Decay Rates ,Radioactivity ,Half life easy question

• helpcometk
In summary, the radioactive nuclides released into the atmosphere by the Chernobyl nuclear accident included both 131I (t1/2=8 days) and 137Cs (t1/2=30 years). Given that 5 times as many 137Cs as 131 I are present in the reactor in steady state, and that 131 I is produced in roughly 1% of all fissions, calculate(a) the ratio of activities ACs/AI immediately following the explosion.(b) how many days before the activities are equal.(c) Given that the Chernobyl reactor produced 1000MW of power, estimate AI 4 daysafter the explosion.
helpcometk

Homework Statement

The radioactive nuclides released into the atmosphere by the Chernobyl nuclear accident
in 1986 included both 131I (t 1/2= 8 days) and 137Cs (t 1/2= 30 years). Given that 5 times as
many 137 Cs as 131 I are present in the reactor in steady state, and that 131 I is produced in
roughly 1% of all fissions, calculate
(a) the ratio of activities ACs/AI immediately following the explosion.
(b) how many days before the activities are equal.
(c) Given that the Chernobyl reactor produced 1000MW of power, estimate AI 4 days
after the explosion.

Homework Equations

it would take me considerable amount of effort to find what means 1% of all fissions produce I 131 .

The Attempt at a Solution

it is A level to find that λ= ln2/ (t1/2) and A= λΝ as is probably the whole exercise.
which gives Acs/AI easily since 5NI =Ncs is given,

b) N=No e^-λt should suffice

c) maybe among the other equations P=Po e^-λt has to be used once the power has been found 4 days after the accident , some other equation must be used to find AI ,note that AI initial is not given ,but only as a function of Acs.

AI initial can be calculated given the reactor power level and the fact that "131 I is produced in roughly 1% of all fissions". I suggest you put in the "considerable amount of effort" to figure out what that statement means.

Ok
What about the other questions.Does anyone know the equation for power?

Think of it this way. If the reactor is operating at a certain power level, there are a certain number of fissions/sec, which you should be able to calculate if you know how much energy is released in each fission. The problem tells you what fraction of the fission events produce I-131, so you should be able to calculate the production rate of I-131. In steady state, the production rate equals the decay rate, so you should be able to calculate the steady state activity of I-131. Does this help?

im afraid this confused me even more .Am i thinking correct for a) and b) ?

What is decay rate?

The decay rate, also known as the activity, is the rate at which a radioactive substance decays or disintegrates over time. It is measured in units of becquerel (Bq) or curie (Ci).

Radioactivity is the spontaneous emission of radiation from the nucleus of an unstable atom. This radiation can take the form of alpha particles, beta particles, or gamma rays.

What is half life?

Half life is the amount of time it takes for half of the atoms in a radioactive sample to decay. It is a constant value for each radioactive isotope and can be used to determine the age of a sample.

How is half life calculated?

The half life of a radioactive substance can be calculated using the formula t1/2 = ln(2)/λ, where t1/2 is the half life, ln is the natural logarithm, and λ is the decay constant of the substance.

What factors affect decay rates?

The decay rate of a substance is affected by factors such as temperature, pressure, and the presence of other chemicals. However, these factors do not change the half life of the substance.

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