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) | |
X, v tC Attachment
2 IN 89-82 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 solenoid valve;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 IN 89-82 December 7, 1989 Attachment
I IN 87-29 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 -
$ I Attachment
3 IN 89-82 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.
t .a 4 Attachment
4 IN 89-82 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 Temporary
Modifications
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
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.OL
- Operating
License CP
- Construction
Permit UNITED STATES NUCLEAR REGULATORY
COMMISSION
WASHINGTON, D.C. 20555 OFFICIAL BUSINESS PENALTY FOR PRIVATE USE, 5300 PIRST CLASS MAIL IPOSTAGE & FEES PAID USNAC PERMIT No. 0 p-U Sup SvCs -' -. 4 A HVCS SVCS SECT OC 20555 1