Fast neutron dosemeter using pixelated detector Timepix.

A Timepix detector covered with polyethylene convertors of different thicknesses is presented as a fast neutron real-time dosemeter. The application of different weighting factors in connection with the position of a signal in a Timepix detector enables one to obtain an energy-dependent signal equal to neutron dose equivalents. A simulation of a Timepix detector covered with polyethylene convertors using monoenergetic neutrons is presented.

A fast and simple approach for the estimation of a radiological source from localised measurements after the explosion of a radiological dispersal device.

After an explosion of a radiological dispersal device, decision-makers need to implement countermeasures as soon as possible to minimise the radiation-induced risks to the population. In this work, the authors present a tool, which can help providing information about the approximate size of source term and radioactive contamination based on a Gaussian Plume model with the use of available measurements for liquid or aerosolised radioactivity. For two-field tests, the source term and spatial distribution of deposited radioactivity are estimated.

Field tests using radioactive matter 2.

Results of field tests with explosive dispersal of a radioactive substance (RaS) are presented. The paper deals with tests exploiting artificial obstacles as a continuation and expansion of the tests used in this study performed in free area described previously. The essential goal of the tests was to estimate the distribution of the released RaS in the case of intentional abuse of radioactive sources and to get a set of data applicable to testing physical or mathematical models of propagation.

Field tests using radioactive matter.

During recent years, the assessment of possible radiological consequences of a terrorist attack associated with a release of radioactive substances (RaS) has been in the focus of interest of emergency preparedness and radiation protection specialists, as well as experts dealing with the dispersion of harmful substances in the atmosphere. Suitable tools for these analyses are applications of mathematical and physical models and simulation of this attack under 'realistic' conditions. The work presented here summarises the results of four tests, in which a RaS (a Tc-99 m solution) was dispersed over a free area with the use of an industrial explosive.

Testing of a thermoluminescent personal dosimeter at interim storages for spent nuclear fuel.

The National Radiation Protection Institute in Prague is about to use a commercially available multi-element whole-body thermoluminescence dosimeter for its radiation personnel. During the phase of practical verification of the method, the dosimeter was tested, among others, in mixed neutron-photon fields in the area of interim storages for spent nuclear fuel of the Czech nuclear power plant Dukovany. The testing was made with the intention to get information about accuracy of H(p)(10) determination for cases when no site-specific calibration is available or neutron spectra are not known.

The Austria-Czech Republic co-operation in the field of radiation-emergency preparedness.

An overview on the long-term information exchange and co-operation between Austria and the Czech Republic in the field of radiation emergency preparedness and evaluation of radiological consequences of NPP accidents is provided. Initiated by the 'Melk Protocol' between the Czech and Austrian governments in December 2000 and its follow-up activities, the information exchange and co-operation between the Czech Republic and Austria in the field of radiation-emergency preparedness have been extended. Among others, a Working Group to compare radiological consequences of Beyond Design Basis Accident with a detailed inter-comparison program concerning atmospheric dispersion models, dose assessment methods and counter- measures was established.

Radioprotective effects of amifostine (WR-2721) or cystamine on radiation damage and its repair in rats whole body exposed to fission neutrons.

Sulphur containing radioprotective drugs amifostine (gammaphos, WR-2721) or cystamine (disulfide of meracaptoethylamine) of Czechoslovak production were examined in whole body fission neutrons irradiated rats in the thermal column of reactor VVR-S. Using the split-dose technic the first sublethal neutron dose in the range 1-2 Gy was followed by second lethal exposures in the two time intervals (3 or 6 days) using whole body fission neutrons irradiations (3 days interval) or whole body gamma-irradiations (6 days interval) for LD50/30 evaluation within next 30 days survival observation. In other experiments the mean survival time (MST) in days was estimated in different rats group, when animals were whole body fission neutrons irradiated twice with 3-days interval using the total lethal doses of 4 or 5 Gy.

Medical radiation exposure of the Czech Republic paediatric population due to diagnostic nuclear medicine.

Background: The information on the results of the survey of collective effective dose SE to children in the Czech Republic (CR) due to nuclear medicine examinations performed during the one-year period July 1995-June 1996.

Methods: The estimate of SE was based on the annual frequency of nuclear medicine procedures and the type and amount of administered radiopharmaceuticals provided by the General Health Insurance Company covering 75% of the CR population.

Results: In the period considered, 15,281 examinations of children younger than 18 years were performed, which represented 7.

The system of personal monitoring and the evaluation of occupational exposure in the Czech Republic.

New legislation concerning radiation protection, which was effective in the Czech Republic from 1997, followed from the recommendations of ICRP Publication 60 and the IAEA BSS, and included all new basic principles for the protection of radiation workers given in these documents. The requirements for the personal monitoring of category A workers and the recognition of the capacity of dosimetry services were identified as being very significant for radiation practice, and will be licensed by the State Office for Nuclear Safety (SONS). The license application will include the methodology of effective dose evaluation, the description of QA and QC of the service, the system of customer communication and dose recording and reporting.

Early warning system in the Czech Republic.

Since the 1950's early warning networks (EWN) for monitoring of the radiation situation on the state territory have been established in the most European countries. In the Czech republic the radiation monitoring network exists, but new requirements, especially after accident at the Chernobyl nuclear power plants, called for restructure of EWN so that be able of permanent and telemetrized measurements. Based on these requirements, the program of the EWN establishment in the Czech republic is prepared.