Non-Destructive Tests through Gammagraphy: Technical Job with Rigorous Improvisation

1. Non-destructive tests through gammagraphy : « a technical job as well as some necessary rigorous improvisation and astutes » Alain Garrigou, Univ. of Bordeaux 1, France Chantal Tannière, Perpectives Ergonomie Gabriel Carballeda, Formation en Ergonomie Alain Garrigou

2. Introduction • Role and stakes of industrial grammagraphy ; • Several incidents in the past years ; • A wish for reducing exposure to ionising radiations ; Alain Garrigou

3. Presentation schedule • An ergonomical study • Safety management and gammagraphy • First representation of gammagraphy activities • Some results from the activity analysis • Discussion Alain Garrigou

4. 1 - An ergonomical study • The demand • The methodology used Alain Garrigou

5. 2 - Safety management and gammagraphy See Abéla & Blandin about : • NDT activities preparation ; • Lockout requests linked with the planning of the shutdown; • Exposure permit and boundary map ; • Devices considered as secure by the manufacturers Alain Garrigou

6. 3 – A first representation gammagraphy activities • An activity little known ; • An easy job : It would only…. • A risky job; • A simplistic representation among deciders ; • The accidents are due to Human Factor Alain Garrigou

7. 4 - Some results from activity analysis 4.1 - Some variabilities in situation 4.2 - Necessary skills 4.3 - Some difficulties 4.4 - Radiological risk assessment Alain Garrigou

8. 4.1 - Some variabilities in situation • Accessibility to the organ to be controlled ; • Crowded spaces; • Well-lit or semi-darkness; • Presence of scaffoldings or biologicalprotection Alain Garrigou

9. 4.2 - Necessary skills • Technical knowledge ; • Many rigorous improvisation or astutes for : • Defining the restricted area • Fixing the film cassette and the guiding tube ; • Centring the film ; • Calculation of exposure; • Etc. Alain Garrigou

10. Defining the restricted area Alain Garrigou

11. Fixing the film cassette and the guiding tube Alain Garrigou

12. 4. 3 - Some difficulties • Transport of the equipment ; • Loading; • Handling and risky postures ; Alain Garrigou

13. Transport of the equipment Alain Garrigou

14. Risky and uncomfortable postures Alain Garrigou

15. Risky and uncomfortable postures Alain Garrigou

16. 4.4 - Radiological risk assessment • A risk well known ; • Sources of 60 curies (still used by gammagraphers ) ; • Use of a radiation meter at the beginning of the test ; • The gammagraph indicators not adapted ( not really visible ) Alain Garrigou

17. 4.4 - Radiological risk assessment • Uncertainty about the position of the source : how many revolutions ? • Not reminding information available ; • Necessity of an alarm system development; • Taking into account the real conditions of equipment use ! Alain Garrigou

18. 5 - Discussion • The role of an ergonomics point of view: • The detour by activity understanding ; • The identification of high stress situations; • Uncertainty, decisions taking and vigilance Alain Garrigou

19. 5 - Discussion • From Human error to organisational reliability ; • Taking into account the traditional risks ! Alain Garrigou

20. 5 - Discussion • The status of skills and rigorous improvisation ; • The status of cautiousness skills ; • The on going study Alain Garrigou

21. Alain Garrigou