Journal of Nuclear and Radiochemical Sciences, Vol. 1, No. 1, pp. 23−26, 2000

23

Century of Radiochemistry: History and Future
B. F. Myasoedov*
V.I. Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Kosygin str.,19,117975 Moscow, Russia
Received: October 13, 1999
Several periods in radiochemistry development history are observed. In the report the sources of radionuclide
income into environment are examined including long-lived transuranic elements on the different stages of fullnuclear fuel cycle. Radioactive substance contamination analysis is given for different regions of Russia from natural and man-caused sources. Potential danger of long-lived radionuclide and transuranic element presence in thewastes of nuclear fuel cycle plants is shown. Data related with the sequences of nuclear weapon testing on theproving grounds near Semipalatinsk, and Novaya Zemlya are presented. The modern radioecological situation
around the reprocessing plant “Mayak”, which was constructed more than 40 years ago for the production of plutonium for military purposes, is overviewed. The following topics are considered: lake Karachay; artificial water
reservoirs contaminated by radionuclides; solid radioactive wastes and their vitrification. Some new approaches,
methods and tools developed at the Vernadsky Institute of Russian Academy of Sciences for determination of different radionuclides in various environmental samples from the impact zone of the facility are discussed. The dataon distribution, occurrence forms and migration processes of 90Sr, 137Cs, 237Np, 239Pu, and 241Am in aquatic and terrestrial ecosystems are presented.

1. Introduction
A hundred years ago Henri Becquerel discovered the phenomenon of radioactivity. Seventy years are passed also frompublishing of the pioneer work by George von Hevesy and
Hilde Levi opened using of activation analysis. Chemistry was
widely used during the long history of radioactivity study.
Moreover, important regularities of this phenomenon were discovered due to application of radiochemistry.
In the history of radiochemistry it is possible to distinguishfew periods.1 The first period of radiochemistry formation as
an independent scientific direction, was closely related withthe discovery of new radioactive elements, understanding of
the main laws of radioactive substance behavior.
During the second period (40−50-th years) the radiochemical investigations were focused on the practical utilization of
nuclear energy, studying of the chemical properties of artificially obtained elements, development of technology of processing of the irradiated nuclear fuel, resolving of the problemof radioactive wastes burial.
The intensive development of activation analysis in the 50th years was also definitely stimulated by needs in qualitatively
new materials for nuclear technology (high pure carbon, beryllium, zirconium and others ). Comparatively with known atthat time analytical methods, only NAA due to its high sensitivity was suitable for impurities control in course of technology development.
In the 60−70-th the serious attention was paid to the analysis
of different semi-conductors (silicon, germanium, gallium
arsenide, tellurium, cadmium telluride and other substances),
geological materials.
Later years the method begins widely to be applied for the
analysis of environmental samples, for investigations inmedicine and biology. Therefore, one can trace the similartendencies in priorities like in the case of radiochemistry: theexclusive work for purposes of nuclear technology is replacedby maintenance of diverse needs of the society.
From the 60-th the society step by step began realize the*Corresponding author. E-mail: bf@ncrc.msk.ru. FAX: +7-095938-2054.

global character of consequences of the contemporary activityof mankind. The main attention shifted to the problems of
maintenance of the sustainable development, including suchaspects as: remediation of the polluted territories, study of theradionuclides behavior in nature, reduction of the amount of
unavoidable (for the current nuclear technology) radioactive
wastes, development of technology of long-term radioactive
wastes storage and many other things.
Today radioactive isotopes are less often used for the elements determination, but they find more and more wide application in medicine, environmental science, biology for the
purposes of diagnostics, elements speciation and migration,
studying of fine biochemical processes.
Environmental problems are known to be among the mostimportant issues of humankind. Solutions to these problems in
Russia are considerably aggravated by heavy nuclear pollution
in many regions of the country. A number of factors havemade artificial radionuclides a persistent and very dangerous
environmental problem. Among these are tests of nuclear
weapons in the atmosphere and underground; the activity of
nuclear power plants with nuclear fuel cycles producing andaccumulating weapon-grade plutonium (USA: Hanford,
Savannah River, and Idaho; Russia: Mayak Production
Association in Ozersk, Siberian Chemical Plant in Seversk,
Mining and Chemical Plant in Krasnoyarsk- 26); the activity of
nuclear power stations and, especially, the numerous accidents
that occur at them; and the unsanctioned submersion of nuclear
waste and the disposal of active solutions from ships and submarines with nuclear power units into various regions of theoceans. Rehabilitation of territories contaminated withradionuclides is an important environmental, economical, andsocial problem.
2. The Main Sources of Nuclear Pollution in Some Regionsof Russia
2.1. Nuclear Tests. In the USSR, nuclear tests in theatmosphere were carried out from 1949 to 1962 in the
Semipalatinsk area (124 explosions with a total capacity of 6.3
Mt releasing 0.1MCi 90Sr, and 0.2MCi 137Cs), and on the North
Land (87 explosions, including 3 submarine ones with a total© 2000 The Japan Society of Nuclear and Radiochemical Sciences

Myasoedov

24 J. Nucl. Radiochem. Sci., Vol. 1, No. 1, 2000
90137

capacity of 250Mt releasing 4.2 and 8.0MCi of Sr and Cs,
respectively).
In addition, Russia performed 81 commercial nuclear explosions, including those aimed at intensifying oil production, andfor seismic surveying, and construction. Some of the explosions (for example, “Kristall” (l974) and “Kraton-3” (1978) in
Yakutia) resulted in the emission of radioactive vapor and gas
into the atmosphere, including a small amount of plutonium.
The tests of nuclear weapons have resulted in the emission
into the environment of a considerable amount of uranium,
plutonium, and their fission products, which were distributed
as aerosols and gases across large distances and produced theanthropogenic radioactive background on the earth's surface,especially in the northern hemisphere.
The density of pollution (Bq/m2) with the most dangerous
radionuclide, plutonium, varies in different countries as follows: Germany, 67−148; Ireland, 33−l27; Great Britain, 33−
122; Russia: Leningrad Nuclear Power Plant region, 14−262,
Beloyarka Nuclear Power Plant region, 116−183; Mayak, up to
1400; Ukraine: Chernobyl Nuclear Power Plant (30-km zone),
3700; and Japan, 90.
2.2. Nuclear Power Plants. The commercial use of atomic
energy was launched in 1954 by the installation of the first 5MW nuclear power station in Obninsk. According to theInternational Atomic Energy Agency, by the time of theChernobyl accident, 417 nuclear power units in 26 countries
functioned and produced 285×10 9 W of electrical energy.
According to the same agency, it is suggested that nuclear
energy will continue to develop to the year 2000, and its fraction in the world's production of electrical energy will continue
to grow.
By the end of 1998, 29 nuclear power units of Russia's nine
nuclear power plants with an established electric capacity of21242 MW accounted for 11.8% of total Russia's electricalenergy supply. The work of a nuclear power plant is environmentally less hazardous than that of a power station that uses
natural coal. Nuclear power plants release a certain amount oflong-lived radionuclides (85Kr, 3H, 14C, and 129I) into the atmosphere.
Overall, the contribution of nuclear power plants to the doseof natural background radiation was less than 0.1% in the early
1980’s2 and will be less than 1% in 2000, if the expectations of
its development are justified. The annual dose due to theeffect of the nuclear fuel cycle (mining, processing, and extraction of uranium, production of fuel elements; work of nuclear
power plants; and the reprocessing of spent nuclear fuel) is
currently equivalent to the radiation that a person gains during
an hour's flight in an airplane.
The main problems in the development of nuclear energy
are to ensure its safety and to dispose of the high-level radioactive waste safely. In this context, potential use of the thorium
fuel cycle with fluoride melts, utilization of highly enriched(up to 99.9%) 235U, new technological approaches to the reprocessing of spent nuclear fuel, and transmutations of nuclear
waste are now discussed.
2.3. Plutonium Production for Military Purposes andReprocessing of Irradiated Nuclear Fuel. The production
association “Mayak” (hereafter “Mayak”) is located at 55o44'
N and 60o54' E, 70 km north of Chelyabinsk and 15 km east of
the town Kyshtym in the southern Urals and covers an area
about 200 km 2 including the town Ozersk. “Mayak” wasestablished in late 40's for production of plutonium for military
purposes and for processing fissile materials to achieve a parity
in the nuclear arms race. In 1945 a governmental decision was
taken on selection of a construction site and the first industrial
nuclear reactor was started to be built on the southern shore of
the Kysyltash, while the settlement for the specialists in thefield was built in a peninsula in the southern part of the Irtyashlake. 3 The first continental reactor facility, named“Annushka”, was put into operation on 19 June, 1948. This
day may be considered a birthday of “Mayak” and the nuclear
industry of that country as a whole.
Regretfully, at the early stage of running in a number of
unique and complicated technologies some serious technicalmistakes were made. They aggravated ecological situation
around “Mayak”, harmed population and brought about intolerance among local people toward the “Mayak” activity.
The region of location of “Mayak” facilities is a unique area
as regards both the scale of environmental contamination andthe variety of objects subjected to the radiation impact.
Significant territories around “Mayak” have undergone
radioactive contamination as result of the 1957 and 1967 accidents and technological discharges into atmosphere.
Discharges of liquid wastes to the river Techa at early stages of“Mayak” operation have resulted in contamination of its floodplane and radiation exposure of the local population inhabiting
the shore area. At total a huge amount of radioactive wastes
have been accumulated and stored at “Mayak” (about 1 billion
Curies), which represent a great ecological hazard.
Nowadays, the reactor division of “Mayak” includes two
operating reactors producing radionuclides both for military
purpose and general applications and five uranium graphite
reactors, which were shut down in 1987−1991. Production of
the weapon grade plutonium at “Mayak” was stopped in 1987.
The new plant operation started in 1977 and since then thestaff of it has been involved in spent fuel reprocessing fromdifferent power reactors, as well as from transport and research
reactors. For the whole operation period 2380 tons of spent
fuel were received from a number of domestic and the foreign
power plants. The plant comprises a spent fuel storage pool,three chopping-dissolution process lines, a PUREX extraction
with separated plutonium, and technetium streams output. In
January 1996 the waste partitioning facility was put into operation after a prolonged preparatory period. Currently the work
is under way on development of the cementation and bituminization facilities for the medium level wastes utilization.
3. Current Radioecological Situation around “Mayak”
The region in which the “Mayak” facilities are located isunique with respect to both the scale of environmental contamination and the variety of objects subjected to the radiation
impact. Significant territories around “Mayak” have undergone radioactive contamination as result of the 1957 and 1967
accidents and technological discharges into atmosphere.
Discharges of liquid wastes to the river Techa at early stages of“Mayak” operation have resulted in contamination of its floodplain and radiation exposure of the local population inhabiting
the shore area.
The river “Techa” belongs to the Iset-Tobol-Irtysh-Ob river
system. In its upper reaches it passes “Mayak”. Liquid waste
was released 6 km from the Techa source. About 76 million
m3 of wastes which contain 2.7 million Ci of radionuclides
were discharged into Techa directly. 4 About 95% of thisamount (4300 Ci/day on the average) was discharged in the
period from March 1950 to November 1951 and it was
deposited within the first 35 km of downstream. Most part ofthese radionuclides were accumulated in the upper reaches of
the river; however, the Iset', Tobol, and Ob' rivers, which drain
successively into each other, were also contaminated. The
average concentration of 90Sr, 137Cs and 239Pu in the bottom
sediments of Techa river in 1993 at the Muslimovo settlement,
which is located 78 km downstream, amounted to 2.2, 0.3, and0.025 pCi/kg respectively.
The accident of 1957 was happened due to violation of thetemperature regime in the storage tank for high radioactive
wastes of the plutonium production facility, which containedlarge amounts of sodium nitrate and acetate salts.5 The liquidCentury of Radiochemistry

J. Nucl. Radiochem. Sci., Vol. 1, No. 1, 2000 25

sludge ejected to the atmosphere up to the height of 1−2 km
formed a radioactive cloud which moved for 345 km to NorthEast from the storage site and formed a trace on the groundsurface due to the aerosol precipitation. The region covered,
which is named as the Ural Trace, was approximately 15000−
23000 km2 within the territories of Chelyabinsk, Sverdlovsk
and Tyumen regions. The contamination of nearly 1000 km2
exceeded 2 Ci/km 2 . The percentage of the contaminatedarable, haying and grazing lands within this area totalled to40.9 and 12% respectively.
The total amount of the radionuclide substances released tothe atmosphere according to different sources varies from 2 to
20 MCi (7.4−74 × 1016 Bq).
The major part of radionuclides has been deposited in thevicinity of the accident site. At the closest area 1 to 2 km
along the trace axis 0.5−1.0 km wide the density of the soil
contamination amounted to 140000 Ci/km2, while at the area
75 km long and 7 km wide it was equal to 28 Ci/km2.
The major part of the radioactive release consisted of theshort-lived fission products (106Ru, 144Ce, etc.) and 90Sr; theircontent in soils 0.5−1.0 km away from the accident site
totalled to 15×103 and 4×103 Ci/km2, respectively. Due to the
decay process 90Sr has gradually become the main source ofthe radioactive contamination of the area (99.3%). 137Cs is
playing a notable role. The release contained also little
amounts of plutonium and uranium. The fifty years of operation of the first plutonium producing enterprise have resulted
in local accumulation of large amounts of radioactive wastes(several hundred million Curies, distributed between the low-,
middle- and high level liquid wastes, solid wastes in different
forms).
As result of accomplishment of the military program about
19000 m3 of highly radioactive wastes (both solutions and suspensions) with the total radioactivity of 135 MCi have been
accumulated. Part of the wastes (about 8000 m3) originatedfrom extraction process is stored in tanks as highly radioactive
nitric acid solutions with the total radioactivity of 200 MCi. In
addition, every year about 2000−3000 m3 of HLW is produced
as result of nuclear fuel reprocessing from nuclear power
plants and marine reactors (totalled to 100 MCi). Some dataon quantity of HLW as of March 1, 1995 are shown in Table 1.
The wastes accumulated are stored in the 18 special vessels
with the total volume of 316 m3 and the working volume of
285 m3 (5 m height × 9 m diameter). Evaporated nitric acidsolutions are kept in 3 tank units made from stainless steel withthe working volume of 1500 m3 each.
The wastes in form of suspensions are put into 20 storage
tanks comprising concrete chambers of 19.5 × 9.5 × 7 m plated
by stainless steel with the working volume of 1170 m 3 .
Currently produced HLW originated from nuclear fuel reprocessing are subject to evaporation followed by fluxing withTABLE 1: Amount of High Radioactive Wastes Accumulated
at “Mayak”
Type of waste
Suspensions
Nitric acid solutions
Vitrified wastes

Amount, m3
19000
11700
1974

Total activity, MCi
135
249
246

TABLE 2: Amount of Wastes Vitrified at “Mayak”
Year
1987−1990
1991
1992
1993
1994
1995
Total

Amount, tons
162
178
563
448
407
216
1974

Activity, MCi
3.96
28.2
77.7
46.8
57.4
31.7
245.76

phosphoric acid and sodium nitrate and, finally, to vitrification
in a furnace of direct electrical heating with the processing
capacity up to 500 L/hr. Table 2 shows some data on amountof wastes having been vitrified over various periods at“Mayak”. The molten mass is casted into special containers of
a 200 L volume, which are assembled in groups of three units
inside a larger container for the storage in a temporary repository. The rated specific activity of the molten mass is 2500
Ci/L, while the specific activity of the glass produced amounts
to 200−600 Ci/L.
A wider scale HLW processing can be accomplished only
after their special pretreatment involving partition technologies
with application of the electric furnace installation with isolated electrodes or microwave heating unit. Currently a new partition facility for the HLW fractionation incorporating an
extraction recovery of Cs and Sr by the chlorinated cobalt
dicarbolide is developed. The work is under way on optimization of technological scheme of selective isolation of the longlived alpha-emitters (uranium, neptunium, plutonium) fromradioactive effluents, which is based on their extraction by thebydentate neutral organophosphorus compounds.
4. Environmental Monitoring at the “Mayak” Area
The long term radiation hazard to the contaminated territories arises primarily from the presence of long-lived radionuclides among which the actinide isotopes play a notable role.
Decontamination of ground waters, basins, soils and other natural and technogenic objects from these radionuclides is themost important and very difficult problem.
In this context the knowledge of the dynamics of radionuclide migration with surface and underground waters becomesof principal importance, since it allows estimation of the efficiency of these rather expensive remediation measures.
Therefore, some institutes of the Russian Academy of Sciences
pursue studies on interactions between ground waters and bed
rocks and on chemical and mineralogical composition of thesamples taken from various sites of this zone and from various
depths of boreholes. We have performed radiochemical analysis of liquid and solid samples and determined the content andthe forms of occurrence of radionuclides. It should be notedthat prediction of migration process is a very complex scientific problem even for such a small location owing to diversity ofchemical and mineralogical compositions of environmental
matrices.
Radionuclide content in rocks and waters has been determined in accordance with the procedure developed at the
Vernadsky Institute.6−10 It makes it possible to determine several radionuclides out of the same sample which saves labortime spent on sample preparation and dissolving. Analysis ofsoils, rocks and other solid samples includes air drying, disintegrating (milling), sieving through a 1 mm siever, igniting at atemperature of approximately 550 oC to destroy the organic
matter, which takes several days.10 Radionuclides from thewater samples have been concentrated by evaporation (at the
Vernadsky Institute) and ultrafiltration (at the central “Mayak”
plant laboratory). The last procedure enables to concentrate
plutonium out of the water sample of 2 to 50 L in volume. The
degree of the plutonium fixation during the water filtration
through a Ripor-4 membrane (water-soluble polymers polyethyleneimin-ethylenediamintetraacetate PEI-EDTA) is practically independent of the content of the organic matter which plays
an important role in colloid and complex formation. Thisdegree amounts to 90−99% for the samples from the industrial
reservoirs 10B and 11B, and 87−98% for the water samples fromthe peat bog containing 3.2, 3.3, and 29 mg of the organic carbon per liter. For the determination of radionuclides in theunderground water samples collected near the Karachay Lake
10 to 100 mL of the sample is enough.

Myasoedov

26 J. Nucl. Radiochem. Sci., Vol. 1, No. 1, 2000
On the first stage of the applied analytical scheme prior toradiochemical analysis the gamma spectrometry using Ge(Li)detector has been performed. Determination of Sr and TUE
which are pure β and α-emitters can be done only radiometrically with the radionuclide separation from a big sample ofcomplicated chemical and radiochemical composition. This
procedure needs very careful purification, especially during
separation of radionuclides having almost similar energies of βand α-emission. This concerns natural radionuclides, in particular which amounts in the environments are 2 to 3 orders higher as compared with those of artificial ones. To transfer
radionuclides from the ashed residue or the water concentrates
it is enough to treat the samples with 7−8 M HNO, in presenceof potassium bromate after their pretreatment by a mixture of
HF and H2SO4. Further plutonium concentration and radiochemical separation has been carried out on the anionite VP1Ap; for americium and curium the complexation sorbent polyarsenazo-n has been used; for Sr, the porous copolymer ofstyrol with divinylbenzole (TVEKS), impregnated with 10%
dicyclohexyl-18-crown-6 (DCH18C6) in tetrachloroethane.
This method is pretty selective for 90Sr, but needs its carefulseparation from 210 Pb if the latter is present in comparable
quantities. Therefore, the “Mayak” samples needed additional
purification by preliminary elution of the radioactive 210Pb by
sodium oxalate solution. Radioactivity of the separated TUE
has been measured at an alpha-spectrometer facility consistingof the ionization camera with a grid and an analyzer AI-4096.
Extraction and determination of neptunium is a more complicated procedure as compared with that of plutonium andamericium due to the lower concentrations of the former. The
method developed at the Vernadsky Institute is based on theneptunium extraction with the potassium phosphortungstate
during their sorption on the porous teflon membrane impregnated with 0.5M solution of trioctylammonium nitrate(TOMAN) in toluene, which is followed by the luminescentdetermination. PbMoO4 has been used as a crystallophosphor9.
Detection limits of the radionuclides determination underabove mentioned procedures are shown in Table 3.
TABLE 3: Detection Limits Attained for a Number ofRadionuclides of Environmental Concern
Radionuclide
60
Co
90
Sr
237
Np
239
Pu
241
Am

Detection limit, Bq/g
1.2 × 10−3
4.5 × 10−3
2.6 × 10−6
1.3 × 10−5
2.6 × 10−5

To predict the migration of radionuclides and to develop
remediation approaches, it is necessary to determine not only
the content of radionuclides in particular components ofbiogeocenoses, but their occurrence forms as well. As for speciation of radionuclides in solid materials, it seemed mostappropriate to determine the geochemical forms of mobility.10
These data are usually obtained by selective leaching. For
loamy materials, which mostly accumulate radionuclides, thefraction of relatively mobile forms is maximum for radiostrontium, whereas for plutonium it usually does not exceed 10%.
This fact explains the high concentration of 90Sr in groundwater from various sites of the region as compared to plutonium
and radiocesium. It is also interesting that the mobility ofradiostrontium is higher than that of its natural analogues, calcium and magnesium. Our results show that the migration
ability of radionuclides in the ecosystems in question increases
in the following series: 137Cs < 239, 240Pu < 241Am < 90Sr < 60Co <237

Np. The data on distribution of radionuclides, 90Sr, 137Cs,
Np, 239Pu, and 241Am between components of various ecosystems of Southern Ural region as well as their forms of occurrence show that 90Sr, 237Np, and 241Am mostly involved in compounds of fulvic acids, that's why they have a high mobility inthe environment. On the contrary, considerable amounts of137
Cs and 239Pu have been found in low soluble humid acids
bonded primarily with calcium and relatively low mobilehydroxides. The data on vertical migration of plutonium,
radiostrontium and radiocesium in various types of soils havebeen obtained and corresponding coefficients have been calculated. We consider that one of the most important factors
affecting migration resistance of soil media is the content andnature of organic substances. In particular, the clear dependence between diffusion resistance of upper soil layers to plutonium and radiostrontium mass-transfer and content of humus
in these layers has been determined. The correlation between
migration coefficients and the content of the most mobile plutonium forms has been revealed.
237

5. Conclusion
It should be emphasized the most important problems ofmodern radiochemistry.
1. Radioactive waste management:• The creation of brand new processes of the spent nuclear
fuel reprocessing.
• The fractionation of the accumulated radioactive waste.
• The new approaches to the ensuring of long terms ecologically safe radioactive nuclides storage (repository).
• The development of new matrices and new methods ofvitrification of radionuclides with different half lives.
• The development of new types of barriers (natural andman-caused) for the safe storage of the spent nuclear fueland radioactive wastes.
2. The behavior of radioactive substance in biosphere:• The development of principles and approaches ofradiomonitoring in regions affected by nuclear plants andcenters.
• The elaboration of new methods and techniques of radioecological analyses of the environment samples.
• Data gathering, systematization and computation on content and speciation of radionuclides in the environment.
• The long term forecast of the radionuclides behavior after
their output into the environment.
6. References(1) B. F. Myasoedov, Environmental Science 1, 3 (1998).
(2) N. S. Babaev, V. F. Dermin, and L. A. Il'in et al., In
Nuclear Energy: Hurnans and the Environment (Moscow,
Atomizdat, 1984).
(3) V. I. Fetisov, Radiation Safety Problems 1, 5 (1996).
(4) Yu. G. Mokrov, Radiation Safety Problems 3, 19 (1996).
(5) G. N. Romanov, D. A. Spirin, and R. M. Aleksakhin,
Priroda 5, 53 (1990).
(6) B. F. Myasoedov, Journal of Alloys and Compounds
213/214, 290 (1994).
(7) N. Yu. Kremlyakova, A. P. Novikov, S. G. Korpusov, andB. F. Myasoedov, Patent Rus., 4924649/25 (1991).
(8) A. P. Novikov, M. N. Mikheeva, T. I. Trofimov, and Yu.
M. Kulyako, Patent Rus., 4897664/23 (1990).
(9) A. P. Novikov, S. A. Ivanova, M. N. Mikheeva, and B. F.
Myasoedov, Patent Rus., 5146273/27 (1992).
(10) B. F. Myasoedov, A. P. Novikov, and F. I. Pavlotskaya,
Zhurnal Analyticheskoy Khimii 51, 124 (1996).