Upload
brent-gray
View
217
Download
0
Tags:
Embed Size (px)
Citation preview
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
June 2014 – Management of emergencies in industrial radiography
• 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
June 2014 – Management of emergencies in industrial radiography
June 2014 – Management of emergencies in industrial radiography
UESExpertise in
radiation protection for
radioactive sources
Context
June 2014 – Management of emergencies in industrial radiography
National register for radioactive sources
Technical support
June 2014 – Management of emergencies in industrial radiography
Context
Working Group on industrial radiography
Incidents in France
Working Group
June 2014 – Management of emergencies in industrial radiography
Markup crossing
Loss of control of sources
June 2014 – Management of emergencies in industrial radiography
Working Group on industrial radiography
Context
Markup crossing
1. Source stuck in the device
2. Source disconnected from the drive cable
3. Source out of the device
Loss of control of sources
Incidents in France
Working Group
June 2014 – Management of emergencies in industrial radiography
June 2014 – Management of emergencies in industrial radiography
Context
Markup crossing
Loss of control of sources
Technical solutions for recovering a source in
case of a loss of control
Incidents in France
Working Group
Working Group on industrial radiography
June 2014 – Management of emergencies in industrial radiography
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
Working Group on industrial radiography
June 2014 – Management of emergencies in industrial radiography
June 2014 – Management of emergencies in industrial radiography
Methodology
June 2014 – Management of emergencies in industrial radiography
June 2014 – Management of emergencies in industrial radiography
Methodology
Circumstances,causes
Real situations
Incidents in France
Loss of control
Databases
Internet
June 2014 – Management of emergencies in industrial radiography
June 2014 – Management of emergencies in industrial radiography
Methodology
Study of equipment
Potential situations Scenarii
Circumstances/causes
Real situations
Databases
Internet
Incidents in France
Loss of control
June 2014 – Management of emergencies in industrial radiography
June 2014 – Management of emergencies in industrial radiography
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
June 2014 – Management of emergencies in industrial radiography
June 2014 – Management of emergencies in industrial radiography
Equipment
Source holder
Exposure container
Description
June 2014 – Management of emergencies in industrial radiography
June 2014 – Management of emergencies in industrial radiography
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
June 2014 – Management of emergencies in industrial radiography
June 2014 – Management of emergencies in industrial radiography
Equipment Description
June 2014 – Management of emergencies in industrial radiography
June 2014 – Management of emergencies in industrial radiography
Methodology Location of the source
June 2014 – Management of emergencies in industrial radiography
June 2014 – Management of emergencies in industrial radiography
Methodology Location in the guide tube
June 2014 – Management of emergencies in industrial radiography
June 2014 – Management of emergencies in industrial radiography
Methodology Location in the guide tube
▌Source-holder connected to the drive cable
June 2014 – Management of emergencies in industrial radiography
▌Source-holder disconnected from the drive cable
June 2014 – Management of emergencies in industrial radiography
Scenarii
June 2014 – Management of emergencies in industrial radiography
June 2014 – Management of emergencies in industrial radiography
Scenarii
Object in the guide tube
Object in the guide tube
Object in the container
Object in the container
June 2014 – Management of emergencies in industrial radiography
June 2014 – Management of emergencies in industrial radiography
Scenarii
Damage of the guide tube
Damage of the guide tube
June 2014 – Management of emergencies in industrial radiography
June 2014 – Management of emergencies in industrial radiography
Scenarii
Crank failure
Crank failure
Crank failure
Crank failure
Rupture of shutter control
Rupture of the source holder
June 2014 – Management of emergencies in industrial radiography
June 2014 – Management of emergencies in industrial radiography
Scenarii
Connection drive cable/source holder
Connection of the collimator
Connection of the collimator
June 2014 – Management of emergencies in industrial radiography
June 2014 – Management of emergencies in industrial radiography
Other points to consider
▌ Where is the equipment ?
▌ Access conditions ?
Environment
Radioactive source
▌Half-life
▌Activity
June 2014 – Management of emergencies in industrial radiography
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
June 2014 – Management of emergencies in industrial radiography
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
June 2014 – Management of emergencies in industrial radiography
Definition of a summary sheet
• Stakeholders to inform
• Intervention definition
• Intervention implementation- operators,- assessed doses - received doses- successful attempt or not
Emergency response
June 2014 – Management of emergencies in industrial radiography
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
June 2014 – Management of emergencies in industrial radiography
• 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
June 2014 – Management of emergencies in industrial radiography
• 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
June 2014 – Management of emergencies in industrial radiography
Source holder
Tool
Guide tube
June 2014 – Management of emergencies in industrial radiography
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
June 2014 – Management of emergencies in industrial radiography
Working group prospects
Authorizations to implement procedures
Implementation
Finish writing all the procedures
Communication of a report
Annual meetings-> feed back-> procedures improvements
June 2014 – Management of emergencies in industrial radiography
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
June 2014 – Management of emergencies in industrial radiography
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