What you need to know -the "graded approach".
From January 2018, all employers who undertake work with ionising radiations on nuclear premises* are required to either notify, register, or obtain consent via the ONR process in compliance with the Ionising Radiations Regulations 2017
Of the Ionising Radiation Regulations 2017, employers must comply with:
Regulation 5 - Notification of certain work,
Regulation 6 - Registration of certain practices, and/or
Regulation 7 - Consent to carry out specified practices.
The above three regulations together represent the UK's transposition of the 'Graded Approach' introduced in the EU Directive 2013/59/EURATOM