Information Notice 1987-29, Recent Safety-Related Incidents at Large Irradiators
| ML031190114 | |
| Person / Time | |
|---|---|
| Issue date: | 06/26/1987 |
| From: | Cunningham R NRC/NMSS/IMNS |
| To: | |
| References | |
| IN-87-029, NUDOCS 8706220303 | |
| Download: ML031190114 (6) | |
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Attachment 2
December 7, 1989 UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS
WASHINGTON, D. C. 20555
June 26, 1987
NRC INFORMATION NOTICE NO. 87-29: RECENT SAFETY-RELATED INCIDENTS AT
LARGE IRRADIATORS
Addressees
All NRC licensees authorized to possess and use sealed sources in large
irradiators.
Purpose
i--
This notice is being issued to inform recipients of recent safety-related
incidents at large irradiators, which could have been prevented by proper
management aictions and attention to preventative maintenance programs. It:
is suggested that recipients review this information and their procedures
and consider actions, if appropriate, to ensure both proper preventative
maintenance programs and proper management actions at their facilities.-
However, suggestions contained In this Information Notice do not constitute
NRC requirements; therefore, no specific action or written response is required.
Description of Circumstances
A description of each of six events is provided in Attachment 1. In summary, these events included:
o
hose failure resulting in a leak, failure to report the incident to NRC,
and deliberate cover-up of this incident when NRC tried to investigate, leading to company fines and personnel probation;
o
intentional bypass of safety interlocks, resulting in'license suspension
and other enforcement actions by NRC;
o
improper pipe routing and inadequate piping material, which broke and
caused partial loss of pool water;
o
source unable to retract to its fully shielded position, due to a frozen
o
a stuck source plaque, due to failure to promptly replace a frayed lift
cable; and
o
a stuck source plaque, due to interference from the product carriers and
shroud.
8706220303
IN 87-29 June 26, 1987 Discussion:
These incidents illustrate a failure by management to assure that proper
safety and maintenance procedures are followed. It is suggested that super- visory personnel, particularly the Radiation Protection Officer and maintenance
personnel, be reminded of their responsibilities to assure safe operation at
their facilities. The incidents discussed in Attachment 1 demonstrate the
importance of:
1. prompt reporting of incidents to the NRC, as required by regulations or
license conditions
2. safety training and periodic retraining of personnel
3. not bypassing interlock systems or other safety systems
4. attention to proper plumbing installation and use of appropriate piping
material
5.
proper maintenance of cables, carrier systems, and other components that
- could prevent radioactive sources from being retracted to a shielded
position.
No specific actions or written response is required by this Information
Notice. If you have any questions about this matter, please contact the
Regional Administrator of the appropriate NRC regional office or this office.
Richard E. Cunningham, Director
Division of Fuel Cycle, Medical,
Academic, and Commercial Use Safety
Office of Nuclear Material Safety
and Safeguards
Technical Contact:
Bruce Carrico, K1SS
(301) 427-4280
Attachments:
1.
Events That Occurred at Large Irradiator Facilities
2. List of Recently Issued NRC Information Notices
Attachment 2
December 7, 1989 Attachment I
June 26, 1987
EVENTS THAT OCCURRED AT LARGE IRRADIATOR FACILITIES
1. While the licensee was attempting to decontaminate pool water because of
a leaking source, a hose on a filtration system ruptured. Contaminated
pool water was then pumped onto the facility floor and leaked outside into
the surrounding soil. The licensee failed to report the incident to NRC,
and made deliberate efforts to prevent NRC's discovery of this incident.
"Subsequently, the licensee was indicted by a Federal Court. *A
conviction
resulted in a $35,000 fine for the company and two years probation for a
management employee. Licensee failure to make required reports prevents
the HRC from performing its radiological health and safety function and
from making a timely assessment of the nature and severity of an incident.
2. A licensee deliberately bypassed the safety interlock systems. The NRC
subsequently learned that licensee personnel had willfully violated
requirements, and that senior licensee management knew, or should have
known, of these violations. When NRC attempted to inspect and investigate
these suspected violations, senior licensee management knowingly provided
false information to the NRC. Subsequent enforcement action included
suspension of the license.
3. A water line fractured in the pool circulation system which resulted in
the loss of 5 feet of pool water.
The line break led to a loss of
shielding water because the intake and outlet pipes were misaligned
during maintenance. The pipe break appears to have occurred because
the pipe was made of polyvinyl chloride, designed for cold water, rather
than for the heated water temperatures typical for the irradiator. The
piping was replaced with polypropylene pipe.
4. A night shift operator noticed that the travel time for the source to
reach the fully unshielded position was excessive. After completing
the next phase of irradiation, the source would not retract to the fully
shielded position, even using emergency equipment. The operator discovered
that the solenoid valve, that was supposed to retract the source to a
shielded position, was frozen due to weather conditions. The valve was
in a room above the irradiator facility. The operator went there and
turned on a room heater to thaw out the valve so that it would operate.
The operator violated license requirements to (1) notify the Radiation
Safety Officer (RSO) that the source had not returned to Its shielded
position because of the frozen valve, and (2) obtain RSO permission to
enter and heat the room housing the valve.
5. A licensee had identified a frayed lift cable a few days previously, but
instead of immediately replacing the cable, the licensee decided to wait
for scheduled maintenance. The cable Jammed and froze the source plaque
in a less than fully shielded position. Employees cut the cables and let
the source plaque free-fall into the pool. The incident could have been
prevented by replacing the frayed cable imuediately, and selecting cable
material with fray-resistant qualities.
Attachment 2
IN 89-82 December 7, 1989 6. A source plaque became stuck In the exposed position.
Conveyors stopped,
'.A :ojirce DOWN 'ight came on, but cell radiation levels remained high.
Cable slack data indicated that the plaque was stuck about five and a half
feet down from its full-up position. The RSO attempted some raising and
lowering maneuvers, but the plaque then stuck in a full-up position. The
RSO, able to run the product containers out of the cell, saw some were
misaligned on the carrier. The RSO notified a State Inspector, who arrived
in the afternoon.
It was determined that the plaque cable was off its pulley.
The bottom of a splice in the cable was resting on the lip of the tube
leading to the cell. After the cable was set on its pulley, the cable was
guided through the tube, and the plaque was lowered, until it caught again.
--A borrowed radiation-resistant camera arrived the next morning. An adequate
view of the plaque was obtained by midnight. Apparently the stationary
aluminum shroud between product containers and plaque had been deflected
and caught on the plaque frame. The plaque was carefully raised and dropped
to break the Jam. On the second try, the plaque broke free and dropped
into the pool. Analysis revealed that a product container had probably
tipped onto the shroud, causing interference with the plaque.
This incident was apparently caused by inadequate design of the shroud.
This led to the shroud deforming, which interfered with plaque motion.
Inadequate maintenance contributed to the problem.
The cable should
have been replaced instead of spliced. A few months later, the entire
source hoist mechanism failed and had to be replaced. This failure oc-
- curred when the source plaque was submerged.
Attachment 2
IN 89-82 December 7, 1989 - 2 -
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Attachment 3
December 7, 1989 LIST OF RECENTLY ISSUED
NMSS INFORMATION NOTICES
Information
Date of
Notice No.
Subject
Issuance
Issued to
89-78
89-60
89-47
89-46
89-37
89-35
89-34
89-25
Failure of Packing Nuts on
One-Inch Uranium Hexafluoride
Cylinder Valves
Maintenance of Teletherapy
Units
Potential Problems with
Worn or Distorted Hose
Clamps on Self-Contained
Breathing Apparatus
Confidentiality of
Exercise Scenarios
Proposed Amendments to 40
CFR Part 61, Air Emission
Standards for Radionuclides
Loss and Theft of Unsecured
Licensed Material
Disposal of Americium
Wel1-Logging Sources
Unauthorized Transfer of
Ownership or Control of
Licensed Activities
11/22/89
08/18/89
05/18/89
05/11/89
04/04/89
03/30/89
03/30/89
03/07/89
All U.S. NRC licensees
authorized to possess
and use source material
and/or special nuclear
material for the heating, emptying, filling, or
shipping of uranium
hexafluoride in 30- and
48-inch diameter cylinders.
All U.S. NRC Medical
Teletherapy Licensees.
All holders of operating
licenses or construction
permits for nuclear power
reactors and fuel
facilities.
All holders of licenses
for fuel cycle facilities
and byproduct material
licensees having an
approved emergency
response plan.
All U.S. NRC licensees.
All U.S. NRC byproduct, source and special
nuclear material licensees.
All holders of U.S. NRC
specific licenses
authorizing well-logging
activities.
All NRC source, byproduct, and special nuclear
material licensees.
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Attachment 4
December 7, 1989
Page 1 of I
LIST OF RECENTLY ISSUED
NRC INFORMATION NOTICES
--- e --
001_____. < _
Inrormaliw
Notice No.
89-59, Supp. I
899C1
89-80
89-79
89-56, Supp. 1
89-78
89-77
89-76 Subject
Suppliers of Potentially
Misrepresented Fasteners
Inadequate Control af
to Safety-Related Systems
Potential for Wdater Hanmre
Thermal Stratification, and
Steam Sinding in High-
Pressure Coolant Injection
Piping
Degraded Coatings and
Corrosion of Steel
Containment Vessels
Questionable Certification
of Material Supplied to
the Defense Department
by Nuclear Suppliers
Failure of Packing Nuts
on One-Inch Uranium
Hexafluoride Cylinder
Valves
Debris in Containment
Emergency Sumps and
Incorrect Screen
Configurations
Biofouling Agent:
Zebra
1Nussel
DJAW Of
Issuance
12/6/89
12/6/89
12/1/89
12/1/89
11/22/89 Issued to
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 LkRs.
All holders of OLs
or CPs for nuclear
power reactors.
11/22/89
All NRC licensees
authorized to possess
and use source material
and/or special nuclear
material for the heating, emptying, filling, or
shipping of uranium
hexafluoride In 30-
and 48-inch diameter
cylinders.
11/21/89
All holders of OLs
or CPs for PURs.
11/21/89
All holders of OLs
or CPs for nuclear
power reactors.
- Operating License
- Construction Permit
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NUCLEAR REGULATORY COMMISSION
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