Table of Contents
- 1 What is the purpose of fuel rods and of control rods?
- 2 Why are there control rods in between the fuel rods of a nuclear reactor?
- 3 What is the purpose of control rods quizlet?
- 4 Why does lowering the control rods reduce the amount of energy released?
- 5 What is the purpose of moderator in nuclear reactor Mcq?
- 6 What is the main functions of moderator?
- 7 What is the operating principle of control rods in nuclear reactors?
- 8 Do marked differences in the behavior of fuel rod channels exist?
What is the purpose of fuel rods and of control rods?
Inside the reactor vessel, the fuel rods are immersed in water which acts as both a coolant and moderator. The moderator helps slow down the neutrons produced by fission to sustain the chain reaction. Control rods can then be inserted into the reactor core to reduce the reaction rate or withdrawn to increase it.
Why are there control rods in between the fuel rods of a nuclear reactor?
Control rods are used in nuclear reactors to control the rate of fission of the nuclear fuel – uranium or plutonium. Their compositions include chemical elements such as boron, cadmium, silver, hafnium, or indium, that are capable of absorbing many neutrons without themselves fissioning.
How are fuel rods and control rods used to control the temperature?
How are fuel rods and control rods used to control the temperature of the water in a nuclear power plant? Control rods absorb the excess neutrons, slowing or stopping fission, lower the temperature. Fuel rods generate the heat.
What is the function of moderators in nuclear reactor?
Moderators are the substance that slows down the neutrons in nuclear reactors. Moderators are made up of materials with light nuclei that do not absorb the neutrons but slow down the speed of neutrons by a series of successive collisions.
What is the purpose of control rods quizlet?
Control rods are used in nuclear reactors to control the fission rate of uranium and plutonium. They are composed of chemical elements such as boron, silver, indium and cadmium that are capable of absorbing many neutrons without themselves fissioning.
Why does lowering the control rods reduce the amount of energy released?
In times of high energy demand, control rods are raised allowing more reactions to take place. In times of low demand, control rods are lowered to absorb neutrons and hence decrease the number of reactions; less reactions = less heat energy produced.
What is the reason that a nuclear chain reaction is possible?
The emission of several neutrons in the fission process leads to the possibility of a chain reaction if at least one of the fission neutrons induces fission in another fissile nucleus, which in turn fissions and emits neutrons to continue the chain.
What is the purpose of the chain reaction in a nuclear power plant?
A chain reaction refers to a process in which neutrons released in fission produce an additional fission in at least one further nucleus. This nucleus in turn produces neutrons, and the process repeats. The process may be controlled (nuclear power) or uncontrolled (nuclear weapons).
What is the purpose of moderator in nuclear reactor Mcq?
The moderator’s function in the reactor is to slow down the fast-moving secondary neutrons produced during the fission. The material of the moderator should be light and it should not absorb neutrons.
What is the main functions of moderator?
Moderator is a material which is used to slow down the speed of neutrons produced during nuclear fission.
What is the difference between a BWR and PWR fuel assembly?
PWR fuel assemblies differ from BWR assemblies in that the control rods (called Rod Control Cluster Assemblies) have 16 to 20 rods and enter tubes in the assembly, as shown in the graphic on the left. The PWR fuel assembly usually has a fuel rod arrangement of 14 x 14 up to 17 x 17.
What is the number of fuel rods in a PWR?
In PWR, the number of fuel rods per assembly has evolved between the 1960s and the 1970s. The 12 × 12 became 14 × 14, and the 15 × 15 became 17 × 17, retaining the same outer dimensions. One design even uses an 18 × 18 lattice.
What is the operating principle of control rods in nuclear reactors?
Operating principle. Control rods are usually used in control rod assemblies (typically 20 rods for a commercial PWR assembly) and inserted into guide tubes within a fuel element. A control rod is removed from or inserted into the central core of a nuclear reactor in order to increase or decrease the neutron flux,…
Do marked differences in the behavior of fuel rod channels exist?
Marked differences in the behavior of individual channels can be expected. Limiting draining of the fuel rod channels due to CCFL in the side-inlet orifices at the bottom of the fuel channels is important for cooling of the fuel rods during blowdown, refill, reflood, and spray periods. B. Michel,