Environmental Engineering Reference

In-Depth Information

Problem 6.1

(a) Calculate the mass deficit (

m
) in atomic mass units (amu) of the following fission reaction.

(Use literature values for the exact masses of the isotopes and neutrons.)

235
U

139
Xe

95
Sr

+

n

→

+

+

2n

(b) Calculate the energy (MeV) released per one fission. (c) Calculate the energy released per

kilogram of
235
U, and compare it to the energy released in the combustion of 1 kg of carbon.

Problem 6.2

(a) Calculate the mass deficit (

m
) in atomic mass units (amu) of the following fusion reaction.

2
D

3
T

4
He

+

→

+

n

(b) Calculate the energy released (MeV) per one fusion. (c) Calculate the energy released per

kilogram of deuterium.

Problem 6.3

In a nuclear accident there is a release of
90
Sr that emits

γ

rays with a half-life of 28.1 y. Suppose

1

g was absorbed by a newly born child. How much would remain in the person's body after 18

and 70 years if none is lost metabolically?

µ

Problem 6.4

The isotope
223
Ra has a half-life of 11.4 days.
223
Ra decays at a rate of 1 Ci per gram of radium

isotope. (Ci

3.7E(10) disintegrations/sec.) What will be the decay rate (Ci) of the 1-gram

sample after 10, 100, and 1000 days?

=

Curie

=

Problem 6.5

The isotope
129
I has a half-life of 15.7 years. In a nuclear power plant accident, 1 kg of the iodine

isotope is dispersed into the surroundings of the plant. How much of the iodine isotope will remain

in the surroundings after 1, 10, and 100 years?

Problem 6.6

Define the following terms and give examples as appropriate:

fissile nucleus

fertile nucleus

chain reaction