The document discusses various topics related to radioactivity including its sources, types of radiation emitted, units of radioactivity, applications in medicine, and examples of nuclear disasters. It provides background on radioactivity and its discovery. Key points include that radioactivity is the spontaneous emission of radiation from unstable atomic nuclei, the three main types of radiation are alpha, beta, and gamma, and applications of radioactivity include uses in medicine such as medical imaging and carbon dating. Nuclear disasters discussed include Chernobyl and Fukushima.
This document provides an overview of radioactivity including its discovery, sources, applications, and health effects. It discusses how radioactivity was discovered by Becquerel and the Curies. Sources include primordial radionuclides in the Earth, cosmogenic radionuclides from cosmic rays, and anthropogenic radionuclides from nuclear activities. Applications include uses in medicine, industry, electricity generation, space exploration and food preservation. Examples of nuclear disasters like Chernobyl and Fukushima are provided along with effects of radiation exposure.
Radioactive contamination occurs when radioactive material is deposited on or in an object or a person. Radioactive materials released into the environment can cause air, water, surfaces, soil, plants, buildings, people, or animals to become contaminated.
The document discusses sources of environmental radiation including natural sources like radon and cosmic rays, which contribute most of average annual radiation exposure, as well as artificial sources from radioisotopes, accelerators, nuclear reactors, and atomic bomb explosions. It also examines nuclear weapons programs in countries like the US and Russia and their resulting radioactive waste legacies. Several nuclear radiation disasters are described like atomic bombings in Japan and the Chernobyl accident. Both benefits and risks of low-level radiation are discussed.
Radioactivity refers to the particles emitted from unstable atomic nuclei and includes alpha, beta, and gamma radiation. Different types of radioactive decay lead to different decay paths that transform nuclei into other elements. The rate of radioactive decay is measured by half-life, which is the time for half of a radioactive substance to decay.
This document provides biographical information about Vivek Khandai, including his educational background and contact details. It also discusses various topics related to environmental radiation, including natural and artificial sources, hazards of nuclear radiation, nuclear disasters like Chernobyl and Hiroshima/Nagasaki bombings, effects of radiation exposure, and perspectives on radiation as both a risk and potential benefit in small doses.
This document discusses different types of radiation and their sources. It describes two main types - non-ionizing radiation which does not have enough energy to ionize atoms, and ionizing radiation which does. Ionizing radiation includes alpha, beta, gamma, x-rays and neutron radiation. Sources of ionizing radiation include natural background radiation from cosmic rays, radioactive elements in the earth's crust, and radon gas; as well as artificial sources like nuclear weapons testing, medical equipment, industrial uses, and the nuclear fuel cycle.
This document discusses nuclear accidents and radiation hazards. It begins with the historical background of nuclear fission and the Manhattan Project that developed the first nuclear bombs. It then describes the nuclear bomb explosions over Hiroshima and Nagasaki in 1945. The document further discusses nuclear arsenals and waste in countries like the US and Russia. It covers notable nuclear accidents at Chernobyl and Fukushima. The document also mentions natural sources of radiation and some purported health benefits of low-level radiation exposure.
This document discusses nuclear accidents and radiation hazards. It begins with the historical background of nuclear fission and the Manhattan Project that developed the first nuclear bombs. It then describes the nuclear bomb explosions over Hiroshima and Nagasaki in 1945. The document further discusses nuclear arsenals and waste in countries like the US and Russia. It covers notable nuclear accidents at Chernobyl and Fukushima. The document also mentions natural sources of radiation and some purported health benefits of low-level radiation exposure.
This document provides an overview of radioactivity including its discovery, sources, applications, and health effects. It discusses how radioactivity was discovered by Becquerel and the Curies. Sources include primordial radionuclides in the Earth, cosmogenic radionuclides from cosmic rays, and anthropogenic radionuclides from nuclear activities. Applications include uses in medicine, industry, electricity generation, space exploration and food preservation. Examples of nuclear disasters like Chernobyl and Fukushima are provided along with effects of radiation exposure.
Radioactive contamination occurs when radioactive material is deposited on or in an object or a person. Radioactive materials released into the environment can cause air, water, surfaces, soil, plants, buildings, people, or animals to become contaminated.
The document discusses sources of environmental radiation including natural sources like radon and cosmic rays, which contribute most of average annual radiation exposure, as well as artificial sources from radioisotopes, accelerators, nuclear reactors, and atomic bomb explosions. It also examines nuclear weapons programs in countries like the US and Russia and their resulting radioactive waste legacies. Several nuclear radiation disasters are described like atomic bombings in Japan and the Chernobyl accident. Both benefits and risks of low-level radiation are discussed.
Radioactivity refers to the particles emitted from unstable atomic nuclei and includes alpha, beta, and gamma radiation. Different types of radioactive decay lead to different decay paths that transform nuclei into other elements. The rate of radioactive decay is measured by half-life, which is the time for half of a radioactive substance to decay.
This document provides biographical information about Vivek Khandai, including his educational background and contact details. It also discusses various topics related to environmental radiation, including natural and artificial sources, hazards of nuclear radiation, nuclear disasters like Chernobyl and Hiroshima/Nagasaki bombings, effects of radiation exposure, and perspectives on radiation as both a risk and potential benefit in small doses.
This document discusses different types of radiation and their sources. It describes two main types - non-ionizing radiation which does not have enough energy to ionize atoms, and ionizing radiation which does. Ionizing radiation includes alpha, beta, gamma, x-rays and neutron radiation. Sources of ionizing radiation include natural background radiation from cosmic rays, radioactive elements in the earth's crust, and radon gas; as well as artificial sources like nuclear weapons testing, medical equipment, industrial uses, and the nuclear fuel cycle.
This document discusses nuclear accidents and radiation hazards. It begins with the historical background of nuclear fission and the Manhattan Project that developed the first nuclear bombs. It then describes the nuclear bomb explosions over Hiroshima and Nagasaki in 1945. The document further discusses nuclear arsenals and waste in countries like the US and Russia. It covers notable nuclear accidents at Chernobyl and Fukushima. The document also mentions natural sources of radiation and some purported health benefits of low-level radiation exposure.
This document discusses nuclear accidents and radiation hazards. It begins with the historical background of nuclear fission and the Manhattan Project that developed the first nuclear bombs. It then describes the nuclear bomb explosions over Hiroshima and Nagasaki in 1945. The document further discusses nuclear arsenals and waste in countries like the US and Russia. It covers notable nuclear accidents at Chernobyl and Fukushima. The document also mentions natural sources of radiation and some purported health benefits of low-level radiation exposure.
Radioactive waste comes from various sources and poses health and environmental risks if not properly disposed of. There are different types of radioactive waste - low, intermediate, and high level - which are classified based on their radiation levels. While radioactive waste has historically come from nuclear power and weapons programs, it also originates from medical, industrial, and research applications. Safe disposal methods aim to isolate radioactive materials from the environment for long periods of time until they are no longer hazardous. Common approaches involve underground storage in stable geological formations or deep ocean and polar ice disposal sites. Proper management requires regulation and oversight from specialized agencies to protect human and ecological health.
Radioactive pollution occurs when radioactive substances are present where they are not desired, such as in the air, soil, water, or within other materials. The two main sources of radioactive pollution are nuclear accidents and disposal of radioactive waste. The Chernobyl disaster in 1986 and Fukushima Daiichi nuclear disaster in 2011 both resulted in widespread radioactive contamination of the surrounding environment due to atmospheric release and water contamination. Exposure to ionizing radiation emitted by radioactive materials can increase cancer risks in both humans and animals. Protective measures aim to limit exposure and proper disposal methods seek to isolate radioactive waste.
Nuclear medicine is an imaging specialty that uses radioactive tracers and detection systems to examine organ and tissue function. Tracers are introduced into the body and selectively taken up by organs, then detected by gamma cameras to create functional images. Common tracers include technetium-99m, iodine-131, and fluorine-18. The field has its origins in the late 19th century discoveries of x-rays and radioactivity by Roentgen, Becquerel, and the Curies. Pioneering work by Rutherford, Bohr, Chadwick, Lawrence and others led to an understanding of nuclear structure and the development of cyclotrons to produce artificial radionuclides for medical use. Tech
This presentation covers nuclear pollution from nuclear power and reactions. It discusses sources of ionizing radiation including natural sources like cosmic rays and terrestrial radiation, as well as man-made sources such as nuclear weapon testing, uranium mining, and nuclear power plant operation. The effects of radiation on plants, animals, and aquatic life are addressed. Major nuclear accidents at Chernobyl and Three Mile Island are summarized. Ways to control nuclear pollution through safe storage, disposal, and plant regulations are provided. The conclusion covers the risks of nuclear pollution but also the potential for sustainable nuclear energy.
RADIOACTIVE POLLUTION
INTRODUTION
Radiation And Radioactivity:
The application of radioactive elements in nuclear weapons, X-rays, MRI and other medical equipment causes their exposure to human beings.
The deposition of these radioactive gases in water bodies also cause radioactive contamination.
Radiation is the transport of energy through space.
Two types of radiation. - Ionizing radiation
- Non ionizing radiation
Sources of radioactive pollution
Natural sources of radiation: Natural sources of radiation are mentioned below:
In natural sources of radioactive pollution, atomic radioactive minerals are one among them.
Cosmic rays possess high energy ionizing electromagnetic radiation.
Another source of radioactive radiation is naturally occurring radioisotopes. Radioisotopes are found in soil in small quantity.
Radioactive elements like radium, thorium, uranium, isotopes of potassium and carbon occur in lithosphere
Anthropogenic sources of radiation
Human activities mentioned below include in sources of radioactive pollution:
Nuclear tests
Nuclear reactors
Diagnostic medical applications
Nuclear Wastes
Nuclear explosions
Nuclear metal processing
Nuclear Reactor Accidents
Almost 99 such nuclear accidents have been occur through out worldwide. 56 of 99,have been occurred only in USA.
Kyshtym, Russia (former Soviet Union) – 29,september,1957 (INES Level 6)
200 people died on direct radiation and almost 8000 people died in 32 years of this nuclear accidents
Major nuclear accidents
Three Mile Island, United States – 28 March, 1979 (INES Level 5)
one of the elements of the power plant’s system malfunctioned
Chernobyl, Ukraine (former Soviet Union) – 26,april,1986 (INES Level 7)
A series of events led to the explosion of the reactor number four at the Chernobyl Nuclear Power Plant
Fukushima, Japan –11,march 2011 (INES Level 7)
9.0 magnitude earthquake struck off the coast of Japan. The resulting tsunami (49 feet tall) hit the Fukushima I Nuclear Power Plant 51 and experienced meltdown
NUCLEAR BOMBS
August 6, 1945, Hiroshima
directly killing an estimated 80,000 people. By the end of the year, injury and radiation brought total casualties to 90,000–140,000
On August 9, 1945, Nagasaki
Almost 75,000 people died and more affected by radiation.
Radiation Health Effects
Radionuclides are carcinogens and at high doses can also cause rapid sickness and death.
The health effects of exposure to radiation depend on many factors.
the amount of energy it deliver
the length of exposure time
the organs and tissues exposed
characteristics of the exposed person
How does radiation injure people?
High energy radiation breaks chemical bonds.
This creates free radicals, like those produced by other insults as well as by normal cellular processes in the body.
The free radicals can change chemicals in the body.
These changes can disrupt cell function and may kill cells.
1. Radiation is energy that travels through space in the form of waves or particles. There are two main types: ionizing radiation which can disrupt atoms and molecules, and non-ionizing radiation which does not have enough energy to do so.
2. Sources of radiation include natural background radiation like cosmic rays from space, radioactive elements in the ground and air, and internal radioactive isotopes in the body. Man-made sources include medical x-rays, nuclear power plants, consumer products, and fallout from nuclear weapons tests and disasters.
3. Ionizing radiation includes alpha particles, beta particles, gamma rays, and x-rays. They are able to ionize or change atoms and molecules and
This document summarizes different types of radiation sources. It discusses natural background radiation from cosmic rays, terrestrial sources like uranium and thorium in soil, and internal radiation from radioactive materials inside the body. It also describes man-made sources of radiation used in medicine for diagnostic imaging and cancer treatment, as well as other applications in industry. The document provides context on radiation risk and exposure limits set based on natural background levels.
1. Radioactivity can be detected using photographic film or a Geiger-Muller detector. Background radiation comes from natural sources like radon gas emanating from rocks and internal radiation from radioactive elements inside our bodies.
2. The activity of a radioactive source is measured in becquerels and refers to the number of decays per second. It decreases over time as the radioactive material decays. Half-life refers to the time it takes for half the radioactive material or nuclei to decay and is different for each isotope.
3. Calculating half-lives involves determining the amount of radioactive material or activity remaining after set time periods equal to the half-life. Graphing the decay of an isotope over time can also
This document discusses radioactive pollution and nuclear accidents. It begins with an overview of topics to be covered, including radiation, sources of radioactive pollution, types of radioactive pollution, effects of radiation exposure, nuclear energy, nuclear hazards and accidents, and prevention measures. It then covers radiation and its sources, natural sources of radiation like cosmic rays and terrestrial radiation, and artificial sources like nuclear power plants and medical waste. It discusses the types, toxicity and health effects of radioactive pollution. The document provides a brief history of nuclear energy and accidents like Chernobyl and Fukushima. It concludes with suggestions for preventing radioactive pollution like proper waste disposal and regular monitoring.
Radioactive pollution is defined as the release of radioactive substances or particles into the environment from human activities like nuclear weapon testing, nuclear power plants, or accidents. It can cause serious health effects like cancer due to radiation exposure and remains toxic for centuries. Sources include natural processes like radioactive minerals as well as human activities involving nuclear materials, weapons, power plants, and medical isotopes. Effects range from acute radiation sickness to long-term mutations and increased cancer risks. Monitoring, safe waste disposal, and prevention of leaks and accidents are important for controlling radioactive pollution.
Nuclear engineering harnesses the power of the atom to do work. It involves understanding nuclear physics principles like fission and fusion, designing and operating nuclear reactors, developing nuclear medicine applications, ensuring nuclear non-proliferation, and managing radioactive waste. Some key areas of nuclear engineering include power generation, weapons development, space applications, medical imaging and treatment, food irradiation, and more. Nuclear engineers work in government, national labs, power companies, the military, medicine, and academia developing and overseeing applications of nuclear technology.
- There are two main systems for measuring radiation - the conventional US system and the International System of Units (SI).
- Radioactivity is measured in curies (Ci) in the US system and becquerels (Bq) in the SI system. 1 Ci equals 37 billion Bq.
- Exposure rate is measured in roentgens (R) per hour in the US system. The SI unit is the coulomb per kilogram (C/kg).
- Absorbed dose is measured in rads in the US system and grays (Gy) in the SI system. 1 Gy is equal to 100 rads.
The Chernobyl nuclear disaster of 1986 was the worst nuclear power plant accident in history. On April 26, 1986, a reactor explosion at the Chernobyl Nuclear Power Plant in Ukraine released large amounts of radioactive material into the atmosphere. Over 100,000 people had to be evacuated and large areas became contaminated with radiation. Long term impacts included increased cancer rates, environmental contamination, and economic impacts due to agricultural and land restrictions.
Radioactive pollution occurs when radioactive materials are released into the environment through natural processes like radioactive decay of elements in the Earth's crust, interaction of cosmic rays in the atmosphere, and background radioactivity in seawater. Anthropogenic sources of radioactive pollution include nuclear weapons testing, nuclear waste disposal, operations of nuclear power plants, and improper storage and disposal of radioactive materials. The radioactive pollution can enter the food chain and pose health risks to organisms and humans through ingestion of contaminated food and water over time. Proper methods for disposing, storing, labeling and reusing radioactive waste, banning nuclear weapons tests, utilizing alternative energy sources, and individual precautions can help reduce radioactive pollution.
Ionising radiation is radiation that has sufficient energy to cause ionisation by removing electrons from atoms. It includes alpha particles, beta particles, gamma rays, X-rays, protons and neutrons. Ionising radiation can come from natural sources like radon gas or cosmic rays, or artificial sources like medical X-rays. Different types of ionising radiation penetrate tissue to different degrees and can be absorbed through the skin, inhaled or ingested, posing greater or lesser health risks depending on the dose and radiation type.
Nuclear reactors carry risks of accidents and radiation exposure that can harm human health and the environment. Major accidents like Chernobyl and Fukushima have caused widespread contamination and required large evacuations. While nuclear waste is small in volume compared to fossil fuels, it remains highly radioactive for extremely long periods and requires careful disposal. New reactor designs aim to reduce risks through passive safety systems and using alternative fuels like uranium-238 that produce less long-lived waste. Public education about radiation risks and emergency plans is also important to prevent overreaction during accidents.
This document discusses nuclear hazards and radioactive waste. It begins by defining nuclear elements and different types of radiation such as alpha, beta, and gamma particles. It then discusses nuclear power generation and major forms of nuclear fuels. The remainder of the document focuses on nuclear waste, including definitions and types of low-level, intermediate-level, and high-level waste. It describes storage, disposal, and transportation of nuclear waste, as well as international scales for nuclear events. Finally, it discusses some human health risks of radiation such as radiation sickness, cancer, and genetic mutations.
This document provides an overview of fundamentals of radiation protection including:
- Atomic definitions such as isotope identification, activity, and half-life.
- Common types of radioactive decay including alpha, beta, positron, and gamma emissions.
- Units used to measure radiation exposure such as becquerel and curie.
- Key factors that reduce radiation exposure including distance, shielding, and time.
- Biological effects of radiation exposure and typical annual radiation doses from various sources.
- Regulations for radiation exposure limits set by organizations like the ICRP.
CHL308_Radioactive Waste And Its Disposal.pptHajiAdeel1
This document discusses radioactive waste and its disposal. It defines radioactive waste as waste that emits rays, waves or particles. It describes the types of radioactive waste including low, intermediate and high level waste. It outlines sources of radioactive waste such as nuclear power plants, medical facilities, and naturally occurring materials. The document then discusses the health risks of exposure to radioactive waste and various proposed methods for disposal, including deep geological repositories and ocean dumping. It notes the complex regulatory environment surrounding radioactive waste management and concludes that radioactive waste poses long-term challenges due to its persistence.
Radioactive waste comes from various sources and poses health and environmental risks if not properly disposed of. There are different types of radioactive waste - low, intermediate, and high level - which require different handling and disposal methods due to varying levels of radioactivity. Common disposal methods include deep geological repositories, sub-seabed burial, and space disposal. Proper management of radioactive waste is important to isolate it and prevent negative impacts on humans and the environment.
Anti-Universe And Emergent Gravity and the Dark UniverseSérgio Sacani
Recent theoretical progress indicates that spacetime and gravity emerge together from the entanglement structure of an underlying microscopic theory. These ideas are best understood in Anti-de Sitter space, where they rely on the area law for entanglement entropy. The extension to de Sitter space requires taking into account the entropy and temperature associated with the cosmological horizon. Using insights from string theory, black hole physics and quantum information theory we argue that the positive dark energy leads to a thermal volume law contribution to the entropy that overtakes the area law precisely at the cosmological horizon. Due to the competition between area and volume law entanglement the microscopic de Sitter states do not thermalise at sub-Hubble scales: they exhibit memory effects in the form of an entropy displacement caused by matter. The emergent laws of gravity contain an additional ‘dark’ gravitational force describing the ‘elastic’ response due to the entropy displacement. We derive an estimate of the strength of this extra force in terms of the baryonic mass, Newton’s constant and the Hubble acceleration scale a0 = cH0, and provide evidence for the fact that this additional ‘dark gravity force’ explains the observed phenomena in galaxies and clusters currently attributed to dark matter.
CLASS 12th CHEMISTRY SOLID STATE ppt (Animated)eitps1506
Description:
Dive into the fascinating realm of solid-state physics with our meticulously crafted online PowerPoint presentation. This immersive educational resource offers a comprehensive exploration of the fundamental concepts, theories, and applications within the realm of solid-state physics.
From crystalline structures to semiconductor devices, this presentation delves into the intricate principles governing the behavior of solids, providing clear explanations and illustrative examples to enhance understanding. Whether you're a student delving into the subject for the first time or a seasoned researcher seeking to deepen your knowledge, our presentation offers valuable insights and in-depth analyses to cater to various levels of expertise.
Key topics covered include:
Crystal Structures: Unravel the mysteries of crystalline arrangements and their significance in determining material properties.
Band Theory: Explore the electronic band structure of solids and understand how it influences their conductive properties.
Semiconductor Physics: Delve into the behavior of semiconductors, including doping, carrier transport, and device applications.
Magnetic Properties: Investigate the magnetic behavior of solids, including ferromagnetism, antiferromagnetism, and ferrimagnetism.
Optical Properties: Examine the interaction of light with solids, including absorption, reflection, and transmission phenomena.
With visually engaging slides, informative content, and interactive elements, our online PowerPoint presentation serves as a valuable resource for students, educators, and enthusiasts alike, facilitating a deeper understanding of the captivating world of solid-state physics. Explore the intricacies of solid-state materials and unlock the secrets behind their remarkable properties with our comprehensive presentation.
Radioactive waste comes from various sources and poses health and environmental risks if not properly disposed of. There are different types of radioactive waste - low, intermediate, and high level - which are classified based on their radiation levels. While radioactive waste has historically come from nuclear power and weapons programs, it also originates from medical, industrial, and research applications. Safe disposal methods aim to isolate radioactive materials from the environment for long periods of time until they are no longer hazardous. Common approaches involve underground storage in stable geological formations or deep ocean and polar ice disposal sites. Proper management requires regulation and oversight from specialized agencies to protect human and ecological health.
Radioactive pollution occurs when radioactive substances are present where they are not desired, such as in the air, soil, water, or within other materials. The two main sources of radioactive pollution are nuclear accidents and disposal of radioactive waste. The Chernobyl disaster in 1986 and Fukushima Daiichi nuclear disaster in 2011 both resulted in widespread radioactive contamination of the surrounding environment due to atmospheric release and water contamination. Exposure to ionizing radiation emitted by radioactive materials can increase cancer risks in both humans and animals. Protective measures aim to limit exposure and proper disposal methods seek to isolate radioactive waste.
Nuclear medicine is an imaging specialty that uses radioactive tracers and detection systems to examine organ and tissue function. Tracers are introduced into the body and selectively taken up by organs, then detected by gamma cameras to create functional images. Common tracers include technetium-99m, iodine-131, and fluorine-18. The field has its origins in the late 19th century discoveries of x-rays and radioactivity by Roentgen, Becquerel, and the Curies. Pioneering work by Rutherford, Bohr, Chadwick, Lawrence and others led to an understanding of nuclear structure and the development of cyclotrons to produce artificial radionuclides for medical use. Tech
This presentation covers nuclear pollution from nuclear power and reactions. It discusses sources of ionizing radiation including natural sources like cosmic rays and terrestrial radiation, as well as man-made sources such as nuclear weapon testing, uranium mining, and nuclear power plant operation. The effects of radiation on plants, animals, and aquatic life are addressed. Major nuclear accidents at Chernobyl and Three Mile Island are summarized. Ways to control nuclear pollution through safe storage, disposal, and plant regulations are provided. The conclusion covers the risks of nuclear pollution but also the potential for sustainable nuclear energy.
RADIOACTIVE POLLUTION
INTRODUTION
Radiation And Radioactivity:
The application of radioactive elements in nuclear weapons, X-rays, MRI and other medical equipment causes their exposure to human beings.
The deposition of these radioactive gases in water bodies also cause radioactive contamination.
Radiation is the transport of energy through space.
Two types of radiation. - Ionizing radiation
- Non ionizing radiation
Sources of radioactive pollution
Natural sources of radiation: Natural sources of radiation are mentioned below:
In natural sources of radioactive pollution, atomic radioactive minerals are one among them.
Cosmic rays possess high energy ionizing electromagnetic radiation.
Another source of radioactive radiation is naturally occurring radioisotopes. Radioisotopes are found in soil in small quantity.
Radioactive elements like radium, thorium, uranium, isotopes of potassium and carbon occur in lithosphere
Anthropogenic sources of radiation
Human activities mentioned below include in sources of radioactive pollution:
Nuclear tests
Nuclear reactors
Diagnostic medical applications
Nuclear Wastes
Nuclear explosions
Nuclear metal processing
Nuclear Reactor Accidents
Almost 99 such nuclear accidents have been occur through out worldwide. 56 of 99,have been occurred only in USA.
Kyshtym, Russia (former Soviet Union) – 29,september,1957 (INES Level 6)
200 people died on direct radiation and almost 8000 people died in 32 years of this nuclear accidents
Major nuclear accidents
Three Mile Island, United States – 28 March, 1979 (INES Level 5)
one of the elements of the power plant’s system malfunctioned
Chernobyl, Ukraine (former Soviet Union) – 26,april,1986 (INES Level 7)
A series of events led to the explosion of the reactor number four at the Chernobyl Nuclear Power Plant
Fukushima, Japan –11,march 2011 (INES Level 7)
9.0 magnitude earthquake struck off the coast of Japan. The resulting tsunami (49 feet tall) hit the Fukushima I Nuclear Power Plant 51 and experienced meltdown
NUCLEAR BOMBS
August 6, 1945, Hiroshima
directly killing an estimated 80,000 people. By the end of the year, injury and radiation brought total casualties to 90,000–140,000
On August 9, 1945, Nagasaki
Almost 75,000 people died and more affected by radiation.
Radiation Health Effects
Radionuclides are carcinogens and at high doses can also cause rapid sickness and death.
The health effects of exposure to radiation depend on many factors.
the amount of energy it deliver
the length of exposure time
the organs and tissues exposed
characteristics of the exposed person
How does radiation injure people?
High energy radiation breaks chemical bonds.
This creates free radicals, like those produced by other insults as well as by normal cellular processes in the body.
The free radicals can change chemicals in the body.
These changes can disrupt cell function and may kill cells.
1. Radiation is energy that travels through space in the form of waves or particles. There are two main types: ionizing radiation which can disrupt atoms and molecules, and non-ionizing radiation which does not have enough energy to do so.
2. Sources of radiation include natural background radiation like cosmic rays from space, radioactive elements in the ground and air, and internal radioactive isotopes in the body. Man-made sources include medical x-rays, nuclear power plants, consumer products, and fallout from nuclear weapons tests and disasters.
3. Ionizing radiation includes alpha particles, beta particles, gamma rays, and x-rays. They are able to ionize or change atoms and molecules and
This document summarizes different types of radiation sources. It discusses natural background radiation from cosmic rays, terrestrial sources like uranium and thorium in soil, and internal radiation from radioactive materials inside the body. It also describes man-made sources of radiation used in medicine for diagnostic imaging and cancer treatment, as well as other applications in industry. The document provides context on radiation risk and exposure limits set based on natural background levels.
1. Radioactivity can be detected using photographic film or a Geiger-Muller detector. Background radiation comes from natural sources like radon gas emanating from rocks and internal radiation from radioactive elements inside our bodies.
2. The activity of a radioactive source is measured in becquerels and refers to the number of decays per second. It decreases over time as the radioactive material decays. Half-life refers to the time it takes for half the radioactive material or nuclei to decay and is different for each isotope.
3. Calculating half-lives involves determining the amount of radioactive material or activity remaining after set time periods equal to the half-life. Graphing the decay of an isotope over time can also
This document discusses radioactive pollution and nuclear accidents. It begins with an overview of topics to be covered, including radiation, sources of radioactive pollution, types of radioactive pollution, effects of radiation exposure, nuclear energy, nuclear hazards and accidents, and prevention measures. It then covers radiation and its sources, natural sources of radiation like cosmic rays and terrestrial radiation, and artificial sources like nuclear power plants and medical waste. It discusses the types, toxicity and health effects of radioactive pollution. The document provides a brief history of nuclear energy and accidents like Chernobyl and Fukushima. It concludes with suggestions for preventing radioactive pollution like proper waste disposal and regular monitoring.
Radioactive pollution is defined as the release of radioactive substances or particles into the environment from human activities like nuclear weapon testing, nuclear power plants, or accidents. It can cause serious health effects like cancer due to radiation exposure and remains toxic for centuries. Sources include natural processes like radioactive minerals as well as human activities involving nuclear materials, weapons, power plants, and medical isotopes. Effects range from acute radiation sickness to long-term mutations and increased cancer risks. Monitoring, safe waste disposal, and prevention of leaks and accidents are important for controlling radioactive pollution.
Nuclear engineering harnesses the power of the atom to do work. It involves understanding nuclear physics principles like fission and fusion, designing and operating nuclear reactors, developing nuclear medicine applications, ensuring nuclear non-proliferation, and managing radioactive waste. Some key areas of nuclear engineering include power generation, weapons development, space applications, medical imaging and treatment, food irradiation, and more. Nuclear engineers work in government, national labs, power companies, the military, medicine, and academia developing and overseeing applications of nuclear technology.
- There are two main systems for measuring radiation - the conventional US system and the International System of Units (SI).
- Radioactivity is measured in curies (Ci) in the US system and becquerels (Bq) in the SI system. 1 Ci equals 37 billion Bq.
- Exposure rate is measured in roentgens (R) per hour in the US system. The SI unit is the coulomb per kilogram (C/kg).
- Absorbed dose is measured in rads in the US system and grays (Gy) in the SI system. 1 Gy is equal to 100 rads.
The Chernobyl nuclear disaster of 1986 was the worst nuclear power plant accident in history. On April 26, 1986, a reactor explosion at the Chernobyl Nuclear Power Plant in Ukraine released large amounts of radioactive material into the atmosphere. Over 100,000 people had to be evacuated and large areas became contaminated with radiation. Long term impacts included increased cancer rates, environmental contamination, and economic impacts due to agricultural and land restrictions.
Radioactive pollution occurs when radioactive materials are released into the environment through natural processes like radioactive decay of elements in the Earth's crust, interaction of cosmic rays in the atmosphere, and background radioactivity in seawater. Anthropogenic sources of radioactive pollution include nuclear weapons testing, nuclear waste disposal, operations of nuclear power plants, and improper storage and disposal of radioactive materials. The radioactive pollution can enter the food chain and pose health risks to organisms and humans through ingestion of contaminated food and water over time. Proper methods for disposing, storing, labeling and reusing radioactive waste, banning nuclear weapons tests, utilizing alternative energy sources, and individual precautions can help reduce radioactive pollution.
Ionising radiation is radiation that has sufficient energy to cause ionisation by removing electrons from atoms. It includes alpha particles, beta particles, gamma rays, X-rays, protons and neutrons. Ionising radiation can come from natural sources like radon gas or cosmic rays, or artificial sources like medical X-rays. Different types of ionising radiation penetrate tissue to different degrees and can be absorbed through the skin, inhaled or ingested, posing greater or lesser health risks depending on the dose and radiation type.
Nuclear reactors carry risks of accidents and radiation exposure that can harm human health and the environment. Major accidents like Chernobyl and Fukushima have caused widespread contamination and required large evacuations. While nuclear waste is small in volume compared to fossil fuels, it remains highly radioactive for extremely long periods and requires careful disposal. New reactor designs aim to reduce risks through passive safety systems and using alternative fuels like uranium-238 that produce less long-lived waste. Public education about radiation risks and emergency plans is also important to prevent overreaction during accidents.
This document discusses nuclear hazards and radioactive waste. It begins by defining nuclear elements and different types of radiation such as alpha, beta, and gamma particles. It then discusses nuclear power generation and major forms of nuclear fuels. The remainder of the document focuses on nuclear waste, including definitions and types of low-level, intermediate-level, and high-level waste. It describes storage, disposal, and transportation of nuclear waste, as well as international scales for nuclear events. Finally, it discusses some human health risks of radiation such as radiation sickness, cancer, and genetic mutations.
This document provides an overview of fundamentals of radiation protection including:
- Atomic definitions such as isotope identification, activity, and half-life.
- Common types of radioactive decay including alpha, beta, positron, and gamma emissions.
- Units used to measure radiation exposure such as becquerel and curie.
- Key factors that reduce radiation exposure including distance, shielding, and time.
- Biological effects of radiation exposure and typical annual radiation doses from various sources.
- Regulations for radiation exposure limits set by organizations like the ICRP.
CHL308_Radioactive Waste And Its Disposal.pptHajiAdeel1
This document discusses radioactive waste and its disposal. It defines radioactive waste as waste that emits rays, waves or particles. It describes the types of radioactive waste including low, intermediate and high level waste. It outlines sources of radioactive waste such as nuclear power plants, medical facilities, and naturally occurring materials. The document then discusses the health risks of exposure to radioactive waste and various proposed methods for disposal, including deep geological repositories and ocean dumping. It notes the complex regulatory environment surrounding radioactive waste management and concludes that radioactive waste poses long-term challenges due to its persistence.
Radioactive waste comes from various sources and poses health and environmental risks if not properly disposed of. There are different types of radioactive waste - low, intermediate, and high level - which require different handling and disposal methods due to varying levels of radioactivity. Common disposal methods include deep geological repositories, sub-seabed burial, and space disposal. Proper management of radioactive waste is important to isolate it and prevent negative impacts on humans and the environment.
Anti-Universe And Emergent Gravity and the Dark UniverseSérgio Sacani
Recent theoretical progress indicates that spacetime and gravity emerge together from the entanglement structure of an underlying microscopic theory. These ideas are best understood in Anti-de Sitter space, where they rely on the area law for entanglement entropy. The extension to de Sitter space requires taking into account the entropy and temperature associated with the cosmological horizon. Using insights from string theory, black hole physics and quantum information theory we argue that the positive dark energy leads to a thermal volume law contribution to the entropy that overtakes the area law precisely at the cosmological horizon. Due to the competition between area and volume law entanglement the microscopic de Sitter states do not thermalise at sub-Hubble scales: they exhibit memory effects in the form of an entropy displacement caused by matter. The emergent laws of gravity contain an additional ‘dark’ gravitational force describing the ‘elastic’ response due to the entropy displacement. We derive an estimate of the strength of this extra force in terms of the baryonic mass, Newton’s constant and the Hubble acceleration scale a0 = cH0, and provide evidence for the fact that this additional ‘dark gravity force’ explains the observed phenomena in galaxies and clusters currently attributed to dark matter.
CLASS 12th CHEMISTRY SOLID STATE ppt (Animated)eitps1506
Description:
Dive into the fascinating realm of solid-state physics with our meticulously crafted online PowerPoint presentation. This immersive educational resource offers a comprehensive exploration of the fundamental concepts, theories, and applications within the realm of solid-state physics.
From crystalline structures to semiconductor devices, this presentation delves into the intricate principles governing the behavior of solids, providing clear explanations and illustrative examples to enhance understanding. Whether you're a student delving into the subject for the first time or a seasoned researcher seeking to deepen your knowledge, our presentation offers valuable insights and in-depth analyses to cater to various levels of expertise.
Key topics covered include:
Crystal Structures: Unravel the mysteries of crystalline arrangements and their significance in determining material properties.
Band Theory: Explore the electronic band structure of solids and understand how it influences their conductive properties.
Semiconductor Physics: Delve into the behavior of semiconductors, including doping, carrier transport, and device applications.
Magnetic Properties: Investigate the magnetic behavior of solids, including ferromagnetism, antiferromagnetism, and ferrimagnetism.
Optical Properties: Examine the interaction of light with solids, including absorption, reflection, and transmission phenomena.
With visually engaging slides, informative content, and interactive elements, our online PowerPoint presentation serves as a valuable resource for students, educators, and enthusiasts alike, facilitating a deeper understanding of the captivating world of solid-state physics. Explore the intricacies of solid-state materials and unlock the secrets behind their remarkable properties with our comprehensive presentation.
Candidate young stellar objects in the S-cluster: Kinematic analysis of a sub...Sérgio Sacani
Context. The observation of several L-band emission sources in the S cluster has led to a rich discussion of their nature. However, a definitive answer to the classification of the dusty objects requires an explanation for the detection of compact Doppler-shifted Brγ emission. The ionized hydrogen in combination with the observation of mid-infrared L-band continuum emission suggests that most of these sources are embedded in a dusty envelope. These embedded sources are part of the S-cluster, and their relationship to the S-stars is still under debate. To date, the question of the origin of these two populations has been vague, although all explanations favor migration processes for the individual cluster members. Aims. This work revisits the S-cluster and its dusty members orbiting the supermassive black hole SgrA* on bound Keplerian orbits from a kinematic perspective. The aim is to explore the Keplerian parameters for patterns that might imply a nonrandom distribution of the sample. Additionally, various analytical aspects are considered to address the nature of the dusty sources. Methods. Based on the photometric analysis, we estimated the individual H−K and K−L colors for the source sample and compared the results to known cluster members. The classification revealed a noticeable contrast between the S-stars and the dusty sources. To fit the flux-density distribution, we utilized the radiative transfer code HYPERION and implemented a young stellar object Class I model. We obtained the position angle from the Keplerian fit results; additionally, we analyzed the distribution of the inclinations and the longitudes of the ascending node. Results. The colors of the dusty sources suggest a stellar nature consistent with the spectral energy distribution in the near and midinfrared domains. Furthermore, the evaporation timescales of dusty and gaseous clumps in the vicinity of SgrA* are much shorter ( 2yr) than the epochs covered by the observations (≈15yr). In addition to the strong evidence for the stellar classification of the D-sources, we also find a clear disk-like pattern following the arrangements of S-stars proposed in the literature. Furthermore, we find a global intrinsic inclination for all dusty sources of 60 ± 20◦, implying a common formation process. Conclusions. The pattern of the dusty sources manifested in the distribution of the position angles, inclinations, and longitudes of the ascending node strongly suggests two different scenarios: the main-sequence stars and the dusty stellar S-cluster sources share a common formation history or migrated with a similar formation channel in the vicinity of SgrA*. Alternatively, the gravitational influence of SgrA* in combination with a massive perturber, such as a putative intermediate mass black hole in the IRS 13 cluster, forces the dusty objects and S-stars to follow a particular orbital arrangement. Key words. stars: black holes– stars: formation– Galaxy: center– galaxies: star formation
(June 12, 2024) Webinar: Development of PET theranostics targeting the molecu...Scintica Instrumentation
Targeting Hsp90 and its pathogen Orthologs with Tethered Inhibitors as a Diagnostic and Therapeutic Strategy for cancer and infectious diseases with Dr. Timothy Haystead.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
Immersive Learning That Works: Research Grounding and Paths ForwardLeonel Morgado
We will metaverse into the essence of immersive learning, into its three dimensions and conceptual models. This approach encompasses elements from teaching methodologies to social involvement, through organizational concerns and technologies. Challenging the perception of learning as knowledge transfer, we introduce a 'Uses, Practices & Strategies' model operationalized by the 'Immersive Learning Brain' and ‘Immersion Cube’ frameworks. This approach offers a comprehensive guide through the intricacies of immersive educational experiences and spotlighting research frontiers, along the immersion dimensions of system, narrative, and agency. Our discourse extends to stakeholders beyond the academic sphere, addressing the interests of technologists, instructional designers, and policymakers. We span various contexts, from formal education to organizational transformation to the new horizon of an AI-pervasive society. This keynote aims to unite the iLRN community in a collaborative journey towards a future where immersive learning research and practice coalesce, paving the way for innovative educational research and practice landscapes.
Describing and Interpreting an Immersive Learning Case with the Immersion Cub...Leonel Morgado
Current descriptions of immersive learning cases are often difficult or impossible to compare. This is due to a myriad of different options on what details to include, which aspects are relevant, and on the descriptive approaches employed. Also, these aspects often combine very specific details with more general guidelines or indicate intents and rationales without clarifying their implementation. In this paper we provide a method to describe immersive learning cases that is structured to enable comparisons, yet flexible enough to allow researchers and practitioners to decide which aspects to include. This method leverages a taxonomy that classifies educational aspects at three levels (uses, practices, and strategies) and then utilizes two frameworks, the Immersive Learning Brain and the Immersion Cube, to enable a structured description and interpretation of immersive learning cases. The method is then demonstrated on a published immersive learning case on training for wind turbine maintenance using virtual reality. Applying the method results in a structured artifact, the Immersive Learning Case Sheet, that tags the case with its proximal uses, practices, and strategies, and refines the free text case description to ensure that matching details are included. This contribution is thus a case description method in support of future comparative research of immersive learning cases. We then discuss how the resulting description and interpretation can be leveraged to change immersion learning cases, by enriching them (considering low-effort changes or additions) or innovating (exploring more challenging avenues of transformation). The method holds significant promise to support better-grounded research in immersive learning.
ESA/ACT Science Coffee: Diego Blas - Gravitational wave detection with orbita...Advanced-Concepts-Team
Presentation in the Science Coffee of the Advanced Concepts Team of the European Space Agency on the 07.06.2024.
Speaker: Diego Blas (IFAE/ICREA)
Title: Gravitational wave detection with orbital motion of Moon and artificial
Abstract:
In this talk I will describe some recent ideas to find gravitational waves from supermassive black holes or of primordial origin by studying their secular effect on the orbital motion of the Moon or satellites that are laser ranged.
The debris of the ‘last major merger’ is dynamically youngSérgio Sacani
The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the
‘last major merger.’ Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor
collided with the MW proto-disc 8–11 Gyr ago, and the Virgo Radial Merger (VRM), where the progenitor collided with the
MW disc within the last 3 Gyr. These two scenarios make different predictions about observable structure in local phase space,
because the morphology of debris depends on how long it has had to phase mix. The recently identified phase-space folds in Gaia
DR3 have positive caustic velocities, making them fundamentally different than the phase-mixed chevrons found in simulations
at late times. Roughly 20 per cent of the stars in the prograde local stellar halo are associated with the observed caustics. Based
on a simple phase-mixing model, the observed number of caustics are consistent with a merger that occurred 1–2 Gyr ago.
We also compare the observed phase-space distribution to FIRE-2 Latte simulations of GSE-like mergers, using a quantitative
measurement of phase mixing (2D causticality). The observed local phase-space distribution best matches the simulated data
1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’
did not collide with the MW proto-disc at early times, as is thought for the GSE, but instead collided with the MW disc within
the last few Gyr, consistent with the body of work surrounding the VRM.
Evidence of Jet Activity from the Secondary Black Hole in the OJ 287 Binary S...Sérgio Sacani
Wereport the study of a huge optical intraday flare on 2021 November 12 at 2 a.m. UT in the blazar OJ287. In the binary black hole model, it is associated with an impact of the secondary black hole on the accretion disk of the primary. Our multifrequency observing campaign was set up to search for such a signature of the impact based on a prediction made 8 yr earlier. The first I-band results of the flare have already been reported by Kishore et al. (2024). Here we combine these data with our monitoring in the R-band. There is a big change in the R–I spectral index by 1.0 ±0.1 between the normal background and the flare, suggesting a new component of radiation. The polarization variation during the rise of the flare suggests the same. The limits on the source size place it most reasonably in the jet of the secondary BH. We then ask why we have not seen this phenomenon before. We show that OJ287 was never before observed with sufficient sensitivity on the night when the flare should have happened according to the binary model. We also study the probability that this flare is just an oversized example of intraday variability using the Krakow data set of intense monitoring between 2015 and 2023. We find that the occurrence of a flare of this size and rapidity is unlikely. In machine-readable Tables 1 and 2, we give the full orbit-linked historical light curve of OJ287 as well as the dense monitoring sample of Krakow.
6. • Japanese Fukushima nuclear disaster (2011 )
• shut down the nation's 54 nuclear power
plants.
• 2013 repots - highly radioactive, with some
160,000 evacuees still living in temporary
housing.
• Some land will be unfarmable for centuries.
• The difficult cleanup job will take 40 or more
years
• Cost tens of billions of dollars
7. • Fukushima Daichi, March 11, 2011
An 8.9 magnitude earthquake and subsequent
tsunami overwhelmed the cooling systems of an
aging reactor along Japan's northeast coastline. The
accident triggered explosions at several reactors at
the complex, forcing a widespread evacuation in the
area around the plant.
8. August 10. 1985, Russia, the Echo II class submarine
suffered an explosion, sending a radioactive cloud of gas
into the air. Ten sailors were killed in the incident and 49
people were observed to have radiation injuries.
9. The abandoned city of Prypiat, Ukraine,
Chernobyl disaster, Russia (1986).
10. • One of the worst nuclear accidents till date.
• The accident killed 30 people directly and damaged
approximately $7 billion of property.
• A study published in 2005 estimates that there will
eventually be up to 4,000 additional cancer deaths
related to the accident among those exposed to
significant radiation levels.
• Radioactive fallout from the accident was concentrated
in areas of Belarus, Ukraine and Russia. Approximately
350,000 people were forcibly resettled away from these
areas soon after the accident.
11. • Chernobyl, April 26, 1986
The Chernobyl disaster is considered to be the worst
nuclear power plant disaster in history. On the
morning of April 26, 1986, reactor number four at
the Chernobyl plant exploded. More explosions
ensued, and the fires that resulted sent radioactive
fallout into the atmosphere. Four hundred times
more fallout was released than had been by the
atomic bombing of Hiroshima.
12. Mushroom cloud from the atomic explosion over
Nagasaki, Japan rising 60,000 feet into the air on the
morning of August 9, 1945.
13. • On August 6, 1945, the uranium-type nuclear weapon,
code named "Little Boy" was detonated
over Hiroshima with an energy of about 15 kilotons of
TNT
• Destroying nearly 50,000 buildings and killing
approximately 70,000 people.
• On August 9, a plutonium-type nuclear weapon code
named "Fat Man" was used against the Japanese city of
Nagasaki with the explosion equivalent to about 20
kilotons of TNT.
• Approximately 35,000 people killed.
14. What is radioactivity?
Nuclear decay or radioactivity, is the process by
which a nucleus of an unstable atom loses energy
by emitting ionizing radiation.
A material that spontaneously emits this kind of
radiation which includes the emission of alpha
particles, beta particles, gamma
rays and conversion electrons
16. Why are elements radioactive?
Unstable nucleus:
• Has excess energy.
• Wants to go to “ground
state.”
• Becomes stable by emitting
ionizing radiation.
17. Alpha Particles (2n, 2p)
Beta Particles (e- or +)
Photons (hv)
(x or gamma rays)
Paper Concrete
Radiation Types
18. Dr Manjunatha S, CCIS
Three Common Types of Radioactive
Emissions
Alpha
Beta
Gamma
20. Half life and mean life
Half-life is the time required for half of the atoms
of a radioactive material to decay to another
nuclear form.
Mean life is average of all half lives
21. (i) Primordial Radionuclides
That radionuclides that are present since the creation of earth
and having long half-lives, e.g. 210Pb, 226Ra, K40
(ii) Cosmogenic Radionuclides
That radionuclides that are produced in the upper
atmosphere as a result of cosmic rays interaction with light
particles (carbon, Nitrogen and Oxygen), e.g. C14, 7Be, 22Na,
32P, 32S
(iii)Anthropogenic Radionuclides
That radionuclides that are produced as a result of man-made
activities such as nuclear fuel fabrication, enrichment, nuclear
power generation, nuclear accidents etc., e.g. 137Cs, 134Cs, 131I,
90Sr etc.
Sources of radioactivity
22. Units of Radioactivity
• The Becquerel (Bq): Disintegration per second, dps
• The curie (Ci)
1 Ci = 37,000,000,000 Bq
so 1 mCi = 37 MBq; and 1 µCi = 37 kBq
• rem: Rem is the term used to describe equivalent
or effective radiation dose.
• In the International System of Units, the Sievert
(Sv) describes equivalent or effective radiation
dose. One Sievert is equal to 100 rem.
23. Natural background radiation
• The natural radiation energy between few KeV to MeV
from primordial radionuclides are called background
radiation.
• Background radiation is of terrestrial and extra-
terrestrial origin.
PLANTS
ATMOSPHERE
SOURCE (BEDROCK) MAN, ANIMALS
SOILS
24. 1. Terrestrial radiation components
• The terrestrial component originates from primordial
radionuclides in the earth’s crust, present in varying
amount.
• Components of three chains of natural radioactive
elements viz. the uranium series, the thorium and
actinium series.
• 238U, 226Ra, 232Th, 228Ra, 210Pb, 210Po, and 40K,
contribute significantly to natural background
radiation.
25. 2. Extra terrestrial radiation
• Among the singly occurring radionuclides tritium and
carbon-14 (produced by cosmic ray interactions) and
40K (terrestrial origin) are prominent.
• Radionuclides from these sources are transferred
to man through food chains or inhalation.
1. Terrestrial radiation components contd…
• The extra terrestrial radiation originates in outer space
as primary cosmic rays.
• The primary cosmic rays mainly comprise charged
particles, ionised nuclei of heavy metals and intense
electromagnetic radiation.
26. 3. Artificial Radionuclides
• Over the last few decades man has artificially
produced hundreds of radionuclides.
• Artificial radioisotopes to the atmosphere during the
course of operation of the nuclear fuel cycle, nuclear
tests (mainly atmospheric) and nuclear accidents
• Most of the artificial radioisotopes decay -short half-
lives. Therefore only a few of them are significant
from the point of human exposure.
27. Radon
• Radon is a radioactive gas decay product of radium,
created during the natural breakdown of uranium in
rocks and soils
• It is one of the heaviest substances that remains a
gas under normal conditions and is considered to be
a health hazard causing cancer
• It has three isotopes, namely, 222Rn (238U), 220Rn
(232Th) and 219Rn (235U). 222Rn has longer half life
(3.84 days) than the other two isotopes
28. Radon in Buildings
There are two main sources for the radon in home's
indoor air, soil and water supply.
31. Dr Manjunatha S, CCIS
Radioactivity – is it a health problem?
• The Alpha, Beta and Gamma particles all add energy
to the body’s tissues. The effect is called the Ionizing
Energy. It can alter DNA.
• Even though Alpha particles are not very penetrative
if the decaying atom is already in the body
(inhalation, ingestion) they can cause trouble.
33. External Dose
Radiation Dose
Dose or radiation dose is a generic term for a measure of
radiation exposure. In radiation protection, dose is
expressed in millirem.
X-Ray
Machine
Image (film)
After
Radiation dose (single chest x
ray = 5-10 mrem).
34. Contamination
Contamination is the presence of a radioactive
material in any place where it is not desired,
and especially in any place where
its presence could be harmful.
Yuck!
35. The radium dial painters
• Watch-dial painters - United States Radium factory in Orange,
New Jersey, around 1917 .
• The Radium Girls (4000) were female factory workers who
contracted radiation poisoning from painting watch dials
withself-luminous paint.
• They were used to tip (i.e., bring to the lips) their radium-laden
brushes to achieve a fine point.
• Unfortunately this practice led to ingested radium, and many of
the women died of sicknesses related to radiation poisoning.
• The paint dust also collected on the workers, causing them to
“glow in the dark.”
• Some also painted their fingernails and teeth with the glowing
substance.
36.
37.
38.
39. Who’s the Famous “Madame” of
Radiological Fame?
Marie Curie
• With her husband
Pierre, discovered
radium and coined the
term “radioactive”
• First woman to win
two Nobel Prizes
40. 40
Medical Applications
Radioisotopes with short
half-lives are used in nuclear
medicine because they have
the same chemistry in the
body as the nonradioactive
atoms.
• In the organs of the body,
they give off radiation that
exposes a scan giving an
image of an organ.
Thyroid scan
41. To find the location of a leak in a shallowly buried
pipe without excavation
42. Leak Detection
This use of radionuclide tracers to find leaks or flow
paths has wide applications:
Finding the location of leaks in oil-well casings,
Determining the tightness of abandoned slate
quarries for the temporary storage of oil,
Locating the positions of leaks in refrigeration coils,
Finding leaks in heat exchanger piping,
Locating leaks in engine seals.
43. Thickness control
The manufacture of aluminium foil, β emitter is placed above the foil and a
detector below it.
Some β particle will penetrate the foil and the amount of radiation is
monitored by the computer.
The computer will send a signal to the roller to make the gap smaller or
bigger based on the count rate
44. Living Tissue 14C/12C, Tissue ratio same as atmospheric ratio
Dead Tissue 14C/12C < 14C/12C, tissue ratio is less than atmosphere
p
C
n
N
14
14
t ½ = 5730 yr.
45. 45
Mummified remains found frozen in the
Italian Alps
At least 5000 years old By carbon-
14 dating
In 1991, hikers discovered the body of a
prehistoric hunter that had been
entombed in glacial ice until the ice
recently moved and melted.
46. Space Exploration
Radioisotope Thermoelectric Generator (RTG)
If two dissimilar metals were joined at two
locations that were maintained at different
temperatures, an electric current would flow in a
loop.
In an RTG, the decay of a radioisotope fuel
provides heat to the “hot” junction, while the other
junction uses radiation heat transfer to outer
space to maintain itself as the “cold” junction.
48. An RTG loaded with 1 kilogram of plutonium (238) dioxide fuel
would generate between 21 and 29 watts of electric power for
the spacecraft.
After five years of travel through space, this plutonium-fueled
RTG would still have approximately 96 percent of its original
thermal power level available for the generation to electric
power
49. Power Generation
Nuclear power
supplies 19.4 percent
of energy in the
United States.
There are 104
nuclear power plants
in the United States.
Photo by Karen Sheehan
50.
51.
52. Nuclear Medicine
Diagnostic Procedures
• Short half-life
radioactive injection
• Pictures taken with
special gamma camera
• Many different studies:
Thyroid
Lung
Cardiac
White Blood Cell
Photo by Karen Sheehan
60. Preservation of food and agricultural product by
radiation
An alternate method of food preservation by irradiation
of X ray or gamma rays.
It is used to prolong the shelf life of many food and
agricultural products, destroy bacteria and
microorganisms in food (pre packed or bulk) and
grains(rice, corn..).
The food exposed to controlled amount of ionizing
radiation in shielded area for a specific time to achieve
desirable objectives.
The sources are gamma rays from Cobalt 60 or Cesium
137, X-rays up to 5 MeV or electron accelerators up to 10
MeV.
61. Does the irradiation process make food
radioactive?
Irradiation under controlled condition does not
make food radioactive.
Irradiation involves passing the food through
and allow to absorb desired radiation energy.
Radiation processing of food do not induce any
radioactivity.
69. Dentures
• Uranium is added to false teeth to provide a shine
to the material (about 10% of the teeth)
• Concentration of uranium is quite low – about
300 parts per million
71. Annual Radiation Dose Limits
General Public vs. Occupational
Established by the
Nuclear Regulatory Commission
• General Public Limit - 100 mrem
• Occupational Limit - 5,000 mrem
Remember – We get approximately 300 mrem per year from
natural background exposure.
72. For more information about radiation you may
contact the Health Physics Society.
Health Physics Society
Specialists in Radiation Safety
http://www.HPS.org
73. Additional References
• Hall E. Radiation and life, 2nd ed. New York:
Pergamon Press; 1984.
• Bushong SC. Radiologic science for technologists, 7th
ed. St Louis, MO: Mosby, Inc.; 2001.