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CE 3231 - Introduction to Environmental Engineering and Science. Readings for Next Class :. O hio N orthern U niversity. Chemistry, Microbiology & Material Balance. Introduction. Water & Air Pollution. Env Risk Management. Nuclear Chemistry
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CE 3231 - Introduction to Environmental Engineering and Science Readings for Next Class: Ohio Northern University Chemistry, Microbiology & Material Balance Introduction Water & Air Pollution Env Risk Management Nuclear Chemistry Radiation occurs naturally all around us. In this class we will cover the three types of radiation along with nuclear fission (used to make power). We will take a look at calculating half-lives and also the most common units to describe radiation dosing.
Radiation • Three types released from unstable nucleus alpha 2 protons, 2 neutrons beta electron or positron gamma electromagnetic radiation
Ionizing Radiation a, b and g carry enough kinetic energy to liberate an e- from an impacted particle… ..therefore shielding is important! A note about x-rays: X-rays are ionizing radiation (really like gamma rays), but they are generated by electron transitions rather than from an unstable nucleus
Radiation Units • curie (Ci) decay • becquerel (Bq) decay • roentgen (R) ionizations • rad (radiation absorbed dose) dose • rem (roentgen equivalent man) equivalent dose
Nuclear Fission Include: Ce-137 Sr-90 I-131 Reaction gives off particles with kinetic energy. The KE builds within the uranium fuel pellet resulting in heat gain within the pellet. The heat is transferred to water through the fuel rod (metal tube)
Making Uranium Pellets Uranium Mining and Milling
Making Power How a Nuclear Power Plant Works
Managing Radioactive Waste Wastes
Radioactive Decay – The challenge Radiation fragments in waste (Ce-137, Sr-90, I-131) will continue to give off ionizing radiation and must be safely shielded and stored for a very long time. Estimated by: N = Noe-0.693t/t where: N = final number of atoms or curies No = initial number of atoms or curies t = time t = half-life of atom
Radioactive Decay – The challenge ElementHalf Life Ce-137 30.17 years Sr-90 28.79 years I-131 8.01 days