Technical Guidance

What do lead codes mean and how do they relate to thickness? Often you might calculate a certain level of lead radiation shielding required (e.g. for an x-ray inspection enclosure) and need to supply this information to an architect who is helping you design the facility. They will ask you -"what code lead do we need to use? Find out what you need to know in this article.

A rule of thumb updated for 2024! This article considers the following expression D=ME/6r² which has turned up in text books and training courses, but there appears to be no direct reference to when it was created and by whom. We start by using the expression with Cs-137 and see how the results compare with other resources available for calculating dose rates for chosen radionuclides with given activity and distance. We then hand over to Dr Chris Robbins of Grallator who is a maths, physics and nuclear physics whizz who derives this expression from first principles, outlining the good, the not so good and how it can be improved.

Consider the situation where you move up to a radioactive source, perform some operations for a period of time, and then move away. What total dose will be received?

H-3 (Tritium) radiation safety data from Ionactive.

C-14 (Carbon-14) radiation safety data from Ionactive.

F-18 (Fluorine-18) radiation safety data from Ionactive.