Garching / Cadarache 25/04/06 Introduction and objectives

1. Meeting on Revision of the Occupational Radiation Exposure assessment for the Port-Interfacing Systems (WBS5.0) Garching / Cadarache 25/04/06 Introduction and objectives Vincent MASSAUT Vincent MASSAUT Meeting 28/03/2006

2. Occupational Radiation Exposure (ORE) evaluation: main objectives • The main general objectives of the ORE optimisation has important impact on: • The safety of the operation personnel • The availability of the machine • The overall impact of fusion • For the safety analysis and the licensing, the ALARA approach of the operation of the machine is important and makes part of the overall safety approach of the fusion plant. Vincent MASSAUT Meeting 28/03/2006

3. KOM Radioprotection 23rd of March 2006 From CEA: In the RPrS  3 chapters • Radiological zoning • Network survey • Proof of the ALARA into the design Vincent MASSAUT Meeting 28/03/2006

4. ALARA approach and radioprotection optimization in the overall safety approach Vincent MASSAUT Meeting 28/03/2006

5. The ALARA approach • Not only the reduction of doses • Not only the “good practice” • But mostly an optimization (…as Reasonably Achievable) based on other factors like economical factors, industrial safety, ethical values, etc… • A complete ALARA approach should need to review the process from A to Zincluding the waste management, disposal etc. (NB this is in reality never done; but the overall principle should be kept in mind) Vincent MASSAUT Meeting 28/03/2006

6. The tasks involved • There is an ITER/ITA task proposal (ITA 81-11), in the process to be signed, concerning “Occupational Safety to ensure worker safety and preliminary assessment to support licensing”.The present analysis and report belong mostly to the second deliverable of this task. • Within EFDA it belongs to the task TW4-TSS-SEA2.1.a, contract 04/1205 Vincent MASSAUT Meeting 28/03/2006

7. After various studies and reports, the current report summarizes the findings on the WBS 5.0 • S. Sandri, “Analysis of the ORE assessment process applied to ITER project”, ENEA FUS-TN-SA-SE-R-50, September 2002 • J. Uzan-Elbez, “Justification of ALARA for ITER (design 2001)”, CEA/DEN/CAD/DTAP/CASI DO 389 25/11/03, Cadarache (France) • A. Natalizio, M. T. Porfiri, "Worker Dose Estimates for NB & LH Heating & Current Drive Systems", ENEA FUS-TN-SA-SE-R-132, October 2005 Some of the main reports/studies previously available: Vincent MASSAUT Meeting 28/03/2006

8. Definition of WBS 5.x(following ITER documents) • WBS 5.1 ITER Ion Cyclotron Resonance Heating and Current Drive (Task Officer :David Swain and A.Sakasai) • WBS 5.2 Electron Cyclotron Resonance Heating Systems (ECRH) (Task Officer :A.Sakasai) • WBS 5.3 ITER Neutral Beam (Task Officer :A.Sakasai) • WBS 5.4 no info on ITER site (formerly LH&CD?) • WBS 5.5 ITER Diagnostic (Task Officer :?) • WBS 5.6 Test-Blanket Module (Task Officer :Masaaki Morimoto) Vincent MASSAUT Meeting 28/03/2006

9. The analysis of the ORE has been carried out with a “best practice” engineering approach • The occupational exposure evaluation needs three main elements: • The dose rate or better the radiation field in the concerned areas • These data are only partially known, and request often to make assumptions • Only “general” values for the different working areas could be taken without taking into account the actual geometry, inner sources, ACP, etc. • Internal exposure was not taken into account for this analysis • The work force (in terms of number of individuals concerned): • here also, the data are based on assumptions for the main maintenance activities to be carried out • The duration (and frequency) of the intervention: • the best engineering practices have been taken, based on the known design. But the actual design and maintenance scheme is important to better define this aspect Vincent MASSAUT Meeting 28/03/2006

10. Some other uncertainties also affect this analysis • The effects of difficulties for the workers (e.g. working in height, use of scaffolding, the wearing of masks or pressurized suits, the temperature in the rooms, the accessibility of the components to be worked on, etc… • The use of portable/removable shielding; the potential for partial decontamination of hot spots, the use of semi-autonomous tooling, etc… • The actual frequency of maintenance (probably to be discussed here) of the different concerned components • Etc… Vincent MASSAUT Meeting 28/03/2006

11. Therefore, only important factors susceptible to change the figures are relevant to discuss • The approach being still at the “pre-design” level, we must regard this study in view of the needs of the licensing documents and of what would then be asked for the “final” safety reports after the construction (it would be difficult to justify an important increase in the operators exposure at the time of start up !) • So for this approach we need to remain pragmatic, realistic (in the limits of the current design) and, if possible, conservative. Vincent MASSAUT Meeting 28/03/2006

12. The main goals of this meeting are thus • To review briefly the analysis done and the principles used throughout the study • To analyze and discuss the comments and remarks gathered from designers and specialists of the concerned equipments • To look how these comments can be integrated in the current study to improve it and tend towards the objectives (pragmatic, realistic and conservative) • To define how the interaction between designers, physics specialists and health physics analysts can be enhanced to avoid too much discrepancies between the analyzed machine and the current one • To define how the potential detection of dose distributing events or components can be taken into account in the design, or how collaboration can be set up to decrease these levels. Vincent MASSAUT Meeting 28/03/2006

13. Proposal of agenda Proposal Vincent MASSAUT Meeting 28/03/2006

14. Thanks for your attention Vincent MASSAUT Meeting 28/03/2006