Protecting People and the EnvironmentUNITED STATES NUCLEAR REGULATORY COMMISSION
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS
WASHINGTON, D.C. 20555
March 22, 1990
Information Notice No. 90-20: PERSONNEL INJURIES RESULTING FROM
IMPROPER OPERATION OF RADWASTE
INCINERATORS
Addressees:
All U.S. Nuclear Regulatory Commission licensees who process or incinerate
radioactive waste.
Purpose:
This information notice is intended to inform recipients of recent
industrial accidents involving the operation of radioactive waste
incinerators. It is expected that licensees will review this information,
distribute the notice to responsible safety staff and equipment operators,
and consider actions, as appropriate, to preclude similar accidents from
occurring at their facilities. However, suggestions contained in this
notice do not constitute new NRC requirements, and no written response is
required.
Description of Circumstances:
Two uranium fuel fabrication facilities have reported personnel injuries,
resulting in the accidental amputation of fingers, involving the operation
of radioactive waste incinerators. A description of each of the accidents
is provided in Attachment 1, and were reported to the Occupational Safety
and Health Administration (OSHA) by NRC. In summary, the accidents ap-
parently involved:
o Unauthorized removal of a safety shield
o Failure to follow proper procedures
o Operator error
o Component failure
o Poor safety design
o Inadequate sorting of waste products
The accidents did not directly involve radiation safety hazards. However,
any serious personnel injury in the vicinity of radioactive material has the
potential to escalate to a situation which could result in a radiation
hazard.
Discussion:
Serious personnel injuries can occur when personnel ignore or circumvent
safety systems and equipment. To help prevent such injury, it is important
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IN 90-20
March 22, 1990
Page 2 of 2
that personnel strictly adhere to procedures and operating parameters. It
is also important that maintenance and safety inspectors routinely observe
the operation of equipment and be alert to unauthorized modifications, un-
safe operating conditions and practices, and equipment malfunctions.
When unsafe conditions and practices are noted, it is imperative that unsafe
operations be halted, corrective action taken to resolve the problem, and
employees advised of the conditions and corrective actions. Merely
correcting an unsafe practice and condition without also advising the
affected workforce does not advance the safety goal of eliminating
accidents.
No specific action or written response is required by this information
notice. If you have any questions about this matter, please contact the
technical contact listed below or the appropriate regional office.
Richard E. Cunningham, Director
Division of Industrial and
Medical Nuclear Safety
Office of Nuclear Material Safety
and Safeguards
Technical Contacts: Cynthia Perny, Region II
(404) 331-5559
Charles Hooker, Region V
(415) 943-3784
Attachments:
1. Description of Events
2. List of Recently Issued NMSS Information Notices
3. List of Recently Issued NRC Information Notices
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Attachment 1
IN 90-20
March 22, 1990
Page 1 of 2
DESCRIPTION OF EVENTS
Note: The following descriptions are based on reports from licensee
personnel. They are for informational purposes to illustrate the importance
of following proper safety procedures. The Nuclear Regulatory Commission
makes no representation as to the accuracy of the specific details of the
reports. The licensees also reported these events to OSHA field offices.
Advanced Nuclear Fuels Corporation, Richland, WA.
On September 29, l989, an employee was filling a drum with ash from a
uranium-contaminated waste incinerator. The employee lowered the drum to
check the ash level, but could not get the lift to raise the drum back up.
The worker placed his right hand on the lip of the drum and then reached
around the drum to jiggle the rear limit switch (this switch tells the
controller that the drum is in the proper location). As the worker reached
around the drum, the lift activated and lifted the drum to the cooling
chamber discharge port gasket lip. This crushed and severed the tip of the
right middle finger above the first joint.
The worker reacted by reaching behind him to activate the emergency-off
control. This did not lower the drum. The worker then pulled the emergency
off control again, which turned the system on again, and hit the down
control to release the lift. The lift still did not lower the drum. At
this point, the worker began moving his trapped hand and was able to free
it. Immediately after the hand was freed, the lift activated and the drum
was lowered. Further amputation was required at a hospital, due to the
extent of damage to the finger. No radioactive contamination was found in
or around the wound.
The licensee's investigation identified the cause of the accident as the
failure of the upper limit switch which controls raising of the scissors
lift. The switch failed in the upper or closed position. The controller
believed that the drum was in the up position when, in fact, the worker had
lowered it to look inside the drum. When the worker reached inside the hood
to jiggle the rear limit switch, the upper limit switch activated (opened)
and the lift actuated, lifting the drum.
Follow-up actions by the licensee included:
o Fabrication of a position guide to center drums under the cooling
chamber discharge port
o Installation of proximity switches on the access doors of the cooling
chamber discharge port hood, to disable the lifting sequence when the
doors are opened
o Installation of a second emergency stop button on the hood (new
location)
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Attachment 1
IN 90-20
March 22, 1990
Page 2 of 2
o Installation of handles on the drums, to eliminate the need for
personnel to place their hands on the drum lip
o Engineering review of replacement of upper limit switch with a hydraulic
pressure control system
o Engineering review of lift with lift vendor, to determine if the speed
of the scissors lift could be decreased
General Electric Co., Wilmington, N.C.
On October, 4, l989, an employee was attempting to clear a blockage in a
uranium-contaminated waste incinerator ash discharge chute, when the
horizontal discharge slide activated and severed two fingers on her left
hand below the nail. The employee had removed a plexiglass cover from the
front of the discharge chute and reached up the chute to dislodge banding
material. At the same time, the employee's right hand was on the hydraulic
control lever for the horizontal discharge slide. The slide is a metal
plate that closes the chute opening prior to the discharge chamber being
filled.
The employee had activated the hydraulic start button for the discharge
station pump. The employee then removed the plexiglass cover and with her
right hand pushed the discharge control lever. When the employee reached up
the chute with her left hand to dislodge some blockage, her right hand slid
off the slide control lever, enabling the slide to close and sever her
fingers.
Slight contamination was detected on the finger ends. Based on follow-up
bioassay information, no internal exposure to uranium is believed to have
occurred.
Follow-up actions by the licensee have included:
o Conversion of the hydraulic ash discharge slide system to a manual
system
o Retraining for incinerator operators
o Revision of procedural instructions on ash clean-out
o Installation of a new plexiglass cover for discharge enclosure
o Provision of special tools for clearing choke-ups
o Review and analysis of waste going to the incinerator. Reemphasizing
to waste-sorting personnel the importance of separating combustibles
from non-combustibles.
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