1. Accident scenarios for MTA beam line Igor Rakhno June 8, 2007

2. The scenarios Several spatial locations were examined: –beam pipe 5 m US the 12-ft sh.block; –beam pipe 2.5m US the 12-ft sh.block; –beam stop itself; –beam pipe inside the 12-ft sh.block, ≈ under the penetrations; –quad 5 m DS the 12-ft sh.block The beam stop in all the cases is in upper position (beam pipe is clear). Two penetrations are in the model: coax and rectangular (modeled as circular). 2

3. Plan view @ beam line elevation 3

4. Penetrations: elevation view 4

5. Penetrations: plan view @ elevation of X=370 cm 5

6. Calculated dose in the penetrations @ X=370 cm Location Dose (mrem/pulse) Beam pipe 5 m US the 12-ft sh.block 1 Beam pipe 2.5m US the 12-ft sh.block 1 Beam stop itself 1 Beam pipe inside the 12-ft sh.block 25 Quad 5 m DS the 12-ft sh.block 240 There is no cross-talk between the penetrations, so that we have two spots 240 mrem/pulse each, not one spot 480 mrem/pulse. 6

7. Accident on quad; plan view @ X=370 cm 7

8. Accident inside the 12-ft block 8