Nuclear Reactor - UNSOLVED PRACTICE SET

Q7. Name the main components of a nuclear reactor and state the function of each.

Q8. Why is heavy water preferred over ordinary water as a moderator in some reactors?

Q9. What is the difference between a breeder reactor and a conventional reactor? What fuel does a breeder reactor produce?

Q10. Why are control rods made of materials like cadmium or boron?

Q11. What is the role of the coolant in a nuclear reactor? Name two coolants used in different types of reactors.

Q12. Explain why a nuclear reactor cannot explode like an atomic bomb.

Q13. Describe the construction and working of a nuclear reactor. Explain the function of each component: fuel, moderator, control rods, coolant, and shielding.

Q14. Explain the working of a pressurized heavy water reactor (PHWR). Why is this design particularly suitable for India's nuclear program?

Q15. Discuss the safety features of modern nuclear reactors. How do multiple barriers and containment structures prevent the release of radioactive materials?

Q16. A nuclear reactor produces 1000 MW of electrical power with an overall efficiency of 33%.

(a) Calculate the thermal power produced in the reactor core.

(b) Calculate the number of fissions per second required.

(c) Calculate the mass of U-235 consumed per day.

(d) If the reactor uses 3% enriched uranium, calculate the mass of natural uranium required per year.

Q17. A reactor uses 200 tonnes of natural uranium annually. The uranium is enriched to 3% U-235.

(a) Calculate the mass of U-235 in the fuel.

(b) If the burn-up efficiency is 50%, calculate the actual mass of U-235 consumed.

(c) Calculate the energy produced if each fission releases 200 MeV.

(d) If the reactor operates at 30% thermal efficiency, calculate the electrical energy produced per year in kWh.

Q18. In your school's career guidance session, a guest from NPCIL (Nuclear Power Corporation of India Limited) discusses India's nuclear program.

(a) She explains that India's PHWRs use natural uranium as fuel and heavy water as moderator. Explain why this design was chosen given India's limited uranium reserves but abundant thorium deposits.

(b) The guest mentions that India's three-stage nuclear program aims to eventually use thorium-232 as fuel. Explain how Th-232 is converted into U-233 in a breeder reactor, and write the nuclear reactions involved.

(c) The student calculates that India's current nuclear capacity is about 7 GW from 22 reactors. If the target is 20 GW by 2030, calculate how many additional 1000 MW reactors need to be commissioned.

(d) A classmate is concerned about nuclear waste. The guest explains that reprocessing spent fuel can recover unused uranium and plutonium. If spent fuel contains 96% uranium, 3% fission products, and 1% plutonium, calculate how much plutonium can be recovered from 100 tonnes of spent fuel annually, and explain why this is valuable.

(e) The guest mentions the Prototype Fast Breeder Reactor (PFBR) at Kalpakkam. Explain what a fast breeder reactor is, why it doesn't need a moderator, and how it helps India's thorium utilization program.