Information Notice 1991-23, Accidental Radiation Overexposures to Personnel Due to Industrial Radiography Accessory Equipment Malfunctions
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS
WASHINGTON, D.C. 20555
March 26, 1991 NRC INFORMATION NOTICE NO. 91-23: ACCIDENTAL RADIATION OVEREXPOSURES TO
PERSONNEL DUE TO INDUSTRIAL RADIOGRAPHY
ACCESSORY EQUIPMENT MALFUNCTIONS
Addressees
All Nuclear Regulatory Commission (NRC) licensees authorized to use sealed
sources for industrial radiography.
Purpose
This information notice is being issued to alert licensees to recent
radiography incidents involving both extremity and whole body overexposures
of radiographers. These occurred during industrial radiographic operations
as a result of:
(1) not surveying a radiographic exposure device and source
guide tube after each exposure; or (2) using either a magnetic or non-magnetic
stand for applications that applied stresses exceeding the limits of the stand.
It is expected that licensees will review this notice, distribute it to
responsible staff, and consider actions, as appropriate, to avoid similar
problems. However, suggestions contained in this information notice do not
constitute any new NRC requirements, and no written response is required.
Description of Circumstances
The following cases are recent events reported to NRC that have resulted in
radiation overexposures to radiographers and radiography assistants as a
result of improper handling of radioactive sealed sources and inattention
to radiation safety procedures.
Case 1:
A radiographer had been performing exposures of welds at the base
T a 300,000 gallon waste storage6tank, with a radiography camera equipped
with a 14-foot guide tube. A tungsten collimator had been positioned on the
end of a guide tube that was clamped to a stand that was magnetically attached
to the tank wall. After cranking out the 80-curie iridium-192 (Ir-192) source
for an exposure approximately 10 feet above the base of the tank, the radiogra- pher heard the collimator fall. After straightening out the guide tube, the
radiographer fully retracted the cable, and consequently thought that the
source was in the shielded position of the camera. Subsequently, the radiogra- pher removed his dosimetry, picked up a survey instrument, walked up to the end
of the source guide tube and removed the collimator, without observing the meter
reading.
As he was unscrewing the nozzle of the guide tube, the source fell-to
the ground. The radiographer immediately left the area, and notified the proper
authorities. Exposure estimates to the radiographer, based on source activity
and exposure time estimates, are 8.9 rem whole body, and 1070 rem to the right
hand.
IN 91-23 March 26, 1991 Case 2: A radiographer and his assistant were performing radiographic
exposures of welds on a 48-inch diameter tank.
After the sixth exposure, the radiographer left the immediate area to load film in a belt. While the
radiographer was away, the assistant set up the seventh exposure and cranked
out the source. The assistant had turned the crank about two or three times
when he saw that the magnetically mounted stand, that held the guide tube
near the exterior of the tank, had fallen.
When the stand fell, the assistant's
personnel dosimeter (chirper) began to alarm, so he quickly cranked the source
back into the shielded position. Because his chirper stopped alarming, he
thought that the source was in the shielded position, so he did not survey
the area (the licensee later reported that the chirper was found to be
malfunctioning due to a shorted ground wire). Instead, he walked over to the
tank, repositioned the magnetic stand and source guide tube with his right
hand, and returned to the camera to proceed with the exposure. When he cranked
out the 50-curie Ir-192 source, he noted that his chirper did not alarm, so he
looked at his pocket dosimeter and noticed that it was off scale high. When
the radiographer returned, the assistant told him what had happened and that
his pocket dosimeter had gone off scale. The assistant told the radiographer
that he did not think he had received an overexposure, but that he thought his
pocket dosimeter was off-scale because he had bumped it earlier. The radiographer
and his assistant continued to work and did not inform the Radiation Safety
Officer of the incident until the assistant's hands showed clinical signs of
radiation injury.
From reenactments, clinical observations, and calculations, the overexposure to the assistant radiographer's hand was estimated to be
between 1500 and 3000 rem. The attending physician stated that amputation of
one or more fingers could be necessary. The whole body dose to the assistant, as measured by his TLD, was 365 millirem.
Case 3:
This radiographic operation involved the use of an 80-curie Ir-192 source. After completing two radiographs of a pipe weld, an assistant
radiographer disassembled the equipment in order to move the exposure device
to another location. While doing this, he removed the source guide tube and
draped it around his neck so that his hands would be free to carry the
remaining equipment approximately 50 feet.
As he removed the guide tube from
around his neck, he noticed that the sealed source fell from the tube to the
ground.
The assistant notified the radiographer, who telephoned the company
owner and, following his direction, successfully retrieved the source to a
shieldeG position within the exposure device.
The radiographer's film badge
was immediately sent for processing (the assistant radiographer was not wearing
a dosimeter and was immediately sent to a hospital for a medical examination).
The cytogenetic studies revealed equivalent whole body doses of 17 rem for the
radiographer and 24 rem for the assistant.
The assistant developed an area of
redness on the left side of his neck, which later showed signs of more
significant damage to skin tissue in an area approximately 10 centimeters in
diameter. The physician determined that the observed effect corresponded to
an overexposure to the skin of 5000-7000 rem. There were no medical effects
observed for the radiographer.
IN 91-23 March 26, 1991 Discussion:
All licensees are reminded of the importance of ensuring the safe performance
of licensed activities, in accordance with NRC regulations, requirements of
their licenses, and accepted health physics practices. The aforementioned
cases illustrate: the lack of radiation surveys following the retraction of a
sealed source; failure to wear a direct reading pocket dosimeter and either a
film badge or TLD; failure to personally supervise an assistant radiographer
while using radiographic exposure devices; the improper use of a magnetic or
non-magnetic stand that cannot hold the weight of the intended equipment
(such as a 12-pound collimator); the necessity of consistently following
standard operating and, when necessary, emergency procedures; and the need to
understand the significance of radiation doses that result from the misuse of
large radiographic sources. Sealed sources for radiography are capable of
delivering significant unintended exposures to radiographers, assistants, and
members of the general public, when source management procedures are not
followed.
Although it might seem obvious that common sense would prevent radiation
workers from picking up highly radioactive sources or guide tubes that might
inadvertently contain a dislodged radiographic source, the number of
unplanned radiation exposures of this type indicates that "common sense'
cannot be counted on, in such a situation. Licensees are responsible for
ensuring the safe performance of licensed activities in accordance with NRC
regulations and the terms of their licenses. In so doing, licensees should
not only provide adequate training, but should also exercise close supervision
over their employees, to ensure compliance with procedures and with NRC or any
other applicable requirements. All'workers should understand the consequences
of improperly handling a radiographic source containing large quantities of
Ir-192. Such improper handling can cause a significant, undesired, radiation
dose to both the whole body and extremities, and can easily result in the
amputation of several fingers, the development of a tumor, or death.
No written response is required by this information notice.
If you have any- questions about this matter, please contact the appropriate regional office
or this office.
Richard E. Cunningham, Director
Division of Industrial and
Medical Nuclear Safety
Office of Nuclear Material Safety
and Safeguards
Technical Contact:
Cynthia G. Jones, NMSS
(301) 492-0629 Attachments:
1. List of Recent NMSS Information Notices
2. List of Recent NRR Information Notices
Attachment 1
March 26, 1991 LIST OF RECENTLY ISSUED
NMSS INFORMATION NOTICES
Information
Date of
Notice No.
Subject
Issuance
Issued to
91-16
91-14
91-03
91-02
Unmonitored Release Pathways
from Slightly Contaminated Re- cycle and Recirculation Water
Systems At A Fuel Facility
Recent Safety-Related Inci- dents at Large Irradiators
Management of Wastes Contam- inated with Radioactive
Materials ("Red Bag" Waste
and Ordinary Trash)
Brachytherapy Source Management
Requirements for Use of
Nuclear Regulatory Comm- ission-(NRC-)Approved
Transport Packages for
Shipment of Type A Quanti- ties of Radioactive Materials.
Fitness for Duty
Denial of Access to
Current Low-Level Radio- active Waste Disposal
Facilities
Effective Use of Radiation
Safety Committees to
Exercise Control Over
Medical Use Programs
03/06/91 All fuel cycle facilities.
03/05/91
All Nuclear Regulatory
Commission (NRC) licensees
authorized to possess and
use sealed sources at
large irradiators.
01/07/91 All medical licensees.
01/07/91
All Nuclear Regulatory
Commission (NRC) medi- cal licensees author- ized to use byproduct
material for medical
purposes.
12/31/90
All registered users
of NRC-approved
packages.
12/24/90
All U.S. Nuclear
Regulatory Commission
(NRC) and non-power
reactor licensees.
12/5/90
All Michigan holders
of NRC licenses.
11/6/90
All NRC licensees
authorized to use
byproduct material
for medical purposes.
90-82
90-81
90-75
90-71
Attachment 2
I'
N 91-23
.
March 26, 1991 LIST OF RECENTLY ISSUED
NRC INFORMATION NOTICES
Information
Date of
Notice No.
Subject
Issuance
Issued to
91-22
91-21
91-20
90-43, Supp. 1
91-19
91-18
90-25, Supp. 1
91-17
91-16 Four Plant Outage Events In- volving Loss of AC Power or
Coolant Spills
Inadequate Quality Assurance
Program of Vendor Supplying
Safety-Related Equipment
Electrical Wire Insulation
Degradation Caused Failure in
A Safety-Related Motor
Control Center
Mechanical Interference with
Thermal Trip Function in GE
Molded-Case Circuit Breakers
Steam Generator Feedwater
Distribution Piping Damage
High-Energy Piping Failures
Caused by Wall Thinning
Loss of Vital AC Power with
Subsequent Reactor Coolant
System Heat-Up
Fire Safety of Temporary
Installations or Services
Unmonitored Release Pathways
from Slightly Contaminated
Recycle and Recirculation
Water Systems at A Fuel
Facility
03/19/91
All holders of OLs or
CPs for nuclear power
reactors.
03/19/91
All holders of OLs or
CPs for nuclear power
reactors and all
recipients of NUREG-004(
"Licensee Contractor an(
Vendor Inspection Statu!
Report" (White Book).
03/19/91
All holders of OLs or
CPs for nuclear power
reactors.
03/13/91
All holders of OLs or
CPs for nuclear power
reactors.
03/12/91
All holders of OLs or
CPs for pressurized
water reactors (PWRs).
03/12/91
All holders of OLs or
CPs for nuclear power
reactors.
03/11/91
All holders of OLs or
CPs for nuclear power
reactors.
03/11/91
All holders of OLs or
CPs for nuclear power
reactors.
03/06/91
All fuel cycle
facilities.
OL = Operating License
CP = Construction Permit
IN 91- March , 1991 Discussion:
All licensees are reminded of the importance of ensuring the safe performance
of licensed activities, in accordance with NRC regulations, requirements of
their licenses, and accepted health physics practices.
The aforementioned
cases illustrate: the lack of radiation surveys following the retraction of a
sealed source; failure to wear a direct reading pocket dosimeter and either a
film badge or TLD; failure to personally supervise an assistant radiographer
while using radiographic exposure devices; the improper use of a magnetic or
non-magnetic stand that cannot hold the weight of the intended equipment
(such as a 12-pound collimator); the necessity of consistently following
standard operating and, when necessary, emergency procedures; and the need to
understand the significance of radiation doses that result from the misuse of
large radiographic sources.
Sealed sources for radiography are capable of
delivering significant unintended exposures to radiographers, assistants, and
members of the general public, when source management procedures are not
followed.
Although it might seem obvious that common sense would prevent radiation
workers from picking up highly radioactive sources or guide tubes that might
inadvertently contain a dislodged radiographic source, the number of
unplanned radiation exposures of this type indicates that "common sense"
cannot be counted on, in such a situation.
Licensees are responsible for
ensuring the safe performance of licensed activities in accordance with NRC
regulations and the terms of their licenses.
In so doing, licensees should
not only provide adequate training, but should also exercise close supervision
over their employees, to ensure compliance with procedures and with NRC or any
other applicable requirements.
All workers should understand the consequences
of improperly handling a radiographic source containing large quantities of
Such improper handling can cause a significant, undesired, radiation
dose to both the whole body and extremities, and can easily result in the
amputation of several fingers, the development of a tumor, or death.
No written response is required by this information notice.
If you have any
questions about this matter, please contact the appropriate regional office
or this office.
Richard E. Cunningham, Director
Division of Industrial and
Medical Nuclear Safety, NMSS
Technical Contact:
Cynthia G. Jones, NMSS
(301) 492-0629 Attachment:
1. List of Recent NMSS Information Notices
2. List of Recent NRR Information Notices
Editor/NMSS
EKraus
3/06/91
- See previous concurrence
OFC :IMOB*
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NAME :CJones/cj/ll:CTrottier
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DATE :3/05/91
- 3/11/91
- 3/14/91
- 3A15 91
- 3/ \\/91
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OFFICIAL RECORD COPY
INRADIO
IN 91- March
, 1991 Discussion:
All licensees are reminded of the importance of ensuring the safe performance of
licensed activities, in accordance with NRC regulations, requirements of their
licenses, and accepted health physics practices.
The aforementioned cases
illustrate: the lack of radiation surveys following the retraction of a sealed
source; failure to wear a direct reading pocket dosimeter and either a film
badge or TLD; failure to personally supervise an assistant radiographer while
using radiographic exposure devices; the improper use of a magnetic or
non-magnetic stand that cannot hold the weight of the intended equipment (such
as a 12-pound collimator); the necessity of consistently following standard
operating and, when necessary, emergency procedures; and the need to understand
the significance of radiation doses that result from the misuse of large
radiographic sources.
Sealed sources for radiography are capable of delivering
significant unintended exposures to radiographers, assistants, and members of
the general public, when source management procedures are not followed.
Although it might seem obvious that common sense would prevent radiation workers
from picking up highly radioactive sources or guide tubes that might inadvertently
contain a dislodged radiographic source, the number of unplanned radiation
exposures of this type indicates that "common sense" cannot be counted on, in
such a situation.
Licensees are responsible for ensuring the safe performance
of licensed activities in accordance with NRC regulations and the terms of
their licenses.
In so doing, licensees should not only provide adequate training, but should also exercise close supervision over their employees, to ensure
compliance with procedures and with NRC or any other applicable requirements.
All workers should understand the consequences of improperly handling a radiographic
source containing large quantities of Ir-192.
Such improper handling can cause
a significant, undesired, radiation dose to both the whole body and extremities, and can easily result in the amputation of several fingers, the development of
a tumor, or death.
No written response is required by this information notice.
If you have any
questions about this matter, please contact the appropriate regional office or
this office.
Richard E. Cunningham, Director
Division of Industrial and
Medical Nuclear Safety, NMSS
Technical Contact:
Cynthia G. Jones, NMSS
(301) 492-0629 Attachments:
1. List of Recent NMSS Information Notices
2. List of Recent NRR Information Notices
Editor/NMSS
EKraus
3/06/91
- See previous concurrence
OFC :IMOB*
- IMO
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- IMNS
- IMNS
NAME :CJones/cj/ll:CTrittier
- J t
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JGl n
- GSjoblom
- RECunningham:
DATE :3/05/91
- 3/1/191
- 3Ii/l
- 3/11491
- 3/ /91
- 3/ /91
OFFICIAL RECORD COPY
INRADIO
IN 91- March , 1991 Discussion:
All licensees are reminded of the importance if ensuring the safe performance of
licensed activities, in accordance with NRC regulations, requirements of their
licenses, and accepted health physics practices. The aforementioned cases
illustrate: the lack of radiation surveys following the retraction of a sealed
source; failure to wear a direct reading pocket dosimeter and either a film
badge or TLD; failure to personally supervise an assistant radiographer while
using radiographic exposure devices; the improper use of a magnetic or
non-magnetic stand which cannot hold the weight of the intended equipment (such
as a 12-pound collimator); the necessity of consistently following standard
operating and, when necessary, emergency procedures; and a need to understand
the significance of radiation doses that result from the misuse of large
radiographic sources. Sealed sources for radiography are capable of delivering
significant unintended exposures to radiographers, assistants and members of
the general public, when source management procedures are not followed.
Although it may appear obvious that common sense should prevent radiation
workers from picking up highly radioactive sources or guide tubes that may
inadvertently contain a dislodged radiographic source, the number of unplanned
radiation exposures of this type indicates that "common sense" has not been
effective. Licensees are responsible for ensuring the safe performance of
licensed activities in accordance with NRC regulations and the terms of their
licenses.
In so doing, licensees should not only provide adequate training, but
should also exercise close supervision over their employees to ensure compliance
with procedures and with NRC or any other applicable requirements. All workers
should have a clear understanding of the significance of improperly handling a
radiographic source containing large quantities of Ir-192. Consequently, the
potential for causing a significant, undesired radiation dose to both whole body
and extremities are great, and can easily result in severe radiation consequences:
the amputation of several fingers, the development of a tumor, or death.
No written response is required by this information notice. If you have any
questions about this matter, please contact the appropriate regional office or
this office.
Richard E. Cunningham, Director
Division of Industrial and
Medical Nuclear Safety, NMSS
Technical Contact:
Cynthid G. Jones, NMSS
(301) 492-0629 Attachments:
1. List of Recent NMSS Information Notices
2. List of Recent NRR Information Notices
Editor/NMSS
EKraus
3/ /91 OFC
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DATE :3/1/<91
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- 3/ /91
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OFFICIAL RECORD COPY
INRADIO