Table of Contents
What is the purpose of control rods in a BWR or PWR reactor?
BWRs have capacities of up to 1400 MW and an efficiency of around 33\%. The BWR uses enriched uranium as its fuel. This fuel is placed into the reactor in the form of uranium oxide pellets in zirconium alloy tubes. There may be as much as 140 tonnes of fuel in 75,000 fuel rods.
How do control rods work in a nuclear reactor?
A control rod is a device that is used to absorb neutrons so that the nuclear chain reaction taking place within the reactor core can be slowed down or stopped completely by inserting the rods further, or accelerated by removing them slightly.
What is the difference between control rod and moderator?
Moderators are made from materials with light nuclei which do not absorb the neutrons but rather slow them down by a series of collisions. Control rods are made from material with the ability to absorb neutrons; Cadmium and Boron are examples of suitable materials.
Which is better PWR or BWR?
PWR has comparatively low thermal efficiency owing to two different loops. BWR offers higher thermal efficiency. In PWR, the control rods are inserted from the top of the nuclear reactor. In BWR, the control rods are inserted from the bottom of the nuclear reactor.
Which is better BWR or PWR?
A major advantage of the BWR is that the overall thermal efficiency is greater than that of a pressurized water reactor because there is no separate steam generator or heat exchanger. Controlling the reactor is a little easier than in a PWR because it is accomplished by controlling the flow of water through the core.
What is the difference between a PWR and a BWR?
Boiling Water Reactors (BWR) Unlike the PWR, inside the boiling water reactor, the primary water system absorbs enough heat from the fission process to boil its water. In contrast to the PWR, the BWR uses only two separate water systems as it has no separate steam generator system.
What is the difference between boiling water reactor and PWR?
Unlike the PWR, inside the boiling water reactor, the primary water system absorbs enough heat from the fission process to boil its water. In contrast to the PWR, the BWR uses only two separate water systems as it has no separate steam generator system.
How many control rods can a BWR/2 move at one time?
The RMCS for the BWR/2 through the BWR/5 product lines allows movement of only a single control rod at a time.
Can BWR power be controlled by natural water circulation?
However some early BWRs used only natural water circulation with no pumps. In these reactors the control rods had to be able to control the power between 0\% and 100\%. There is also a natural moderation feedback process that takes place within the BWR core.