Radiation protection studies for the ESS Activation issues AD seminar Michał Jarosz , Lund

Radiation protection studies for the ESS Activation issues AD seminar Michał Jarosz , Lund (we're changing name, no new logo yet)

Radiation protection studies for the ESS In the last episode...

Radiation protection studies for the ESS Which layout should be used for the ESS Linac ?

Radiation protection studies for the ESS Which layout should be used for the ESS Linac ? Conclusion: All layouts might be adjusted for being valid from the dose rates constraints point of view. The only matter is the price and technological difficulties.

Radiation protection studies for the ESS Which layout should be used for the ESS Linac ? Conclusion: All layouts might be adjusted for being valid from the dose rates constraints point of view. The only matter is the price and technological difficulties.

Radiation protection studies for the ESS Which layout should be used for the ESS Linac ? Conclusion: All layouts might be adjusted for being valid from the dose rates constraints point of view. The only matter is the price and technological difficulties. What about metal shielding ?

Radiation protection studies for the ESS Conclusion: All layouts might be adjusted for being valid from the dose rates constraints point of view. The only matter is the price and technological difficulties. What about metal shielding ? + Very good attenuation properties

Radiation protection studies for the ESS Conclusion: All layouts might be adjusted for being valid from the dose rates constraints point of view. The only matter is the price and technological difficulties. What about metal shielding ? + Very good attenuation properties - Greater activation capability

Radiation protection studies for the ESS Conclusion: All layouts might be adjusted for being valid from the dose rates constraints point of view. The only matter is the price and technological difficulties. What about metal shielding ? + Very good attenuation properties - Greater activation capability Activation studies needed

Radiation protection studies for the ESS Addition to the previous studies (before going into activation):

Radiation protection studies for the ESS Addition to the previous studies: Increase in the final proton energy (possbile upgrade ?)

Radiation protection studies for the ESS

Ratio between 5000 MeV and 2500 MeV dose rates less than 2 Saturation of neutron production around 2.5 GeV; as well as optiumum of neutron production to primary proton energy

Radiation protection studies for the ESS Conclusion: Adding a tenths of centimeters of additional shielding from the beginning might be considered a good idea for the future upgrades.

Radiation protection studies for the ESS Metal shielding

Radiation protection studies for the ESS Metal shielding All proceeding simulations done for highest energy protons (2.5 GeV) considering the 1W/m losses. Please note:

Radiation protection studies for the ESS Metal shielding All proceeding simulations done for highest energy protons (2.5 GeV) considering the 1W/m losses. Materials: Concrete – 'ordinary' Portland Metal – typical shielding composition (stainless steel plus lead with impurities) Soil – exact Lund soil composition, averaged from different excavation points Please note:

Radiation protection studies for the ESS Metal shielding Layouts for the metal shielding:

Radiation protection studies for the ESS Metal shielding Layouts for the metal shielding:

Radiation protection studies for the ESS Metal shielding Layouts for the metal shielding: Metal 45 deg

Radiation protection studies for the ESS Metal shielding

Radiation protection studies for the ESS Metal shielding Air Concrete Metal Soil

Radiation protection studies for the ESS Metal shielding

Radiation protection studies for the ESS Metal shielding Build-up for metal Works as another target

Radiation protection studies for the ESS Metal shielding

Radiation protection studies for the ESS Metal shielding

Radiation protection studies for the ESS Metal shielding

Radiation protection studies for the ESS Metal shielding

Radiation protection studies for the ESS Metal shielding

Radiation protection studies for the ESS Metal shielding

Radiation protection studies for the ESS Metal shielding Dose rates during operation up to 4 orders of magnitude higher than straight after the shutdown (for 40 years of constant irradiation, extreme and rather unrealistic case)

Radiation protection studies for the ESS Metal shielding Conclusions as for now:

Radiation protection studies for the ESS Metal shielding Conclusions as for now: metal shielding has great attenuation properties which is flawed by its radiation build-up process

Radiation protection studies for the ESS Metal shielding Conclusions as for now: metal shielding has great attenuation properties which is flawed by its radiation build-up process → improvement for thickness ~ > 1m

Radiation protection studies for the ESS Metal shielding Conclusions as for now: metal shielding has great attenuation properties which is flawed by its radiation build-up process → improvement for thickness ~ > 1m metal shielding is characterized by longer cooling times than conrete and soil

Radiation protection studies for the ESS Metal shielding Conclusions as for now: metal shielding has great attenuation properties which is flawed by its radiation build-up process → improvement for thickness ~ > 1m metal shielding is characterized by longer cooling times than conrete and soil Using metal shielding only from the bottom of acceleator might have sense: it doesn't protect to bottom layers of soil from the radioactive isotopes 'dripping' from the sides, BUT it can be a great help to prevent the direct irradiation of the water sources that are directly beneath the accelerator (please note, that dose rates during irradiation are few orders of magnitude higher than after the shutdown)

Radiation protection studies for the ESS Irradiation Times

Radiation protection studies for the ESS Irradiation Times Almost no difference

Radiation protection studies for the ESS Irradiation Times

Radiation protection studies for the ESS Irradiation Times Flat. Dose rate at the shutdown does not depend on the irradiation time.

Radiation protection studies for the ESS Irradiation Times

Radiation protection studies for the ESS Irradiation Times Some differences, spliting of the curves...

Radiation protection studies for the ESS Irradiation Times

Radiation protection studies for the ESS Irradiation Times

Radiation protection studies for the ESS Irradiation Times

Radiation protection studies for the ESS Irradiation Times Conclusions:

Radiation protection studies for the ESS Irradiation Times Conclusions: Short-living (<1h half-life) isotopes saturate relatively fast, not giving much differences between different irradiation times.

Radiation protection studies for the ESS Irradiation Times Conclusions: Short-living (<1h half-life) isotopes saturate relatively fast, not giving much differences between different irradiation times. Long-living isotopes are building up all the time the machine is working.

Radiation protection studies for the ESS Irradiation Times

Radiation protection studies for the ESS Irradiation Times Pick your favourite isotope...

Radiation protection studies for the ESS Other remarks

Radiation protection studies for the ESS Other remarks The biggest contribution for the dose rates during operation comes from the secondary neutrons.

Radiation protection studies for the ESS Other remarks The biggest contribution for the dose rates during operation comes from the secondary neutrons. → light materials with high neutron capture capability desired.

Radiation protection studies for the ESS Other remarks The biggest contribution for the dose rates during operation comes from the secondary neutrons. Situation during cooldown is different – the dose rates are generated by wide energy spectrum of photon.

Radiation protection studies for the ESS Other remarks The biggest contribution for the dose rates during operation comes from the secondary neutrons. Situation during cooldown is different – the dose rates are generated by wide energy spectrum of photon → movable iron shield to protect the inner tunnel from the photons coming back from the shielding ?

Radiation protection studies for the ESS Other remarks The biggest contribution for the dose rates during operation comes from the secondary neutrons. Situation during cooldown is different – the dose rates are generated by wide energy spectrum of photon → movable iron shield to protect the inner tunnel from the photons coming back from the shielding ? Removable shielding

Radiation protection studies for the ESS Database

Radiation protection studies for the ESS Database Data generated from simulations results: Dose rates during operation for different layouts (metal around tunnel, metal below tunnel, thin concrete layer and soil surrounding)

Radiation protection studies for the ESS Database Data generated from simulations results: Dose rates during operation for different layouts Residual dose rates for all cases for different cooling times (from shutdown to one year after)

Radiation protection studies for the ESS Database Data generated from simulations results: Dose rates during operation for different layouts Residual dose rates for all cases for different cooling times Full lists of induced residual nuclei in selected layers of shielding for all cases and different cooling times

Radiation protection studies for the ESS Database Data generated from simulations results: Dose rates during operation for different layouts Residual dose rates for all cases for different cooling times Full lists of induced residual nuclei in selected layers of shielding for all cases and different cooling times Energy distribution of the secondary particles through the shielding layers

Radiation protection studies for the ESS Database Data generated from simulations results All data in the text files as well as in spreadsheets for easier operation. Some additional format might be considered for the residual nuclei, as it contains a lot of not easily manageble data

Radiation protection studies for the ESS Water Content

Radiation protection studies for the ESS Water Content Water content found on the site varied approximately from 10 to 18 percent with a mean of 14% (used as a 'normal, regular' water content in previous studies).

Radiation protection studies for the ESS Water Content

Radiation protection studies for the ESS Water Content

Radiation protection studies for the ESS Water Content Calculated a mean from the ratio

Radiation protection studies for the ESS Water Content

Radiation protection studies for the ESS Water Content Clear exponential curve

Radiation protection studies for the ESS Water Content Clear exponential curve → Easy scaling of the results

Radiation protection studies for the ESS Water Content Attenuation is the only parameter that changes rather rapidly with the changes of water content. The induced activity or residual nuclei doesn't change much (oxygen does not induce a lot of activity, and tritium is created in larger quantities elsewhere*, quickly reaching saturation). * in other decay chains, not directly from hydrogen in water

Thank you for your attention Mölle, August 2011