JNTU IV B.Tech I Semester Supplimentary Examinations, February 2008
(Metallurgy & Material Technology)
1. (a) Compare and contract between Nuclear fission and Nuclear fusion.
(b) What is rate of radioactive decay? Derive the expression for decay constant.
2. (a) Explain the terms
i. transient equilibrium &
ii. secular equilibrium in radioactive equilibrium process.
(b) One of the natural radioactive series begins with uranium-235 (half life: 7.04×108
years) which emits an alpha particle to form thorium ?231(half-life 25.5h), the latter being a beta emitter. Starting with uranium-235 from which the decay products have been removed by chemical separation, determine
i. the atomic ratio of thorium-231 to the initial uranium-235
ii. the ratio of the total activity (rate of particle emission) to the initial value after 50h.
iii. the atomic ratio of the two nuclide mentioned when radioactive equilibrium is attained.
3. With the help of a neat sketch explain the working of a first generation tokamak reactor linked to a typical thermal cycle conversion system. Explain the advantage and limitations of this reactor over others.
4. (a) Why is it necessary to provide shielding for reactors? Explain.
(b) What materials are commonly used for this purpose? Why?
5. (a) What are the important minerals of thorium. give their chemical formula and composition.
(b) Explain the occurance of minerals of thorium and write their general characteristics.
6. (a) Write down the flow sheet and explain for the production of thorium form beach sands.
(b) Explain the important properties of thorium.
7. Discuss the properties that make Beryllium particularly interesting engineering material as nuclear material
8. (a) What is a pile reaction in the production process of plutonium. Explain the pile reaction in detail.
(b) Write a short notes on the isotopes of plutonium.