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Unformatted text preview: 1 Radon: NSS and Nonconservative MFB Lecture#13 review reaction kinetics radioactive decay (1 st order kinetics) non steady state (NSS), non conservative (CMFR) ICP #11 Reading V: Ch 5 (pg. 98100; 110111); Handout DFE2; Radon Guide Posted on Website What you should learn today Why is radon a problem in homes? Can we fix the radon problem? How do we set up and solve non steadystate, nonconservative CMFR problems? Reaction kinetics R = rate of reaction (mass/volumetime g/Ld) m rxn = VR units of mass flow ( g/d); for decay; + generation R = kC n Where k is the rate constant, n is the order of reaction, and C is the contaminant concentration reaction order, n n=0; zero order n=1; first order n=2; second order unit of k depends on order such that kC n will give units of g/Ld n=0; k g/Ld n=1; k 1/d n=2; k L/gd Batch with 1 st order reaction kinetics for no flow reaction: dm/dt = m rxn = VR R = kC n for 1 st order reaction, n=1, R = kC (k 1/d) dm/dt = VdC/dt = VkC (for decay) dC/dt = kC dC/C = kt (integrate) C=C exp(kt) dm/dt = VdC/dt = m in m out + m rxn ICP#10 (review) C = C CO exp(k Co t) + C Cr exp(k Cr t) t = 0.693/k Co = (0.693/5.263 yr)(1yr/365d) k Co =3.6x104 d1 t =0.693/k Cr = (0.693/26.5d) k Cr =2.6x102 d1 C Co = 1x103 Ci/L; C Cr = 1 Ci/L C = 100 Ci/L when t = 17.5 yr (dictated by decay rate of 60 Co ( 51 Cr reaches 100 Ci after 1 yr) ICP#10 (cont.) Radioactive Decay 0.0002 0.0004 0.0006 0.0008 0.001 0.0012 5 10 15 20 Time, years C u r i e s Total Cobalt Chromium...
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 Fall '06
 KimF.Hayes
 Radioactive Decay, Kinetics

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