Information Notice 1996-26, Recent Problems with Overhead Cranes
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UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
WASHINGTON, D.C. 20555
April 30, 1996
RECENT PROBLEMS WITH OVERHEAD CRANES
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 alert addressees to recent problems with overhead cranes.
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 are not
NRC requirements; therefore, no specific action or written response is
required.
Description of Circumstances
Failure of Overhead Crane Bridge Rail
At the Trojan Nuclear Plant on July 7, 1995, a section of the reactor building
polar crane bridge rail failed. The rail had a crack across the top of the
top flange and a piece of the flange had been displaced. The end of one
section of the rail had failed through the plane of the rail joint bar bolts
extending up through the top flange. Visual and metallographic examination of
the failure plane indicated that much of the failure was preexisting.
Rust on
the failure surfaces and "peening" of some areas indicated that the initial
crack could extend back to the plant's construction.
The licensee research of construction records determined that a nonconformance
report, dated July 26, 1972, noted that the rails were not slotted for bolts
in accordance with the drawings. The corrective action recommended was to
"burn the slots in the field." The licensee determined the cause of the
failure to be torsional shear and bending at the stress risers from the flame- cut holes. Flame cutting the slots left residual stresses in the material
because of the lack of careful preheating and controlled cooling.
Also, sharp
notches, noted in the area of the flame cutting, concentrated the stresses.
The inappropriate use of a cutting torch created an untempered martensitic
heat-affected zone in the high-carbon steel rail.
This zone was especially
sensitive to hydrogen cracking and subsequent brittle crack propagation. The
crack inducing and propagating loading was primarily due to bending of the
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IN 96-26 April 30, 1996 rail head to the outside during episodes of rail misalignment.
The licensee
had observed rail misalignment to be a continuing problem that had caused or
contributed to 19 bridge truck wheel bearing failures over 23 years of
operation.
The root cause of the failure was the inappropriate use of a cutting torch to
enlarge drilled holes to slots in the web of the rail.
This practice created
an untempered, martensitic, heat-affected zone in the rail material that was
sensitive to hydrogen cracking and subsequent brittle crack propagation.
Actuation of Overhead Crane Safety System
At the Prairie Island Nuclear Generating Plant on May 13, 1995, while lifting
a loaded spent fuel storage cask from the spent fuel pool for transfer to the
transport bay, the single-failure-proof overhead crane handling system
automatically stopped on overload, approximately 13 cm (5 inches] from the
high hook point (peak lift point).
The bottom of the cask was above the water
but approximately 8 cm [3 inches] below the operating deck of the spent fuel
pool.
Upon investigation of the event, the licensee, Northern States Power
Company (NSP) determined that the cause of the event was premature actuation
of the crane overload-sensing system.
The setpoint on the overload-sensing
system was set too low.
Upon actuation of the overload-sensing system, control power is automatically removed from the hoist motor and the
conventional holding brakes are activated.
Subsequent to the actuation on
May 13, the cask remained in the hoisted position until a safety evaluation
was made that supported bypassing the sensing system and resuming the cask
lift.
The lift was resumed about 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> after it was stopped, and the cask
was placed in the decontamination area of the transport bay.
NSP initiated a
root-cause analysis to identify the cause of the actuation.
The conclusion of
this analysis was that the overload-sensing system was inaccurately
calibrated.
This event raises a concern for similarly designed overload-sensing systems
associated with single-failure-proof cranes.
As noted in the analysis
reports, this event was a "nuisance trip" that resulted from inaccurate
initial calibration during load cell setting adjustment.
Improved load cell
accuracy can help to reduce any unbalanced loading condition in the system.
Additional details of these events can be found in Inspection Report
No. 50-344/95-06 issued on September 18, 1995, and Inspection Report
No. 50-282/95-06 issued on June 27, 1995.
'2 '
IN 96-26 April 30, 1996 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.
A
Brian K. Grimes, Acting Director
Division of Reactor Program Management
Office of Nuclear Reactor Regulation
Technical contacts:
Robert J. Pate, Region IV
(510) 975-0246 Internet:rjpl@nrc.gov
David B. Pereira, Region IV
(510) 975-0307 Internet:dbp@nrc.gov
Brian E. Thomas, NRR
(301) 415-1210
Internet:betfnrc.gov
Eric J. Benner, NRR
(301) 415-1171 Internet:ejbl@nrc.gov
Russell L. Bywater, Region III
(612) 388-8209 Internet:rlb3@nrc.gov
Attachme: List of Recently I ued NRC Information Notices
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Attachment
April 30, 1996 LIST OF RECENTLY ISSUED
NRC INFORMATION NOTICES
Information
Date of
Notice No.
Subject
Issuance
Issued to
96-25
96-24
96-23
96-22
96-21 Transversing In-Core Probe
Overwithdrawn at LaSalle
County Station, Unit 1 Preconditioning of Molded-
Case Circuit Breakers
Before Surveillance Testing
Fires in Emergency Diesel
Generator Exciters During
Operation Following Unde- tected Fuse Blowing
Improper Equipment Set- tings Due to the Use of
Nontemperature-Compensated
Test Equipment
Safety Concerns Related
to the Design of the Door
Interlock Circuit on
Nucletron High-Dose Rate
and Pulsed Dose Rate
Remote Afterloading
Brachytherapy Devices
Demonstration of Associ- ated Equipment Compliance
with 10 CFR 34.20
Failure of Tone Alert
Radios to Activate When
Receiving a Shortened
Activation Signal
Compliance with 10 CFR
Part 20 for Airborne
04/30/96
04/25/96
04/22/96
04/11/96
04/10/96
04/04/96
04/02/96
03/25/96
All holders of OLs or CPs
for nuclear power reactors
All holders of OLs or CPs
for nuclear power reactors
All holders of OLs or CPs
for nuclear power reactors
All holders of OLs or CPs
for nuclear power reactors
All U.S. NRC Medical to the
Licensees authorized to use
brachytherapy sources in
high- and pulsed-dose-rate
remote afterloaders
All industrial radiography
licensees and radiography
equipment manufacturers
All holders of OLs or CPs
for nuclear power reactors
All material licensees
authorized to possess and
use thorium in unsealed
form
96-20
96-19
96-18 OL = Operating License
CP = Construction Permit
IN 96-26 April 30, 1996 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.
dbvtRA7 by Man K. Grmes
Brian K. Grimes, Acting Director
Division of Reactor Program Management
Office of Nuclear Reactor Regulation
Technical contacts:
Robert J. Pate, Region IV
(510) 975-0246 Internet:rjpl@nrc.gov
David B. Pereira, Region IV
(510) 975-0307 Internet:dbp@nrc.gov
Brian E. Thomas, NRR
(301) 415-1210
Internet:bet@nrc.gov
Eric J. Benner, NRR
(301) 415-1171 Internet:ejbl@nrc.gov
Russell L. Bywater, Region III
(612) 388-8209 Internet:rlb3@nrc.gov
Attachment:
List of Recently Issued NRC Information Notices
Tech Editor Reviewed and Concurred 1/26/96
- ETB FOR
- SEE PREVIOUS CONCURRENCE
NAME:
96-26.IN
To receive a copy of this document. Indicate in the box: wC" = Copy without enclosures 'E' = Copy with enclosures "N" = No copy
OFFICE
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DATE
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04/16/96
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OFFICIAL RECORD COPY
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IN 96-xx
April xx, 1996 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.
Dennis M. Crutchfield, Director
Division of Reactor Program Management
Office of Nuclear Reactor Regulation
Technical contacts:
Robert J. Pate, Region IV
(510) 975-0246 Internet:rJplnrc.gov
David B. Pereira, Region IV
(510) 975-0307 Internet:dbp~nrc.gov
Brian E. Thomas, NRR
(301) 415-1210
Internet:bet~nrc.gov
Eric J. Benner, NRR
(301) 415-1171 Internet:ejbl@nrc.gov
Russell L. Bywater, Region III
(612) 388-8209 Internet:rlb3@nrc.gov
Attachment: List of Recently Issued NRC Information Notices
Tech Editor Reviewed and Concurred 1/26/96
- ETB FOR
- SEE PREVIOUS CONCURRENCE
NAME: G:\\JRT\\CRANE3.IN
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April xx, 1996 Additional details of these events can be found in Inspection Report
No. 50-344/95-06 issued on September 18, 1995 and Inspection Report
No. 50-282/95-06 issued on June 27, 1995. This information notice requ r --
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specific action or written response. If you have any questions about the
information in this notice, please contact one of the technical conta s
listed below.
Dennis M. Crutchfiel
i
Director
Division of Reactor
rogram Management
Office of Nuclear eactor Regulation
Technical contacts:
Robert J. Pate, Region IV
Brian E. omas, NRR
(510) 975-0246
(301) 4 -1210
Internet: rjpl@nrc.gov
Intern : betenrc.gov
David B. Pereira, Region IV
EriJ. Benner, NRR
(510) 975-0307
(3 1) 415-1171 Internet: dbp@nrc.gov
Jnternet: ejbl@nrc.gov
Russell L. Bywater, Region III
(612) 388-8209 Internet: rlb3@nrc.gov
Attachment: List of Recentl
Issued NRC Information Notices
Tech Editor Reviewed and
ncurred 1/26/96
- ETB FOR
- SEE PREVIOUS CONCUR5NCE
NAME: G:\\JRT\\CRANE3.IN
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IN 96-xx
April xx, 1996 Additional details of these events can be found in Inspection Report
No. 50-344/95-06 issued on September 18, 1995 and Inspection Report
No. 50-282/95-06 issued on June 27, 1995. 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.
Dennis M. Crutchfield,
- rector
Division of Reactor Pr gram Management
Office of Nuclear Re ctor Regulation
Technical contacts:
Robert J. Pate, Region IV
Brian E. Thomas, RR
(510) 975-0246
(301) 415-1210
Internet: rjpl@nrc.gov
Internet: be nrc.gov
David B. Pereira, Region IV
Eric J. B ner, NRR
(510) 975-0307
(301) 4 -1171 Internet: dbp@nrc.gov
Inter
t: ejblnrc.gov
Russell L. Bywater, Region III
(612) 388-8209 Internet: rlb3@nrc.gov
Attachment:
List of Recently ssued NRC Information Notices
Tech Editor Reviewed and C curred 1/26/96
- ETB FOR
- SEE PREVIOUS CONCU
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DATE
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Official Record Copy
DOCUMENT NAME:
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IN 96-xx
March xx, 1996 More detailed descriptions of these events are included in Attachment 1 to
this Information Notice. 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.
1"
Dennis M. Crutchfield, Di etor
Division of Reactor Pro am Management
Office of Nuclear Rea or Regulation
Technical contacts:
Robert J. Pate, Region IV
Brian E. Thomas,
(510) 975-0246
(301) 415-1210
Internet: rjplenrc.gov
Internet: bet@ c.gov
David B. Pereira, Region IV
Eric J. Ben r, NRR
(510) 975-0307
(301) 415i
171 Internet: dbp~nrc.gov
Internet ejbl@nrc.gov
Russell L. Bywater, Region III
(612) 388-8209 Internet: rlb3@nrc.gov
Attachment: List of Recently Iss ed NRC Information Notices
Tech Editor Reviewed and Concu ed 1/26/96
- ETB FOR
- SEE PREVIOUS CONCURRENCE /_____
OFFICE
Contacts**
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DATE
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DOCUMENT NAME:
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IN 96-xx
February xx,
6 Technical contacts:
Robert J. Pate, Region IV
Brian E. Thomas, NRR
(510) 975-0246
(301) 415-1210
Internet: rjpl@nrc.gov
Internet: bet@nrc.gov
David B. Pereira, Region IV
William F. Burton, NRR
(510) 975-0307
(301) 415-2583 Internet: dbp~nrc.gov
Internet: wfblnrc.g
Russell L. Bywater, Region III
(612) 388-8209 Internet: rlb3@nrc.gov
Attachment:
List of Recently Issued NRC Info
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