Ю. Посудін. Моніторинг довкілля з основами метрології Лекція 1 6 a РАДІОЕКОЛОГІЧНИЙ МОНІТОРИНГ

1. Ю. Посудін. Моніторинг довкілля з основами метрологіїЛекція 16 aРАДІОЕКОЛОГІЧНИЙ МОНІТОРИНГ Yuriy Posudin Environmental Monitoring with Fundamentals of Metrology Lecture 16a RADIOECOLOGICAL MONITORING

2. 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, gamma-rays).

3. 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. CLASSIFICATION OF IONIZING RADIATION

4. Radiation dosimetry is the calculation of the absorbed dose in matter and tissue resulting from the exposure to indirectly and directly ionizing radiation. Radiation Dosimetry

5. 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 Exposure Dose

6. 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”) Absorbed Dose

7. 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).

8. The Dose Equivalent The dose equivalent is determined as: Н = DAWR WT, • whereDA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, stomachWT = 0.12; brain, kidney – 0.05; skin – 0.01.

9. 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”)

10. Radioactivity Radioactivity - the radiation, includingalpha particles, nucleons, electrons, and gamma rays, emitted by a radioactive substance.

11. 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 = 3.7×1010 Bq

12. MEASUREMENT OF IONIZING RADIATION СРП-68-01

13. 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.

14. Gas-Filled Detectors Number of ions Geiger Counter Proportional Counter Ionizing Chamber Voltage, V

15. Geiger-Muller Counter

16. Geiger-Muller Counter

17. 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 detector

18. Scintillation Counter

19. Scintillation Counter

20. 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.

21. 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.

22. Natural Radioactivity in Ukraine

23. Ukrainian Crystalline Shield It occupies about 39,6% of all territory

24. Uranium Mines in Ukraine http://www.reachingcriticalwill.org/about/pubs/Inventory/Ukraine.pdf

25. Radon Ukraine has high level of irradiation by radon – up to 3.8 mSv/year

26. 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.

27. 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.

28. 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).

29. 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

30. 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. ENVIRONMENTAL RADIOACTIVITY FROM MILITARY SOURCES

31. The nuclear powers have conducted at least 2,000 nuclear test explosions (numbers are approximated, as some test results have been disputed). Nuclear Tests

32. 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. Japan Sea Contamination http://www1.american.edu/TED/japansea.htm

33. Radioactive contamination • Radioactive contamination, is the uncontrolled distribution of radioactive material in a given environment. • Most anthropogenic radionuclides are short-lived, but some have half-lives of many years: 137Cs - 30 years; 90Sr - 28.1 years.

34. 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

35. Nuclear test by the United States at Bikini Atoll in 1946

36. 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 SS-24 intercontinental ballistic missiles (ICBMs; 1,240 warheads) and 44 strategic bombers.

37. 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, Ukrainedecided to return the weapons to Russia and to join the Nuclear Nonproliferation Treatyas non-nuclear weapons state

38. Radioactive waste is a waste product containing radioactive material. The uranium is fabricated ino fuel rods which are inserted into the nuclear reactor. ENVIRONMENTAL RADIOACTIVITY FROM INDUSTRIAL SOURCES

39. 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. Radioactive waste

40. 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 energyUkraine occupies 8 place in the world and 5 – in Europe.

41. Nuclear Power in Ukraine Chernobyl Rivne Khmelnitsky South Ukraine Zaporizhzhia

42. 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.

43. 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 tonsof radioactive wastes are accumulated in Ukraine; 3. Medical, scientific, industrial and other institutions and organisations; 4. Chornobyl NPP excluded zone– more than 1.1 billionsm3of radioactive wastes are accunulated. Radioactive Wastein Ukraine

44. SURFACE CONTAMINATION • Surface contamination is usually expressed in units of radioactivity per unit of area. Ci/km2 andkBq/km2.

45. Disposal of hazardous object in Ukraine

46. Distribution of exposure dose power in Ukraine 1993

47. Distribution of exposure dose power in Ukraine 2002

48. Distribution of exposure dose power in Ukraine 2008

49. Radiation Contamination of Territory of Ukraine http://www.rri.kyoto-u.ac.jp/NSRG/reports/kr21/kr21pdf/Nasvit1.pdf