Radioactive substances


When working with radioactive substances, staff can be exposed to different types of radiation, which can have a negative effect on their health. In addition to direct effects such as skin erythema and eye lens damage caused by overdose, the long-term effect of cancer in particular is a risk. The absorption of radioactive substances into the body through contamination should especially be prevented.


In order to work with radioactive substances, a UMC must have a permit under the Nuclear Energy Act and the Radiation Protection Decree, with the executive board being the permit holder.


Radiation expert

In the event of a so-called Complex Permit under the Nuclear Energy Act, the executive board is obliged to set up a radiation protection unit and to appoint radiation experts. The tasks of the coordinating radiation expert in the radiation protection unit include the following:

  • Formulating policy;
  • Granting internal permissions;
  • Monitoring the requirements of the Complex Permit under the Nuclear Energy Act;
  • Reporting to the government and the permit holder;
  • Supervising the maintenance of the Nuclear Energy Act file.

Which substances

Radioactive substances are widely used in the diagnosis and treatment of patients in Nuclear Medicine and Oncology.

For these purposes, the following radioactive substances are often used:

  • Technetium;
  • Iodine;
  • Iridium;
  • Cobalt

Laboratory research makes use of materials such as:

  • Radioactive iodine;
  • Radioactive phosphorus;
  • Radioactive tritium.

Risk reduction

 The following requirements apply to working with radioactive substances:

  • Only work with radioactive substances when (internal) permission has been given.
    Without this permission, working with radioactive substances is prohibited.
  • Work only with radioactive substances in specially designated, monitored and controlled areas that are not generally accessible.
  • Mark the monitored and controlled zones with special warning signs. These radionuclide laboratories and patient treatment rooms must meet special interior requirements.
  • Ensure that local supervisors and exposed staff have the required radiation protection expertise.
  • Classify staff who work with radioactive substances (called exposed workers) into the following categories:
    - A workers (with a chance of a dose of more than 6 mSv but less than 20 mSv).
    - B workers (with a chance of a dose of less than 6 mSv but more than 1 mSv).
  • Exposed workers must be registered with NRG. NRG manages the National Dose Registration and Information System (NDRIS) on behalf of the Ministry of Social Affairs and Employment). This is a centralised system for storing radiological control data, which is generally done via the radiation protection unit of your UMC.
  • Ensure that staff wear the personal dosimeters issued to them and have these dosimeters read out periodically. The results must be recorded in a file.
  • Have new category A workers undergo an occupational health examination before starting work for a radiologist and repeat this every year. If the doctor considers it necessary, an occupational health examination should also be carried out when work with radioactive substances is ended, when the dose limits are exceeded or in the event of a radiation accident.
  • Ensure that radiation hygiene measures are taken for operations involving radioactive substances, such as shielding measures, use of containment to prevent dispersal, extraction in the work area, proper waste collection facilities, protective clothing and gloves, contamination monitoring equipment and decontaminants.
  • Provide a written safety instruction.
  • The amount of activity to be handled is limited according to the type of radionuclide laboratory (B, C or D level). The radioactive substances and the quantities of them that are allowed to be used are specified in the internal consent.
  • Only carry out work if permitted by internal approvals and describe it including waste disposal in protocols.
  • Assess the load factor for each radionuclide room according to the system described in the Radionuclide Laboratory Guideline.

Mandatory registrations

To ensure a proper assessment of exposure levels, each UMC must keep a number of mandatory records in the Nuclear Energy Act file. A number of relevant registrations for this are:

  • The NDRIS, which is managed by NRG and records all exposed workers (categories A and B) with identification data, personal data and measured-dose data;
  • The personal medical records of category A workers, which contain information about the nature of the work, the results of the examinations by the radiologist, radiological emergencies (if applicable) and more. these records are to be retained for 30 years;
  • A register of enclosed sources present (type of radionuclide, activity per source);
  • A register of open sources present (total activity, annual throughput in radiotoxicity units);
  • A register of the use of open sources in radionuclide laboratories (type of nuclide, activity per nuclide, overview of radionuclide laboratories by categories B, C and D, type of operation and load factor per radionuclide laboratory);
  • Registration of transfer of radioactive waste to COVRA or discharges into sewers (in radiotoxicity units);
  • Emissions into the environment.

More information

Please refer to the following documentation for an overview of all mandatory measures and registrations:

  • Radiation Protection Decree under the Nuclear Energy Act. (BS 2000);
  • Radionuclide Laboratories Directive;
  • UMC Complex Permit;
  • Internal regulations of the own radiation protection unit / occupational health & safety & environmental department;
  • Requirements under the Internal Consent of the department in question.