Nuclear Power — Set 3

Correct Answer: D. Carbon-14

Carbon-14 is a radioactive isotope that decays at a predictable rate known as its half-life. By measuring the remaining amount in an object, scientists can estimate when the organism died. This technique is widely used in archaeology and geology.

Correct Answer: A. Uranium ore concentrate

Yellowcake is a solid form of uranium oxide obtained during the early stages of processing uranium ore. It is usually a bright yellow or khaki powder that is easy to transport. It must be further processed and enriched before it can be used as fuel.

Correct Answer: D. Sievert

The Sievert (Sv) accounts for the type of radiation and the sensitivity of the organs exposed. It is the standard unit for monitoring radiation safety for workers and the public. Most natural background radiation doses are measured in much smaller milli-Sieverts.

Correct Answer: A. The Nucleus

Nuclear reactions involve changes in the protons and neutrons located within the nucleus. Chemical reactions only involve the rearrangement of electrons orbiting the nucleus. This difference explains why nuclear reactions release much higher amounts of energy.

Correct Answer: D. The process of safely closing and dismantling a plant

Decommissioning involves removing all radioactive materials and restoring the site for other uses. It is a long and expensive process that occurs at the end of a plant's operational life. Safety and environmental protection are the primary concerns during this phase.

Correct Answer: A. Cobalt-60

Cobalt-60 emits high-energy gamma rays that can be targeted to destroy tumor cells. This is a common application of nuclear technology in radiotherapy. It is also used to sterilize medical equipment and preserve food.

Correct Answer: A. A process where one fission event triggers further fissions

In a chain reaction, neutrons released by one splitting atom strike other atoms, causing them to split as well. If at least one neutron from each fission causes another fission, the reaction becomes self-sustaining. Reactors use control rods to keep this chain reaction at a steady, manageable rate.

Correct Answer: C. Uttar Pradesh

Narora is located in the Bulandshahr district of Uttar Pradesh near the Ganges River. It consists of two pressurized heavy water reactors (PHWRs). The plant is notable for its earthquake-resistant design in a seismically active zone.

Correct Answer: D. Combining light nuclei to form a heavier nucleus

Nuclear fusion is the process that powers the Sun and other stars. It requires extremely high temperatures and pressures to overcome the electrical repulsion between nuclei. Unlike fission, fusion produces no long-lived radioactive waste.

Correct Answer: A. Ensuring nuclear non-proliferation

The IAEA inspects nuclear facilities to verify that countries are not developing nuclear weapons. This system of 'safeguards' is a cornerstone of the Treaty on the Non-Proliferation of Nuclear Weapons (NPT). It provides a mechanism for international trust and security.