Heavy water, also known as deuterium oxide, is used in nuclear reactors as a moderator to slow down neutrons to speeds where they are more likely to cause fission in uranium-235. Normal water can also work as a moderator, but heavy water is preferred as it does not absorb neutrons as readily, allowing for more efficient nuclear reactions. Additionally, heavy water is less prone to radioactive activation compared to ordinary water.
Boric acid solution is used to bathe the control rods and fuel bundles of a nuclear reactor. This solution helps control the nuclear reaction by absorbing excess neutrons.
Water is the most common coolant used to remove heat from a nuclear reactor core. In pressurized water reactors (PWRs), water is used both as a coolant and as a moderator.
The coolant used in a pressurized water reactor is typically purified water. This water is pressurized to prevent it from boiling and is circulated through the reactor core to remove heat generated during the nuclear reaction.
Substances commonly used as moderators in nuclear reactors include light water (H2O), heavy water (D2O), and graphite. These materials help slow down fast-moving neutrons to speeds at which they are more likely to cause fission in uranium fuel.
The fuel used in a nuclear reactor is typically uranium. Specifically, the most common type of uranium used is uranium-235, which undergoes nuclear fission to produce energy in the reactor.
The moderator used in the nuclear reactor at Madras Atomic Power Station in Kalpakkam is usually heavy water (deuterium oxide) or light water (ordinary water). These moderators are important for slowing down neutrons produced during nuclear fission reactions to sustain the chain reaction in the reactor.
Water (H2), or heavy water (D2O). Sometimes, liquid sodium is used.
Heavy water can be used in a nuclear reactor to moderate the speed of neutrons, making it easier for uranium-238 to absorb a neutron and become plutonium-239. This process is known as breeding plutonium in a reactor and is one method of producing plutonium for nuclear weapons or fuel.
Control rods are used as moderators in nuclear reactors to regulate the rate of fission reactions by absorbing neutrons. By adjusting the position of the control rods, the reactor can be managed to sustain a controlled chain reaction.
The Kalpakkam nuclear power plant uses heavy water (deuterium oxide) as a coolant and moderator in its Pressurized Heavy Water Reactors (PHWRs). Heavy water has a higher density than regular water, allowing it to efficiently slow down neutrons and regulate the nuclear reaction in the reactor core.
Heavy water (deuterium) functions as a moderator. It slows down fast neutrons released by fission reactions in order to allow the reaction to be sustained. Fast neutrons pass through the reactor before initiating another fission reaction.
Boric acid solution is used to bathe the control rods and fuel bundles of a nuclear reactor. This solution helps control the nuclear reaction by absorbing excess neutrons.
Most current power plants use water, but heavy water, graphite, hydrocarbons, etc. could be used instead.
The pressurised water reactor (PWR)
Many pressurized water reactors use "regular" water (light water) as a primay coolant. That means that "only heavy water" is not a rule as regards reactor design. Reactor design specifies the coolant to be used.
Normal water, or light water, absorbs too many neutrons to be an effective moderator in a nuclear reactor. This absorption can make it difficult to sustain a nuclear chain reaction. Instead, reactors often use heavy water or graphite as a moderator, which have lower neutron absorption rates.
Water is commonly used to cool the reactor in nuclear power stations. This water absorbs the heat generated by the nuclear reactions and carries it away, preventing the reactor from overheating. The cooled water is then circulated back to the reactor to continue the cooling process.