Nuclear Reactors - MCQs with answers
Q1. A CANDU reactor uses __________.a. Highly enriched uranium as fuel and light water as moderator and coolant.
b. Natural uranium as fuel and heavy water as moderator and coolant.
c. Enriched uranium as fuel and ordinary water as moderator and coolant.
d. Only fertile material
View Answer / Hide AnswerANSWER: b. Natural uranium as fuel and heavy water as moderator and coolant.
Explanation: This reactor is Canadian Deuterium Uranium. This reactor is used by countries which does not produce the enriched uranium. So it uses natural uranium as the fuel and heavy water as the moderator. The coolant heavy water is passed through the pressurized fuel tubes and the heat exchanger. Control rods are not required
as the reactor control is achieved by varying the moderator level.
a. Light or heavy water is used as both coolant and moderator.
b. The coolant water boils in the reactor core.
c. Water is used at high pressure
d. Both (a) and (c).
View Answer / Hide AnswerANSWER: d. Both (a) and (c).
Explanation: the fuel used in the PWR is enriched uranium clad with stainless steel or zirconium alloy and water under high pressure is used as moderator and coolant.
It is so designed to prevent the entry of boiling water coolant into the core. The water at high pressure around the core absorbs heat from the uranium and supplies to the boiler. Water spray can be used to condense the steam when pressure is to be reduced.
a. BWR
b. PWR
c. CANDU type
d. Both (a) & (b)
View Answer / Hide AnswerANSWER: a. BWR
Explanation: BWR reactor use enriched uranium and feed water as moderator and coolant. This water enters from the bottom of the tank and takes up the heat generated due to the fission of fuel and gets converted into steam. Feed water passes through the fuel elements in the core as coolant and also as moderator.
a. Steel
b. Stainless steel
c. Zirconium alloy
d. Plutonium Pu-239
View Answer / Hide AnswerANSWER: b. Stainless steel
a. Uranium, as a moderator
b. Boron, as a moderator
c. Uranium, to absorb the neutrons from the fissile material and gets converted into fissile material.
d. Boron, to absorb the neutrons from the fissile material and gets converted into fissile material.
View Answer / Hide AnswerANSWER: c. Uranium, to absorb the neutrons from the fissile material and gets converted into fissile material.
Which material is used for this?a. Aluminium
b. Magnesium
c. Stainless steel
d. All of these.
View Answer / Hide AnswerQ7. The reason for providing the thermal shielding is to _________________.a. Absorb the fast neutrons
b. Protect the operating personnel from exposure to radiations
c. Prevent the reactor wall from getting heated
d. All of the above
View Answer / Hide AnswerANSWER: d. All of the above
Explanation: The main purpose is also to protect from the deadly, α , β and γ radiations. Water passes through the reactor which in turn becomes radioactive. Hence the entire primary circuit including all the major components in the circuit needs to be shielded to protect the personnel handling it and the walls of the reactor from exploding.
