辐射安全常识教学课件

梦 境辐射安全常识1、不要轻言放弃，否则对不起自己。2、要冒一次险!整个生命就是一场冒险。走得最远的人，常是愿意去做，并愿意去冒险的人。“稳妥”之船，从未能从岸边走远。-戴尔卡耐基。3、人生就像一杯没有加糖的咖啡，喝起来是苦涩的，回味起来却有久久不会退去的余香。4、守业的最好办法就是不断的发展。5、当爱不能完美，我宁愿选择无悔，不管来生多么美丽，我不愿失去今生对你的记忆，我不求天长地久的美景，我只要生生世世的轮回里有你。RadioactivityAtoms with too many neutrons or protons are unstable and emit energy to become more stable.Energy is carried away by a a-/b b-particle or x-/g g-ray.These atoms are called radioactive and the process is called radioactive decayRadioactivityNaturalUraniumThoriumPotassium-40Carbon-14(C-14)Hydrogen-3(H-3)(tritium)Man madePhosphorus-32(P-32)Sulfur-35(S-35)Calcium-45(Ca-45)Chromium-51(Cr-51)Zinc-65(Zn-65)Rubidium-86(Rb-86)Iodine-125(I-125)Background Radiationmrem/yrmrem/yrCosmic Cosmic 2727Terrestrial Terrestrial 2828Inhaled Inhaled 200200Internal Internal 3939Man-madeMan-made6 63 3Total:Total:357357RadiationMicrowave light bulbcell phone UV lampradio/TV laserheat lamp x-raysEmission/propagation of energy through space or material medium as waves or particlesIonizing RadiationAlpha Particles2 Protons+2 NeutronsShort Range in AirNot an External Hazard Internal HazardBeta ParticlesNegligible MassLong Range in AirInternal/External HazardChargedGamma Rays/PhotonsGamma photons&X-Ray both electromagnetic differ only by place of origin No mass or chargeHighly-penetratingNeutronsVery Long RangeVery PenetratingDifficult to detectOther modes of DecayPositron emissionElectron captureFissionElectronActivityDecay is a statistical process.Cannot predict when a particular atom will decay.Can predict when certain amount(%)will have decayed.Units of ActivityCurie(Ci)1 Ci=37,000,000,000 dps(3.7 x 1010 dps)or1 Ci=2.22 x 1012 dpm Becquerel(Bq)1 Bq=1 dps1 Ci=37,000,000,000 Bq=37 GBq(Giga Becquerel)Quantities&UnitsBeta and gamma radiation about equally damaging:1 R=1 rad=1 remAlpha radiation causes greater cellular damage 1 rad of a a=20 remDecay Rate Half-life,A=A0 e 0.693t/TA=A0()#of half-livesNon-Ionizing RadiationQuestions?RadiationSafety Industrial Studies 4020Topics in Industrial StudiesEnvironmental Safety ManagementRadiation HazardsExternal Hazard(exposure from outside the body)High-energy beta(i.e.,energy 300 keV or 0.3 MeV)Gamma and X-raysNeutronsInternal HazardRadioactive material enters body by eating/drinking in radiation area,by breathing vapors/aerosols,or skin absorptionIn body,it is treated like non-radioactive elementsIf not incorporated into organ,rapidly excreted and maypose only slight hazardIf stored in organ,slowly excreted(effective half-life)Acute Biological EffectsWhole body,external acute exposure effects25 rad some chromosome aberrations50 rad minor blood changes100 rad 2%radiation sickness400 rad 50%die in 60 days(LD50/60)700 rad lethal single exposure6000 rad cancer therapy(local)Low Dose Biological EffectsALARAAs Low As Reasonably Achievable Benefits outweigh risks?Lower Dose=Lower RiskWhole body badge (TLD)Collar or Ring TLDBioassay-thyroid(iodine)urinalysis(tritium)Monitoring WorkersOccupational Exposure LimitsNot to Exceedmrem/yr rem/yr mSv/yr5,000 5 5015,000 15 15050,000 50 50050,000 50 500Accumulated DoseEquivalent to:Whole BodyLens of the EyeSkin of Whole BodyExtremities of WholeBody-Hands,Feet,etcGeneral Safety MeasuresTIMEExposure increases with timeSHIELDINGPlastic for betaLead for gamma DISTANCEExposure decreases with distancevTime vs ExposureIncreased exposure(risk)over time Linear3 mR/hr*4 hr=?Distance vs Exposure I1d12=I2d22 Exposure&ShieldingThick,dense (i.e.,lead)for gamma/x-raysPlastic betaHydrogeneous(or boron+cadmium)for neutronsNo shielding needed for alpha or low-energy betaDetectors/MonitorsDetectors/Monitors1)Capable of Detecting 2)Efficiency3)Calibration Industrial Uses of Radiationepa.gov/rpdweb00/source-reduction-management/applications.htmlIndustrial Uses of RadiationLasersX-raysGaugesWireless exit signs X-ray Fluorescence(XRF)Industrial Uses of Radiationepa.gov/rpdweb00/source-reduction-management/applications.htmlMoisture/density gaugesRadiographyStatic controlSmoke detectorsEmergency ResponseLifesaving and serious injury take precedence over radiation exposure and contaminationControl Access to AreaCall for HelpRadioactiveWaste Industrial Studies 4020Topics in Industrial StudiesEnvironmental Safety ManagementTypes of Radioactive Waste Spent Fuel-Withdrawn from a nuclear reactor following irradiationHigh-level waste-Highly radioactive material from reprocessing spent nuclear fuelTransuranic-Man-made elements above atomic number 92 Types of Radioactive Waste NORM Naturally-occurring radioactive material (primarily uranium&thoriumSpecial Nuclear-Pu,U-233,or uranium enriched in the Material isotopes U-233 or U-235Low-level waste-not high-level radioactive waste,spent nuclear fuel,transuranic waste,or certain by-product material Solid Waste LandfillDecay IncinerateSupercompactionLSC Vial Waste Aqueous WasteHold for decaySanitary sewerTable IIPOTW Mixed WasteRCRA/AEA Dual regulationEPA/State Conditional exemptionDepartment ofEnergyQuestions?谢谢你的阅读v知识就是财富v丰富你的人生71、既然我已经踏上这条道路，那么，任何东西都不应妨碍我沿着这条路走下去。康德72、家庭成为快乐的种子在外也不致成为障碍物但在旅行之际却是夜间的伴侣。西塞罗73、坚持意志伟大的事业需要始终不渝的精神。伏尔泰74、路漫漫其修道远，吾将上下而求索。屈原75、内外相应，言行相称。韩非