Radiation Protection optimisation 3D planning tools and their applicability to occupational exposure at a fusion power plant F.Vermeersch SCKCEN EFDA 27 juni 2006EFDA monitoring meeting

 Investigate the applicability of 3D dose simulation tools for a fusion power plant  Operation  Maintenance  Decommissioning Aim

Context ALARA is part of the safety culture ALARA evaluation can be very complex 3D tools have shown their effectiveness in nuclear industry (fission) How can we apply this technology in the Fusion Power Plant environment

Dose assessment Dose optimisation Dose assessment is currently based on average dose rates in an area. 3D simulation could be used to evaluate  The effect of non-uniform dose distributions  The introduction of shielding  The effect of design changes  The dose distribution in a changing environment (maintenance, decommissioning)

Can we apply this technology to occupational exposure in the Fusion domain ? Method  Identify typical exposure problems in a fusion installation where this technology where can have an added value (literature study, discussion with designers).  Setting up a small application for demonstration.  Evaluate the in and output  Evaluate the communication, education and training aspects.

Example Eq. Port 1

Simplified Model of Eq.Port 1 Simplified source structure for demonstration Sources include nose section beam line and port flange and port section

Evolution of the radiation field during the maintenance work Removal 5 m Removal 3 m

Evolution of the radiation field during the maintenance work Nose section removedNose section shielded

Dose uptake by the workers Unshielded nose section

Dose uptake by the workers Nose section shielded by lead

Dose uptake by the workers Nose section removed

Effect of shielding the port flange Without shielding With shielding

Dose uptake by the workers Without shielding With shielding

Next steps Better definition of the sources  Better definition of the required information Simulation of the operation at eq. port 1 Increase the detail of the model Dose assessment for the whole operation. Suggestions for dose reduction

Conclusion The use of simulation and 3D representation of the workplace and radiation risks enables  A better communication during the pre-job ALARA studies between the stakeholders.  An implicit training of the ALARA analyst (more scenarios can be tested)  A better final preparation of the worker.  A better awareness of the residual risk and the radiation protection measures put into practice.