Radiation protection - radioactive sources

These guidelines specify the areas of responsibility in the use of open and sealed radioactive sources. They apply to everyone who works with or has responsibility for radioactive sources.

Norsk versjon - Strålevern - radioaktive kilder

Topic page about HSE | Pages labelled with radiation

Radioactive sources #

A radioactive source emits alpha, beta or gamma rays.

  • In a sealed radioactive source, the radioactive material is sealed in order to prevent propagation of the radioactive material to the surroundings.
  • An open radioactive source is defined as all sources that are not sealed. When using an open radioactive source, the radioactive material can be accessed directly.

Work with radioactive sources should be performed so as to minimise the exposure for users and the surroundings, and so that the probability of an accident is small.

You will find a glossary at the bottom of this page.

Responsibility #

Line leader #

The line leader has the main responsibility for responsible radiation protection at the unit. The responsibilities and tasks related to radiation protection are described in the guidelines Radiation protection - responsibility and task delegation.

In addition, the line leader approves class C isotope laboratories.

The line leader should also ensure that individuals who use radioactive sources receive an introductory course in radiation protection and a user’s course in open or sealed radioactive sources. The courses are arranged by NTNU. See skill development at NTNU (in Norwegian) for new course announcements. Users should also have access to local, customised training in the use of radioactive sources.

Academic supervisor #

The academic supervisor for work with radioactive sources is responsible for the tasks described in Radiation protection - responsibility and task delegation.

Additionally, the academic supervisor should ensure that:

  • A risk assessment is conducted. If an open radioactive source is in use, use this checklist and chapter 2.5.1 in these guidelines for the use of open radioactive sources in the laborator (in Norwegian) as guides.
  • The workplace, source and equipment are correctly marked. This can be completed in conjunction with the Local radiation protection coordinator.
  • The need for personal dosimeters is evaluated.
  • The radioactive source is stored responsibly.
  • A system is in place for the return or disposal before the unit purchases sealed radioactive sources.
  • The radioactive material is sealed in accordance with ISO 2919 Sealed radioactive sources - classification (requires login to the NTNU network). Sealing should prevent leaks during regular use and in the case of accidents.
  • Regular checks are performed on equipment that contains sealed radioactive sources. The checks should ensure that the markings on the equipment are legible and that the closure mechanisms work. In addition, the radiation around the equipment should be measured.
  • The unit has a detailed description of the work to be performed with any open radioactive sources. A detailed work plan should be made by a person who understands the work in detail, and with the help of the local radiation protection coordinator. When the work plan is being made, the following factors should be taken into consideration:
  1. The user’s experience level.
  2. Equipment in the laboratory.
  3. The availability of emergency aid in the case of an accident.

The work plan should contain information such as the following:

  • Which open radioactive sources will be used.
  • The permitted amount of work.
  • How the source will be stored.
  • The measurement and person protective equipment that will be used: gloves, bench paper, radiation protection monitor, visors, lead and personal dosimeters.
  • A plan for regular contamination checks and radiation level measurements in the work area. The frequency of the checks should depend upon the amount of work conducted with the source and the likelihood of contamination. The type of check will depend on the type of the source.
  • Waste disposal.

More information about work procedures, contamination control and fume cupboards can be found in chapter 2.4.4 in the Guide for the Use of Open Radioactive Sources in Laboratories (in Norwegian).

  • How the user will perform the work. When the radiativ material is in use, the work should be done as quickly as possible without risking accident.
  • That employees, students and other involved receive local training:
  1. Local guidelines and handbooks.
  2. The use of measurement and personal protective equipment.
  3. Waste disposal.
  4. Local emergency preparedness plans.

More information about training can be found in chapter 2.4.1 in the Guide for the Use of Open Radioactive Sources in Laboratories (in Norwegian).

  • That work with volatile radioactive sources is always performed in a suitable fume cupboard, safety bench or glove box, as described in 6.2 of the the Laboratory and Workshop Handbook.

Local radiation protection coordinator #

The local radiation protection coordinator is responsible for the tasks described in the guidelines Radiation protection - responsibility and task delegation.

Additionally, the local radiation protection coordinator should:

  • Keep a list of isotope laboratories and how they are used.
  • Report changes in the use of isotope laboratories to the central radiation protection coordinator once a year.
  • Report the use of nuclides that haven’t previously been approved for type C isotope laboratories to the central radiation protection coordinator.
  • Apply for the use of nuclides that haven’t previously been approved for use in type B isotope laboratories to the central radiation protection coordinator who will then send the application to the Norwegian Radiation and Nuclear Safety Authority (DSA).
  • Manage the use of personal dosimeters and register users at the unit.

Central radiation protection coordinator #

The central radiation protection coordinator is responsible for the tasks described in the guidelines Radiation protection - responsibility and task delegation.

Additionally, the central radiation protection coordinator should:

Individuals who work with radioactive sources #

Individuals who work with radioactive sources also have responsibilities, as described in the guidelines Radiation protection - responsibility and task delegation.

Permitted amount of activity at NTNU #

Work with open radioactive sources in amounts less than the limits specified in the annex concerning exemption limits in Regulations on Radiation Protection and use of Radiation can be performed in areas not defined as type B or C isotope laboratories. All other work with open radioactive sources must be performed in an isotope laboratory that meets that following criteria:

In type B isotope laboratories, you can work with: #

  • Regular chemicals: up to 10^4 x the limit value for work outside of isotope laboratories.
  • Extraction of stock solutions and dilutions: up to 10^5 x the limit value for work outside of isotope laboratories.
  • Risky work and work with dry substances: up to 10^3 x the limit value for work outside of isotope laboratories.

In type C isotope laboratories, you can work with: #

  • Regular chemicals: up to 10 x the limit value for work outside of isotope laboratories.
  • Extraction of stock solutions and dilutions: up to 100 x the limit value for work outside of isotope laboratories.
  • Risky work and work with dry substances: up to the limit value for work outside of isotope laboratories.

Pregnancy and work with radioactive sources #

Pregnant women exposed by their profession:

The radiation dose to the foetus should not exceeds 1 mSv for the remainder of the pregnancy, from the time when the pregnancy becomes known. If you are pregnant, you should inform your employer as soon as possible. The dose to the foetus during the remainder of the pregnancy should be considered and measures taken to ensure that this limit is not exceeded.

the Norwegian Radiation and Nuclear Safety Authority (DSA) gives the following advice:

  • If the dose is accurately evaluated to be less than 1mSv: the pregnant user can continue with her regular work without taking any special precautions.
  • If the dose is believed to be less than 1 mSv: the pregnant user can continue with her regular work, but might consider taking precautions to reduce exposure to radiation.
  • If the dose is believed to be more than 1mSv: the pregnant user should work on tasks that decrease radiation exposure, or take precautions to avoid exposure to ionising radiation.

Example: the dose to the foetus while working with RIA kits is accurately evaluated to less than 1mSv.

The view of the pregnant employee should also be taken into consideration. If the pregnant employee wishes, the employers should insofar as is practical, offer alternative tasks or relocation.

For more information about pregnancy and work with open radioactive sources, see chapter 4.2 in the Guide for the Use of Open Radioactive Sources in Laboratories (in Norwegian).

Safety and labelling #

Screening and safety equipment #

Necessary screening, technical safety systems and personal protective equipment should be available to minimise the risk of accident and the radiation dose to the users and the surrounding environment.

The unit should have access to a radiation monitor, both for contamination control and dose mapping.

For more information about screening and safety equipment as well as an overview of methods and equipment, see chapter 3.4 in the Guide for the Use of Open Radioactive Sources in Laboratories (in Norwegian).

Labelling and classifying the workplace #

All work areas should be labelled with the standard symbol (sign) for radioactivity with activity above the limit values. Labelling must be in accordance with chapter 5 in the Workplace Regulation  (in Norwegian) from The Norwegian labour inspection authority. The standard symbol can also be found in NS 1029 Symbol for ionizing radiation (requires login to the NTNU network). 

If a risk assessment reveals that the workplace should be classified as a controlled or monitored area, label the doors or entrances to the area with this information. There should also be an explanation of the meaning of these terms.

Set up a room card. If the area is controlled or monitored, this should appear on the room card. Also provide information about the radioactive source’s placement and the risk it might incur. In rooms where only a portion of the room is delegated to work with radioactive sources, this should should be specified on the room card.

Labelling sources #

Radioactive radiation sources should be clearly marked with the standard symbol for ionising radiation. The standard symbol can be found in NS 1029 Symbol for ionising radiation (requires login to the NTNU network). The labelling should provide information about the type of source, series number or other unique information that can be used to identify the radiation source and activity on a particular date.

Labelling equipment #

All equipment that can be contaminated should be marked with the standard symbol for radioactivity. All glass or containers containing radioactive material should be marked with the standard warning sign for radioactivity, as well as information about the source type and the amount of activity on a given date.

Physical safety #

The number of people who come in contact with the radioactive material should be reduced to a minimum. The unit should have a list of the names of all of these people. Also, an access control system for the radioactive source so as to minimise the risk for theft and sabotage, is necessary.

Rooms or areas containing radioactive sources should have:

  • Access limitations that keep unauthorised persons from entering an area where they can be exposed to radiation or from performing theft or sabotage. If radioactive sources are kept in a room without an access control system, they must be kept under constant supervision during regular work hours. If the storage place is a room with an access control system, it does not need to be locked or under constant supervision..
  • Warning signs as well as basic information about the radiation sources and, if relevant, required personal protective equipment.
  • A room card with the radiation source marked on it.
  • Technical measures that prevent theft and sabotage.
  • Technical measures that keep radiation sources from damages from fire or water.

Transport, storage and handling #

Transport #

See the Norwegian Radiation Protection Agency’s booklet number 26: Transporting packaged radioactive material (in Norwegian). These guidelines cover radioactive material that is integrated in another item, such as a clock or other instruments.

Storage #

Radioactive material should be stored in accordance with section 25 in the Regulations on Radiation Protection and Use of Radiation. This covers all types of storage from the source is purchased until it is disposed.

The entire refrigerator or the shelf on which a radioactive solution is stored is counted as a storage area. The same applies to storage in refrigerated rooms or freezers.

Handling #

Radioactive waste that has been used in open or sealed radioactive sources should be disposed of in a manner that does not harm people or the environment. See the guidelines for radioactive waste.

Dosimetry #

The Regulations on Radiation Protection and Use of Radiation requires employees who work in controlled or monitored areas to carry a personal dosimeter or in some other way determine the personal radiation exposure dose. Students who are performing practical work as a part of their studies (i.e. in a laboratory or in practice in an enterprise) are considered as employees, and must therefore carry personal dosimeters. NTNU administers personal dosimeters to students who are about to start a practice period.

The use of a personal dosimeter is not necessary if the following conditions are met.

  • The effective radiation dose experienced by a person is estimated to less than 1mSv/year, or the estimated dose on the hands is less than 50 mSv/year based on dosimeter measurements and the actual use pattern.
  • The coordinator completes regulated contamination checks of areas and equipment.

All work with radioactive isotopes must be risk assessed. This includes an assessment of the necessity of a radiation dosimeter. The unit can decide if it wishes to always use a dosimeter or finger dosimeter for work with specific types of radioactive isotopes. No matter the circumstances, personal dosimeters should be made available to those who ask for it. The local radiation protection coordinator administers the dosimeter service.

The results of dosimeter measurements, measured or estimated, must be given in writing to the applicable user and to the central radiation protection coordinator. The information must be given at least once a year, and may be given electronically. Note that this information is sensitive and should be treated in accordance with §13 in the Freedom of Information Act (in Norwegian).  

The results of dosimeter measurements must be sent to the central radiation protection coordinator along with the annual report to the Norwegian Radiation and Nuclear Safety Authority (DSA). The central radiation protection coordinator also registers the results in the occupational health service journal of the applicable users. Thus, the name and personal identification number of the users must be reported along with the dosimeter results. 

Exposure index #

Working with ionizing radiation may imply registration in the Exposure index. Go to Exposure index to see what actions are necessary. To get into the index: Log into the substance index, click 'Administration' in the menu on the left side, and click 'Exposure'. 

Glossary #

Bq – Becquerel: A radioactive source’s strength or activity is measured in becquerel. The measurement describes how many nuclei decay per second.

Type B isotope laboratory: A special laboratory for where only work with open radioactive sources is performed.

Type C isotope laboratory: An area of laboratory reserved for work with open radioactive sources.

Sealed radioactive sources: Radioactive materials that are sealed to prevent the material spreading to the surroundings.

Contaminated: Polluted with radioactive material. 

Controlled area: The unit should classify the workplace as a controlled area if the employee can be exposed to radiation doses larger than 6 mSv/year, or if the dose experienced by the hands exceeds 150 mSv/year. If physical containment is not possible, the controlled area should be physical separated or in some other way clearly marked.

Decay: Upon decay, the radioactive nuclei sends out radiation and is converted to another element. The words conversion and disintegration are also used about this phenomenon.

Monitored area: The unit should classify the workplace as monitored if the employee can be exposed to radiation doses that exceed 1mSv/year, or if the dose experienced by the hands exceeds 50 mSv/year. Any use of ionising radiation should be shielded and the use limited so that employees in the monitored area do not receive a dose exceeding 1 mSv/year.  

Radioactive source: A radiation source contains radioactive material, which is any material that emits alpha, beta or gamma radiation.

Limit values: Work that does not exceed the limit values given in the appendix of the Regulations on Radiation Protection and Use of Radiation  can be exempt from a number of requirements. Small amount of activity can be performed outside of isotope laboratories. Work on several nuclides simultaneously needs to be given special consideration.

Open radioactive sources: All radioactive sources that are not sealed. When handling open sources, you access the radioactive material directly.

Help #

NTNU regulations #

Legislation #

Contact information #

Approval/signature #

Approved by the head of HSE - December 27th, 2018 (replaces April 30th, 2014) - HMSR38E - ePhorte xxxx/xxxxx 

    

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