b) NDT technician has proposed a RT inspection for welded section of a piping system. The diameter of the pipe is Im and the thickness of the pipe material is 20mm and maximum weld part thickness is 23mm. He is suggesting a single wall single image technique. The radiation source size to be used is 3 mm. He is also proposing the RT with single shot to cover the welded section. As an NDT engineer, evaluate the technician proposal in term of practicality and geometrical unsharpness of the image produced. Use sketch to explain your (20 marks) evaluation. An NDT technician is using a 30 Ci source of Ir-192, he is standing at a distance of 5m. What dose rate will he receive? If he continues standing at his location, how much lead shielding will be required to reduce the dose rate to 0.01 mSv (30 marks) (ImR/h)? (Show your working. Given the e (emissivity or RHM factor) of Ir- 192 is 0.5 R/h at 1 metre.)