Crises (3 June 1997, Topic: Uranium Hexafluoride)
- Information Notice 1997-31, Failures of Reactor Coolant Pump Thermal Barriers and Check Valves in Foreign Plants (3 June 1997)
- Information Notice 1997-32, Defective Worm Shaft Clutch Gears in Limitorque Motor-Operated Valve Actuators (10 June 1997)
- Information Notice 1997-33, Unanticipated Effect of Ventilation System on Tank Level Indications and Engineering Safety Features Actuation System Setpoint (11 June 1997)
- Information Notice 1997-34, Deficiencies in Licensee Submittals Regarding Terminology for Radiological Emergency Action Levels in Accordance with the New Part 20 (12 June 1997, Topic: Deep Dose Equivalent)
- Information Notice 1997-34, Deficiencies in Licensee Submittals Regarding Terminology for Radiological Emergency Action Levels In Accordance with the New Part 20 (12 June 1997, Topic: Deep Dose Equivalent)
- Information Notice 1997-35, Retrofit to Industrial Nuclear Company (Inc) IR100 Radiography Camera to Correct Inconsistency in 10 CFR Part 34 Compatibility (18 June 1997, Topic: Uranium Hexafluoride)
- Information Notice 1997-35, Retrofit to Industrial Nuclear Company (INC) Ir100 Radiography Camera to Correct Inconsistency in 10 CFR Part 34 Compatibility (18 June 1997)
- Information Notice 1997-36, Unplanned Intakes by Worker of Transuranic Airborne Radioactive Materials and External Exposure Due to Inadequate Control of Work (20 June 1997)
- Information Notice 1997-37, Main Transformer Fault with Ensuing Oil Spill Into Turbine Building (20 June 1997)
- Information Notice 1997-38, Level-Sensing System Initiates Common-Mode Faulure of High-Pressure-Injection Pumps (24 June 1997, Topic: Hydrostatic)
- Information Notice 1997-39, Inadequate 10 CFR 72.48 Safety Evaluations of Independent Spent Fuel Storage Installations (26 June 1997, Topic: Uranium Hexafluoride)
- Information Notice 1997-40, Potential Nitrogen Accumulation Resulting from Backleakage from Safety Injection Tanks (26 June 1997)
- Information Notice 1997-41, Revised - Potentially Undersized Emergency Diesel Generator (EDG) Oil Coolers (27 June 1997)
- Information Notice 1997-42, Management Weaknesses Resulting in Failure to Comply with Shipping Requirements for Special Nuclear Material (27 June 1997, Topic: Uranium Hexafluoride)
- Information Notice 1997-43, License Condition Compliance (1 July 1997, Topic: Ultimate heat sink)
- Information Notice 1997-44, Failures of Gamma Metrics Wide-Range Linear Neutron Flux Channels (1 July 1997)
- Information Notice 1997-45, Environmental Qualification Deficiency for Cables & Containment Penetration Pigtails (2 July 1997)
- Information Notice 1997-46, Unisolable Crack in High-Pressure Injection Piping (9 July 1997, Topic: Flow Induced Vibration)
- Information Notice 1997-47, Inadequate Puncture Tests for Type B Packages Under 10 CFR 71.73(c)(3) (27 June 1997)
- Information Notice 1997-48, Inadequate or Inappropriate Interim Fire Protection Compensatory Measures (9 July 1997, Topic: Safe Shutdown, Unanalyzed Condition, Fire Barrier, Emergency Lighting, Continuous fire watch, Fire Protection Program, Fire Watch)
... further results |
---|