Answer to Question #7427 Submitted to "Ask the Experts"

Category: Accelerators — Induced radioactivity

The following question was answered by an expert in the appropriate field:

When demolishing an existing cancer-treatment bunker housing a Linac accelerator, is the concrete waste from the primary protection wall regarded as contaminated waste? Would this principle apply to demountable and relocatable bunkers?

Thank you for your question pertaining to the activation of concrete resulting from the operation of a Linac accelerator. In general, there is a reasonable potential for the concrete shielding barriers to become activated by the radiation produced from accelerator operations. Therefore, an estimation of radioactivity induced in concrete shielding is an important consideration for the decommissioning of accelerator facilities, as it is very likely that the concrete (or at least some portion of the concrete) would be considered as radioactive waste. Specifically, the induced activity probably consists of 3H, 14C, and various gamma-emitting radionuclides such as 60Co and europium isotopes. Sampling and laboratory analyses can be performed to determine the radionuclide concentrations and depth of contamination within the concrete barriers.

Hope this helps.

Eric Abelquist, PhD, CHP

Answer posted on 29 April 2008. The information posted on this web page is intended as general reference information only. Specific facts and circumstances may affect the applicability of concepts, materials, and information described herein. The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice. To the best of our knowledge, answers are correct at the time they are posted. Be advised that over time, requirements could change, new data could be made available, and Internet links could change, affecting the correctness of the answers. Answers are the professional opinions of the expert responding to each question; they do not necessarily represent the position of the Health Physics Society.