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measuring the activity of the carbon present.
Two grams of carbon from a piece of wood found in an ancient temple are analyzed
and found to have an activity of 15 disintegrations per minute. Estimate the
approximate age of the wood, if it is assumed that the current equilibrium specific
activity of C14 in carbon has been constant at 13.56 disintegrations per minute per
The activity A(t) created by irradiating a material in a nuclear reactor follows the
equation: A(t ) = Asat (1 − e − λt ), λ = ln 2
2 15 16 17 Feb. 24 Feb. 27 Mar. 1 Mar. 3 A thin gold foil (0.1 gm) consisting of the 100 percent naturally occurring Au197
isotope is irradiated to produce the Au198 isotope, which has a half life of T1/2 = 64.8
1. After 12 hours in the reactor, the activity reached is 0.90 Curies (Ci). What is the
theoretical saturation activity Asat in Curies (Ci) that can be obtained in the gold
2. Since the saturation activity cannot be reached, and the irradiation process is
costly, the normal practice is to aim at obtaining a fraction of the saturation activity.
How many irradiation hours are needed to obtain 80 percent of the saturation
3. Upon withdrawing the foil from the reactor, what is the fraction of the obtained
activity remaining after 324 hours outside the reactor? Mar. 6 1. Generate the decay chain for U238 using the Chart of the Nuclides.
2. Find the decay diagrams for the following isotopes of radiological concern:
Radon222, Pb210 and Po210.
3. Calculate the specific activity of the alpha emission from the Po210 isotope.
4. Calculate the specific power of Po210 deposited in the lung alveoli of smokers
from tobacco smoke in MeV/(sec.gm). Mar. 8 A space probe needs a Radioisotope Heating Unit (RHU) to heat its equipment in
the cold of space away from the Sun. The isotope Pu238, an alpha emitter is used in
space applications and can produce the needed thermal energy. For a thermal
power of 50 Watts(th) what would be the weight needed for this generator in grams
and in ounces?
Access the Table of the Nuclides and mine for the data concerning its half-life, and
the energy emitted in its alpha particle radioactive decay. Using the following table and assuming a constant consumption rate, estimate the
depletion times for the world’s energy resources. Energy Sources Energy Content
[1012 GJ] Fossil Fuels
Coal and lignite
Tar sands oil
Total 18 Mar. 3 Mar. 13
Uranium for U235 Converters
U238, Th232 Breeders
Lithium for DT Cycle
Oceans at 0.17 ppm Li
Deuterium for DD Cycle
(D2O in oceans)
World Energy Use/y...
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This note was uploaded on 01/24/2014 for the course NPRE 402 taught by Professor Ragheb,m during the Winter '08 term at University of Illinois, Urbana Champaign.
- Winter '08