Information Notice 1987-29, Recent Safety-Related Incidents at Large Irradiators

Recent Safety-Related Incidents at Large Irradiators

ML031190114
Person / Time
Issue date:	06/26/1987
From:	Cunningham R E 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

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

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.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