Potential accidents with modern operative nuclear submarine and with transport of spent nuclear fuel along the Norwegian coastal line have been under evaluation. Hypothetical release scenarios which include immediate discharge of release fraction and constant release of fuel corrosion products, were developed. Modelling work has been done using a compartment model developed at NRPA which includes the dispersion of radioactivity in marine regions, processes of water-sediment interactions and dose assessment modules. Collective dose-rates to man, concentration of radionuclides in biota/sea-foods and doses to marine organisms were calculated. Results from the calculation of concentrations of radionuclides in marine organisms as well as doses to man and biota are discussed.

There has been recent interest in the transport and fate of 36Cl in the environment. The IUR task force on Radioecology and Waste has identified the need for further uptake data. Reported here are the results of a 6-month study of the uptake in ryegrass of 36Cl in five lysimeters. Lysimeters were deployed in a greenhouse from November 2007 to May 2008. Except for an initial watering, exterior reservoirs connected to the base of the lysimeters maintained the water tables at a constant level with a solution containing 36Cl in a chloride form. A destructive analysis of the lysimeters showed that between 75 and 80% of 36Cl added to the system during the course of the experiments was taken up into the plant tissue. The quantities of 36Cl found in weekly soil tests and a simple mass balance provide supporting evidence for the significant bioavailability of 36Cl in a chloride form.

In this paper we examine some critical aspects concerning the justification of simplified radioecological models used in safety assessments for geological repositories. We propose a modelling approach for regulatory review of dose and risk calculations for a nuclear waste repository. The SSI modelling tools are applied to explore uncertainties in the size of the contaminant area due to leakage of radionuclides from a damaged nuclear waste canister. We demonstrate that an improved representation of geosphere transport processes will also enhance our understanding of radionuclide migration in the biosphere and provide a better basis for evaluating radiological consequences in the safety assessment.

The ARGOS Food and Dose Module has been adopted by the RPII to simulate the transfer of radioactivity in the food chain in the event of a large scale nuclear incident and to enhance its capability to assess the radiological consequences. This paper describes adaptation of this model for Irish conditions and its intended use, illustrated with examples from a recent national emergency exercise. By enabling time series of activity concentrations of individual radionuclide or radionuclide groups in a range of food and animal feeds and comparison with appropriate action levels, the model would assist the formulation of early advice regarding countermeasures and would be an important factor in refining a pre-defined sampling strategy. The current implementation provides a basis for more detailed modelling which would inevitably be required in the event of a real incident. As the situation evolved and monitoring results became available, FDM could be refined and used to predict future concentrations or those over a wide spatial area with increased confidence.

One of the primary goals was to estimate the impact of the concentration of radioactive caesium on meio- and macrobenthic organisms in Barents and Kara Seas. It is determine that macrobenthos is more inert component, less subjected to the influence of this factor. Meiobenthos reacts to the radioactive pollution by the change of the taxonomic diversity and quantitative characteristics faster then.

A study of spatial structure of 137Cs contamination field was performed 1,8 km north to set. St. Vyshkov, Bryansk oblast in pine forest on the Iput river terrace with sandy podzolic soils and pronounced relief. 137Cs was used as a tracer of atmospheric pollutant migration to test the hypothesis of a regular character of the secondary 137Cs redistribution in natural landscapes and its dependence on landscape structure. In 2005–2007 95% to 98% of the total 137Cs activity was still preserved in the upper 15–20-cm soil layer. Field gamma–spectrometry performed in nested grids (5 m for the whole area; 1 m for 5 × 5 m plot; 0,2 m for 1 × 1 m plot) revealed a system of 137Cs polycentric anomalies at different scales. Detailed cross-sections along and cross the slopes with the step of 0,5 m and 1 m showed specific wave-like variation of surface activity often inversely related to micro-relief that is believed to result from 137Cs involvement in water and snow-melting mass migration after the aerial fallout. In mosses 137Cs also showed regular spatial distribution related to that in topsoil. The study proved that technogenic radionuclides formed a definite spatial polycentric structure in natural landscapes that should be accounted of in sampling strategy and in estimates of spatial variation.

Spatial distributions of Cs-137, Cu, Ni, Zn, Fe, Mn, K, Na, Ca in sediments, soils and water of conjugated landscapes within floodplain and coastal areas of the lower Yenisey were determined in a South-North direction from set. Ust'-Port to Cape Shaitansky. The study showed that these elements could be used to reveal the impact of natural and technogenic sources on local landscapes. The marine influence was traced by increasing salinity Cl- content and a decrease in (Ca+Mg)/(Na+K) ratios in ground water in a seaward direction. Accumulative landscapes of the island in the frontal zone of the delta area appeared to be most enriched in terrestrial elements and ions (Ca, Mg, carbonates) and Cs-137. Data suggest that this area acts as the estuary's first filter zone for river load transport. Permafrost leads to relatively enhanced concentrations of Cu, Zn and Cs-137 in soil profiles at the bottom of the active layer and to enhanced mobility and accumulation of Fe and Mn in oxidized zones. The applied methodology seems to be helpful for the rapid geo-ecological survey of large areas subject to graduated impact.

Numerous measurements of 131I concentration in milk following the Chernobyl accident have shown a wide range of clarification half-life values. By results of spectrometric measurements of the milk, performed in 1986 in Tula region (Russia), a connection between a 131I decreasing half-life in milk and a level of radioactive contamination in a locality and a level of precipitation during passage of a radioactive cloud is analysed. Values of the 131I half-life in milk increase from 3.0 d at the smallest area contamination by 137Cs to 5.5–6.0 d at the contamination above the 200 kBq/m2. The half-life of 131I removal from milk depends on the precipitation level at the time of radioactive fallouts in places of milk sampling. Tef increases from 2.8–3.5 d (dry deposition) to the value 5.5–6.0 with precipitation increasing up to 6–9 mm. The half-life value does not change with further precipitation increase. This finding should be taken into account in thyroid dose estimations for inhabitants of contaminated areas.

Health Canada maintains detector networks across Canada. One of these networks consists of NaI(Tl) detectors that measure air KERMA [1]. Located beside the NaI(Tl) detector in Ottawa is a radioxenon analyzer [2] that measures the activity concentration of 131m, 133m, 133, 135Xe directly. The ICRU-accepted KERMA to activity concentration conversion factor for 133Xe, for a semi-infinite cloud measured 1 m off the ground, is 9.68 pGy/hr per Bq/m3 [3]. However, on various dates, the two detectors in Ottawa reported a conversion value of 2.6 ± 0.2 pGy/hr per Bq/m3; we have resolved this discrepancy [4] and have expanded on the study of other isotopes by focusing on the NaI(Tl) detector. Greater accuracy in the conversion value between the air KERMA and activity concentration will assist meteorological modellers in verifying their models [1]. Two Monte Carlo methods were used in this investigation. The first is the analogue geometry where the detector is immersed in a semi-infinite radioactive source. A second method is to apply a reciprocal transform of the analogue geometry. This expedited the calculation of larger clouds. By using these two methods together, we have calculated new values for KERMA rate to activity concentration for 4 of isotopes of noble gases, namely 131mXe, 133mXe, 85Kr, 85mKr, 135Xe.

This work is based on the describing a new approach in estimation of Concentration Factor (CF) for marine organisms radionuclides uptake. We considered the dependence of CF from the water salinity (determining the K+ and Ca2+ ions). The radionuclide uptake by the marine biota of Dnieper-Bug Estuary using the numerical compartment-model POSEIDON-R with latest modifications was applied. The levels of radionuclides in the different marine organisms, representing the various types of marine organisms in the different trophic levels of the foodweb, were calculated. The uptake model takes into account both the uptake of radionuclides via food consumption, by describing the predator-prey relations, and the direct uptake of radionuclides from the water via the gills. The influence of the K+ and Ca2+ ions, competitive ions against 137Cs+, 90Sr2+ ions respectively, on the uptake rate was investigated.

The large-scale nuclear accident took place at the production association “Mayak” in the Southern Urals in 1957. About 74 PBq of radioactive substances were released into the atmosphere, which resulted in the contamination of a vast area – East-Ural radioactive trace (EURT). The results of our study have shown that the density of contamination of 90Sr and 137Cs in the frontal part of the EURT are 6700–15000 and 200–400 kBq/m2, respectively. The total deposition for 90Sr within the East-Ural Radioactive State Reserve was 428.2 (286.4–643.4) TBq, for 137Cs – 15.1 (10.2–22.4) TBq, for 239,240Pu – 1.175 (0.623–2.242) TBq.

CBPP Kakanj is one of the most important Coal Burning Power Plants in Bosnia and Herzegovina (producing power of 450 MW, waste storage site of 5 000 000 tons). Mapping of the measured gamma-dose rate has been performed with the goal of identifying the hot spots in the area of 3×3 km surrounding CBPP Kakanj, with special emphasis on the waste storage site (1×1 km). Maximum measured of the gamma-dose rate surrounding CBPP Kakanj was 140 nGy h-1 and in the area of waste storage site 210 nGy h-1. Average levels of natural radionuclide in agricultural soil samples in vicinity of CBPP Kakanj are: for 238U is 41 ± 4 Bq kg-1, 232Th is 32 ± 1 Bq kg-1, 226Ra is 27 ± 2 Bq kg-1 and 40K is 486 ± 9 Bq kg-1. Obtained results in soil-plant-animal products chain does not show significantly increased levels of natural radionuclides due to the fact that mentioned radionuclides, in general, have a low transfer factors in soil-plant-animal products chain.

At present at coasts of Northwest region of Russian Federation there are sites of storage and decommissioning of retired nuclear submarines, their nuclear reactors, spent nuclear fuel and radioactive waste. Some of those sites are not isolated. There is a hazard of release of radioactivity from those sites that can lead to contamination of vast neighborhood areas. The Nuclear Safety Institute of Russian Academy of Sciences has developed the computer model of dispersion of radioactivity in the seas gulfs and bays.

In case of an accident at a radioactively dangerous object it is necessary to assess promptly possible consequences. Such prompt assessments are almost impossible without appropriate software modelling tools. Nuclear Safety Institute of Russian Academy of Sciences has developed the set of computer programs that enables experts to assess promptly impact of possible accidents on population and environment. The set of software tools includes: models of radionuclides transport in the atmosphere and water objects (rivers, lakes and ponds). It also includes models of assessment of doses of radioactive exposure of humans. The adequate modelling is not possible without accurate electronic maps of the neighborhood of a Nuclear Power Plant (NPP). Thus the electronic maps of neighborhood of all Russian NPP's are supplemented to the set of tools. The necessary data on local population and water objects surrounding NPP's is also included and stored in GIS-based (Geographical Information System) database. That enables numerical modelling to be done within tens of minutes at most. The GIS enables use of spatial data on fallout of radioactive substances from the model of atmospheric transport to be used as input data for modelling of transport in water objects.

A project to compare the response of different detector types was started in 1996 at the Schauinsland mountain (1200 m above sea level) close to Freiburg, Germany, where the German office for radiation protection (BfS) runs a trace analysis laboratory since about 50 years. The aim of this inter-calibration experiment is to compare different gamma dose rate detector types over long periods and under rather unfavorable climatic conditions. This allows to characterise different probe types under environmental conditions and it complements the EURADOS inter-comparison exercises, which a carried out every 2 to 3 years. Both projects dealing with the harmonization of gamma dose rate data in the EU are used to derive terrestrial dose rate from the raw data. Using interpolation techniques provided by INTAMAP seasonal maps of the terrestrial dose rate could be generated. It is shown, that this information can be used for the calibration of satellite based soil moisture methods as well for the calculation of radon emission maps on the European scale, which are of interest for the research community, since Radon is used as a passive tracer in atmospheric research to examine transport processes on synoptic time scales.

Precise and accurate measurement of uranium isotope ratio is essential in environmental monitoring of any contamination in nuclear safeguards. 234U, 235U and 238U are naturally occurring alpha-emitting long-lived radionuclides, which are taken up daily at low levels with food and drinking. IUPAC has established natural isotopic composition of 235U/238U to be 0.00725. Therefore, isotope ratio measurements are important to provide information on the origin of uranium. The isotope ratios of uranium, 234U/238U, 235U/238U and 236U/238U were measured using a VG Sector 54 thermal ionization mass spectrometer (TIMS) as well as high resolution inductively coupled plasma mass spectrometry (ICP-MS) in soil samples as well as in some water samples collected in the exclusion zone of Chernobyl nuclear power plant. The isotopic composition of Chernobyl soil samples showed significant deviation from the natural uranium and presence of 236U is quite noticeable. The 234U/238U activity ratio varies in the range 1.06 to 2.1 and 1.42 to 5.75 for soil and water samples, respectively. Enrichment of 235U was also noticeable for soil as well as ground water samples.

Sensitivity analyses have shown major role of foliar transfer for many radionuclides in the context of radiological impact assessments. A review of the published literature about foliar transfer focusing on translocation factors was carried out in order to constitute an updated database on one hand and to use the appropriate existing values of translocation parameters for modeling on the other. Translocation describes the distribution of radionuclides within the plant after foliar deposition and radionuclide absorption onto the surface of leaves. It mainly depends on elements and the plant growth stage. The collected data was derived from both in-field and greenhouse experiments. It was analysed to select those coming from a contamination simulating sprinkling irrigation or rain.

This work not only allowed us to carry out a diagnosis on the values themselves but also enabled us to ascertain missing data needs. In order to compensate for the lack of data on important radionuclides concerning radioactive waste (129I, 36Cl, 79Se), experimental studies have been launched.

Presently, excavation and shipping to a distant waste disposal site is the most commonly used method for handling waste contaminated with radionuclides. Due to international recommendation waste containing enhanced concentration of natural radioactivity should be treated in the same way. In case of TENORMs, which usually occur in huge quantity, this method would be very expensive and can be disruptive to the environment in which the contamination was found as well as direct effects of this pollutant occurrence.

Biological treatment methods, such as phytoextraction or at last phytostabilisation could provide an attractive alternative to the excavation of waste. It is entirely possible that methods successful for heavy metals may be successful for the radioactive elements. Seven-years observation of the a settling pond contaminated with radium isotopes showed that even natural plant transgression into contaminated area can be an effective tool to stabilize pollutants. On the other hand, the assessment of the effectiveness of phytoextraction based on natural plants gave not so promising results.

Since radiation risk is usually considered to be related to nuclear energy or atomic bomb, majority of researches on radiation protection has focused on artificial radionuclides and radioactive waste. Far less attention has been paid to radiation risk caused by exposure to ionizing radiation originating from naturally occurring radioactive materials despite the fact that their presence touches many aspects of our life, especially when a huge amount of bulk waste had been dumped in our vicinity. Existing regulations have pointed out the strong needs to take into account non-nuclear industry where materials containing enhanced natural radioactivity occur and enclose them in frame of formal control of radiation risk but in reality often such cases of radiation risk are still out of, not only control, but even simple monitoring. This is caused by the shortage of information about radiation occurring outside nuclear industry or radioactive source and irradiating apparatus use. Such lacking information can be included in European Waste Catalogue to make the first awareness for the all stakeholders of concern.

Saline waters from underground coal mines in Poland often contain natural radioactive isotopes, mainly 226Ra from the uranium decay series and 228Ra from the thorium series. More than 70% of the total amount of radium remains underground as radioactive deposits due to spontaneous co-precipitation or water treatment technologies, but several tens of MBq of 226Ra and even higher activity of 228Ra are released daily into the rivers along with the other mine effluents from all Polish coal mines. Mine waters can have a severe impact on the natural environment, mainly due to its salinity. Additionally high levels of radium concentration in river waters, bottom sediments and vegetation were also observed. Sometimes radium concentrations in rivers exceeded 0.7 kBq/m3, which was the permitted level for waste waters under Polish law. The investigations described here were carried out for all coal mines and on this basis the total radium balance in effluents has been calculated. Measurements in the vicinity of mine settling ponds and in rivers have given us an opportunity to study radium behaviour in river waters and to assess the degree of contamination. For removal of radium from saline waters a method of purification has been developed and implemented in full technical scale in two of Polish coal mines. The purification station in Piast Colliery was unique, the first underground installation for the removal of radium isotopes from saline waters. Very good results have been achieved – approximately 6 m3/min of radium-bearing waters were treated there, more than 100 MBq of 226Ra and 228Ra remained underground each day. Purification has been started in 1999, therefore a lot of experiences have been gathered during this period. Since year 2006, a new purification station is working in another colliery, Ziemowit, at the level – 650 meters. Barium chloride is used as a cleaning agent, and amount of water to be purified is reaching 9 m3/min. Technical measures such as inducing the precipitation of radium in gobs, decreasing the amount of meteoric inflow water into underground workings etc., have been undertaken in several coal mines, and as a result of these measures the total amount of radium released to the surface waters is much has diminished significantly during the last 15 years.