Dosimetry for working with ionising radiation procedure
To ensure that anyone working with ionising radiation sources is subject to an appropriate dosimetry regime.
Range of application
Applies to all units at the University where ionising radiation sources are used. The use of dosimeters should be considered for all users of ionising radiation sources.
- Management is responsible for ensuring that this procedure is followed. Tasks can be delegated to the local radiation protection coordinator.
- Users of ionising radiation are required to use personal dosimeters where considered necessary.
Determining who will use dosimeters
As a general rule, anyone working with radiation sources in supervised or controlled radiation protection areas should wear personal dosimeters. The exceptions are:
- Working with low-energy isotopes that will not be detected by a dosimeter (e.g. H-3, C-14 or S-35)
- Working with low-energy X-rays that will not be detected by a dosimeter
Anyone working in a supervised or controlled area, but not working with radiation sources shall carry personal dosimeters if they can still receive a dose of more than 1 mSv/year.
If any type of work implies that fingers can get a much larger dose than the rest of the body, finger or wrist dosimeters must be used. This may be appropriate when using large amounts of γ-or β-emitters, e.g. when working with multiple MBqs of P-32.
The use of electronic dosimeters that can provide immediate feedback on cumulative dose should be considered when working in a controlled area of radiation protection.
Dosimeters can be ordered from the Norwegian Radiation Protection Authority or the Institute for Energy Technology (IFE) by letter. Delivery time is about 14 days. Sending a personal identification number by e-mail or fax is forbidden. If the allocation list contains personal identification numbers, it must be wiped out and the allocation list containing personal identification numbers must be shredded as soon as possible.
Electronic dosimeters can be purchased from suppliers of the same.
Dose reports contain personal information and should not be posted on bulletin boards or otherwise made public. If a person has received a dose, they must be informed by the person receiving the report directly.
If a user has received a whole body dose of more than 0.5 mSv or a dose to skin or fingers of more then 25 mSv over a two month period, the manager is responsible for identifying the cause, and re-examining working procedures, risk assessments and job safety analysis. Managers are responsible for the results of reviews being documented and archived. Finger Doses exceeding 25 mS per measurement period shall be followed up in a similar way.
Managers are responsible for everyone using personal dosimeters receiving an individual written report once annually on the dose registered for them over the past year, regardless of whether the person has received dose or not. When another supplier of dosimetry services than the Norwegian Radiation Protection Authority is used, the manager shall ensure that dose reports are sent to the Norwegian Radiation Protection Authority for filing.
Orders and cancellations of orders for dosimeters must be filed as outgoing letters, with the Norwegian Radiation Protection Authority as recipient. The case folder must be titled: “Dosimetry”. The duration of the case folder must be equal to the filing period. The record item must be titled: “Orders for dosimetry services”. If the order contains personal identification numbers or sensitive personal information, a de-personalized version must be attached to the record item and shielded according to Section 13 of the Freedom of Information Act, cf. Section 13 of the Public Administration Act.
Dosage reports from the unit to individual employees/students must be filed as outgoing letters in the personnel folder/student folder with the employee/student as recipient. The record item must be provided with the title: “Dosage report-
- Compiled by: HSE Unit
- Authorized by: University Director Gunn-Elin Aa. Bjørneboe
- Date of authorization: 13.06.2016
- Version: 3
- Case and document no. in ePhorte: 2012/11454-76