Chernobyl accident fallout from

The variograms of the soil variables Cs derived from the Chernobyl accident and from the global fallout showed no spatial dependence within our range limit between 5 and 90 m (Fig. 4a). It was not possible to fit a model (spherical, exponential, linear) to the values with an > 0.2 indicating a spatial dependence below 5 m or a random... 

X Bq of Pu has been released, mostiy from bum-up of the nuclear powered sateUite SNAP-9a and that 3.7 X 10 Bqof + ° Pu was released by the Chernobyl accident (167,168). Many studies have been done to determine the cumulative fallout on sods, plants, bodies of water, animals, and humans. For example, the cumulative Pu fallout ia forest and grasslands and ia the Hver of elderly humans ia Bavaria, Germany are approximately... 

Paatero J, Jaakkola T. 1998. Transfer of plutonium, americium and curium from fallout into reindeer after the Chernobyl accident. Boreal Environment Research 3 181-189. 

Caribou in northern Quebec contained up to 1129 Bq 137Cs/kg muscle FW in 1986/87, but only 10 to 15% of this amount originated from Chernobyl the remainder is attributed to fallout from earlier atmospheric nuclear tests (Crete et al. 1990). The maximum concentration of 137Cs in meat of caribou (Rangifer tarandus granti) from the Alaskan Porcupine herd after the Chernobyl accident did not exceed 232 Bq/kg FW, and this is substantially below the recommended level of 2260 Bq 137Cs/kg FW (Allaye-Chan et al. 1990). Radiocesium transfer in an Alaskan lichen-reindeer-wolf (Canis lupus) food chain has been estimated. If reindeer forage contained 100 Bq/kg DW in lichens and 5 Bq/kg DW in vascular plants, the maximum winter concentrations — at an effective half-life of 8.2 years in lichens and 2.0 years in vascular plants — were estimated at 20 Bq/kg FW in reindeer-caribou skeletal muscle and 24 Bq/kg FW in wolf muscle (Holleman et al. 1990). 

The accident at the Chernobyl, Ukraine, nuclear reactor on April 26, 1986, contaminated much of the northern hemisphere, especially Europe, by releasing large amounts of radiocesium-137 and other radionuclides into the environment. In the immediate vicinity of Chernobyl at least 30 people died, more than 115,000 others were evacuated, and the consumption of locally produced milk and other foods was banned because of radiocontamination. The most sensitive local ecosystems were the soil fauna and pine forest communities. Elsewhere, fallout from Chernobyl measurably contaminated freshwater, marine, and terrestrial ecosystems, including flesh and milk of domestic livestock. Reindeer (Rangifer tarandus) calves in Norway showed an increasing frequency of chromosomal aberrations that seemed to correlate with cesium-137 tissue concentrations tissue concentrations, in turn, were related to cesium-137 in lichens, an efficient absorber of airborne particles containing radiocesium and the main food source of reindeer during winter. A pattern similar to that of reindeer was documented in moose (Alces) in Scandinavia. 

Roed, K.H., I.M.H. Eikelmann, M. Jacobsen, and O. Pedersen. 1991. Chromosome aberrations in Norwegian reindeer calves exposed to fallout from the Chernobyl accident. Hereditas 115 201-206... 

Fig. 3. Graphical illustration of a mixing relationship between two end-member components in a three-isotope normalization diagram (241Am/239+240Pu vs. 23SPu/239+240Pu). It is indicated that the measured anthropogenic actinide isotope ratios are, within uncertainty, identical to the atomic weapon component, therefore clearly indicating that actinide fallout from the Chernobyl accident was insignificant in western Europe.

Table 4. Calculated fractious of U7Cs and wSr in Swiss soil samples contaminated by fallout from previous (40 years agoI atmospheric atomic bomb testing I component AI and from the 1986 Chernobyl accident (component C) (reference date I January 20031... 

Radioactive substances The principal sources of radionuclides released into the environment include nuclear weapon testing fallout from accidents such as the Chernobyl accident in 1986 or from foundering of nuclear submarines from the dumping of nuclear waste into the deep ocean and from discharges from nuclear power plants and nuclear reprocessing plants. 

Devell, L., Tovedal, H., Bergstrom, V., Appelgren, A., Chyssler, J. Andersson, L. (1986) Initial observations of fallout from the reactor accident at Chernobyl. Nature, 321, 192-3. 

Public interest in radioactive aerosols began in the mid-1950s, when world-wide fallout of fission products from bomb tests was first observed. The H-bomb test at Bikini Atoll in 1954 had tragic consequences for the Japanese fisherman, and the inhabitants of the Ronge-lap Atoll, who were in the path of the fallout. In 1957, radio-iodine and other fission products, released in the accident to the Windscale reactor, were tracked over much of Europe, and these events were repeated on a much larger scale after the Chernobyl accident. 

Many lessons were learnt during the period 1955-1965 by analysis of dispersion and fallout from bomb tests and also from the Windscale accident, but some of these had been forgotten by 1986 when the Chernobyl accident happened, so no apology is made for describing some work which is now 30 years old. 

Figure 10.18. y-Ray spectrum of a soil sample from Belarus showing the identification of 4Cs and 1 J7Cs fallout from the Chernobyl accident... 

The total deposition from nuclear test fallout was 2 300 Bq m which today would have decayed to 870 Bq m . The deposition from the Chernobyl accident was 1 400 Bq m which today would have decayed to 900 Bq m. In total we then have about 1 770 Bq In the sediments we find a deposition between 2700 and 3 600 Bq m with a mean of 3 400 +/- 950 Bq m . The integrated deposition in the dam is about twice that from general integrated fallout. It is very common that the accumulation in the aquatic environment is higher than that from estimated fallout due to run off. The conclusion is that there is not any strong accumulation of radiocaesium in the dam. The annual accumulation today is in the order of 20-50 Bq m year compared to 700-800 Bq m year during the maximal fallout period. It shows that there is still some continuous transport of contaminated material from the catchment area and the lake downstream. The lake is very shallow and the sediments are redistributed by waves. 

Environmental radiation monitoring in Japan mainly comprises two different systems. One is radiation measurements and radioactivity analyses of various samples taken from the vicinities of 14 nuclear facilities and the other is a nationwide network consisting of 47 public hygiene institutes of local (prefectural) government with countermeasures against the radioactive fallout due to nuclear explosion tests or a severe accident in a foreign country, such as the Chernobyl accident. 

SSI (Swedish National Institute of Radiation Protection), Activities of the Swedish Authorities following the Fallout from the Soviet Chernobyl Reactor Accident, Report 1986-05-12, May, Stockholm, Sweden, 1986a. 

Steinnes, E. and Njastad, O., Use of mosses and lichens for regional mapping of Cs fallout from the Chernobyl accident. J. Environ. Radioactivity, 21 (1993) 65-73. 

---