Czech results at criticality dosimetry intercomparison 2002

Area of Science:

• Nuclear physics and dosimetry
• Radiation protection and safety

Background:

• Criticality accidents pose significant radiation exposure risks.
• Accurate dosimetry is crucial for assessing accidental doses and ensuring worker safety.
• Existing personal dosimetry services need evaluation for criticality accident scenarios.

Purpose of the Study:

• To assess the reliability of two distinct criticality dosimetry systems.
• To evaluate the performance of routine Czech personal dosimetry equipment in criticality accidents.
• To identify limitations in current dosimetry methods for high-level neutron exposure.

Main Methods:

• Testing of thermoluminescent detectors (TLDs) (Al-P glasses) and Si-diodes as passive neutron dosemeters.
• Evaluation of routine individual dosemeters used in the Czech personal dosimetry service.
• Analysis of etched track detectors with 232Th or 235U-Al alloy for neutron dosimetry.

Main Results:

• The TLD and Si-diode system provided reliable estimations of accidental neutron doses.
• Routine photon dosimetry systems (TLDs, film badges) performed adequately.
• Etched track detectors exhibited track density saturation, limiting accurate neutron dose measurement above approximately 1 Gy for neutrons >1 MeV.

Conclusions:

• The tested passive neutron dosimetry system is suitable for reliable accidental dose assessment.
• Routine photon dosimetry is generally reliable for criticality events.
• Limitations exist for neutron dosimetry at high doses (>1 Gy) with etched track detectors using spark counting.