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Glossary Derived From: Human Research Program Integrated Research Plan, Revision A, (January 2009)
Glossary derived from: Human Research Program Integrated Research Plan, Revision A, (January 2009). National Aeronautics and Space Administration, Johnson Space Center, Houston, Texas 77058, pages 232-280. Report No. 153: Information Needed to Make Radiation Protection Recommendations for Space Missions Beyond Low-Earth Orbit (2006). National Council on Radiation Protection and Measurements, pages 309-318. Reprinted with permission of the National Council on Radiation Protection and Measurements, http://NCRPonline.org . Managing Space Radiation Risk in the New Era of Space Exploration (2008). Committee on the Evaluation of Radiation Shielding for Space Exploration, National Research Council. National Academies Press, pages 111-118. -A- AAPM: American Association of Physicists in Medicine. absolute risk: Expression of excess risk due to exposure as the arithmetic difference between the risk among those exposed and that obtaining in the absence of exposure. absorbed dose (D): Average amount of energy imparted by ionizing particles to a unit mass of irradiated material in a volume sufficiently small to disregard variations in the radiation field but sufficiently large to average over statistical fluctuations in energy deposition, and where energy imparted is the difference between energy entering the volume and energy leaving the volume. The same dose has different consequences depending on the type of radiation delivered. Unit: gray (Gy), equivalent to 1 J/kg. ACE: Advanced Composition Explorer Mission, launched in 1997 and orbiting the L1 libration point to sample energetic particles arriving from the Sun and interstellar and galactic sources. It also provides continuous coverage of solar wind parameters and solar energetic particle intensities (space weather). When reporting space weather, it can provide an advance warning (about one hour) of geomagnetic storms that can overload power grids, disrupt communications on Earth, and present a hazard to astronauts. -
Cherenkov Radiation
TheThe CherenkovCherenkov effecteffect A charged particle traveling in a dielectric medium with n>1 radiates Cherenkov radiation B Wave front if its velocity is larger than the C phase velocity of light v>c/n or > 1/n (threshold) A β Charged particle The emission is due to an asymmetric polarization of the medium in front and at the rear of the particle, giving rise to a varying electric dipole momentum. dN Some of the particle energy is convertedγ = 491into light. A coherent wave front is dx generated moving at velocity v at an angle Θc If the media is transparent the Cherenkov light can be detected. If the particle is ultra-relativistic β~1 Θc = const and has max value c t AB n 1 cosθc = = = In water Θc = 43˚, in ice 41AC˚ βct βn 37 TheThe CherenkovCherenkov effecteffect The intensity of the Cherenkov radiation (number of photons per unit length of particle path and per unit of wave length) 2 2 2 2 2 Number of photons/L and radiation d N 4π z e 1 2πz 2 = 2 1 − 2 2 = 2 α sin ΘC Wavelength depends on charge dxdλ hcλ n β λ and velocity of particle 2πe2 α = Since the intensity is proportional to hc 1/λ2 short wavelengths dominate dN Using light detectors (photomultipliers)γ = sensitive491 in 400-700 nm for an ideally 100% efficient detector in the visibledx € 2 dNγ λ2 d Nγ 2 2 λ2 dλ 2 2 11 1 22 2 d 2 z sin 2 z sin 490393 zz sinsinΘc photons / cm = ∫ λ = π α ΘC ∫ 2 = π α ΘC 2 −− 2 = α ΘC λ1 λ1 dx dxdλ λ λλ1 λ2 d 2 N d 2 N dλ λ2 d 2 N = = dxdE dxdλ dE 2πhc dxdλ Energy loss is about 104 less hc 2πhc than 2 MeV/cm in water from € -
Estimation of the Collective Effective Dose to the Population from Medical X-Ray Examinations in Finland
Estimation of the collective effective dose to the population from medical x-ray examinations in Finland Petra Tenkanen-Rautakoskia, Hannu Järvinena, Ritva Blya aRadiation and Nuclear Safety Authority (STUK), PL 14, 00880 Helsinki, Finland Abstract. The collective effective dose to the population from all x-ray examinations in Finland in 2005 was estimated. The numbers of x-ray examinations were collected by a questionnaire to the health care units (response rate 100 %). The effective doses in plain radiography were calculated using a Monte Carlo based program (PCXMC), as average values for selected health care units. For computed tomography (CT), weighted dose length product (DLPw) in a standard phantom was measured for routine CT protocols of four body regions, for 80 % of CT scanners including all types. The effective doses were calculated from DPLw values using published conversion factors. For contrast-enhanced radiology and interventional radiology, the effective dose was estimated mainly by using published DAP values and conversion factors for given body regions. About 733 examinations per 1000 inhabitants (excluding dental) were made in 2005, slightly less than in 2000. The proportions of plain radiography, computed tomography, contrast-enhanced radiography and interventional procedures were about 92, 7, 1 and 1 %, respectively. From 2000, the frequencies (number of examinations per 1000 inhabitants) of plain radiography and contrast-enhanced radiography have decreased about 8 and 33 %, respectively, while the frequencies of CT and interventional radiology have increased about 28 and 38 %, respectively. The population dose from all x-ray examinations is about 0,43 mSv per person (in 1997 0,5 mSv). -
THE COLLECTIVE EFFECTIVE DOSE RESULTING from RADIATION EMITTED DURING the FIRST WEEKS of the FUKUSHIMA DAIICHI NUCLEAR ACCIDENT Matthew Mckinzie, Ph.D
THE COLLECTIVE EFFECTIVE DOSE RESULTING FROM RADIATION EMITTED DURING THE FIRST WEEKS OF THE FUKUSHIMA DAIICHI NUCLEAR ACCIDENT Matthew McKinzie, Ph.D. and Thomas B. Cochran, Ph.D., Natural Resources Defense Council April 10, 2011 The Magnitude 9.0 earthquake off Japan’s Pacific Coast, which was the initiating event for accidents at four of the six reactors at the Fukushima Daiichi nuclear power plant, occurred at 14:46 local time on March 11th. At 15:41 a tsunami hit the plant and a station blackout ensued. A reconstruction of the accident progression by Areva1 posited that the final option for cooling the reactors – the reactor core isolation pumps – failed just hours later in Unit 1 (at 16:36), failed in the early morning of March 13th in Unit 3 (at 02:44), and failed early in the afternoon of March 14th in Unit 2 (at 13:25). Radiological releases spiked beginning on March 15th and in the Areva analysis are attributed to the venting of the reactor pressure vessels, explosion in Unit 2, and – significantly – explosion and fire in Unit 4. Fuel had been discharged from the Unit 4 reactor core to the adjacent spent fuel pool on November 30, 2010, raising the possibility of a core melt “on fresh air.” The Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT) has posted hourly dose rates by prefecture2 on its website. We do not currently know the geographic coordinates of these radiation monitoring sites. The English language versions of the hourly dose rate measurements by prefecture begin in table form at 17:00 on March 16th, and hourly dose rates are provided as charts3 beginning at 00:00 on March 14th. -
Individual and Collective Dose Limits and Radionuclide Release Limits
UNITED STATES NUCLEAR REGULATORY COMMISSION ADVISORY COMMITTEE ON NUCLEAR WASTE WASHINGTON, D.C. 20555 April 29, 1991 r' Mr. Robert M. Bernero, Director Office of Nuclear Material Safety and Safeguards u.s. Nuclear Regulatory Commission Washington, DC 20555 Dear Mr. Bernero: SUBJECT: INDIVIDUAL AND COLLECTIVE DOSE LIMITS AND RADIONUCLIDE RELEASE LIMITS The Advisory Committee . on Nuclear waste has been developing comments, thoughts, and suggestions relative to individual and collective dose limits and radionuclide release limits. Since we understand that your staff is reviewing these same topics, we wanted to share our thoughts with you. In formulating these comments, we have had discussions with a number of people, including members of the NRC staff and Committee consultants. The Committee also had the benefit of the documents listed. Basic Definitions As a basic philosophy, individual dose limits are used to place restrictions on the risk to individual members of the public due to operations at a nuclear facility. If the limits have been properly established and compliance is observed, a regulatory agency can be confident that the associated risk to individual members of the pUblic is acceptable. Because the determination of the dose to individual members of the pUblic is difficult, the International Commission on Radiological Protection (ICRP) has developed the concept of the "critical group" and recommends that it be used in assessing doses resulting from environmental releases. As defined by the ICRP, a critical group is a relatively homogeneous group of people whose location and living habits are such that they receive the highest doses as a result of radio nuclide releases. -
Nuclear Glossary
NUCLEAR GLOSSARY A ABSORBED DOSE The amount of energy deposited in a unit weight of biological tissue. The units of absorbed dose are rad and gray. ALPHA DECAY Type of radioactive decay in which an alpha ( α) particle (two protons and two neutrons) is emitted from the nucleus of an atom. ALPHA (ααα) PARTICLE. Alpha particles consist of two protons and two neutrons bound together into a particle identical to a helium nucleus. They are a highly ionizing form of particle radiation, and have low penetration. Alpha particles are emitted by radioactive nuclei such as uranium or radium in a process known as alpha decay. Owing to their charge and large mass, alpha particles are easily absorbed by materials and can travel only a few centimetres in air. They can be absorbed by tissue paper or the outer layers of human skin (about 40 µm, equivalent to a few cells deep) and so are not generally dangerous to life unless the source is ingested or inhaled. Because of this high mass and strong absorption, however, if alpha radiation does enter the body through inhalation or ingestion, it is the most destructive form of ionizing radiation, and with large enough dosage, can cause all of the symptoms of radiation poisoning. It is estimated that chromosome damage from α particles is 100 times greater than that caused by an equivalent amount of other radiation. ANNUAL LIMIT ON The intake in to the body by inhalation, ingestion or through the skin of a INTAKE (ALI) given radionuclide in a year that would result in a committed dose equal to the relevant dose limit . -
Interim Guidelines for Hospital Response to Mass Casualties from a Radiological Incident December 2003
Interim Guidelines for Hospital Response to Mass Casualties from a Radiological Incident December 2003 Prepared by James M. Smith, Ph.D. Marie A. Spano, M.S. Division of Environmental Hazards and Health Effects, National Center for Environmental Health Summary On September 11, 2001, U.S. symbols of economic growth and military prowess were attacked and thousands of innocent lives were lost. These tragic events exposed our nation’s vulnerability to attack and heightened our awareness of potential threats. Further examination of the capabilities of foreign nations indicate that terrorist groups worldwide have access to information on the development of radiological weapons and the potential to acquire the raw materials necessary to build such weapons. The looming threat of attack has highlighted the vital role that public health agencies play in our nation’s response to terrorist incidents. Such agencies are responsible for detecting what agent was used (chemical, biological, radiological), event surveillance, distribution of necessary medical supplies, assistance with emergency medical response, and treatment guidance. In the event of a terrorist attack involving nuclear or radiological agents, it is one of CDC’s missions to insure that our nation is well prepared to respond. In an effort to fulfill this goal, CDC, in collaboration with representatives of local and state health and radiation protection departments and many medical and radiological professional organizations, has identified practical strategies that hospitals can refer -
Nuclear Fusion Enhances Cancer Cell Killing Efficacy in a Protontherapy Model
Nuclear fusion enhances cancer cell killing efficacy in a protontherapy model GAP Cirrone*, L Manti, D Margarone, L Giuffrida, A. Picciotto, G. Cuttone, G. Korn, V. Marchese, G. Milluzzo, G. Petringa, F. Perozziello, F. Romano, V. Scuderi * Corresponding author Abstract Protontherapy is hadrontherapy’s fastest-growing modality and a pillar in the battle against cancer. Hadrontherapy’s superiority lies in its inverted depth-dose profile, hence tumour-confined irradiation. Protons, however, lack distinct radiobiological advantages over photons or electrons. Higher LET (Linear Energy Transfer) 12C-ions can overcome cancer radioresistance: DNA lesion complexity increases with LET, resulting in efficient cell killing, i.e. higher Relative Biological Effectiveness (RBE). However, economic and radiobiological issues hamper 12C-ion clinical amenability. Thus, enhancing proton RBE is desirable. To this end, we exploited the p + 11Bà3a reaction to generate high-LET alpha particles with a clinical proton beam. To maximize the reaction rate, we used sodium borocaptate (BSH) with natural boron content. Boron-Neutron Capture Therapy (BNCT) uses 10B-enriched BSH for neutron irradiation-triggered alpha-particles. We recorded significantly increased cellular lethality and chromosome aberration complexity. A strategy combining protontherapy’s ballistic precision with the higher RBE promised by BNCT and 12C-ion therapy is thus demonstrated. 1 The urgent need for radical radiotherapy research to achieve improved tumour control in the context of reducing the risk of normal tissue toxicity and late-occurring sequelae, has driven the fast- growing development of cancer treatment by accelerated beams of charged particles (hadrontherapy) in recent decades (1). This appears to be particularly true for protontherapy, which has emerged as the most-rapidly expanding hadrontherapy approach, totalling over 100,000 patients treated thus far worldwide (2). -
Occupational Radiation Exposure from U.S. Naval Nuclear Plants and Their Support Facilities
REPORT NT-19-2 MAY 2019 OCCUPATIONAL RADIATION EXPOSURE FROM U.S. NAVAL NUCLEAR PLANTS AND THEIR SUPPORT FACILITIES NAVAL NUCLEAR PROPULSION PROGRAM DEPARTMENT OF THE NAVY WASHINGTON, D.C. 20350 This publication was printed on Recycled Paper Report NT-19-2 May 2019 OCCUPATIONAL RADIATION EXPOSURE FROM U.S. NAVAL NUCLEAR PROPULSION PLANTS AND THEIR SUPPORT FACILITIES 2018 Prepared by T. J. Mueller, T. M. Weishar, J. M. Hallworth, CHP, and T. F. Lillywhite Naval Nuclear Propulsion Program Department of the Navy Approved by __________________________________ J. F. CALDWELL, JR. Admiral, U.S. Navy Director, Naval Nuclear Propulsion TABLE OF CONTENTS SUMMARY .................................................................................................................... 1 EXTERNAL RADIATION EXPOSURE .......................................................................... 4 Policy and Limits ...................................................................................................... 4 Source of Radiation ................................................................................................. 5 Control of Radiation During Reactor Plant Operation .............................................. 5 Control of Radiation in Support Facilities ................................................................. 6 Dosimetry ................................................................................................................. 6 Physical Examinations .......................................................................................... -
Office of Radiation Protection
How is Dose Measured? July 2002 Fact Sheet 320-058 Division of Environmental Health Office of Radiation Protection RADIATION DOSE When radioactive material decays and the transformation of the atom occurs there is characteristic energy that is released. This energy is released in the form of what we call radiation. There are different types of radiation, but they all serve the same general purpose, ridding the atom of excess energy after it transforms. These radiations travel until, by losing energy, they “stop”. Radiation loses its energy by interacting with atoms in its pathway and transferring energy to the atom during these interactions. When an interaction with radiation removes an electron from the atom it is called ionization. Other types of interactions include the excitation of an atom, the breaking of molecular bonds, and the heating of an atom or molecule. Ionization, excitation, and molecular bond breaking can cause biological damage; heat transfer does not necessarily cause biological damage. The purely physical event of energy deposited by a radiation in a given volume of material, i.e. tissue, is called the absorbed dose. The unit of absorbed dose is called the Rad, the international unit is the Gray (gy). The absorbed dose quantifies the amount of energy transferred to a volume of material, but it does not reflect the biological damage that potentially occurred. Because of the physics of radiation, the biological effect of the same amount of absorbed energy may vary according to the type of the radiation. A quality factor, Q was developed, to be able to compare absorbed doses from different radiation types. -
1. the Three Types of Nuclear Radiation Are Protons, Electrons, Neutrons
Page 1 of 8 This chapter has 53 questions. Scroll down to see and select individual questions or 0 questions at random and keep in order narrow the list using the checkboxes below. Multiple Choice Questions - (45) Topic: Nuclear reactions and nuclear fission - (4) Fill In The Blank Questions - (8) Topic: Nuclear reactors - (11) Odd Numbered - (27) Topic: Nuclear weapons and nuclear fusion - (9) Even Numbered - (26) Topic: Radioactive decay - (19) Accessibility: Keyboard Navigation - (45) Topic: The structure of the nucleus - (10) Difficulty: Easy - (46) Type: Conceptual - (50) Difficulty: Hard - (1) Type: Definition - (10) Difficulty: Medium - (6) Type: Numerical - (3) 1. The three types of nuclear radiation are protons, electrons, neutrons. electrical, strong nuclear, weak nuclear. radiation, convection, conduction. → gamma, beta, alpha. Accessibility: Keyboard Navigation Difficulty: Easy Topic: Radioactive decay Multiple Choice Question Type: Conceptual MC The three types of nuclear radiation are Type: Definition 2. The word "radioactive" means an atomic nucleus absorbs neutrons. there is significant interference between atomic radiation and radio reception. → there are nuclei present which will spontaneously emit nuclear radiation. an atom spontaneously captures an electron from a neighboring atom. Accessibility: Keyboard Navigation Difficulty: Easy Multiple Choice Question Topic: Radioactive decay MC The word radioactive means Type: Conceptual 3. The discovery of the neutron helped people understand → how two atoms of the same element can have different atomic masses. why the nucleus has a positive charge. how electrons are attracted to the nucleus. why the nucleus is much more massive than the electrons in an atom. Accessibility: Keyboard Navigation Difficulty: Easy Multiple Choice Question Topic: The structure of the nucleus MC The discovery of the neutron helped people u.. -
The Potential Detrimental Impact of Galactic Cosmic Radiation on Central Nervous System and Hematopoietic Stem Cells
THE POTENTIAL DETRIMENTAL IMPACT OF GALACTIC COSMIC RADIATION ON CENTRAL NERVOUS SYSTEM AND HEMATOPOIETIC STEM CELLS By RUTULKUMAR UPENDRABHAI PATEL Submitted in partial fulfillment of the requirements For the degree of Doctor of Philosophy Dissertation Advisor: Dr. Scott M. Welford, Ph.D Department of Pharmacology CASE WESTERN RESERVE UNIVERSITY January, 2019 CASE WESTERN RESERVE UNIVERSITY SCHOOL OF GRADUATE STUDIES We hereby approve the thesis/dissertation of Rutulkumar Upendrabhai Patel Candidate for the Doctor of Philosophy degree *. (signed) Derek Taylor (Committee Chair) Scott M. Welford (Dissertation Advisor) Stanton L. Gerson (Committee Member) Marvin Nieman (Committee Member) Jennifer Yu (Committee Member) (date) December 3rd, 2018 *We also certify that written approval has been obtained for any proprietary material contained therein. ii Dedication I would like to dedicate this dissertation to my parents, Upendrabhai and Ujvalakumari Patel, who supported my wishes and ambitions despite being lived most of their lives in a lower-middle class family income. They sacrificed a lot to make sure a better life for their children. I would also like to dedicate this to my two sisters, Ekta and Vanita, for their support and encouragement over the years. iii Table of Contents Table of Contents ……………………………………………………………….. iv List of Figures ………………………………………………………………….. viii Acknowledgements ……………………………………………………………. xii Abstract ……………………………………………………………….…………. 1 Chapter 1: Introduction and Background ………………………………….. 3 1.1 Radiation, DNA Damage, and Carcinogenesis …………………………... 3 1.1.1 Space Radiation Environment and Induction of DNA Damage …………………………………………………………… 8 1.1.2 Radiation Induced Carcinogenesis ……………….................... 10 1.2 Hematopoietic Stem Cell Niche and Functions …………………………… 12 1.2.1 Low-LET Irradiation and HSC Injuries …………………………. 16 1.2.2 High-LET Irradiation Impact on HSCs ………………………….