Management of emergencies in industrial radiography Meeting IAEA - June 2014 Anne Cordelle - Grégory FONTAINE

Management of emergencies in industrial radiography

Meeting IAEA - June 2014

Anne Cordelle -Grégory FONTAINE

Industrial radiography in France

• 550 gamma radiography devices 500 X ray generators • Recorded exposures : 1 400 000in 2011-> 1/2 on site-> 1/3 on site with Ir 192 • Recorded shielded enclosures : -> 93 for gamma device-> 242 for X ray generators • 1266 radiographers

• 336 radiation protection officers

Storages of gamma device

• 200 agencies • Main fields : nuclear plants, refinery, chemistry factory, foundry…

June 2014 – Management of emergencies in industrial radiography

• Events notified to ASN according to specific requirements

Recent incidents

15

8

67

15

6

2

9

6 6

0

2

4

6

8

10

12

14

16

2008 2009 2010 2011 2012

Incidents occured in BNI

Other incidents

• Only few incidents with dose exceeding regulatory levels (3 incidents)

• Main causes are : controlled areas, source control loss


• Since 2010 ASN has observed the operations to retrieve the source when the source is stuck or misconnected could be improved

- important consequences on industrial safety of the facilities where site radiography is performed

- important consequences on the radiation protection of the workers who carried out these operations

Theses operations must be specifically controlled

→ In 2013, ASN organized a working group to define or to review . Different types of source control loss. Procedures and means to regain the control of the source

Recent incidents



UESExpertise in

radiation protection for

radioactive sources

Context


National register for radioactive sources

Technical support


Context

Working Group on industrial radiography

Incidents in France

Working Group


Markup crossing

Loss of control of sources



Context

Markup crossing

1. Source stuck in the device

2. Source disconnected from the drive cable

3. Source out of the device


Incidents in France

Working Group



Context

Markup crossing


Technical solutions for recovering a source in

case of a loss of control

Incidents in France

Working Group



June 2014 – Management of emergencies in industrial radiography 9/26

Context

Scenarii

Source out of control

Definition of interventions in

advancefor each situation

Working Group




Methodology



Methodology

Circumstances,causes

Real situations

Incidents in France

Loss of control

Databases

Internet



Methodology

Study of equipment

Potential situations Scenarii

Circumstances/causes

Real situations

Databases

Internet

Incidents in France

Loss of control



Equipment

One type of device widely used.

600 devices in France, 90% are Gam80/120.

The Scenarii are mainly defined for Gam80/120

Particularity in France



Equipment

Source holder

Exposure container

Description



Equipment

The canal is linear.

For the connections :1.Drive cable2.Guide tube

A remote control permit to move the source (electric or with a crank)

Description



Equipment Description



Methodology Location of the source



Methodology Location in the guide tube



Methodology Location in the guide tube

▌Source-holder connected to the drive cable


▌Source-holder disconnected from the drive cable


Scenarii



Scenarii

Object in the guide tube

Object in the guide tube

Object in the container

Object in the container



Scenarii

Damage of the guide tube

Damage of the guide tube



Scenarii

Crank failure

Crank failure

Crank failure

Crank failure

Rupture of shutter control

Rupture of the source holder



Scenarii

Connection drive cable/source holder

Connection of the collimator

Connection of the collimator



Other points to consider

▌ Where is the equipment ?

▌ Access conditions ?

Environment

Radioactive source

▌Half-life

▌Activity


Emergency response

Main actions defined by the working group

• (1) Ensure controlled area barriers are in the correct place

• (2) Inform customer

• (3) Inform RPO, qualified expert, source supplier, ASN

• (4) Definition of an intervention to retrieve source

• (5) Intervention

• (6) Report with doses


In compliance with stages described in the IAEA guide

Initial stage Planning stage

Recoverystage

Post emergency

stage

Report stage

(1) (2) (3) (4) (5) (5) (6)

Emergency response

• Description of the incident : - source, device, failure, - dose rates,

- site configuration


Definition of a summary sheet

• Stakeholders to inform

• Intervention definition

• Intervention implementation- operators,- assessed doses - received doses- successful attempt or not

Emergency response


Different types of interventions

Distance with source

Intervention complexity Level 2

Intervention

Level 1Intervention

Intervention to decrease dose rates

Who Training Equipment When

Level 1 intervention

Radiographers Common training (CAMARI)

Common tools Quickly

Level 2 intervention

Qualified expert Specific training Specific tools Need few hours up to few days


• 10 procedures have been written to describe interventions

Emergency response

• Procedures framework :• When the procedure has to be implemented• Material means, operator training• A flow sheet with all steps• A safety assessment• Dose assessment • Maximum dose rates

• Critical intervention : -> Intervention to locate source and to cover it with shielding

Incident scenarios 75 % covered


• With Iridium or Selenium sources-> Maximum dose rate about 50 mSv/h (a distance about 3 m with an Iridium source about 120 Ci)-> An individual dose about 3 mSv

Emergency response

• With important Cobalt sources

-> Dose rates are too important(about 600 mSv / 3m far the source)

-> Robots would be used

Emergency response

• Tools used to retrieve source

-> When the guide tube is damaged and the source has become stuck


Source holder

Tool

Guide tube


Emergency response

• Tools used to retrieve source

-> When the source is disconnected from the control cable

Source holder

Specific tool connected with the control cable-> to push-> to pull (magnetic tool)

Source changer


Working group prospects

Authorizations to implement procedures

Implementation

Finish writing all the procedures

Communication of a report

Annual meetings-> feed back-> procedures improvements


Regulatory projects

• French regulations currently covers

. Gamma radiography device design . Conditions of use of gamma radiography device . Shielded enclosure design . Radiographer certification . Radiation protection organization, dosimeters, health monitoring, controlled area…

• Projects to strengthen implementation of justification/optimization principle :

. Ban site radiography when the object to be controlled may be moved -> Incident consequences are less important in shielded enclosures

. Ban using Ir (or Co) when the thickness is less than 30 mm (steel eq.) to promote Se -> Incident consequences are less important with Se -> Operations to regain control of the situation are easier with Se


Regulatory projects

• Projects to improve the emergency response :

. Availability of suitable means and procedures to regain control of the situation -> needs convention with supplier, qualified expert

Documents

Management of emergencies in industrial radiography Meeting IAEA - June 2014 Anne Cordelle - Grégory FONTAINE