(Very important) Three Fundamental Principles of Radiation Protection

Hello, everyone. My name is Daichi, an expert providing the information on the radiation issues in an easy-to-understand manner.

Do you know that there are three basic approaches, that is, principles for the radiation protection?

In this article the three fundamental principles of radiation protection will be covered.

In other words, today, I would like to respond to the following question:

‘What is the three fundamental principles of radiation protection?’

Table of contents of this article

I have been involved with the radiation-relevant issues, like the policy on the decontamination activities and the management of the Interim Storage Facility, after the accident of the Fukushima Daiichi Nuclear Power Plant in 2011.

I received a doctorate in the field of radiation, while working in Fukushima.

(Very important) Three Fundamental Principles of Radiation Protection

The following three fundamental principles underlie every policy for radiation protection.

– Justification
– Optimization
– Dose limit

Each principle will be elaborated sequentially below.

Justification

The principle of justification is the concept, that the use of radiation is permitted, only when the benefit outweighs the detriment or risk caused by the use of radiation.

For example, let us take the medical exposure as an example.

Even if they can understand well the condition of inside the body, by taking a number of medical check-ups using radiation, if they are exposed to too much radiation which cause negative impact on their health, it doesn’t make sense.

On the other hand, if they doesn’t take any health check-ups and they can successfully reduce the dose as less as possible, if it becomes late to find symptoms for the physical disorders which lead to serious sickness, it also doesn’t make sense.

To make a long story short, the use of radiation brings both advantage and disadvantage, and radiation needs to be used, as long as the advantage is more than the disadvantage.

This is a case under the planned exposure situations, but this principle can also be applied to cases under the emergency and existing exposure situations.

With regard to the types of exposure, please see this article.

For example, under the emergency situation, such as an accident of a nuclear power plant, responders could be exposed to much radiation, compared with ordinary situation.

This action might possibly resulst in large benefits, including the prevention of further severe accident, or life saving.

As another example, the decontamination activities after an accident of a nuclear power plant, under the existing exposure situations, often lead to the reduction of exposure dose, by removing radioactive materials existing in surrounding environment.

On the other hand, excessive decontamination activities might cause additionally second disaster or serious damage on ecosystem.

Therefore, it means that every single activity/policy needs to be determined, by deeply taking account of the balance of merits and demerits.

Optimization

The principle of optimization is the concept, that the dose needs to be kept as low as reasonably achievable, as long as the aforementioned principle of justification is met.

To realize this principle, ‘dose limit’, which is applied under the planned exposure situations, and ‘reference level’, which is applied under the emergency and existing exposure situations, are used.

Regarding the exposure situations, please see this article.

By the way, this concept: As Low As Reasonably Achievable is often called the principle of ALARA, deriving from the capital letters of the phrase.

This principle calls for keeping the dose as low as possible, but it needs to be noted, that there needs to be merits as a whole by the usage of radiation, also taking account of the factors other than radiation-relevant issues, as mentioned in the principle of justification as well as the concept of ALARA.

Dose limit

Dose limit is a management value to reduce the exposure dose deriving from sources to be managed and it is applied under the planned exposure situations.

For detailed information regarding the dose limit, please see this article.

Summary

There are the following three principles of radiation protection:

– Justification
– Optimization
– Dose limit

The principle of justification is the concept, that the use of radiation is permitted, only when the benefit outweighs the detriment or risk caused by the use of radiation.

The principle of optimization is the concept, that the exposure dose needs to be kept as low as reasonably achievable, as long as the principle of justification is met.

The dose limit is a management value to reduce the exposure dose deriving from sources to be managed and it is applied under the planned exposure situations.

By the way, abovementioned contents are summarized in the following videos.

It would be appreciated to visit them at your convenience.

– Japanese version

– English version

You can read the same article in Japanese here.

Thank you very much for reading this article.

See you next time!