Isn't nuclear energy radioactive? - Nuclear for Australia

Aren't nuclear power plants radioactive?

Answer

Firstly, what is radiation?

According to Australia's Nuclear Science and Technology Organisation, "Radiation can be described as energy or particles from a source that travel through space or other mediums.". [1] There are two main categories of radiation based on their wavelength: ionising and non-ionising radiation. 

Ionising radiation is radiation that produces ions (charged particles) and can damage DNA as it passes through the tissue in the body at high levels. Examples include alpha particles, gamma rays and x-rays. [2]

On the other hand, non-ionising radiation does not produce ions (charged particles) and therefore does not directly damage DNA when passing through the body's tissue. Examples include UV, light and infrared. [2]

When discussing radiation and nuclear energy, ionising radiation is what is being referred to. 

Ionising Radiation is all around us.

Ionising Radiation is all around us it occurs naturally in the air that we breathe, to the food that we eat and the building materials we use, it is also produced artificially from radioisotopes used in medical diagnostics and treatment, to nuclear power generation.

It is therefore important when discussing the radiological impacts of Nuclear Power to put it into context of other sources of ionising radiation.

Living next to a 3.2 GW New Nuclear Power Station a conservative estimate of the radiation exposures is of the order a couple of micro-Sieverts per year (this includes from any discharges and the entire operational waste generation).  This is less that than dose you get from drinking a cup of coffee a day and significantly less than taking a transatlantic flight. [3]

In comparison with other sources of energy generation the UN Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) [4] found that:

"The Coal Cycle contributed to more than half of the total radiation exposure to the global public from electricity generation, with the nuclear fuel cycle contributing less than a fifth. In fact the radiation exposure from living next to a Coal Fired Power Station is substantially higher than living next to a Nuclear Power Plant."

They also concluded that:

"The highest occupational (worker) radiation exposure associated with any energy source (for the same amount of installed power) is solar energy plants, followed by wind energy plants. This is approximately 40 times higher than that encountered in the nuclear power sector, and is primarily associated with the extraction of the very low-grade minerals."

What is important to remember is everything in life has risk. So how do we decide if something is safe. Well ultimately that is a personal decision and only you can decide, but to help let’s try and add some context.

Relative comparison of Radiation Exposure (in mSv) from various activities:

How much radiation is too much?

What is important to remember is everything in life has risk. So how do we decide if something is safe. Well ultimately that is a personal decision and only you can decide, but to help let’s try and add some context.

What is widely accepted in the scientific community is the lowest data point we have linking radiation exposure, or dose to an increase cancer risk is ~ 100 mSv. Any form of radiation poisoning only happens at significantly higher exposures, around the 1000 mSv value. We also know that in the UK the average background dose from natural and manmade sources is 2.7 mSv, although as noted earlier 84% of this comes from natural sources.

These all-form useful points which can help us decide what is an acceptable risk.

Author: Peter Bryant

Peter Bryant is the Head of Environment, Decommissioning & Radiation Safety at Sizewell C / EDF and Honorary Professor in Physics at the University of Liverpool with extensive experience with radiation protection. He is also a member of the Australian Radiation Protection Society. 

Sources:

[1] ANSTO

[2] NSW SafeWork

[3] P A Bryant, 2024, Airborne Radioactive Discharges and Human and Environmental Health Effects, IOP Publishing, 2nd Edition (Pending Publication).

[4] TBC