Nuclear Power — Set 1
Technology · परमाणु ऊर्जा · Questions 1–10 of 50
Which process is primarily responsible for generating energy in a standard commercial nuclear power plant?
Correct Answer: A. Nuclear Fission
Nuclear fission involves splitting a heavy nucleus into smaller parts to release energy. This process is controlled using fuel rods and moderators within the reactor core. It currently provides a significant portion of the world's carbon-free electricity.
Which isotope is most commonly used as fuel in the majority of nuclear reactors worldwide?
Correct Answer: C. Uranium-235
Uranium-235 is the primary fissile isotope used because it can sustain a nuclear chain reaction. Although it makes up only about 0.7% of natural uranium, it is enriched for reactor use. Uranium-238 is much more abundant but is non-fissile by itself.
What is the function of a 'Moderator' in a nuclear reactor?
Correct Answer: D. To slow down neutrons
A moderator slows down fast-moving neutrons so they can effectively cause further fission in U-235. Common moderators used in reactors include ordinary water, heavy water, and graphite. This slowing down process is essential for maintaining a steady chain reaction.
Which material is frequently used for control rods to regulate the rate of fission in a reactor?
Correct Answer: A. Boron
Control rods are made of neutron-absorbing materials like boron or cadmium. By inserting or withdrawing these rods, the number of available neutrons can be precisely managed. This mechanism allows operators to increase, decrease, or stop the power output.
Where was the world's first commercial nuclear power plant, Obninsk, located?
Correct Answer: C. Soviet Union
The Obninsk nuclear power plant began operations in 1954 in the Soviet Union. It was the first plant to successfully connect nuclear-generated electricity to a power grid. This event proved the feasibility of using atomic energy for peaceful domestic purposes.
Which type of nuclear reactor uses heavy water (Deuterium oxide) as both a moderator and a coolant?
Correct Answer: C. PHWR
Pressurized Heavy Water Reactors (PHWR) are designed to utilize heavy water for efficient neutron moderation. This specific design allows the use of natural uranium as fuel without requiring enrichment. India's nuclear power program relies heavily on this technology.
What is the primary purpose of the 'Containment Building' in a nuclear power plant?
Correct Answer: D. To prevent radioactive leaks into the environment
The containment building is a robust reinforced concrete structure designed to withstand high pressure. It acts as a final barrier to shield the environment from radiation in case of an accident. These structures are built to resist extreme events like earthquakes or aircraft impacts.
Which element is the main focus of 'Stage 3' in India’s three-stage nuclear power program?
Correct Answer: A. Thorium
India possesses one of the world's largest deposits of Thorium, making it central to long-term energy security. In Stage 3, Thorium-232 is converted into fissile Uranium-233 to generate power. This program was originally formulated by Dr. Homi J. Bhabha.
In a nuclear power plant, what is used to turn the turbine that generates electricity?
Correct Answer: C. High-pressure Steam
Heat produced by nuclear fission is used to boil water and produce high-pressure steam. This steam then drives a turbine connected to an electrical generator. The basic thermodynamic process is similar to that of a coal-fired power plant.
What is 'Enrichment' in the context of nuclear fuel production?
Correct Answer: D. Increasing the concentration of Uranium-235
Enrichment is the process of increasing the percentage of fissile U-235 in natural uranium. Most commercial light-water reactors require fuel enriched to about 3% to 5%. This higher concentration is necessary to maintain a sustained chain reaction in specific reactor designs.