Information Notice 2003-03, Part 21 - Inadequately Staked Capscrew Renders Residual Heat Removal Pump Inoperable: Difference between revisions

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{{#Wiki_filter:UNITED STATESNUCLEAR REGULATORY COMMISSIONOFFICE OF NUCLEAR REACTOR REGULATIONWASHINGTON, DC 20555-0001January 27, 2003NRC INFORMATION NOTICE 2003-03:PART 21 - INADEQUATELY STAKEDCAPSCREW RENDERS RESIDUAL HEAT
{{#Wiki_filter:UNITED STATES


===REMOVAL PUMP INOPERABLE===
NUCLEAR REGULATORY COMMISSION
 
OFFICE OF NUCLEAR REACTOR REGULATION
 
WASHINGTON, DC 20555-0001 January 27, 2003 NRC INFORMATION NOTICE 2003-03:                  PART 21 - INADEQUATELY STAKED
 
CAPSCREW RENDERS RESIDUAL HEAT
 
REMOVAL PUMP INOPERABLE


==Addressees==
==Addressees==
Line 23: Line 31:


==Purpose==
==Purpose==
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice to informaddressees of recently observed inadequately staked capscrews on casing wear rings of
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice to inform


residual heat removal pumps. It is expected that recipients will review the information for
addressees of recently observed inadequately staked capscrews on casing wear rings of
 
residual heat removal pumps. It is expected that recipients will review the information for


applicability to their facilities and consider actions, as appropriate, to avoid similar problems.
applicability to their facilities and consider actions, as appropriate, to avoid similar problems.
Line 34: Line 44:


==Description of Circumstances==
==Description of Circumstances==
At Vogtle Electric Generating Plant (VEGP) Unit 2, on October 22, 2002, while the unit wasdefueled, residual heat removal (RHR) pump A was started for dynamic fill and vent of the RHR
At Vogtle Electric Generating Plant (VEGP) Unit 2, on October 22, 2002, while the unit was


system.  Moments later, the pump tripped.  Personnel found that the pump shaft could not be
defueled, residual heat removal (RHR) pump A was started for dynamic fill and vent of the RHR


hand-turned. An investigation determined that a casing wear ring capscrew had come loose
system. Moments later, the pump tripped. Personnel found that the pump shaft could not be


and lodged between the impeller and the back casing wear ring.  It was found that the pump
hand-turned. An investigation determined that a casing wear ring capscrew had come loose


was last operated on October 11, 2002, when the unit was in Mode 6 (refueling). It is believed
and lodged between the impeller and the back casing wear ring. It was found that the pump
 
was last operated on October 11, 2002, when the unit was in Mode 6 (refueling). It is believed


that the capscrew came loose and lodged between the impeller and the back casing wear ring
that the capscrew came loose and lodged between the impeller and the back casing wear ring


as the pump was being placed into standby status on October 11, 2002. The root cause of this event was determined by the licensee to be the failure of themanufacturer to properly stake the back casing wear ring capscrews.  Each capscrew is
as the pump was being placed into standby status on October 11, 2002.


torqued and staked as a redundant measure to hold the capscrews in place. Although the back
The root cause of this event was determined by the licensee to be the failure of the
 
manufacturer to properly stake the back casing wear ring capscrews. Each capscrew is
 
torqued and staked as a redundant measure to hold the capscrews in place. Although the back


casing wear rings had been staked, the staking was inadequate to prevent at least one of the
casing wear rings had been staked, the staking was inadequate to prevent at least one of the
Line 54: Line 70:
capscrews from backing out of the back casing wear ring after it had lost its torque and become
capscrews from backing out of the back casing wear ring after it had lost its torque and become


loose. RHR pump B was inspected and found to have a similar condition. Spare back casing
loose. RHR pump B was inspected and found to have a similar condition. Spare back casing


wear rings in the warehouse were also inspected and found to have inadequately staked
wear rings in the warehouse were also inspected and found to have inadequately staked


capscrews. Capscrews on the back casing rings of both RHR pumps were properly staked
capscrews. Capscrews on the back casing rings of both RHR pumps were properly staked
 
prior to the pumps being returned to service.
 
Discussion
 
The improperly staked capscrews on both RHR pumps represented a condition that could have


prior to the pumps being returned to service.  DiscussionThe improperly staked capscrews on both RHR pumps represented a condition that could haveprevented fulfilment of a safety function of a system needed to remove residual heat. There is
prevented fulfilment of a safety function of a system needed to remove residual heat. There is


also the potential for loose parts to result in unpredictable damage to safety related
also the potential for loose parts to result in unpredictable damage to safety related


components for accident mitigation. Discussions with pump vendor personnel determined that there are approximately 60 of thesepumps in service in the nuclear industry, most with several years of service, and that this was
components for accident mitigation.
 
Discussions with pump vendor personnel determined that there are approximately 60 of these


the first failure of this type. Additionally, 15 of these pumps, including the 4 pumps in VEGP
pumps in service in the nuclear industry, most with several years of service, and that this was
 
the first failure of this type. Additionally, 15 of these pumps, including the 4 pumps in VEGP


Units 1 & 2, had undergone a coupling modification in recent years that replaced the back
Units 1 & 2, had undergone a coupling modification in recent years that replaced the back


casing ring. However, it is not known if the back casing ring defect is limited to only those
casing ring. However, it is not known if the back casing ring defect is limited to only those


casing rings that were procured for the modifications or if the original pump back casing rings
casing rings that were procured for the modifications or if the original pump back casing rings


also have this defect. Nonetheless, this was the first failure of this type for any of the 60
also have this defect. Nonetheless, this was the first failure of this type for any of the 60
pumps.Vendor: Ingersoll-RandModel No: 8X20WDFBack Casing Ring Part No: 6BCapscrew No: 118CThis information notice requires no specific action or written response.  If you have anyquestions about the information in this notice, please contact one of the technical contacts
pumps.
 
Vendor: Ingersoll-Rand
 
Model No: 8X20WDF


listed below or the appropriate project manager from the NRC's Office of Nuclear Reactor
Back Casing Ring Part No: 6B


Regulation (NRR). /RA/William D. Beckner, Program Director
Capscrew No: 118C
 
This information notice requires no specific action or written response. If you have any
 
questions about the information in this notice, please contact one of the technical contacts
 
listed below or the appropriate project manager from the NRCs Office of Nuclear Reactor
 
Regulation (NRR).
 
/RA/
                                                William D. Beckner, Program Director
 
Operating Reactor Improvements Program


===Operating Reactor Improvements Program===
Division of Regulatory Improvement Programs
Division of Regulatory Improvement Programs


Office of Nuclear Reactor RegulationTechnical contacts: D. Billings, NRRG. Bedi, NRR 301-415-1175301-415-1393 E-mail: deb1@nrc.govE-mail: gsb2@nrc.govJ. Zeiler, Region 2706-554-9901 E-mail: jxz@nrc.govAttachment: List of Recently Issued NRC Information Notices
Office of Nuclear Reactor Regulation
 
Technical contacts:       D. Billings, NRR              G. Bedi, NRR
 
301-415-1175                  301-415-1393 E-mail: deb1@nrc.gov          E-mail: gsb2@nrc.gov
 
J. Zeiler, Region 2
                          706-554-9901 E-mail: jxz@nrc.gov
 
Attachment: List of Recently Issued NRC Information Notices
 
*See previous concurrence
 
DOCUMENT NAME: G:\RORP\OES\Staff Folders\Billings\VogCapscrewIN.wpd
 
OFFICE      OES:RORP:DRIP              Tech Editor          Region II              Region II
 
NAME        DBillings                  PKleene*              JZeiler*                BRBonser*
  DATE          /      /2003            01/14/2003            01/21/2003              01/22/2003 OFFICE      DE:EMEB                    DE:EMEB              SC:OES:RORP:DRIP        PD:RORP:DRIP
 
NAME        BSGurjendra                DTerao*              TReis                  WDBeckner
 
DATE          /      /2003            01/23/2003            01/24/2003              01/27/2003
 
Attachment LIST OF RECENTLY ISSUED
 
NRC INFORMATION NOTICES


*See previous concurrenceDOCUMENT NAME: G:\RORP\OES\Staff Folders\Billings\VogCapscrewIN.wpdOFFICEOES:RORP:DRIPTech EditorRegion IIRegion IINAMEDBillingsPKleene*JZeiler*BRBonser*DATE      /        /200301/14/200301/21/200301/22/2003OFFICEDE:EMEBDE:EMEBSC:OES:RORP:DRIPPD:RORP:DRIPNAMEBSGurjendraDTerao*TReisWDBecknerDATE      /        /200301/23/200301/24/200301/27/2003
_____________________________________________________________________________________
______________________________________________________________________________________OL = Operating License
Information                                              Date of


CP = Construction PermitAttachment LIST OF RECENTLY ISSUEDNRC INFORMATION NOTICES
Notice No.              Subject                          Issuance      Issued to


_____________________________________________________________________________________InformationDate of
_____________________________________________________________________________________
2003-02          Recent Experience with                01/16/2003      All holders of operating licenses


===Notice No.        SubjectIssuanceIssued to===
Reactor Coolant System                                 or construction permits for
_____________________________________________________________________________________2003-02Recent Experience withReactor Coolant System


===Leakage and Boric Acid===
Leakage and Boric Acid                                 pressurized water reactors
Corrosion01/16/2003All holders of operating licensesor construction permits for


pressurized water reactors
Corrosion                                              (PWRs).


(PWRs).2003-01Failure of a Boiling WaterReactor Target Rock Main
2003-01          Failure of a Boiling Water            01/15/2003      All holders of operating licenses


Steam Safety/Relief Valve01/15/2003All holders of operating licensesor construction permits for
Reactor Target Rock Main                              or construction permits for


nuclear power reactors, except
Steam Safety/Relief Valve                              nuclear power reactors, except


those that have permanently
those that have permanently
Line 115: Line 182:
permanently removed from the
permanently removed from the


reactor.2002-35Changes to 10 CFR Parts 71and 72 Quality Assurance
reactor.
 
2002-35          Changes to 10 CFR Parts 71            12/20/2002      All holders of 10 CFR Part 71 and 72 Quality Assurance                               quality assurance program
 
Programs                                              approvals and all 10 CFR Part 72 licensees and certificate holders.
 
2002-34          Failure of Safety-Related              11/25/2002      All holders of operating licenses
 
Circuit Breaker External                              or construction permits for
 
Auxiliary Switches at Columbia                        nuclear power reactors.
 
Generating Station
 
2002-33          Notification of Permanent              11/22/2002      All teletherapy and radiation
 
Injunction Against Neutron                            processing licensees.
 
Products Incorporated of
 
Dickerson, Maryland
 
2002-29          Recent Design Problems in              11/06/2002      All holders of operating licenses


Programs12/20/2002All holders of 10 CFR Part 71quality assurance program
(Errata)          Safety Functions of Pneumatic                          or construction permits for


approvals and all 10 CFR Part 72 licensees and certificate holders.2002-34Failure of Safety-RelatedCircuit Breaker External
Systems                                                nuclear power reactors.


===Auxiliary Switches at Columbia===
Note:            NRC generic communications may be received in electronic format shortly after they are
Generating Station11/25/2002All holders of operating licensesor construction permits for


nuclear power reactors.2002-33Notification of PermanentInjunction Against Neutron
issued by subscribing to the NRC listserver as follows:
                To subscribe send an e-mail to <listproc@nrc.gov >, no subject, and the following


===Products Incorporated of===
command in the message portion:
Dickerson, Maryland11/22/2002All teletherapy and radiationprocessing licensees. 2002-29(Errata)Recent Design Problems in Safety Functions of Pneumatic
                                    subscribe gc-nrr firstname lastname


Systems11/06/2002All holders of operating licensesor construction permits for
______________________________________________________________________________________
OL = Operating License


nuclear power reactors.Note:NRC generic communications may be received in electronic format shortly after they areissued by subscribing to the NRC listserver as follows:To subscribe send an e-mail to <listproc@nrc.gov >, no subject, and the followingcommand in the message portion:subscribe gc-nrr firstname lastname}}
CP = Construction Permit}}


{{Information notice-Nav}}
{{Information notice-Nav}}

Latest revision as of 05:00, 24 November 2019

Part 21 - Inadequately Staked Capscrew Renders Residual Heat Removal Pump Inoperable
ML030240029
Person / Time
Site: Vogtle Southern Nuclear icon.png
Issue date: 01/27/2003
From: Beckner W
NRC/NRR/DRIP/RORP
To:
Billings, Danny, NRR/OES/ROR, 415-1175
References
TAC M7213 IN-03-003
Download: ML030240029 (5)
v • d • e


UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, DC 20555-0001 January 27, 2003 NRC INFORMATION NOTICE 2003-03: PART 21 - INADEQUATELY STAKED

CAPSCREW RENDERS RESIDUAL HEAT

REMOVAL PUMP INOPERABLE

Addressees

All holders of operating licenses or construction permits for nuclear power reactors.

Purpose

The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice to inform

addressees of recently observed inadequately staked capscrews on casing wear rings of

residual heat removal pumps. 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 in this information notice are not NRC requirements; therefore, no

specific action or written response is required.

Description of Circumstances

At Vogtle Electric Generating Plant (VEGP) Unit 2, on October 22, 2002, while the unit was

defueled, residual heat removal (RHR) pump A was started for dynamic fill and vent of the RHR

system. Moments later, the pump tripped. Personnel found that the pump shaft could not be

hand-turned. An investigation determined that a casing wear ring capscrew had come loose

and lodged between the impeller and the back casing wear ring. It was found that the pump

was last operated on October 11, 2002, when the unit was in Mode 6 (refueling). It is believed

that the capscrew came loose and lodged between the impeller and the back casing wear ring

as the pump was being placed into standby status on October 11, 2002.

The root cause of this event was determined by the licensee to be the failure of the

manufacturer to properly stake the back casing wear ring capscrews. Each capscrew is

torqued and staked as a redundant measure to hold the capscrews in place. Although the back

casing wear rings had been staked, the staking was inadequate to prevent at least one of the

capscrews from backing out of the back casing wear ring after it had lost its torque and become

loose. RHR pump B was inspected and found to have a similar condition. Spare back casing

wear rings in the warehouse were also inspected and found to have inadequately staked

capscrews. Capscrews on the back casing rings of both RHR pumps were properly staked

prior to the pumps being returned to service.

Discussion

The improperly staked capscrews on both RHR pumps represented a condition that could have

prevented fulfilment of a safety function of a system needed to remove residual heat. There is

also the potential for loose parts to result in unpredictable damage to safety related

components for accident mitigation.

Discussions with pump vendor personnel determined that there are approximately 60 of these

pumps in service in the nuclear industry, most with several years of service, and that this was

the first failure of this type. Additionally, 15 of these pumps, including the 4 pumps in VEGP

Units 1 & 2, had undergone a coupling modification in recent years that replaced the back

casing ring. However, it is not known if the back casing ring defect is limited to only those

casing rings that were procured for the modifications or if the original pump back casing rings

also have this defect. Nonetheless, this was the first failure of this type for any of the 60

pumps.

Vendor: Ingersoll-Rand

Model No: 8X20WDF

Back Casing Ring Part No: 6B

Capscrew No: 118C

This information notice requires no specific action or written response. If you have any

questions about the information in this notice, please contact one of the technical contacts

listed below or the appropriate project manager from the NRCs Office of Nuclear Reactor

Regulation (NRR).

/RA/

William D. Beckner, Program Director

Operating Reactor Improvements Program

Division of Regulatory Improvement Programs

Office of Nuclear Reactor Regulation

Technical contacts: D. Billings, NRR G. Bedi, NRR

301-415-1175 301-415-1393 E-mail: deb1@nrc.gov E-mail: gsb2@nrc.gov

J. Zeiler, Region 2

706-554-9901 E-mail: jxz@nrc.gov

Attachment: List of Recently Issued NRC Information Notices

  • See previous concurrence

DOCUMENT NAME: G:\RORP\OES\Staff Folders\Billings\VogCapscrewIN.wpd

OFFICE OES:RORP:DRIP Tech Editor Region II Region II

NAME DBillings PKleene* JZeiler* BRBonser*

DATE / /2003 01/14/2003 01/21/2003 01/22/2003 OFFICE DE:EMEB DE:EMEB SC:OES:RORP:DRIP PD:RORP:DRIP

NAME BSGurjendra DTerao* TReis WDBeckner

DATE / /2003 01/23/2003 01/24/2003 01/27/2003

Attachment LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

_____________________________________________________________________________________

Information Date of

Notice No. Subject Issuance Issued to

_____________________________________________________________________________________

2003-02 Recent Experience with 01/16/2003 All holders of operating licenses

Reactor Coolant System or construction permits for

Leakage and Boric Acid pressurized water reactors

Corrosion (PWRs).

2003-01 Failure of a Boiling Water 01/15/2003 All holders of operating licenses

Reactor Target Rock Main or construction permits for

Steam Safety/Relief Valve nuclear power reactors, except

those that have permanently

ceased operations and have

certified that fuel has been

permanently removed from the

reactor.

2002-35 Changes to 10 CFR Parts 71 12/20/2002 All holders of 10 CFR Part 71 and 72 Quality Assurance quality assurance program

Programs approvals and all 10 CFR Part 72 licensees and certificate holders.

2002-34 Failure of Safety-Related 11/25/2002 All holders of operating licenses

Circuit Breaker External or construction permits for

Auxiliary Switches at Columbia nuclear power reactors.

Generating Station

2002-33 Notification of Permanent 11/22/2002 All teletherapy and radiation

Injunction Against Neutron processing licensees.

Products Incorporated of

Dickerson, Maryland

2002-29 Recent Design Problems in 11/06/2002 All holders of operating licenses

(Errata) Safety Functions of Pneumatic or construction permits for

Systems nuclear power reactors.

Note: NRC generic communications may be received in electronic format shortly after they are

issued by subscribing to the NRC listserver as follows:

To subscribe send an e-mail to <listproc@nrc.gov >, no subject, and the following

command in the message portion:

subscribe gc-nrr firstname lastname

______________________________________________________________________________________

OL = Operating License

CP = Construction Permit


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