Everything in the world is made up of extremely small building blocks called atoms.
Most atoms are stable, but some unstable atoms break apart and release particles (alpha, beta and neutrons) and electromagnetic waves (e.g. gamma rays). This release of these energetic particles and waves is called radioactivity and the released particles and electromagnetic waves are called radiation. This is a natural phenomenon and all matter has some level of radioactivity including ourselves. The human body has an average of 8,000Bq.
The amount of radioactivity given off by a radioactive substance decreases over time. This is called radioactive decay. The time it takes for the amount of radioactivity to decrease by 50% is called the half-life.
Background radiation is around us all the time. It comes from many sources, including the sky above, the ground below, the air we breathe and the food we eat and drink.
The total amount of radiation we experience day-to-day is low. Radiation is both natural and man-made. On average, about 84% of background radiation is from natural sources and 16% from medical practices, such as X-rays. Less than 0.3% comes from nuclear power, industrial and defence activities.
In the UK, about half of the radiation we receive comes from natural radon gas. Radon gas is produced from the decay of natural uranium found in rocks and soils in the ground.
Radioactive materials have many uses in industry, agriculture, medicine and research.
We use radioactive materials to:
- produce electricity in nuclear energy power stations
- diagnose diseases and injuries by using X-rays and CT scans
- treat cancer through radiation therapy and radiopharmaceuticals
- preserve food by killing bacteria
- sterilise medical equipment
- measure the thickness of structures and materials
- measure the density of placed materials as they are being engineered
- detect the presence of smoke in smoke alarms
- enable scientific research to understand the behaviour of biological and environmental systems
Radiation isn’t necessarily always dangerous, but it has to be properly controlled in order to prevent harmful effects. LLW is low in activity and is therefore considered to be low risk. A radiation dose can be received by eating or breathing in radioactive materials or by being exposed to external radiation. The use of radioactive materials is tightly controlled, and a number of protective measures are used to prevent exposure to higher doses. This includes legislation to limit exposure and physical barriers to contain sources of high radiation.
All types of radiation decrease in intensity as they travel further away from the source. Any barriers, such as packaging or soil, can significantly reduce the travel distance. The materials accepted at the site will be safe for the site workforce to handle without the need for any radiation protective equipment, therefore, the risk to the public at substantially greater distance from the waste will be negligible. No measurable dose has been detected on the personal dosimeters worn by the site workforce in the nine years that LLW has been accepted at ENRMF.