What is ionising radiation?
Ionising radiation carries enough energy to remove electrons from atoms or molecules, creating ions. It can take the form of particles or electromagnetic radiation. X-rays and gamma rays are examples of ionising radiation; radio waves and visible light are not.
Exposure depends on the type of radiation, dose, duration and route of exposure. High doses can cause acute effects, while lower exposures may contribute to long-term health risks. Assessing risks to people and ecosystems requires specialised scientific evidence and should not be reduced to simplistic comparisons between technologies.
How it appears in LCA studies
Some Life Cycle Assessment (LCA) methods include an impact category related to ionising radiation. The inventory may account for radionuclide emissions to air and water across supply chains, including raw-material extraction and processing, energy production, industrial operations and waste management.
Nuclear power can make a significant contribution in some electricity systems, but it is not the only anthropogenic source of radionuclides. Material extraction and processing, coal combustion and other activities can also contribute. The magnitude and interpretation of results depend on geographical and technological context.
The indicator is not a direct measure of an individual's dose
Impact-assessment methods use models to connect emissions, environmental dispersion, exposure and potential effects. ReCiPe 2016, for example, provides an ionising-radiation potential indicator at midpoint level and also models human-health effects at endpoint level. Other methods, such as the Environmental Footprint, use their own indicators and units.
Results from different methods should therefore not be compared without checking the indicator, unit, modelled substances, time horizon and assumptions. An LCA result does not represent the dose received by a particular person and is not a substitute for a radiation-safety assessment.
A balanced interpretation
This category should be considered alongside the other impact categories. A technology may perform better in one category and worse in another. LCA can reveal these differences when the data are suitable and limitations are communicated clearly.
The aim is not to rank a technology using a single indicator, but to understand contributions across the life cycle and support transparent decisions.