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Glossary of definitions and units
Glossary of Definitions and Units A dose of radiation is determined as the energy of ionizing radiation absorbed by unit mass of a medium being exposed to that radiation. The following definitions of doses of ionizing radiation which reflect features of the energy transfer to a substance, with consideration of the properties of the radiation and the substance irradiated, are widely used in dosimetry (both the obsolete special units and new units of the SI system). The absorbed dose, D, is the energy transferred by ionizing radiation to a substance in some elementary volume, divided by the mass of substance in this volume. The unit of absorbed dose is the rad (rad is the abbreviation for "radiation absorbed dose"), equal to an energy of 100 erg or 10 -7 Joule absorbed by one gram of a substance (100 erg/g = 10 -2 J/kg). In the SI system, the unit of absorbed dose is the Gray (Gy). 1 G y - 1 Joule per kg (J/kg). 1 G y - 100 rad. The rad can serve as the unit of absorbed dose of any type of irradiation in any medium. However, difficulties of direct measurement in different substances and especially in biological tissue stimulated specialists in dosimetry to measure the absorbed dose in an equivalent medium in which measurements are possible (in the given case, this is a tissue-equivalent medium, e.g., air). The exposure dose (exposure) is a dose stemming from absorption of ionizing radiation by the air. It corresponds to the total charge of ions of the same sign appearing in the air after complete slowing down of all the secondary electrons which were generated by the photons in a small air volume, divided by the air mass in the same volume. The unit Roentgen is used for measurements of exposure dose. It is measured by the ionization in the air using ionizing chambers or other air-equivalent instruments. The Roentgen, R, is a unit of absorbed dose in air of X-radiation or v-radiation such that the corpuscular emission (i.e., electrons) associated with this dose generates in 0.0012930 g of air mass (at 0 ~ temperature and a pressure of 1013 hPa) ions carrying a charge of one electrostatic unit (e.s.u.) of electricity. Hence the absorbed dose expresses the absorbed energy of the irradiation, while the exposure dose expresses the energy transferred to the charged particles. They are equal to one another only under conditions of electron equilibrium (balance), i.e., under conditions when the absorbed energy of the irradiation in some volume of a medium is equal to the total kinetic energy of the ionizing particles formed within the same volume. The generation of one pair of ions (p.i.) in air needs, on average, the expenditure of 34 eV of energy (within the 10 keV-3 MeV radiation energy range). One electrostatic unit of charge corresponds to 1 94.8 x 10 -10 - 2.08 x 109 p.i., from which the energy equivalent of the Roentgen is equal 2.08 x 109 x 34 - 7.07 x 10 l~ eV - 0.114 erg (per cm 3 of air). In this case, 1 g of air absorbs 88 erg or 5.39 x 1013 eV. The Roentgen is a special unit of the exposure dose. 1 R - 0.258 mC/kg. In the SI system, the Roentgen is measured in C/kg units. Note that all definitions of the Roentgen include the work of ionization which is determined by experiment, on average xxi
xxii
Radioactive Fallout after Nuclear Explosions and Accidents
being 34 eV per pair of ions. This leads to the energy equivalent of the Roentgen being approximately 88 erg/g [1]. With this energy equivalent (88 erg/g) for air, 1 rad - 1.136 R and 1 R -- 0.88 rad. The energy spent by electrons or X-radiation in formation of one pair of ions has been estimated by different authors for different ranges of energy of X-radiation, v-radiation and electrons within the interval 33.4-34.2 eV [4] and these can lead to slightly different equivalents of the Roentgen. For example, paper [3] presents a value of 87.3 erg/g. To determine the energy absorbed by a biological tissue, a unit called the "tissue Roentgen" or the physical equivalent of the Roentgen was used earlier (one "tissue Roentgen" is equal in value to the energy absorbed by tissue at a point with a measured exposure dose of 1 Roentgen). One "tissue Roentgen" corresponded to an absorbed energy of 93 erg/g of tissue [5]. When determining a value for the biological effect on a tissue or organ caused by different types of nuclear radiation (i.e., the ultimate hazard to human health), it was found that, for the same absorbed dose from different radiation types, the damage can be rather different and distinct. This led to the necessity to introduce the concept of the equivalent dose. The equivalent dose, H, is the absorbed dose, D, in a tissue multiplied by an average coefficient for the quality factor, k (a weighting coefficient), of the ionizing radiation in a given volume of biological tissue, i.e., H = Dk (for X-, V- and/3-radiation, k = 1.0, while for or-radiation, k = 20). The special unit for the equivalent dose is the rem. The rem is a unit of absorbed dose, expressed in rads (100 erg/g), multiplied by the quality factor of the radiation. In the SI system, 1 rem = 10 -2 Sievert. Sometimes one can find in the literature the unit "Roentgen-equivalent-man" [2]. In this case, the energy equivalent for the X-, V- and/~-radiation amounts to 88 erg/g [ 1]. In the Russian literature, the term "biological equivalent of Roentgen" (ber) exists with the energy equivalent 88 erg/g [5]. In the SI system, the unit of equivalent radiation dose is the Sievert, Sv. 1 Sv = 1 J/kg with the quality factor of the radiation equal to 1.0. Under this condition, 1 Sv = 1 Gy or 100 rad. The effective dose is a dose corresponding to the sum of the products of the equivalent doses in all organs and tissues of a body multiplied by corresponding weighting coefficients for the same organs and tissues (it is used for biological purposes). In the SI system, the unit of effective dose is the Sievert. Below we indicate some additional important definitions and units: -
A dose rate is the rate (possible or real) of absorption of the dose per unit time,
for example: Roentgen/hour (Rhr -1, mRhr -1, ~tRhr-1); Sievert/hour (Svhr-1), cSv hr-1 = 1 R hr-1, etc. A Roentgen/hour is an energy of 88 erg/g absorbed by the air during 1 hour in the course of formation of the charges of ionizing particles, as determined for the Roentgen (see above). - The activity, A, of a radioactive substance is the number of spontaneous nuclear transformations, dN, in this material in a small time interval dt, divided by this interval, A = dN/dt. - The density of radioactive contamination of a (land or other) surface is the value of activity per unit area of the surface (for example, Curie/kin 2, kBq/m 2, etc.). At a level of 1 m from an ideal flat isotropic source with a contamination density of 1 Ci/km 2 of gamma-radiating radionuclides (137Cs + 137mBa), a field of radiation is
.,,
Glossary of Definitions and Units
XXlll
Table 1 Comparison of irradiation dose and activity units (older and SI systems) New name and notation
The same in other SI units
Old special unit and its notation
Conversion factor
Inverse conversion factor
Exposure dose Absorbed dose Equivalent dose Activity
Gray (Gy) Sievert (Sv)
C/kg J/kg J/kg
Roentgen (R) rad (rad) rem (rem)
1 C/kg ~ 3876 R 1 Gy = 100 rad 1 Sv = 100 rem
1 R = 88 erg/g 1 rad -- 10 - 2 Gy 1 rein--- 10 -2 Sv
Becquerel (Bq)
s -1
Curie(Ci)
1Bq=2.7x
1Ci=3.7xl010Bq
Density of radioactive contamination
Becquerel/m 2 (derivative unit)
s-1 m - 2
Curie/m 2 (Ci/m 2)
1Bq/m 2 = 2 . 7 x 1 0 - 1 1 Ci/m 2
1Ci/m 2 = 3.7 x 1010 Bq/m 2 -- 3.7 x 107 kBq/m 2
Concentration of radioactive contamination
Becquerel/m 3
s- 1m-3
Curie m -3 (Ci/m 3)
1Bq/m 3 = 2 . 7 x 1 0 -11 Ci/m 3
1Ci/m 3 = 3.7 x 1010 Bq/m 3
10 - l l C i
created with a dose rate of l0 ~tR/hr (micro-Roentgens per hour) or (in SI units) above a contamination density of 1 kBq/m 2, the corresponding absorbed dose rate amounts to 23.8 nGy/hr.
Units of activity The Curie is a special unit of activity, Ci. 1 Ci - 3.7 x l01~ nuclear transformations (decays) per second. The Becquerel, Bq (in the SI system) is one nuclear transformation (decay) per second or 0.027 nCi. For tritium: 1 tritium unit (TU) (tritium ratio TR) is the unit of tritium concentration, i.e., 1 atom of tritium per 1018 atoms of hydrogen, 1 TU is equal to an activity of 0.118 Bq/kg of water. When carrying out a radiometric survey in a radioactive fallout zone, the most used units (or their fractional values), in both the early and SI systems, are as shown in Table 2. We present here such a detailed description of the definitions and units used in dosimetry over the last 50 years in order to explain how these definitions and units have been used in this book, how they should be correctly understood and what units should be used, bearing in mind the problem of the new units introduced with the SI system. It is necessary to emphasize that this book is the generalization of a large body of material accumulated on radioactive fallout over a period of more than 50 years (since 1949, in fact). Many real data were obtained at explosions and accidents of the 1950's and 1960's and these are now absolutely unique (i.e., were only once published in special reports or papers). So, the units used were related to this period. Whether we can now recalculate these data and present them in new units, for instance in the SI units, is a great question?
xxiv
Radioactive Fallout after Nuclear Explosions and Accidents
Table 2 Parameter
Obsolete units
New SI units
Exposure dose Exposure dose rate Absorbed dose Absorbed dose rate Equivalent dose Equivalent dose rate Activity Density of radioactive contamination Concentration of radioactive contamination
Roentgen (R), mR, ~tR R/hr, R/s, mR/hr, ~tR/hr, mR/s rad, mrad, ~trad rad/hr, mrad/s, mrad/hr, ~trad/hr, mrad/s rem, mrem rem/hr, rem/s, mrem/hr Ci, mCi, ~tCi, nCi Ci/km 2, Ci/m 2, mCi/km 2, ~tCi/m 2
Gy, cGy = 1 rad, nGy Gy/hr, cGy/hr, Gy/year Sv, cSv = 1 rem Sv/hr, cSv/hr, Sv/year 1 Bq, kBq, MBq 1 Bq/m 2, kBq/m 2 , MBq/km 2
Ci/km 3 , Ci/m 3 , mCi/km 3 , gCi/cm 3 , nCi/cm 3 , pCi/cm 3
1 Bq/m 3 , kBq/m 3 , Bq/cm 3 , kBq/m 3
Note: c is centi (10-2), m is milli (10-3), ~t is micro (10-6), n is nano (10-9), p is pico (10-12), k is kilo (103), M is mega (106). Other abbreviations used later in this book are: G is giga (109), T is tera (1012), P is peta (1015) and E is exa (1018).
It is also necessary to note that this book is a physical and geophysical book on radioactive fallout. It is very useful for biologists as well but it is not a biological book; this is why we have rarely used here units like rem or biological equivalent of Roentgen, though at the present time, the most-used units for evaluating doses and dose rates (as well as for estimating external dose on a land site and internal dose to man) are the SI system units, i.e., Sievert, which is the biological equivalent of the absorbed dose in rad units. In the 1950's- 1960's, the main unit used in dosimetry was the Roentgen (R) or mR, ~tR (to measure doses), and R/hour, mR/hour, ~.tR/hour to measure dose rates. The Roentgen unit is a very convenient unit for a measurement as, in this case, the exposure dose can be measured directly by an ionizing chamber (via the electric charge) or any other instrument with an air-equivalent sensor calibrated by the ionizing chamber (these instruments were called Roentgen-meters). An important and historic example of such measurements was the dose rate measurement mission immediately after the Chernobyl accident. A large official group of specialists (headed by the author) measured the dosimetric characteristics in the area using air-equivalent Roentgen-meters. But many geologists (and the scientific community at large) had "Crystal" (or "SRP") instruments in which the detector of the radiation was a NaI(T1) scintillator, i.e., obviously non-air-equivalent but sensitive to the gamma-radiation for geological survey work. Having been calibrated for a single source of gamma-radiation (6~ or 137Cs), this equipment showed similar data to the airequivalent instrument during measurement of point sources at a close distance. However, in the case of land contamination (when intense scattered "soft" radiation appeared) the "Crystal" instrument showed an excessive "dose" (2-4 times larger) and this caused many misunderstandings (the dose measured by the population at large exceeded by several times that obtained by the official survey). In this case, a special decision of the State Commission, headed by the President of the USSR Academy of Sciences, academician A. E Alexandrov (a famous specialist in the field of nuclear energy), was needed in order to solve this problem quickly and supporting the use of the air-equivalent instruments.
Glossary of Definitions and Units
XXV
In the context of the above, therefore, we should note here that the primary data on doses and dose rates presented in this book in maps and tables and in the text itself are given first in the form in which they were actually obtained so that we could avoid the introduction of errors in the process of conversion of the units used into those in the SI system. This is why we retain in the book the primary dose notation in Roentgens, the dose rates in R/hr, R/year, mR/hr, ~tR/hr, etc. and in some sections we use the units "rad" and "rem". When doing this, we indicate that 1 Roentgen = 0.88 rad (1 rad = 1.136 R) and, when converting into the SI system, 1 rem -- 0.01 Sv - 1 cSv; 1 rad -- 0.01 Gy; 1 Gy = 100 rad (if k -- 1.0). In tables which present values of activity, the data have generally been converted from Curie units into Becquerels (Bq, kBq, MBq, etc.). In most cases throughout the book, however, in order to make the data and the scientific content as intelligible as possible to both young and old, we have either provided handy conversion factors in the relevant places or we have presented the data in both systems of units, the secondary data in parentheses. We hope that you will now be able to follow the story without too much confusion!
References [1] Aglintsev, K. K. (1957). Dosimetry of Ionizing Irradiation (503 p.). Moscow: State Publ. of Techn.-Theoret. Literature. [2] Rahn, E J., Adamantiades, A. G., Kenton, J. E., & Braun, Ch. (1984). A Guide to Nuclear Power Technology (752 p.). New York: Willey. [3] Warner, S. E & Kirchmann, R. J. C. (Eds.) (2000). Nuclear Test Explosions, SCOPE-59 (269 p.). Chichester. [4] Eger, R. (1961). Dosimetry and Protection against Irradiation (translated from German) (211 p.). Moscow: State Publisher of Literature in the Field of Atomic Science and Engineering. [5] Ivanov, V. I. (1970). Dosimetry (392 p.). Moscow: Atomizdat.
xxii
Radioactive Fallout after Nuclear Explosions and Accidents
being 34 eV per pair of ions. This leads to the energy equivalent of the Roentgen being approximately 88 erg/g [1]. With this energy equivalent (88 erg/g) for air, 1 rad - 1.136 R and 1 R -- 0.88 rad. The energy spent by electrons or X-radiation in formation of one pair of ions has been estimated by different authors for different ranges of energy of X-radiation, v-radiation and electrons within the interval 33.4-34.2 eV [4] and these can lead to slightly different equivalents of the Roentgen. For example, paper [3] presents a value of 87.3 erg/g. To determine the energy absorbed by a biological tissue, a unit called the "tissue Roentgen" or the physical equivalent of the Roentgen was used earlier (one "tissue Roentgen" is equal in value to the energy absorbed by tissue at a point with a measured exposure dose of 1 Roentgen). One "tissue Roentgen" corresponded to an absorbed energy of 93 erg/g of tissue [5]. When determining a value for the biological effect on a tissue or organ caused by different types of nuclear radiation (i.e., the ultimate hazard to human health), it was found that, for the same absorbed dose from different radiation types, the damage can be rather different and distinct. This led to the necessity to introduce the concept of the equivalent dose. The equivalent dose, H, is the absorbed dose, D, in a tissue multiplied by an average coefficient for the quality factor, k (a weighting coefficient), of the ionizing radiation in a given volume of biological tissue, i.e., H = Dk (for X-, V- and/3-radiation, k = 1.0, while for or-radiation, k = 20). The special unit for the equivalent dose is the rem. The rem is a unit of absorbed dose, expressed in rads (100 erg/g), multiplied by the quality factor of the radiation. In the SI system, 1 rem = 10 -2 Sievert. Sometimes one can find in the literature the unit "Roentgen-equivalent-man" [2]. In this case, the energy equivalent for the X-, V- and/~-radiation amounts to 88 erg/g [ 1]. In the Russian literature, the term "biological equivalent of Roentgen" (ber) exists with the energy equivalent 88 erg/g [5]. In the SI system, the unit of equivalent radiation dose is the Sievert, Sv. 1 Sv = 1 J/kg with the quality factor of the radiation equal to 1.0. Under this condition, 1 Sv = 1 Gy or 100 rad. The effective dose is a dose corresponding to the sum of the products of the equivalent doses in all organs and tissues of a body multiplied by corresponding weighting coefficients for the same organs and tissues (it is used for biological purposes). In the SI system, the unit of effective dose is the Sievert. Below we indicate some additional important definitions and units: -
A dose rate is the rate (possible or real) of absorption of the dose per unit time,
for example: Roentgen/hour (Rhr -1, mRhr -1, ~tRhr-1); Sievert/hour (Svhr-1), cSv hr-1 = 1 R hr-1, etc. A Roentgen/hour is an energy of 88 erg/g absorbed by the air during 1 hour in the course of formation of the charges of ionizing particles, as determined for the Roentgen (see above). - The activity, A, of a radioactive substance is the number of spontaneous nuclear transformations, dN, in this material in a small time interval dt, divided by this interval, A = dN/dt. - The density of radioactive contamination of a (land or other) surface is the value of activity per unit area of the surface (for example, Curie/kin 2, kBq/m 2, etc.). At a level of 1 m from an ideal flat isotropic source with a contamination density of 1 Ci/km 2 of gamma-radiating radionuclides (137Cs + 137mBa), a field of radiation is
.,,
Glossary of Definitions and Units
XXlll
Table 1 Comparison of irradiation dose and activity units (older and SI systems) New name and notation
The same in other SI units
Old special unit and its notation
Conversion factor
Inverse conversion factor
Exposure dose Absorbed dose Equivalent dose Activity
Gray (Gy) Sievert (Sv)
C/kg J/kg J/kg
Roentgen (R) rad (rad) rem (rem)
1 C/kg ~ 3876 R 1 Gy = 100 rad 1 Sv = 100 rem
1 R = 88 erg/g 1 rad -- 10 - 2 Gy 1 rein--- 10 -2 Sv
Becquerel (Bq)
s -1
Curie(Ci)
1Bq=2.7x
1Ci=3.7xl010Bq
Density of radioactive contamination
Becquerel/m 2 (derivative unit)
s-1 m - 2
Curie/m 2 (Ci/m 2)
1Bq/m 2 = 2 . 7 x 1 0 - 1 1 Ci/m 2
1Ci/m 2 = 3.7 x 1010 Bq/m 2 -- 3.7 x 107 kBq/m 2
Concentration of radioactive contamination
Becquerel/m 3
s- 1m-3
Curie m -3 (Ci/m 3)
1Bq/m 3 = 2 . 7 x 1 0 -11 Ci/m 3
1Ci/m 3 = 3.7 x 1010 Bq/m 3
10 - l l C i
created with a dose rate of l0 ~tR/hr (micro-Roentgens per hour) or (in SI units) above a contamination density of 1 kBq/m 2, the corresponding absorbed dose rate amounts to 23.8 nGy/hr.
Units of activity The Curie is a special unit of activity, Ci. 1 Ci - 3.7 x l01~ nuclear transformations (decays) per second. The Becquerel, Bq (in the SI system) is one nuclear transformation (decay) per second or 0.027 nCi. For tritium: 1 tritium unit (TU) (tritium ratio TR) is the unit of tritium concentration, i.e., 1 atom of tritium per 1018 atoms of hydrogen, 1 TU is equal to an activity of 0.118 Bq/kg of water. When carrying out a radiometric survey in a radioactive fallout zone, the most used units (or their fractional values), in both the early and SI systems, are as shown in Table 2. We present here such a detailed description of the definitions and units used in dosimetry over the last 50 years in order to explain how these definitions and units have been used in this book, how they should be correctly understood and what units should be used, bearing in mind the problem of the new units introduced with the SI system. It is necessary to emphasize that this book is the generalization of a large body of material accumulated on radioactive fallout over a period of more than 50 years (since 1949, in fact). Many real data were obtained at explosions and accidents of the 1950's and 1960's and these are now absolutely unique (i.e., were only once published in special reports or papers). So, the units used were related to this period. Whether we can now recalculate these data and present them in new units, for instance in the SI units, is a great question?
xxiv
Radioactive Fallout after Nuclear Explosions and Accidents
Table 2 Parameter
Obsolete units
New SI units
Exposure dose Exposure dose rate Absorbed dose Absorbed dose rate Equivalent dose Equivalent dose rate Activity Density of radioactive contamination Concentration of radioactive contamination
Roentgen (R), mR, ~tR R/hr, R/s, mR/hr, ~tR/hr, mR/s rad, mrad, ~trad rad/hr, mrad/s, mrad/hr, ~trad/hr, mrad/s rem, mrem rem/hr, rem/s, mrem/hr Ci, mCi, ~tCi, nCi Ci/km 2, Ci/m 2, mCi/km 2, ~tCi/m 2
Gy, cGy = 1 rad, nGy Gy/hr, cGy/hr, Gy/year Sv, cSv = 1 rem Sv/hr, cSv/hr, Sv/year 1 Bq, kBq, MBq 1 Bq/m 2, kBq/m 2 , MBq/km 2
Ci/km 3 , Ci/m 3 , mCi/km 3 , gCi/cm 3 , nCi/cm 3 , pCi/cm 3
1 Bq/m 3 , kBq/m 3 , Bq/cm 3 , kBq/m 3
Note: c is centi (10-2), m is milli (10-3), ~t is micro (10-6), n is nano (10-9), p is pico (10-12), k is kilo (103), M is mega (106). Other abbreviations used later in this book are: G is giga (109), T is tera (1012), P is peta (1015) and E is exa (1018).
It is also necessary to note that this book is a physical and geophysical book on radioactive fallout. It is very useful for biologists as well but it is not a biological book; this is why we have rarely used here units like rem or biological equivalent of Roentgen, though at the present time, the most-used units for evaluating doses and dose rates (as well as for estimating external dose on a land site and internal dose to man) are the SI system units, i.e., Sievert, which is the biological equivalent of the absorbed dose in rad units. In the 1950's- 1960's, the main unit used in dosimetry was the Roentgen (R) or mR, ~tR (to measure doses), and R/hour, mR/hour, ~.tR/hour to measure dose rates. The Roentgen unit is a very convenient unit for a measurement as, in this case, the exposure dose can be measured directly by an ionizing chamber (via the electric charge) or any other instrument with an air-equivalent sensor calibrated by the ionizing chamber (these instruments were called Roentgen-meters). An important and historic example of such measurements was the dose rate measurement mission immediately after the Chernobyl accident. A large official group of specialists (headed by the author) measured the dosimetric characteristics in the area using air-equivalent Roentgen-meters. But many geologists (and the scientific community at large) had "Crystal" (or "SRP") instruments in which the detector of the radiation was a NaI(T1) scintillator, i.e., obviously non-air-equivalent but sensitive to the gamma-radiation for geological survey work. Having been calibrated for a single source of gamma-radiation (6~ or 137Cs), this equipment showed similar data to the airequivalent instrument during measurement of point sources at a close distance. However, in the case of land contamination (when intense scattered "soft" radiation appeared) the "Crystal" instrument showed an excessive "dose" (2-4 times larger) and this caused many misunderstandings (the dose measured by the population at large exceeded by several times that obtained by the official survey). In this case, a special decision of the State Commission, headed by the President of the USSR Academy of Sciences, academician A. E Alexandrov (a famous specialist in the field of nuclear energy), was needed in order to solve this problem quickly and supporting the use of the air-equivalent instruments.
Glossary of Definitions and Units
XXV
In the context of the above, therefore, we should note here that the primary data on doses and dose rates presented in this book in maps and tables and in the text itself are given first in the form in which they were actually obtained so that we could avoid the introduction of errors in the process of conversion of the units used into those in the SI system. This is why we retain in the book the primary dose notation in Roentgens, the dose rates in R/hr, R/year, mR/hr, ~tR/hr, etc. and in some sections we use the units "rad" and "rem". When doing this, we indicate that 1 Roentgen = 0.88 rad (1 rad = 1.136 R) and, when converting into the SI system, 1 rem -- 0.01 Sv - 1 cSv; 1 rad -- 0.01 Gy; 1 Gy = 100 rad (if k -- 1.0). In tables which present values of activity, the data have generally been converted from Curie units into Becquerels (Bq, kBq, MBq, etc.). In most cases throughout the book, however, in order to make the data and the scientific content as intelligible as possible to both young and old, we have either provided handy conversion factors in the relevant places or we have presented the data in both systems of units, the secondary data in parentheses. We hope that you will now be able to follow the story without too much confusion!
References [1] Aglintsev, K. K. (1957). Dosimetry of Ionizing Irradiation (503 p.). Moscow: State Publ. of Techn.-Theoret. Literature. [2] Rahn, E J., Adamantiades, A. G., Kenton, J. E., & Braun, Ch. (1984). A Guide to Nuclear Power Technology (752 p.). New York: Willey. [3] Warner, S. E & Kirchmann, R. J. C. (Eds.) (2000). Nuclear Test Explosions, SCOPE-59 (269 p.). Chichester. [4] Eger, R. (1961). Dosimetry and Protection against Irradiation (translated from German) (211 p.). Moscow: State Publisher of Literature in the Field of Atomic Science and Engineering. [5] Ivanov, V. I. (1970). Dosimetry (392 p.). Moscow: Atomizdat.