14 June 2011

Nuclear Power Plant Job Interview Questions 1

How energy is generated in Nuclear power plant?

Answer: In Nuclear power plant energy is released by nuclear fission. Nuclear fission is the process in which heavy nucleus such as 23392U, 23592U,and 23994Pu when bombarded by certain particles ( protons, neutrons, X-rays), the heavy nucleus will split into two or more smaller nuclei, ejection of two or more neutrons and liberation of vast amount of energy. Therefore this split of heavy nucleus into two or more smaller nuclei is called fission process.

What are the particles used in nuclear fission?

Answer: High energy alpha particles, protons, deuterons, X-rays as well as neutrons can be used for the fission process. However neutrons are chosen because neutrons are electrically neutral in nature and thus they do not require high kinetic energy to overcome electrical repulsion from the positively charged nuclei and can participate in fission reaction.

What is fertile material and fissile material?

Answer: Not all the Uranium extracted from the ore can be used as fuel for plant for carrying out the fission reaction. Natural uranium consists of 99.3% of 23892U and only 0.7% of 23592U. Out of these isotopes, 23592U is used in fission reaction
Materials such as 23392U, 23592U,and 23994Pu are called fissile material or fissionable materials. This material is required to carry out the fission reaction.
Materials such as  23892U and 23290Th which occur in nature are called fertile materials. Fissile materials (23392U,  23994Pu ) can also be artificially be produced using fertile materials.

What is Chain reaction and how it is controlled in Nuclear reactor?

Answer: In fission reaction during every stage two or more daughter nuclei is released, two or more neutrons and vast energy is released. Each neuron produced  further participate in fission reaction and results in release of more neutrons, this reaction continues results in nuclear explosion. However in nuclear reactor the excess neutrons produced will be absorbed using moderator and control rods allowing only one neutron per fission to carryout further chain reaction.

What is half life and its significance?

Answer: The half life or half life period is defined as the time required for the radio-activity of an isotope to reduce to half of its original value. Radioactive material is dangerous because of its half life periods. Half life for radio active materials such as uranium, plutonium lasts for thousands of years.When the radio activity is exposed to the environment, the element will exist in the environment for thousands of years before it decays results in making the environment ( land, water, habitation ) radioactive for thousands of decades.



No comments: