CHM 111 Lecture Notes - Lecture 19: Roentgen Equivalent Man, Relative Biological Effectiveness, Sievert
27 Apr 2018
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CHM 111: Thursday, April 19th
Day 19 Notes
Chemistry in Modern Society
Nuclear Reactor
• This picture is a true overview of what has been discussed so far regarding Nuclear
Power
How Long does it Take?
• Half Life (t1/2): time required for the level of radioactivity to fall to one half its initial
value
o This DOES NOT depend on the initial amount
CHM 111: Thursday, April 19th
Day 19 Notes
Decay Series
• Radioactive isotopes undergo decay until they reach a stable species
• All isotopes of all elements with atomic 84 (Po) and higher are radioactive
• Some isotopes have extremely long half-lives and it can take a very long time for a
radioactive isotope to reach a stable product
Radiation Exposure
• “No Safe Radiation”
o Nuclear radiation is only weakly carcinogenic and body has numerous
mechanisms to repair damage
Document Summary
Day 19 notes: this picture is a true overview of what has been discussed so far regarding nuclear. How long does it take: half life (t1/2): time required for the level of radioactivity to fall to one half its initial value, this does not depend on the initial amount. Radiation exposure: no safe radiation , nuclear radiation is only weakly carcinogenic and body has numerous mechanisms to repair damage. Reward: cost, safety, efficiency, environmental impact, weapons connection, pu-239 by-product of u-235 fission, re-processing nuclear warheads for reactor fuel. World energy projections: us energy information administration projects a 48% increase in world energy consumption by 2040. What else is being developed: burning garbage as fuel. It is a lot easier to find the materials need for fusion: not as easily controlled as fission, need a large (more costly) reactor, us, china, japan, and france all working on this. **** all pictures and charts are taken directly from the class presentations****
