April 18, 2023: What is heavy water? What is the purpose of nuclear reactors? How does it work? Read the ReferencePepper by Sreshtha and Ranjini to know more!
By Pepperazzis Sreshtha and Ranjini
The setting up of 10 nuclear reactors across five Indian states has received approval from the Center. Dr. Jitendra Singh, the minister of atomic energy, disclosed the details in Parliament. According to the minister, the government has contracted with a public sector organisation to set up the reactors.
A collection of 10 indigenous 700 MW pressurised heavy water reactors has received administrative permission and financial sanction from the Center.
The ten reactors will be constructed in the states of Rajasthan, Madhya Pradesh, Haryana, and Karnataka. Two nuclear reactors will be added to each of the nuclear power facilities in Kaiga, Chutka, and Gorakhpur, while four reactors will be added to the Mahi Banswara nuclear power plant in Rajasthan.
What is heavy water?
Simply explained: Water is made up of tiny particles called atoms, and the atoms in water are special because they can come in different types. Imagine if water had a cousin that was a little heavier than regular water. This "heavy" water is called heavy water because it has a special type of hydrogen called deuterium, which makes it denser than normal water. Regular water has two light hydrogen atoms and one oxygen atom, but heavy water has two heavier deuterium atoms and one oxygen atom. Heavy water is not very common in nature, and it is used for special purposes in things like nuclear reactors and scientific experiments. It's called 'heavy' water because it's a bit heavier than regular water due to the different type of hydrogen atoms it contains.
Deuterium, which is represented by the letters "2H" or "D," is a component of the molecule known as heavy water. Deuterium oxide is popularly known as heavy water.
Deuterium oxide is a crucial component in heavy water nuclear reactors, where it serves as a coolant and a neutron moderator.
The moderator is a chemical that reduces the speed of the fission reaction, whereas the coolant is a substance that acts as a conductor of heat and absorbs the thermal [heat] energy produced by fission.
A pressurised heavy water reactor (PHWR) is a nuclear power plant that employs heavy water (deuterium oxide).
The minister added that during 2021–2022 nuclear power plants produced 47,112 million units of electricity, or about 3.15 percent, of the nation's total electricity production.
As India plans to increase its production and supply of cleaner and greener energy, the government is sanctioning construction of more nuclear power plants. In fact, if the official statements are to be believed, 20 more power facilities, including the 10 already mentioned, have already been planned over the next 10-15 years. This will take the total tally up to more than the existing tally’s double.
Last February, a few government officials had announced that the north-Indian state of Haryana will harbour a 1,400-MW facility, comprising two 700-MW pressurised heavy-water reactors (PHWR), which is already under construction near Gorakhpur village, about 90 miles northwest of New Delhi. Both the PHWRs are built on an Indian design.
According to the deal that the United States and India signed in 2019, the former had set up a goal of constructing at least six nuclear power plants in India. In fact, about two months ago in February, the two countries reworked their previous assignments, from as long ago as 2008, to help the U.S enhance its facilitation work in India.
Other than deals with the U.S, India has also signed civil nuclear cooperation agreements with around 12 more countries, including Russia, Canada, and France. These associations can bolster the attachment of other necessary reactors.
“India is looking to reduce its fossil fuels by half by 2032; building nuclear plants is seen as a central part of that strategy,” said Irina Tsukerman, a geopolitical analyst and president of Scarab Rising, a Connecticut-based business advisory group. “From a safety perspective, it is not a significant risk given that India is already a nuclear power. Civilian plants would not necessarily introduce any greater risk; the key would be cooperation with reputable companies and Western states toward building safe and well-maintained facilities.”
Yes, but what is nuclear energy, really?
Simply explained:
The energy that is released from the nucleus, the core of atoms, or the smallest building block of any matter, made up of protons and neutrons, is known as nuclear energy.
Atoms are like the building blocks of everything around us, and they are made up of even tinier parts called protons, neutrons, and electrons. In the center, or nucleus, of an atom, there are protons and neutrons, and they're held together really tightly.
Nuclear energy is a form of energy that can be produced in two ways: fission and fusion.
When nuclei of atoms split up into several parts, we call it fission, and when they fuse together, we call it fusion.
In nuclear fission, we can split the nucleus of an atom, like breaking it apart. When the nucleus splits, it releases a huge amount of energy in the form of heat and light.
This released energy can be used to generate electricity, just like how we use other sources of energy like coal, natural gas, or sunlight. The heat from nuclear fission is used to produce steam, which turns a turbine, and then the turbine generates electricity.
Nuclear energy is used in nuclear power plants to make electricity, and it doesn't produce any air pollution like burning fossil fuels does.
However, it's important to handle nuclear energy very carefully because the materials used in nuclear fission can be dangerous if not handled properly. That's why nuclear power plants have strict safety measures to protect people and the environment.
While the technology required to extract electricity from fusion is still at the elementary research phase, nuclear fission can be utilised successfully to generate nuclear energy around the world today. Nuclear fission is a reaction where the nucleus of an atom splits into two or more smaller nuclei, and this splitting releases energy.
How does a nuclear power plant work?
Simply explained:
- Fuel: Think of fuel as the "food" that the nuclear reactor needs to produce heat. Just like a car needs gasoline to run, a nuclear reactor uses special materials called nuclear fuel, like uranium or plutonium, to create heat. Mostly it's Uranium-235.
- Moderator: Imagine the moderator as a "speed bump" for the fast-moving particles inside the reactor. When the nuclear fuel breaks apart, it releases tiny particles called neutrons that move really fast. The moderator's job is to slow down these fast neutrons, so they can cause more fuel to break apart and produce more heat.
- Control rods: Think of control rods like the "brakes" for the nuclear reactions in the reactor. They are long rods made of special materials that can absorb neutrons and slow down the nuclear reactions. By moving the control rods in or out of the reactor, we can control how fast or slow the reactions happen and how much heat is produced.
- Coolant: Just like a car needs a radiator to cool down its engine, a nuclear reactor needs a coolant to keep it from getting too hot. The coolant is like a "cooling system" for the reactor. It's usually water or some other special liquid that flows around the reactor and carries the heat away to make steam, which can be used to generate electricity.
- Fuel rods full of uranium pellets are placed in water.
- Inside the fuel rods, uranium atoms split, releasing energy.
- This energy heats water, creating steam.
- The steam moves through a turbine, which turns a generator to create electricity.
- The steam cools back into water, which can then be used over again. At some nuclear power plants, extra heat is released from a cooling tower.
Source: https://archive.epa.gov/climatechange/kids/solutions/technologies/nuclear.html
Overall, the fuel, moderator, control rods, and coolant work together to control the nuclear reactions and produce heat, which can be used to generate electricity in a nuclear power plant.
Currently, over 400 such reactors in 32 countries provide about 10 percent of the world’s electricity.
The International Atomic Energy Agency is an intergovernmental organisation that promotes and maintains the peaceful use of nuclear energy and forbids its deployment in military assignments, including nuclear weapons.