What is a Radiological Exposure Device?

• A. A radioactive source hidden in a stationary position to expose people to high levels of radiation without their knowledge.
• B. A portable detector used to identify radioactive sources in public spaces.
• C. A stationary shielding device used for exposure control.
• D. A handheld device used to measure dose rates.

Answer: (A)

A Radiological Exposure Device is a stationary, concealed radioactive source whose purpose is to irradiate people externally by proximity, without their knowledge. The key idea is that the source stays in one place and delivers a dose by being near the target, rather than releasing or dispersing radioactive material into the environment. This makes it different from devices used to detect or measure radiation, or from shielding meant to reduce exposure, or from devices designed to disperse radioactive material. In safety and security contexts, recognizing the presence of an unseen, fixed source helps explain why the objective is exposure through contact with the stationary source rather than contamination from dispersed material.