Ю. Посудін.
Моніторинг довкілля з основами метрології
Лекція 16 a
РАДІОЕКОЛОГІЧНИЙ МОНІТОРИНГ
Yuriy Posudin
Environmental Monitoring with Fundamentals of
Metrology
Lecture 16a
RADIOECOLOGICAL MONITORING
IONIZING RADIATION
•
Radiation of sufficiently
high energy to cause
ionization in the medium
through which it passes.
•
It may consist of a
stream of high-energy
particles (e.g. electrons,
protons, alpha-particles) or
short-wavelength
electromagnetic radiation
(ultraviolet, X-rays, gammarays).
CLASSIFICATION OF IONIZING
RADIATION
• Alpha (α) radiation consists of
a fast moving Helium nuclei
and is stopped by a sheet of
paper.
• Beta (β) radiation, consisting
of are high-energy, high-speed
electrons or positrons, is halted
by an aluminium plate.
• Gamma (γ) radiation, turned
out to be the electromagnetic
radiation having the
wavelength shorter than 10-11
metres, is eventually absorbed
as it penetrates a dense
material.
Radiation Dosimetry
• Radiation dosimetry is the calculation of the
absorbed dose in matter and tissue resulting
from the exposure to indirectly and directly
ionizing radiation.
Exposure Dose
• A measurement of radiation, at
a given point, in relation to its
ability to produce ionization.
The unit of measurement of
the exposure dose is the
roentgen.
• Roentgen unit of X-radiation or
gamma-radiation, the amount
that will produce, under normal
conditions of pressure,
temperature, and humidity, in
1 kg of air, an amount Q of
positive or negative ionization
equal to 2.58 × 10−4 coulomb
X = dQ/dm
[C/kg]
1 Roentgen =
2.58×10−4 C/kg
dE
dm
Absorbed Dose
Absorbed dose is a
measure of the energy
deposited in a medium
by ionizing radiation. It
is equal to the energy
deposited per unit mass
of medium, and so has
the unit J/kg, which is
given the special name
Gray (Gy).
DA = dE/dm
The unit of dose is the gray
(Gy) where
1 Gy = 1 J/kg
of tissue
1 rad = 0.01 Gy
(rad
– “Radiation Absoirbed Dose”)
Equivalent Dose
• Equivalent dose relates the absorbed
dose in human tissue to the effective
biological damage of the radiation. Not all
radiation has the same biological effect,
even for the same amount of absorbed
dose. Equivalent dose is measured in an
SI unit called the Sievert (Sv).
The Dose Equivalent
The dose equivalent is determined as:
Н = DAWR WT,
• where DA  is the absorbed dose; WR  radiation
weighting factor; WT  tissue weighting factor .
• For x-rays and gamma rays and electrons
absorbed by human tissue, WR is 1; WR is 10 for
neutrons; for alpha particles it is 20.
• For bones, lung, stomach WT = 0.12;
kidney – 0.05; skin – 0.01.
brain,
The Dose Equivalent
The unit of dose equivalent is called the
Sievert (Sv):
1 Sv = 1 J/kg tissue × constant
1 rem = 0.01 Sv
(rem – “Radiation Equivalent in Man”)
Radioactivity
Radioactivity - the radiation,
including alpha particles, nucleons,
electrons, and gamma rays, emitted
by a radioactive substance.
Units of Radioactivity
• The becquerel (symbol Bq) is the SI derived unit of
radioactivity.
• One Bq is defined as the activity of a quantity of
radioactive material in which one nucleus decays per
second.
1 Bq = s-1.
• The Bq unit is therefore equivalent to a decay rate of s−1.
• The curie (symbol Ci) is a unit of radioactivity, defined
as
1 Ci =
10
3.7×10
Bq
MEASUREMENT OF IONIZING
RADIATION
СРП-68-01
Gas-Filled Detectors
• The central electrode, or anode, collects negative charges. The
anode is insulated from the chamber walls and the cathode, which
collects positive charges. A voltage is applied to the anode and the
chamber walls.
• As a charged particle passes through the gas-filled chamber, it
ionizes some of the gas (air) along its path of travel.
The positive anode attracts the electrons, or negative particles. The
detector wall, or cathode, attracts the positive charges.
• The collection of these charges reduces the voltage across the
capacitor, causing a pulse across the resistor that is recorded by an
electronic circuit. The voltage applied to the anode and cathode
determines the electric field and its strength.
Gas-Filled Detectors
Number
of ions
Proportional
Counter
Geiger
Counter
Ionizing
Chamber
Voltage, V
Geiger-Muller Counter
Geiger-Muller Counter
Scintillation detector
• Scintillators are usually solids
that give off light when
radiation interacts with them.
• The light is converted to
electrical pulses that are
processed by electronics and
computers.
• Examples are sodium iodide
(NaI) and bismuth germanate
(BGO).
• These materials are used for
radiation monitoring, in
research, and in medical
imaging equipment.
Scintillation Counter
Scintillation Counter
Radioecological Monitoring
This is complex informational and
technical system of observation,
investigation,
estimation
and
forecasting of radiation state of
biosphere, territories near nuclear
stations, that were suffered from
radiating incidents.
ENVIRONMENTAL RADIOACTIVITY
FROM NATURAL SOURCES
• Background radiation is constantly present in
the environment and is emitted from a variety of
natural
and
artificial
sources.
Primary
contributions come from:
• Sources in the Earth: Soils and Rock, Building
materials;
• Sources from space, in the form of cosmic rays;
• The radon gas that is released from the Earth's
crust.
Natural Radioactivity in Ukraine
Ukrainian Crystalline Shield
It occupies about 39,6% of all territory
Uranium Mines in Ukraine
http://www.reachingcritical
will.org/about/pubs/Invento
ry/Ukraine.pdf
Radon
Ukraine has high
level of irradiation
by radon – up to
3.8 mSv/year
The radon in indoor air decays to heavy
metals lead and bismuth, which attach
themselves to dust particles in air and
are retained in the lungs, when breathed
in.
Without the fan, radon enters the home
through the floorboards and enters the
indoor air.
Radon is produced from decay of radium-226 in the ground, and
seeps into the underfloor region of a house
The fan draws the radon out
from the underfloor region,
and allows it to pass
harmlessly into outside air
Natural Background Radiation
• A number of radioactive materials occur
naturally in the earth itself. These
radioactive materials all have very long
half lives, and have been present in the
earth since its creation.
• It is considered that background radiation
is not dangerous for people because of
their adaptation during long period of time.
Background Radiation in Kiev
• According to the data of observation posts,
which are situated in Kiev, gamma
background in 2002 was within 9-16
microR/h and made on the average 12
microR/h.
Man-made Background
Radiation
This is the radiation which is emitted
from isotopes that have escaped into
surroundings from:
• nuclear tests;
• industrial uses of atomic energy;
• accidents (Chernobyl).
ENVIRONMENTAL RADIOACTIVITY
FROM MILITARY SOURCES
• During the final
stages of World War
II in 1945, the United
States conducted two
atomic bombings
against Japan in the
cities of Hiroshima
and Nagasaki.
ENVIRONMENTAL RADIOACTIVITY
FROM MILITARY SOURCES
• Within the first two
to four months of the
bombings, the acute
effects killed
90,000–166,000
people in Hiroshima
and 60,000–80,000
in Nagasaki.
Nuclear Tests
• The nuclear powers
have conducted at
least 2,000 nuclear
test explosions
(numbers are
approximated, as
some test results
have been disputed).
Japan Sea Contamination
http://www1.american.edu/TED/japansea.htm
• The former Soviet Union and
Russia had dumped
radioactive waste on many
occasions in the Far East
water area including the Sea
of Japan since 1950s.
• Soviet Union/Russia had
several dump sites in the
Sea of Japan and the North
Pacific Ocean off Kamchatka
peninsula.
• In the face of strong
resentment in Japan, the
United States and other
countries, the Russian
government reluctantly
announced that it would
suspend the dumping.
Radioactive contamination
• Radioactive contamination, is the uncontrolled
distribution of radioactive material in a given
environment.
• Most anthropogenic radionuclides are shortlived, but some have half-lives of many years:
137Cs
- 30 years;
90Sr - 28.1 years.
Nuclear Tests
•
•
•
•
•
•
•
•
United States: 1,054 tests
Soviet Union: 715 tests
France: 210 tests
United Kingdom: 45 tests
China: 45 tests
India: 6 underground tests
Pakistan: 6 underground tests
North Korea: 2 tests
Atomic tests reached a peak in the early 1060s
Nuclear test by the
United States at
Bikini Atoll in 1946
Nuclear Weapon in Ukraine
Upon the breakup of the Soviet Union,
Ukraine inherited a considerable nuclear
potential, in the form of 176 SS-19 and SS24 intercontinental ballistic missiles (ICBMs;
1,240 warheads) and 44 strategic bombers.
Nuclear Weapon in Ukraine
• Following the collapse of the Soviet Union, Ukraine
inherited a sizeable nuclear weapons infrastructure.
• Ukraine's sudden possession of the third largest nuclear
arsenal in the world left the newly independent country
with a strategic decision of whether or not to return these
weapons to Russia or be considered a nuclear weapons
state.
• In the end, Ukraine decided to return the weapons to
Russia and to join the Nuclear Nonproliferation Treaty as
non-nuclear weapons state
ENVIRONMENTAL RADIOACTIVITY
FROM INDUSTRIAL SOURCES
• Radioactive waste is
a waste product
containing radioactive
material.
• The uranium is
fabricated ino fuel
rods which are
inserted into the
nuclear reactor.
Radioactive waste
Once the fuel rods
are removed from the
reactor, they must be
cooled at least for the
first year or two in a
spent-fuel storage
bay.
Nuclear Power in Ukraine
• Ukraine is heavily dependent on
nuclear energy - it has 15 reactors
generating about half of its electricity.
• In terms of nuclear energy Ukraine
occupies 8 place in the world and 5 – in
Europe.
Nuclear Power in Ukraine
Chernobyl
Rivne
Khmelnitsky
South Ukraine
Zaporizhzhia
Radioactive waste
• Ukraine previously sent its spent fuel to Russia
to be reprocessed, but this course became a
contentious issue after Russia passed a law in
1992 prohibiting the import of radioactive
material into Russia.
• This action resulted in storage crisis at Ukrainian
power plants. In 6/93, however, Russia passed a
new law that allows Ukrainian spent fuel to be
reprocessed, but not stored, in Russia.
Radioactive Waste in Ukraine
•
Over the territory of Ukraine are
situated over 8 thousand different
institutions and organisations
whose operation generates
radioactive waste:
•
1. NPPs;
•
2. Uranium mining and uranium
processing industry – about 65.5
millions tons of radioactive wastes are
accumulated in Ukraine;
•
3. Medical, scientific, industrial and
other institutions and
organisations;
•
4. Chornobyl NPP excluded zone –
more than 1.1 billions m3 of radioactive
wastes are accunulated.
SURFACE CONTAMINATION
• Surface contamination is usually expressed in
units of radioactivity per unit of area.
Ci/km2 and kBq/km2.
Disposal of hazardous object
in Ukraine
Distribution of exposure dose power in
Ukraine 1993
Distribution of exposure dose power in
Ukraine 2002
Distribution of exposure dose power in
Ukraine 2008
Radiation Contamination of
Territory of Ukraine
http://www.rri.kyoto-u.ac.jp/NSRG/reports/kr21/kr21pdf/Nasvit1.pdf
Contamination of Foods
• In many European countries levels of I-131, Cs134/137, Sr-90, and other radionuclides in milk,
dairy products, vegetables, grains, meat, and
fish increased drastically (sometimes as much
as 1,000-fold) immediately after the catastrophe.
• As of 2000, up to 90% of the wild berries and
mushrooms exceeded permissible levels of Cs137 in Rovno and Zhytomir provinces, Ukraine.
Standards of Radionuclides in Foods
Значення допустимих рівнів вмісту радіонуклідів (Бк/кг, Бк/л)
(Горбунов та інш., 2005)
Назва продукту
Cs-137
№
з/п
1.
Хліб, хлібопродукти
20
2.
Картопля
60
3.
Овочі (листові, коренеплоди)
40
4.
Фрукти
70
5.
М'ясо і м'ясні продукти
200
6.
Риба і рибні продукти
150
7.
Молоко і молочні продукти
100
8.
Яйця (шт.)
6
9.
Вода питна
2
10. Молоко згущене і концентроване
300
11. Свіжі дикі ягоди і гриби
500
12. Сушені дикі ягоди і гриби
2500
13. Лікарські рослини
600
14. Інші продукти
600
15. Продукти дитячого харчування
40
Sr-90
5
20
20
10
20
35
20
2
2
60
50
250
200
200
5
MUSHROOMS
• Many people enjoy wild
mushrooms as a tasty
contribution
to
their
menu.
• But even more than two
decades after the reactor
accident of Chernobyl,
the Federal Office for
Radiation
Protection
measures
enhanced
activities
of
the
radionuclide Cs-137 in
some mushroom species.
FISH
• Several species of
fish (bottom fish)
are
able
to
accumulate
radionuclides from
sediments.
UTILIZATION OF RADIOACTIVE
WASTES
• About 1.7
millions m3
of liquid
radioactive
waste are
created
during one
year in
NPP.
UTILIZATION OF RADIOACTIVE
WASTES
• The main approaches to
managing radioactive
waste to date have been
segregation and storage
for short-lived wastes,
near-surface disposal for
low wastes, and deep
and secure burial for the
long-lived high-level
wastes.
UTILIZATION OF RADIOACTIVE
WASTES
UTILIZATION OF RADIOACTIVE
WASTES Yucca Mountain, Nevada
Yucca Mountain,
457 м Nevada
457 m
457 м
Radioactive waste in USA
Alternative Methods of Utilization
Space disposal
• Space disposal is an attractive
notion because it permanently
removes nuclear waste from
the environment.
• However, it has significant
disadvantages, not least of
which is the potential for
catastrophic failure of a launch
vehicle.
• Furthermore, the high number
of launches that would be
required makes the proposal
impractical (for both economic
and risk-based reasons).
The system of early prevention
GAMMA 1
The system of early prevention about
radioactive accident GAMMA 1 was
created in Ukraine in 1994-1998.
It includes two subsystems of
radiation monitoring, information and
analytical centers, and system of
communication which are located in
Kharkiv.
RADIATION AND NUCLEAR
EMERGENCY INFORMATION
• The RODOS (Real-time On-line Decision
Support) system for off-site emergency
management.
• As a result of these collaborative actions,
a comprehensive decision support system
(RODOS) has been developed which can
be applied within Europe
RODOS (Real-time On-line
Decision Support)system
European decision support
systems (RODOS)
Невирішеність питань ліквідації наслідків аварії, у
тому числі безпосередньо на ЧАЕС, недієвість
економічних важелів у підтримці належних рівнів
радіаційної безпеки на неядерних підприємствах,
недостатність фінансування протирадіаційних
заходів, недосконалість ядерного законодавства в
частині фінансового забезпечення національних
програм поводження з радіоактивними відходами,
відпрацьованим ядерним паливом, зняттям ядерних
об'єктів з експлуатації посилюють негативне
ставлення населення до радіації взагалі та атомної
енергетики зокрема. В державі виникла нагальна
потреба значних обсягів коштів та матеріальних
ресурсів для приведення стану радіаційної безпеки і
захисту персоналу, населення й навколишнього
середовища у відповідність до вимог національного
законодавства
(Україна.
Радіаційна
безпека.
Всеукраїнська Екологічна Ліга, 2004).
Radiation - in every house
• Information was published in No122 (1220) "Po-Kievski
Newspaper" 2008, May, 31th.
• On these days special services of the country declared about
exposure of the whole criminal group, which organized large-scale
"business" on export from the "zone" of everything, for that it’s
possible to gain money.
• During the last sortie thieves took out the steel pipes taken from a
burial on utilization of wastes contaminated by radiation.
• When dosimeter was brought to a body of the car - the radiation
background was in 30 times above normal.
• Arrested persons have already confessed that they took out not only
pipes, but also parts of cars, wood and even the caught fish.
• It is hardly to believe, but thieves even tried to take out the whole
helicopter of Mi-8 (!) from Chernobyl in order to resell it then, under
arrangement of original cafe.
• Punishment – up to three years of prison.