Authorization and Inspection of Cyclotron Facilities Design Layout

Authorization and Inspection of Cyclotron Facilities Design, Layout and Shielding

Authorization and Inspection of Cyclotron Facilities Objective To give an overview of the different components of a facility. To understand the different elements in shielding design. Perform simple calculations.

Authorization and Inspection of Cyclotron Facilities Facility Design Main components of a facility:

Authorization and Inspection of Cyclotron Facilities Description of areas– Type III facility Function Classification Area (m 2) Entrance for the personnel Non-controlled 4 Staff offices Non-controlled 60 Kitchen Non-controlled 11 Quarentine room Non-controlled 5 Technical gases room Non-controlled 4 Raw materials room Non-controlled 20 Transport containers room Non-controlled 13

Authorization and Inspection of Cyclotron Facilities Description of areas– Type III facility Función Clasificación Area (m 2) Toilets Non-controlled 9 Personnel airlock Controlled 10 Preparation laboratory Controlled 13 Packing room Controlled 13 Radiopharmaceutical production laboratory Controlled 32 Research lab. Controlled 27

Authorization and Inspection of Cyclotron Facilities Description of areas– Type III facility Función Clasificación Area (m 2) Service corridor for hot cells Controlled 13 Radioactive waste Controlled 4 QC labs Controlled 44 Control room Controlled 10 Power supply room Controlled 9 Service room Controlled 21

Authorization and Inspection of Cyclotron Facilities Description of areas– Type III facility Bunker 80 m 2 (24 m 2 internal) Controlled

Authorization and Inspection of Cyclotron Facilities • Some considerations: • All controlled areas (vaults and labs) grouped together • To limit transport of radioactive materials through uncontrolled areas and to keep distances short! • Distance between production target and hot cells as short as possible • Irradiation rooms adjacent to cyclotron vault • To optimise beam transport and shielding! • Some technical areas are to be considered as controlled area (ventilation)

Authorization and Inspection of Cyclotron Facilities • Some considerations (cont): • A place for storing highly activated components is recommended. • A transfer hatch for loading/unloading radioactive materials should be considered. • A lock with sequential air pressure drop (lower pressure towards the higher risk area) should be installed between controlled area and public area. • Regulatory Body and the supplier should both be consulted as early is possible in the project!

Authorization and Inspection of Cyclotron Facilities

Authorization and Inspection of Cyclotron Facilities Shielding design • Shielding needs during cyclotron operation Activation Primary beam No shielding Secondary neutrons Shielding Photons Shielding

Authorization and Inspection of Cyclotron Facilities Hot Cells q Gamma rays of 511 ke. V 5, 5 Sv/h per m. Ci!

Authorization and Inspection of Cyclotron Facilities Shielding materials neutrons q Shielding needed against fast neutrons; q Moderation: most efficient through elastic scattering on light nuclei; q H-rich materials like water, paraffin, concrete, …

Authorization and Inspection of Cyclotron Facilities Shielding materials photons q Prompt gamma flux; q Final product in the hot cells; ; q High-density materials.

Authorization and Inspection of Cyclotron Facilities q Density of 2. 35 g/cm 3; q Addition of aggregate materials; q Low cost?

Authorization and Inspection of Cyclotron Facilities Neutron Source term Intensity + energy spectrum + angular distribution Depends on the type and energy of the particles, the target material and geometry of the assembly. • Cyclotrons dedicated for radionuclide production: 1 (or 2) particles, 1 energy and 1 (or 2) types of target • Cyclotrons multi-particle, multi-energy: conservative approach

Authorization and Inspection of Cyclotron Facilities Literature data Spectrum Neutrons

Authorization and Inspection of Cyclotron Facilities q Although particle emission varies with the angle, by considering an isotropic emission we are being conservative (recommended).

Authorization and Inspection of Cyclotron Facilities What are the doses? Neutrons IBA 18/9 320 m. Sv/h per µA at 1, 76 m

Authorization and Inspection of Cyclotron Facilities What are the doses? Neutrons GE PETtrace 300 m. Sv/h per µA at 1, 00 m

Authorization and Inspection of Cyclotron Facilities TVL in concrete! 33 cm 200 cm is 6 TVL

Authorization and Inspection of Cyclotron Facilities What are the doses? Photons (n, ) q Monte Carlo simulations indicate. . . In small wall depths , the neutron dose is 100 times higher than the photons dose. TVL 42 cm 3 m. Sv/h per µA

Authorization and Inspection of Cyclotron Facilities What are the doses? Photons (cells) Source of 511 ke. V 16 mm

Authorization and Inspection of Cyclotron Facilities q The cyclotron operates with 60 µA, producing a neutron dose H 0, at 1 m from the target. q What is the necessary concrete thickness in order to have a dosis of 20µSv/week in a point situated at 5. 5 m?

Authorization and Inspection of Cyclotron Facilities Neutrons 300 m. Sv/h per µA 60 µA 18 Sv/h at 5, 5 m: H 0 at 1, 00 m 18 Sv/h X (1 m)2 =D’ X (5, 5 m)2 = 595 m. Sv/h

Authorization and Inspection of Cyclotron Facilities for 40 hours/week: 40 h/sem X 595 m. Sv/h = 23, 8 Sv/week

Authorization and Inspection of Cyclotron Facilities The required transmission for a shielding that will reduce the dose of 23. 8 Sv/wk to 20 µSv/wk, is: B= 20 µSv/wk 23, 8 Sv/wk = 8, 4 x 10 -7

Authorization and Inspection of Cyclotron Facilities A = (1/B) = 10(X/TVL) X is the necessary shielding thickness (1/ 8, 4 x 10 -7) = 10(X/33 cm) X= 200 cm Concrete 2. 35 g/cm 3

Authorization and Inspection of Cyclotron Facilities Photons 3 m. Sv/h per µA 60 µA at 5, 5 m: 180 m. Sv/h H 0 at 1, 00 m 180 m. Sv/h X (1 m)2 =D’ X (5, 5 m)2 = 5, 95 m. Sv/h

Authorization and Inspection of Cyclotron Facilities The required transmission for a shielding that will reduce the dose of 0, 24 Sv/wk to 20 µSv/wk, is: B= 20 µSv/sem = 8, 3 x 10 -5 O, 24 Sv/sem

Authorization and Inspection of Cyclotron Facilities A = (1/B) = 10(X/TVL) X is the necessary shielding thickness (1/ 8, 3 x 10 -5) = 10(X/42 cm) X= 171 cm Concrete 2. 35 g/cm 3

Authorization and Inspection of Cyclotron Facilities 20 µSv/sem T Non-controlled! The occupancy factor has to be considered!

Authorization and Inspection of Cyclotron Facilities Ducts Monte Carlo!

Authorization and Inspection of Cyclotron Facilities SELF-SHIELDED q Ensures that some dose rate values are not exceded in the self shielding surface!

Authorization and Inspection of Cyclotron Facilities “Local shielding”