Naturally Occurring Radioactivity (NOR) in natural and anthropic environments
1. Naturally Occurring Radioactivity (NOR) in natural and anthropic environments [email_address] contact C.U.G.RI. interUniversity Centre for Research on the Prediction and Prevention of Major Hazards, Italy ____________________________________________________
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3. The term radiations generally refers to a number of different physical phenomena, which all have in common the propagation of energy in space and time When radiations hit or penetrate inside matter the energy is absorbed, causing , i. e. an increase of temperature around the absorption point. Radiations
4. Radiations For example , the visible light , the radio-TV waves, the emission of particles or photons (X o ) by a radioactive element, are all different forms of radiations . Radiations can be simply subdivided into: • particle-like radiations having a mass like the electrically charged particles and the neutrons, and • wave-like radiations like phtotons ( X o ) which are massless and electrically charge less
13. Waves The energy carried by EM radiation increases with its frequency and diminishes with its wavelength Waves’ main characteristics: wavelength and amplitude amplitude wavelength ( λ )
14. Electromagnetic (EM) waves IR - VISIBLE - UV = 1mm – 10 -9 m heat, light, chemical reactions X-RAYS – GAMMA RAYS = 10 -8 – 10 -12 m Medical diagnostic tools MICROWAVES = 10cm – 1mm radar, mobile phones, ovens RADIO = 1km – 10cm Radio-TV broadcasting
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16. EM spectrum Increasing energies (frequences ) Increasing wavelength ( ) Infrared red orange giallo green blue purple ultraviolet Example: heat example: sun tanning bed
17. 1fm 1pm 1nm 1 μ m 1m m 1m GAMMA RAYS X-RAYS ULTRA- VIOLET INFRA- RED MICRO- WAVES RADIO WAVES EM spectrum WAVELENGTH (m) VISIBLE 10 -14 10 -12 10 -10 10 -8 10 -6 10 -4 10 -2 1 10 2 ENERGY
18. Brief Review of Radioactivity and Radionuclides basic concepts
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20. Periodic table of Atomic Elements (by Dimitri Ivanovic MENDELEEV, 1869 ) Z number of protons period group
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23. Isotopes and other iso- 222 Rn 220 Rn Isotopes Z 89 89 N 133 131 ---- ----- ------ A 222 220
77. M. Guida, Università di Salerno, Italia Universidad Nacional del Altiplano, Puno, Perù, 7 Febbraio 2006 Actividades que pueden generar NORM Minerales y materiales extraídos Otros procesos Aluminio Cobre Yeso Hierro Mo Fosfato Fósforo Tierras raras Estaño Titanio Zirconio Térmicas de carbón Energía geotérmica Petróleo y gas Tratamiento aguas residuales Pasta de celulosa Fabricación de cerámica Dióxido de titanio Fundición metales (Fe, Cu, etc.) Arenas abrasivas y refractarias Materiales de construcción Electrónica
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80. Principal radionuclides occurring M. Guida, Università di Salerno, Italia Universidad Nacional del Altiplano, Puno, Perù, 7 Febbraio 2006 Radionucleido Semivida Tipo de radiación Comentarios 40 K 1.28·10 9 a β , γ No genera cadena 238 U 234 U 230 Th 226 Ra 222 Rn 210 Pb 210 Po 4.47·10 9 a 2.5·10 5 a 7.54·10 4 a 1600 a 3.82 d 22 a 138.4 d α , γ α α , γ α , γ α β , γ α , γ Genera fraccionamiento de 4 subseries con T1/2 alto: 238 U, 230 Th, 226 Ra y 210 Pb 235 U 231 Pa 227 Ac 7.04·10 8 a 3.3·10 4 22 a α , γ α , γ α , γ Poco interés radiológico ya que: ( 235 U) = 0.044 ( 238 U) 232 Th 228 Ra 228 Th 1.41·10 10 a 5.75 a 1.91 a α , γ β α Genera fraccionamiento de 3 subseries con T1/2 alto: 232 Th, 228 Ra y 228 Th
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87. Origins of NORM in the Oil & Gas Industry Courtesy by Gas/Oil Separation Plants (GOSP)
127. WATER PROCESSING: DRINKING and WASTE WATERS EUROPEAN COMMISSION, Sewage Sludge, Directorate General for the Environment, EC, Brussels, http://europa.eu.int/comm/environment/sludge/index.htm . T. Gafvert, C. Ellmark, E. Holm. Removal of radionuclides at a waterworks. Journal of Environmental Radioactivity 63 (2002) 105–115. ACTIVIDAD (Bq/kg seco) en lodos Al(OH) 3 y Fe(OH) 3 Lodos 239/240 Pu 232 Th 234 U 238 U 137 Cs 210 Pb 7 Be Al(OH) 3 0.86 4.53 45.0 61.8 < 2 230 280 Fe(OH) 3 0.72 4.54 43.7 62.8 < 2 368 353
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129. Uranium-238 4.5 By Radon-222 3.8 d Radium-226 1620 Y Th-234 Pa-234 U-234 Th-230 . Principal decay Scheme of Uranium Radon – Daughters
130. RADIACTIVIDAD NATURAL La radiación natural a la que está expuesta la población proviene de la desintegración de isótopos radiactivos en la corteza terrestre, de la radiación cósmica y de los isótopos radiactivos que forman parte de los seres vivos, también llamada radiación interna Radón 40% Tratamientos Médicos 17% Rayos Cósmicos 12% Radiación Gamma 15% Radiación Interna 15% Otros 1% M. Guida, Università di Salerno, Italia Universidad Nacional del Altiplano, Puno, Perù, 7 Febbraio 2006
131. Diagnóstico Radiológico (Rayos X) Medicina Nuclear Radioterapia RADIACIÓN EN MEDICINA El uso de la radiación en el diagnóstico y el tratamiento de enfermedades se ha convertido en una herramienta básica en medicina . Con ella se ha podido realizar exploraciones del cerebro y los huesos, tratar el cáncer y usar elementos radiactivos para dar seguimiento a hormonas y otros compuestos químicos de los organismos. M. Guida, Università di Salerno, Italia Universidad Nacional del Altiplano, Puno, Perù, 7 Febbraio 2006
132. Corso di Laurea in Ingegneria Civile UNIVERSITA’ DEGLI STUDI DI SALERNO Facoltà di Ingegneria Building Materials brick granite Radioactiviy Index I : (Radiation Protection 112, 2000) I = A Th /200+A Ra /300+A K /3000 Concrete block
134. Corso di Laurea in Ingegneria Civile UNIVERSITA’ DEGLI STUDI DI SALERNO Facoltà di Ingegneria Radioactivity Index I in building materials F. Vigorito, Tesi di Laurea in Ingegneria Civile, Università di Salerno, 2006
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137. The three primary sources for natural radon are the parent isotopes of the two uranium series ( 238 U and 235 U) and the Thorium series ( 232 Th). U 238 4,5 10 9 y Ra 226 1622 y Rn 222 3,82 d Po 218 3.05 min Pb 214 26,8 min Bi 214 19,7 min Po 214 1,6 10 -4 s Pb 210 22,2 y Bi 210 5,03 d Po 210 138,4 d Pb 206 stable
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141. Release Mechanism Inside the same mineral grain From one mineral to adjacent mineral From mineral to water Stopped by intergranural material
142. If the pore space contains water, the ejected radon atom will rest in the liquid and is free to diffuse from the water or be transported by it. If the interstitial space is dry (i.e. filled only with soil gas) and not wide enough to stop the recoiling radon, it will enter a neighboring grain.
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151. 222 Rn: a Naturally Occurring Tracers for investigation of transport phenomena in the Litosphere: Emanation and Exhalation
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157. Radon Entry Into a Home 1. Cracks in Solid Floors 2. Construction Joints 3. Cracks in Walls 4. Gaps in Floors 5. Gaps around Pipes 6. Cavities in Walls 7. Water Supply (wells only) 3. 4. 1. 2. 7. 6. 5.
158. Main sources of Radon in a confined space building materials 2-5% water < 1% soil: 85-90% + diffusion 1-4%
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167. UNIVERSITA’ DEGLI STUDI DI SALERNO Facoltà di Ingegneria Corso di Laurea in Ingegneria Civile per l’Ambiente ed il Territorio Indagine nazionale sulla radioattività naturale nelle abitazioni (ANPA, ISS;1989 - 1993) Lithological Map 97 Bq/m 3 Campania Annual mean concentrations of Indoor Radon Italia: 70 Bq/m 3 Europa: 59 Bq/m 3 World: 40 Bq/m 3
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169. Journal of Technical & Environmental Geology, XVI, 2 (April/June), 38-62, 2008). General Functional Scheme of the Interdepartment Research Programme RAD_CAMPANIA in collaboration with C.U.G.RI., and the Regional Agency for the Environmental Protection ,ARPA Campania
171. Multiscalar hierarchical levels for the assessment of the Areas with the highest potential concentrations of exhalated soil-gas Radon (Radon-prone Areas) Journal of Technical & Environmental Geology, XVI, 2 (April/June), 38-62, 2008). Region Level: scale <1:250,000 Province level: scale <1:100,000 District Level : scale <1:25,000 Zone Level : scale <1:5,000-2,000 Site Level : scale 1: 2,000
173. Preliminary assessment from the lithological map and literature (Cuomo A., Tesi di Laurea in Ing. Civile A&T, 2007; Journal of Technical & Environmental Geology, XVI, 2 (April/June), 38-62, 2008).
174. Preliminary map of the Radon-prone Areas after the application of the multiscalar hierarchical adaptive approach (Cuomo A., Tesi di Laurea in Ing. Civile A&T, 2007; Journal of Technical & Environmental Geology, XVI, 2 (April/June), 38-62, 2008). PRIGNANO
175. Flow-chart diagram showing the applied methodology for the production of the Radon-prone Areas . Journal of Technical & Environmental Geology, XVI, 2 (April/June), 38-62, 2008).
176. UNIVERSITA’ DEGLI STUDI DI SALERNO Facoltà di Ingegneria Corso di Laurea in Ingegneria Civile per l’Ambiente ed il Territorio Procedura adottata per le misure eseguite con RAD7 (Pelosi A., Tesi di Laurea in Ingegneria, 2007)
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178. UNIVERSITA’ DEGLI STUDI DI SALERNO Facoltà di Ingegneria Corso di Laurea in Ingegneria Civile per l’Ambiente ed il Territorio Set di dati a cui sono stati applicati dei criteri di selezione Interpolazione mediante kriging dei dati di concentrazione (Pelosi A., Tesi di Laurea in Ingegneria, 2007) ID_MIS COD_S_RN COD_MIS DATA RN_CONC 1 _01 _01 12/10/2007 913 [Bqm -3 ] 2 _02 _01 12/10/2007 70.500 [Bqm -3 ] 3 _03 _01 13/10/2007 10.200 [Bqm -3 ] 4 _04 _01 13/10/2007 51.000 [Bqm -3 ] 5 _05 _01 13/10/2007 7.870 [Bqm -3 ] 6 _06 _01 13/10/2007 57.800 [Bqm -3 ] 7 _07 _01 15/10/2007 55.000 [Bqm -3 ] 8 _08 _01 15/10/2007 4.120 [Bqm -3 ] 9 _09 _01 16/10/2007 43.100 [Bqm -3 ] 10 _10 _01 19/10/2007 56.000 [Bqm -3 ] 11 _11 _01 20/10/2007 25.800 [Bqm -3 ] 12 _12 _01 20/10/2007 2.950 [Bqm -3 ] 13 _13 _01 20/10/2007 9.030 [Bqm -3 ] 14 _14 _01 20/10/2007 121.000 [Bqm -3 ] 15 _15 _01 27/10/2007 8.370 [Bqm -3 ] 16 _16 _01 27/10/2007 7.000 [Bqm -3 ] 17 _17 _01 02/11/2007 4.310 [Bqm -3 ]
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181. RADON -222 : A Naturally Occurring Radioactive Tracer in Hydrosphere UNIVERSITA’ DEGLI STUDI DI SALERNO Facoltà di Ingegneria Assessment of the Submarine Groundwater Discharge (SGD) Evaluation of the contamination of aquifers Assessment of the Groundwater Discharges in Lakes
182. How to measure RADON-IN-WATER: RAD7: Radon Monitor RAD7 has an internal sample cell of a 0.7L hemisphere, with a solid state detector at the center. The inside of the hemisphere is coated with an electrical conductor which is charged to a potential of 2-4 kV relative to the detector. Positive charged progeny decayed from 222Rn and 220Rn are driven by the electric field towards the detector. When a progeny atom reaches the detector and subsequently decays and emits an alpha particle , the alpha particle has a 50% probability of being detected by the detector. As a result an electrical signal is generated with the strength being proportional to the alpha energy. RAD7 will then amplify and sort the signals according to their energies. The RAD7 spectrum is a scale of alpha energies from 0 to 10 MeV, which is divided into 200 channels each of 0.05 MeV width.
183. RAD7 Alpha Energy Spectrum The alpha energies associated with 222 Rn and 220 Rn are in the range of 6-9 MeV. The channels related to them are grouped in 4 energy windows (labeled as A-D) 6.00 MeV Alpha from 218 Po (t 1/2 = 3 min) 6.78 MeV Alpha from 216 Po (t 1/2 = 0.15 s) 7.69 MeV Alpha from 214 Po 8.78 MeV Alpha from 212 Po
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186. RADH2O System The technique consists in bubbling air directly into water The internal air pump of the RAD7 circulates the air at a flow rate of about 1L/min through the water and continuously extracts the radon The radon from the water sample circulates through the desiccant column, then through the RAD7’s chamber, and then back to water sample until an equilibrium between radon in water and in air is reached The RADH2O system reaches this state of equilibrium within 5 minutes After the radon air-water equilibrium is obtained, the radon activity concentration in the air loop is measured by counting alpha particles emitted by radon daughters in the chamber
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189. Comparison Measurements Comparison measurements (21/11/09) C water = 7.5 ± 0.9 Bq/L (RADH2O) C air = 23000 ± 600 Bq/m 3 (Water Probe) K w = 0.312 -> C water = K w · C air = 7.2 ± 0.5 Bq/L (D. Guadagnuolo, PhD Thesis in Physics, 2009)
195. The Middle Bussento Segment, comprising the WWF Oasis reach, is located in the Morigerati gorge, a typical epigenetic valley, along which groundwater inflows from epikarst springs, conduit springs and cave springs, supply a perennial streamflow in a step-and-pool river type. The Middle-Lower Bussento Segment is located more downstream. It comprises the Sicilì Bridge Reference reach, a plane bed river slightly entrenched in alluvial terrace and bedrock.
228. Karst groundwater is extremely susceptible to pollution… Urban pollution of groundwater: sewage, pavement runoff containing petrochemicals, trash, domestic and industrial chemicals Rural pollution of groundwater: sewage, fertilizers, pesticides, herbicides, dead livestock, and trash
229. Contaminants associated with agricultural activities, such as nitrates, bacteria from livestock waste, and pesticides, are common in karst groundwater. Also, contaminants associated with urban runoff, such as lead, chromium, oil and grease, and bacteria from pet-animal wastes may be a threat to people using karst water supplies and to aquatic cave life.
230. Karst landscape: a very complex network for groundwater From: USGS (2002) Exploring Caves, Washington, D.C., pp. 61.
237. SGDCILERAD “ Submarine Groundwater Discharge assessment on the interregional coastal areas of Cilento, southern Italy, with measurements of natural isotopic tracers like 222-Radon”
238. Our Project is funded by: Regional Water Authority – Autorità di Bacino in Sinistra Sele National Park of Cilento and Vallo di Diano CONSAC – Consorzio Acquedotto del Cilento Provincia di Salerno – Assessorato all’Ambiente University of Salerno Istituto Nazionale di Fisica Nucleare
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249. C.U.G.RI. ____________________________________________________ C.U.G.RI. Centro Universitario per la Previsione e Prevenzione dei Grandi Rischi University Centre for the Prediction and Prevention of Large Hazards Prof. Eugenio Pugliese Carratelli Director Barcellona 2009 www.cugri.unisa.it
250. C.U.G.RI. is a Consortium between the University “Federico II” of Naples and the University of Salerno. It was established in 1993 by the Italian National Law Università degli Studi di Napoli “Federico II” Università degli Studi di Salerno
251. Goals and operation CUGRI acts as a front end for the two founding Universities in the fields of the prediction and prevention of large hazards, natural and industrial. It works – mostly – under contracts from public bodies and private companies, by carrying out applied research , consultancy and field monitoring activities It also operates with its own funds (Italian Ministry of Research) to perform basic research . All the staff from the two Universities can operate within CUGRI But it also operates in association with Private Companies , other Universities , and other Scientific Institutions
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256. Management of the hydrogeologic emergency in the City of Naples Technical and scientific support to the analysis of the hydrogeologic hazard and to the definition of a strategy for hazard mitigation. HYDRAULICS, SOIL MECHANICS ____________________________________________________
257. Outline of the Geografic Information System for Liri-Garigliano and Volturno River Catchments, in the hydraulic and geological hazard mitigation field HYDRAULICS, GEOLOGY, SOIL MECHANICS ____________________________________________________
258. REGIONE PIEMONTE Hydrological studies for the hydro-meteorological flood risk assessment Priola 05 November 1994 Pictures from the flooding of Alta Valle Tanaro e surroundings HYDRAULICS, HYDROLOGY ____________________________________________________
259. HYDRAULICS ____________________________________________________ ITALIAN NATIONAL DAM MONITORING AND REGULATING AUTHORITY Dipartimento dei Servizi Tecnici Nazionali Evaluation of the studies about artificial flood waves produced by dam gates operation or by dam break events Breached dam during the Oder flood in 1998. View looking downstream, through the breached dam section.
260. Provincia Salerno HYDRAULICS, GEOLOGY, SOIL MECHANICS ____________________________________________________ Scientific support in the development of the Risk Prevention Plan
262. A special thought to a very special friend and colleague Sandro Pietrofaccia that recently left us and whose human and professional virtues will be forever a very important example and reference
263. Having fun with scientific research Working very hard on the field
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265. Macroscopic World Tens of meters/meters Tens of cm / centimeters (10 -2 m) millimeters (10 -3 m) Objects from everyday’s life Measuring tools:
266. Microscopic World 10 micrometers (1 m = 10 -6 m) 100 nanometers (1 nm = 10 -9 m) cromosomes microelectronical circuits Cells Measuring tools:
267. Angstrom (1 Å = 10 -10 m) 1 10 Fermis (1 F = 10 -15 m) < 10 -18 m Atomic and Subatomic World Atom Nucleus Proton (1.7 x 10 -27 kg) Neutron Quark “ up” Quark “ down” Electrons (m= 9 x 10 -31 kg, q = - 1.6 x 10 -19 C) measuring tools: 1 F
268. Earth Sun (eclipse) spiral galaxy Cluster of galaxies “ Bubbles” of galaxies 10 7 m 10 9 m the Milky Way Our Galaxy 10 20 m 1 light-year = 10 16 m = 10000 billions of km 10 23 m 10 25 m Macrocosm measuring tools
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272. The approach 1) Produce beams of accelerated particles p article accelerators
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275. The approach 4) Analyze all the informations collected
276. Why do we need particle accelerators so large?
281. New forms of matter produced in high energy collisions E = Mc 2 (c = velocity of light in the vacuum = 300.000 km/s) A spoon filled with water contains a quantity of matter equivalent to the amount of energy needed to power an apartment for 5 kyears.
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283. - 1 0 5.1 x 10 -4 < 2 x 10 -8 Electron Neutrino e Electron e LEPTONS Name Mass (GeV/c 2 ) Charge - 1 0 0.106 < 3 x 10 -4 Muon Neutrino Muon - 1 0 1.784 4 x 10 -2 Tau Neutrino Tau QUARKS Name Mass (GeV/c 2 ) Charge + 2/3 - 1/3 4 x 10 -3 7 x 10 -3 Up Down u d + 2/3 - 1/3 1.5 0.15 Strange c Charm s + 2/3 - 1/3 175 4 .7 Bottom t Top b F A M I L Y I II III
284. Relative strength 20 1 10 -38 10 -7 Strong interaction responsible for the build-up of the nucleus EM inteaction responsible for the stability of the atom Weak interaction responsible of radioactive decays Gravitational interaction responsible of the stability of the solar system The 4 fundamental interactions
285. Particle Interaction mediated by the exchange of other particles? A pictorial view ... The exchange of the ball « generates » a repulsive force
286. W+, W-, Z° g ??? Gravity Weak EM Strong Interactions Messengers (interaction quanta) INTERMEDIATING BOSONS Name Mass (GeV/c 2 ) Charge 0 0 0 91.19 Z Photon Z + 1 80.6 W + 0 0 Gluon g - 1 80.6 W - W + W -
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288. fixed target Energy+0 Center of mass energy = 2m•Energy p p
291. LEP : Large Electron Positron collider (1989-2000) LHC: Large Hadron Collider (2007-2020) 27 km CERN European Center for Particle Physics LEP/ LHC SPS CERN GINEVRA LEP/ LHC SPS CERN GENEVA
292. CERN LEP e + -e - ( 200 Gev) LHC- 2007 pp ( 16000 Gev) 27 Km
295. + + + + + + Enable to determine particle trajectory and if used with a magnetic field measurement of its momentum is enabled too. Wire Chambers gas + -
296. Wire Chambers NB: the particle is not destroyed !!! Space resolution 0,05 0,1 mm gas In campo magnetico
297. Calorimeter NB: the particle is destroyed !! Energy transformed into fluorescence light Fe/Pb ... Fotomultiplier (PM) scintillator
298. The typical structure of a detector on colliders Fascio Tracciatore Muoni Calorimetro Tracciatore
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300. ZEUS- Hamburg Particle Jet Electron after collision Electron (30 GeV) Proton (820 GeV) Calorimeter Tracker
323. CDS – NA 4 Luglio 2011 Gruppo Collegato di Salerno ALICE Status ALICE Detector Status Complete since 2008 : ITS, TPC TOF, HMPID, FMD, T0, ZDC, PMD, ACORDE, MuonArm, DAQ Installation 2010 : 4/10 EMCAL 7/18 TRD 3/5 PHOS ~60% HLT Installation 2011 : 10/10 EMCAL 10/18 TRD (to be completed end 2011) HMPID EMCAL PHOS ITS TPC TRD TOF L3 Magnet
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326. Having fun with scientific research … and working very hard on the field!!!! Thank you so much for your patience and good luck for your life!!
Hinweis der Redaktion
09/09/11 L’indagine dell’Universo affascina. I metodi per studiarlo sono attraverso le particelle che riceviamo, la radiazione elettromagnetica, e sul posto. Sul posto direi che è difficile se si eccettua lo studio dell’Eliosfera e dei pianeti. Le particelle interferiscono col mezzo che attraversano, eccetto le particelle neutre (neutroni e neutrini) Inoltre la Terra è per fortuna nostra ben protetta: magnetosfera, atmosfera.. Questa protezione vale anche per la radiazione, ma parte di questa riesce a penetrare l’atmosfera. La radiazione ha tre caratteristiche: Intensità, spettro e polarizzazione. Dualismo onda-fotone. L’occhio umano è in grado di misurare due di queste tre grandezze: intensità e spettro solo nel visibile. Chi produce la radiazione? Ci sono le vere e propire sorgenti di luce e quelle sorgenti che si dicono secondarie.
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Radioactivity is defined as spontaneous nuclear transformations that result in new radioactive elements. There are three kinds of radiation. An Alpha particle is a high energetic helium nucleus ejected by the nuclei of some unstable atoms. These are large subatomic fragments consisting of 2 protons and 2 neutrons. They travel only a few inches through air and can easily be stopped with a sheet of paper. A Beta particle is an ordinary electron that is ejected from the nucleus of an unstable radioactive atom; this particle has a negative electrical charge and very small mass. Beta particles can travel a few feet through air and can be stopped with a few sheets of aluminum foil. Gamma rays are waves, not particles. Gamma rays (gamma photons) are emitted from the nucleus of some unstable (radioactive) atoms. Gamma photons are the most energetic photons in the electromagnetic spectrum. Gamma rays have a high penetrating power - it takes a thick sheet of metal such as lead, or concrete, to significantly reduce them. Gamma rays do not directly ionize other atoms, although they may cause atoms to emit other particles which will then cause ionization.
NORM is an acronym for Naturally Occurring Radioactive Material. NORM is any nuclide that is radioactive in its natural state (i.e., not man-made), but does not include source, by-products or special nuclear material. NORM has been present in the earth’s crust since its formation, is found in trace quantities everywhere and in the tissues of all living beings. There are over fifty naturally-occurring radio nuclides, the most common being Uranium, Thorium and Potassium-40, and their radioactive decay products, such as Radium and Radon.
The sources of most NORM are isotopes of Uranium-238 and Thorium -232, which are naturally present in subsurface formations, from which oil and gas are produced. The primary radionuclide of concern in NORM wastes is Radium-226, which is derived from the Uranium 238 series. This chart shows the decay scheme of Uranium-238 series. This has a half life of 4.5 billion years.
NORM was first recognized as a potential problem in the Canadian oil fields in 1904. The earliest reports about NORM’s existence in oil fields were released in 1930, but these reports were scattered, rare, and went unnoticed. At the same time, elevated levels of Radium were also detected in the Russian oil fields. These findings were paid little attention as the whole radiation protection field was in its early stages. It only started to develop in the 1950’s and 1960’s. In 1953, the United States geological society published the first paper on Uranium in gas formations. In 1985, when high levels of NORM were detected in facilities operating in the North Sea, it became a cause for concern for the oil and gas industry located in this area. After 1985, more attention was paid to the issue of NORM, and measures were taken to address these issues. The American Petroleum Institute (API), and the International Atomic Energy Agency (IAEA), came out with guidelines and regulations to govern NORM.
There are many NORM nuclides in the earth’s crust, but it is the nuclides that tend to accumulate in the oil and gas facilities that are of concern to us. These nuclides are Ra-226 (Radium), Ra-228 (Radium), U-238 (Uranium), Rn-222 (Radon), Pb-210 (Lead), and Po-210 (Polonium).
The origins of NORM in the oil&gas industry, indicating where NORM can accumulater in the extraction, transport and processing phases.
The radiation that is emitted by NORM also falls under these three categories: Radium-226 and Lead-210 are Gamma rays, Radium-228, Lead-210, Bismuth-210 are Beta particles Radium-226, Uranium-238, Polonium-210 and Lead-210 are Alpha particles
The natural levels of NORM can be significantly increased or “enhanced” as a result of activities like mining and oil production. This enhancement is referred to as TENORM – Technically Enhanced Naturally Occurring Radioactive Material. Sometimes, NORM can accumulate at much higher concentrations than its original natural level due to these activities. In the oil and gas industry, NORM tends to accumulate in media such as scale, sludge, scrapings and thin films in gas plants.
There are two main types of scale – Sulfate and Carbonate. Radium falls in the category of group II-A in the chemical periodic table, hence it behaves chemically similar to Calcium (Ca), Barium (Ba) and Strontium (Sr), which also fall under the same category in this chart. Therefore it co-precipitates with Ca, Ba and Sr to form physically radioactive scales, like Calcium Carbonate, Strontium Sulphate and Barium Sulphate (CaCO3, SrSO4 and BaSO4). The formation of scale is also enhanced when Sulfate-rich water, such as seawater, is injected into oil reservoirs, which contain formation water with high concentrations of barium and/ or strontium. When the seawater is injected into the reservoirs, there is an incompatibility between the two elements, which enhances the formation of scale. Scale accumulates in various parts of the production line, such as production tubing, well head, valves, pumps, etc. Scale inhibitors, like In-process addition and Down-hole squeezing, where the NORM is moved downstream, reduce scaling to a certain extent.
Fluids flowing from wells are viscous and contain a mixture of oil, gas, water, and sand. Sulfate-reducing bacteria extract Uranium from this fluid and deposit it on the walls of the pipes. This results in accumulation on the interior surfaces of pipelines over a period of time. Pipelines are “scrapped” regularly, using a device called a scrapper. This device is inserted in one end of the pipeline, and it scrapes the residues on the inner surfaces of the pipeline, pushing it until it reaches a scrapper trap, where the waste “scrapings” are collected. On completion, the scraper is removed.
When Radon is produced with oil and gas, it usually follows the gas stream. Radon has a boiling point between that of ethane and propane. Therefore, if natural gas is broken into fractions, a disproportionately high percentage of Radon can concentrate in the propane stream in comparison to the ethane stream. Radon-222 produces radioactive nuclides. In the oil and gas industry, Po-210 and Pb-210 are of significance. Bi-210 (5 d) can also be found. Most Radon decay products (90-99 per cent) are attached to ambient aerosols, airborne particulates or surfaces. This could result in the formation of thin radioactive films on the inner surfaces of gas processing equipment, such as scrubbers, compressors, reflux pumps, control valves and product lines. When Radon is produced with oil and gas, it usually follows the gas stream. Radon has a boiling point between that of ethane and propane. Therefore, if natural gas is broken into fractions, a disproportionately high percentage of Radon can concentrate in the propane stream in comparison to the ethane stream. Radon-222 produces radioactive nuclides. In the oil and gas industry, Po-210 and Pb-210 are of significance. Bi-210 (5 d) can also be found. Most Radon decay products (90-99 per cent) are attached to ambient aerosols, airborne particulates or surfaces. This could result in the formation of thin radioactive films on the inner surfaces of gas processing equipment, such as scrubbers, compressors, reflux pumps, control valves and product lines.
There are two scenarios of potential exposure to enhanced levels of NORM. The first exposure scenario is contamination: When an unprotected worker is exposed to the interior surfaces of NORM-contaminated equipment, he could be exposed to external as well as internal radiation. This could be through inhalation, ingestion and absorption of NORM radioactive nuclides. The second scenario could arise when a worker is in close vicinity to contaminated equipment. Here he can be exposed to gamma radiation that is penetrating through the steel walls. This exposure scenario is very unlikely, firstly because only Ra-226 can emit gamma radiation with enough energy to penetrate through thin steel walls, and secondly, extremely high levels of NORM contamination are required for significant exposure to take place.
The health hazards associated with exposure to NORM are generally low. Even high concentrations of NORM are usually less radioactive than man-made sources. Therefore, radiation–induced, acute or life-threatening effects are not expected after a short period of exposure to NORM. However, chronic exposure to NORM without the use of adequate protection equipment could increase the likelihood of incurring cancer.
The International Atomic Energy Agency (IAEA) recommends the limit of 270 pico curies per gram (pCi/g) for Ra-226 and its sub-elements (nine, including Ra-226). In 1996, the European Council issued radiation protection regulations, which require all member countries to develop and implement NORM-specific guidelines. In Saudi Arabia, there are no NORM specific guidelines as yet. The King Abudulaziz City for Science and Technology (KACST ) issued the first radiation protection standards in 1997, which closely follows the IAEA standards. The 1997 standards only contain surface contamination limits.
To what extent could NORM accumulate in oil and gas producing facilities? SHELL conducted a survey of NORM levels reported by oil companies worldwide. This table summarizes the concentration of world-wide reported levels of NORM in scale, sludge and scrapings. The lower levels of NORM are on the left and the maximum NORM levels reported are on the right. As shown in the table, these values can be significantly higher than the natural levels of NORM. In Saudi Aramco, the highest measured concentration is approximately 8500 pCi/g of Uranium. However, more samples need to be analyzed specially for sludge and scrapings to have a better assessment of NORM levels in Saudi Aramco facilities.
This chart displays levels of Radon gas (Rn-222) in natural gas, NGL and propane. This is just one element in NORM. The EPA limit for Radon in air is 4 pCi/ liter.
A worker’s radiation dose depends on many factors, such as the type of work that he does, the NORM activity assigned, the time spent on this activity, and the protective measures he employs. For example, a worker cleaning a vessel with sludge that contains 700 pCi/g Ra-226 and Ra-228, spends about 2000 hours per year in this activity, and is more prone to receiving high radioactive doses. Here he is exposed to 36.4 milli sievert (mSv) per year, while the recommended level is 1 mSv
The first step toward workers’ protection is identifying NORM-contaminated equipment by using adequate detection instruments. If contamination is suspected, than methods to locate the contamination and bring about awareness should be implemented immediately. NORM potential negative health effects can be significantly reduced by wearing suitable protective clothes such as gloves and coveralls. The use of adequate respirators will prevent the inhalation and ingestion of NORM nuclides. Only a small percentage of workers need to wear Personal Protection Equipment (PPE) for a limited time while performing certain activities, such as maintenance or cleanup of contaminated equipment.
NORM nuclides are found as part of the natural composition of earth crust in trace amounts. In reservoir rock formations such as sandstone and limestone, uranium and Thorium are found in varying concentrations on the order of ppm As you can see from the table Uranium & Thorium concentrations vary significantly from one rock formation to another During geological time frame, these nuclides leach into formation water mainly, and decay producing series of other radioactive materials such as radium. One of NORM decay product chain is Radon, Radon is a radioactive gas which accumulates with natural petroleum gas. Another source of NORM accumulation that we encounter in Saudi Aramco is originating from Seawater. It is a well known fact that Uranium exists in seawater in parts per billion concentration
The sources of most NORM are isotopes of Uranium-238 and Thorium -232, which are naturally present in subsurface formations, from which oil and gas are produced. The primary radionuclide of concern in NORM wastes is Radium-226, which is derived from the Uranium 238 series. This chart shows the decay scheme of Uranium-238 series. This has a half life of 4.5 billion years.
Additional term
In nuclear physics , secular equilibrium is a situation in which the quantity of a radioactive isotope remains constant because its production rate (due, e.g., to decay of a parent isotope) is equal to its decay rate. Secular equilibrium can only occur in a radioactive decay chain if the half-life of the daughter radionuclide B is much shorter than the half-life of the parent radionuclide A. In such a situation, the decay rate of A, and hence the production rate of B, is approximately constant, because the half-life of A is very long compared to the timescales being considered.
Distance Ranges that it can cover before stopping
Radon is a noble gas, with a half-life of 3.8 days. It is not chemically active and is around long enough to migrate through porous materials like the ground and your house foundation. Radon enters the home through any of the seven mechanisms listed above. The radon itself has a small chance of decay as you breath it in and out. Most of our actual dose comes from the decay products of radon, sometimes called radon daughters or radon progeny. These radon progeny are particles not gases, and can be deposited in your lungs as you breath. There they have some chance of decaying before your body can get rid of them, resulting in a radioactive dose. With respect to the water supply, it is estimated that a concentration of 10,000 pCi/liter of water results in an increase of indoor air radon levels of 1 pCi/liter.
Scrivere meglio le fasi della procedura di misure
It is partitioned by Weigel’s equation
Struttura metallica aperta
TRADURRE Polje= large flat plain
Leggermente arroccato
riserve This model assumes that the rate of exchanges of gases between the water and the atmosphere is controlled by molecular diffusion through a stagnant film, tens of microns thick, at the water-air interface.
metodo del tempo di volo e importanza della separazione k/pi pi/k…