Radiation Protection optimisation3D planning tools and their applicability to occupational exposure at a fusion power

plant

F.Vermeersch

SCK•CEN

EFDA 27 juni 2006 EFDA 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 assessmentDose 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 mRemoval 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.