Emergency Response to Industrial Radiography Source Retrievals

In the early years of industrial radiography, source retrievals were common occurrences. We will never know the exact number due to the lack of regulations and reporting of the incidents.

The RSO or managers of companies usually performed the retrievals themselves. Some handled the situation well while others did not.

This responsibility of retrievals was passed down to the most experienced personnel within in the company.

Industrial Radiography equipment of those times had very few safety features that is seen today.

There were few regulatory requirements or commercially offer training classes for Emergency Source Retrievals.

The number of source retrievals has decreased in recent years due to many factors such as;

(1) Increased regulations.

(2) Better training of radiographers.

(3) Equipment manufactured to higher quality standards and enhanced safety features.

(4) Increased emphasis on the necessity for inspection and maintenance.

Be prepared before it happens!!

Have procedures and policies in place before you have to respond to a retrieval.

Training- Have personnel that are trained to respond to a retrieval.

Have the proper equipment to safely perform the retrieval.

Emergency Retrieval Response

Notification Identify the problem for proper response

and reactionSite Assessment Locate the sourcePlan of actionShielding the source ???Execute retrieval planSecure the device/source.

Retrieval Sequence

Description of the problem.

Any overexposures to radiographers or general public?

Restricted Areas secured?

Additional help needed?

Details of the area.

Notification

Determine possible plan of action.

Decide who will respond.

What type of equipment will be needed?

Travel to the site.

Identify the Problem

Check restricted area boundaries.

Interview Radiographers-verify information from initial notification.

Visual assessment of the area and equipment.

Environmental conditions.

Any other safety concerns?

Site Assessment

Visually locate the source if possible.

Use Tetetector to locate the source if available .

Use other means to locate the source such as lead tunnel brick, collimator, or lead shot bags.

Locate the Position of the Source

Plan the retrieval steps and each persons role.

Review and determine possible exposure.

Practice dry runs if necessary.

Do not let “Other” conditions influence your planning or decision making.

Plan of Action

Shield the source when applicable to perform retrieval.

Only use appropriate amount of shielding.

Use care when placing the shielding on the source so that no additional damage is done to the equipment.

Shielding the source ???

Perform the retrieval plan.

Record dose rates as the retrieval plan is executed.

Execute Retrieval Plan

Secure the source in the original device or source changer. (Transportable if possible)

Perform surveys of device or container.

Leak test of the device and source.

Record final surveys and dose rates.

Determine actions to be taken in regard to the equipment and source. ( Remove from service, etc.)

Secure the Source

Suggested Tool Box Contents

Retrieval Equipment

Teletector

Handling Tongs

Lead shot bags

Fishing Cable ( Modifi ed Drive cable-550)

Source disconnects

Equipment failure Lack of maintenance and inspection Improper setup Damage to equipment during use Improper use of equipment Environmental conditions Use of non-approved aftermarket parts

Possible Causes of Source Retrievals

Retrieval Scenarios Source Hung Up in Source Guide Tube

Source Disconnect

Camera damage and malfunctions

Control damage and malfunctions

Shield the source

Hammer dented area out of the guide tube

Cut damaged area out of the guide tube

Repositioning of the guide tube

Source Hang-Up In Guide tube

Shield –Cut – Push Method

Direct hot stick into device outlet port of another device

Direct hot stick into device if possible

Direct hot stick into source changer

“Fishing Method” on certain devices and sources

Source Disconnect

Shield source to a point that you can safely work on the controls and camera.

Equipment Damage or Malfunctions

Not being prepared ahead of timeNot having the proper equipment available Not having trained personnel

Training Training is the most difficult issue to overcome. Available training classes?? Training classes plus experience ( Classes

alone?/experience?) Personnel must have strong radiation safety background,

understand the principles of time, distance, and shielding along with a working knowledge of the equipment involved.

Issues that can lead to problems with Source Retrievals

Be prepared before a retrieval occurs. Have trained personnel.

Have the proper equipment to perform the retrieval.

Do not let “other” conditions influence your decision making and planning.

Review

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Source Disconnect

Retract drive cable halfway towards exposure device, shake the source assembly to the mid-point

section of the source guide tube.

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Shield the sealed source remotely……….

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Add more shielding on the tunnel-brick…form the source guide tube into a “U”

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Cut the source stop off the end of the source guide tube…………………………………..

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Remove remote controls, put the locking mechanism in the “expose position”, re-attach the source guide tube to the device outlet port. Duct-tape the remote controls to the severed end of the source guide tube………………….

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Remotely, push (expose) the source assembly into the exposure device, secure by pulling source connector..

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Knowing how to perform maintenance, provides options to retrieve disconnected source assemblies.

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