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Ionising radiation

Environmental Radioactivity - Medicine - Occupational Radiation Protection - Nuclear Hazards Defence

Ionisierende Strahlung

Interlaboratory comparisons

One of the major tasks of the Federal Office for Radiation Protection's (BfS) Coordinating Office on Incorporation Monitoring is to support the approved laboratories for incorporation monitoring (ALfIM) in their quality assurance in all stages in assessing the internal dose. This means that the Coordinating Office has to take special care of the regular performance of intercomparisons in the in-vivo laboratories (whole body and partial body counter) and the in-vitro laboratories (excretion analysis).

These intercomparisons generally consist of two parts:

  • a practical part where the laboratories have to determine the activity in a body phantom or the activity concentration in an excretion sample, and
  • a theoretical part, the so-called case study, where the internal dose has to be assessed by using monitoring data.

Also German non-governmental laboratories and laboratories from abroad may participate in the interlaboratory comparisons of the Coordinating Office on Incorporation Monitoring of the BfS.

In-vivo Intercomparisons

The in-vivo intercomparisons are carried out once a year. They generally include alternatively

  • the measurement of the activity of a whole body phantom (replication of a human body) with a homogeneous distribution of given radionuclides and
  • the measurement of the activity of a thyroid gland-neck phantom (thyroid gland activity of iodine).

Rough scheme for the performance of an in-vivo intercomparison (IC)
ActionDate
Announcement Beginning of the year
Preparation of phantoms
Carrying out the measuring campaign Late summer
Deadline for reevaluationsUp to two weeks after the measuring campaign
Information about the first evaluations by e-mail By beginning of the following year
Statistic evaluation of the ICSpring of the following year
Possibility of statements by the IC participants

In-vitro-Intercomparisons

The in-vitro intercomparisons are carried out once a year as well. They generally include the determination of the activity concentration of given radionuclides in urine (and/or in faeces).

Performance of In-vitro Intercomparisons
ActionDate
Announcement Middle of the year
Preparation resp. production of IC samples
Forwarding of the samples to the IC participants Second half of the year
IC participants inform about their results Beginning of the following year
Evaluation of IC results
Informing IC participants about first results (by e-mail) First quarter of the following year
Carrying out a workshop with the German-speaking IC participants Middle of the following year
Officially informing IC participants about the results including the respective BfS report. End of the following year

Realisation of case studies

Additionally to the intercomparisons for quality assurance of laboratories for incorporation monitoring dosimetrical case studies are carried out once a year as well. Also German non-governmental laboratories and laboratories from abroad may participate in the evaluation of case studies of the Coordinating Office on Incorporation Monitoring of the BfS.

In this theoretical part, on the basis of monitoring data the internal dose has to be assessed. This data can be fictitious or can be based on a real case of in-vivo or/and in-vitro monitoring.

The time of the realisation of the case studies is matched with the intercomparisons. Announcement, distribution, and evaluation of the case studies are taking place in the fourth quarter of the running year. The final results including a model answer will be dispatched in the first quarter the following year.

State of 2016.10.07

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