Introduction to
Incorporation Monitoring
When handling open radioactive substances it may occur that radionuclides are incorporated into the body, e.g. by inhalation, ingestion, through the skin or through an open wound. This leads to internal radiation exposure. It is the task of incorporation monitoring to assess the internal doses retrospectively.
When handling open radioactive substances, the body dose can be composed of external and/or internal radiation exposure, depending on working conditions, the chemical form of the used substances and the type of radionuclides.
Methodes of Responsibility
The monitoring of incorporation is regulated in the National Guideline of Physical Radiation Protection Control. The following monitoring methods for the determination of the incorporated activity are commonly used:
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In-vivo methods: Direct determination of activities in the body and in the organs.
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In-vitro methods: Determination of activity concentration in excretions.
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Room air measurements: Determination of activity concentration in the air at the work place.
Retrospective Assessment
It is the task of incorporation monitoring to assess doses retrospectively. In general if people of public or workers are occupationally exposed by handling open radioactive sources or after a nuclear event, in general incorporation monitoring is necessary. The activity possibly incorporated is determined and the body dose resulting from this uptake is assessed using the monitoring data. This means that incorporation monitoring on the basis of measurements serves to determine retrospectively a radiation exposure.
Techniques of Investigation
In-vivo monitors
Incorporation monitors (In-vivo counters) are designed to protect workers and people of public in the field of medical therapy and diagnostic, fertilizer and oil industry, waste and military applications, NPP’s, industry, universities, research institutes as well as miners and further fields of applications.
Types of in-vivo monitoring geometries we realised:
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Whole an Partial body counter WBC, PBC
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Fix and variable detector positions
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Scanning bed and scanning detector technologies
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Organ counters:
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Lung & Liver counter LC,
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Stomach counter SC,
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Bone counter BC: head and knee and back
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Special counters:
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Thyroid counter TC and scanner TSc
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Beta/Gamma counter BGC
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Individual research counter
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Types of shielding geometries we realised:
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Mobile chamber version with shadow shield inside
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Standard room version with light shadow shield inside
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Heavy chamber version for basements
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Heavy and light labyrinth version for basement and standard rooms
Types of detector we used:
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All usable types of detector: HPGe-, NaI-, Scintillation-, Proportional Detectors
Important radionuclides to be measured:
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All measurable radio-nuclides: natural primordial/cosmogenic and anthropogenic
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Incorporation from medical therapy and diagnostic, fertilizer and oil industry, waste and military applications as well as phosphate and other mines.
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Natural radionuclides: U-238, Th-232, U-235 and there daughters in equilibrium as well as Ra-226, 228, 225 and their daughters like Pb-210 but also K-40, Cs-137 and additional nuclides of interest like actinides as Pu-isotopes.
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Energy range: 20 keV up to 2 MeV
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It covers also fission and activation products, e.g from full-outs and workplaces contamination as well as Pu isotopes in the lung.
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Some radionuclides as K-40, Cs-137, Th - isotopes are homogeneously distributed in the body tissue and muscles.
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U-, Ra- and Sr-isotopes and Pb-210: most parts are in the bones if ingestion is the primary path of intake and in the lung if inhalation is the primary way of intake.
State of the art technology
Install state-of-the-art incorporation monitoring technology
to measure γ-rays with high resolution HPGe detectors in fully or shaddow shielded lead chambers for all measuring geometries
(partly & whole body as well organs) on the human body.
Applicable for homogeneous and inhomogeneous distributed radionuclides in the human body for γ- and β-rays as well as Bremsstrahlung.
Below are some examples for in-vivo monitors:
Partial Body Counter
State Hospital at Graz Austria
Shadow shielded HPGe/BGO partial body counter to measuring children and adults under supervision of nurse and/or mother in a standard room
Whole Body Counter
BfS Munich Germany
Fully shielded labyrinth measuring chamber using 4 HPGe & NaI detectors in bed geometry to measure the total body radioactivity (picture with IGOR calibration phantom).
Whole Body Counter
Seibersdorf Laboratories Austria
Partially shielded measuring room using 2 shielded HPGe detectors in scanning bed geometry to measure the total body radioactivity (picture with bottles calibration phantom).
Lung counter
KWU Germany
Fully shielded compact measuring chamber using four medium-energy HPGe detectors to measure occupational people working with open radioactive materials
Scanning whole body counter
PLLL USA
Fully shielded measuring chamber using 3 HPGe detectors in scan bed geometry to measure the total body radioactivity distribution
Sr-90/Cs-137 counter
BfS Munich Germany
Special mobile incorporation monitor using a shaddow shield design for beta and photon head measurements and for simultaneously photon stomach measurements.