The Experimental Advanced Superconducting Tokamak (EAST) is a nuclear fusion reactor in China that has made a significant breakthrough by maintaining a plasma at 100 million degrees Celsius for 1,066 seconds. This is important because nuclear fusion could become a clean, nearly limitless source of energy in the future.

1. What is Nuclear Fusion and Why is it Important?

• Fusion happens when two atomic nuclei combine to form a new nucleus, releasing huge amounts of energy.
• It is the same process that powers the Sun and other stars.
• Unlike nuclear fission (used in current nuclear power plants), fusion:
• Does not produce harmful radioactive waste
• Generates much more energy per unit of fuel
• Uses abundant fuel sources, mainly hydrogen isotopes (Deuterium and Tritium)

If we can control fusion on Earth, we can get clean energy with minimal environmental damage.

2. The Challenge of Achieving Fusion Energy

Fusion is very difficult because:

• Extreme temperatures required → To make fusion happen, we need temperatures of 100 million degrees Celsius (hotter than the Sun!).
• Plasma needs to be controlled → At such high temperatures, matter exists as plasma (a state where atoms are stripped of electrons). Controlling this plasma inside a reactor is very hard.
• Fuel availability → Deuterium is abundant in seawater, but Tritium is rare and difficult to produce.

To solve these challenges, scientists are experimenting with different reactor designs.

3. What is a Tokamak and How Does it Work?

EAST is a Tokamak, a doughnut-shaped reactor that uses magnetic fields to trap superheated plasma.

🔹 How does a Tokamak Work?

1.   Hydrogen gas (Deuterium/Tritium) is heated to millions of degrees, turning it into plasma.

2.   Super-powerful electromagnets create a magnetic field, confining the plasma so that it doesn’t touch the reactor walls.

3.   The nuclei in the plasma move at high speeds and collide, overcoming their natural repulsion.

4.   Fusion occurs, releasing enormous energy, which can be used to generate electricity.

📌 EAST is unique because it uses both toroidal and poloidal magnetic fields to better control the plasma.

4. EAST’s Achievements and Why They Matter

• EAST set a new record by sustaining a 100 million °C plasma for 1,066 seconds (almost 18 minutes).
• Previous records:
• 2016: Sustained plasma for 60 seconds
• 2017: Sustained plasma for 100 seconds
• 2023: Maintained plasma for 403 seconds
• These records show steady progress in sustaining nuclear fusion, which is crucial for future reactors like ITER.

5. The ITER Project and Its Challenges

🔹 What is ITER?

• ITER (International Thermonuclear Experimental Reactor) is a global fusion megaproject involving India, China, the EU, the US, Russia, Japan, and South Korea.
• It aims to build the first fusion reactor that produces more energy than it consumes.

🔹 Challenges with ITER:

• Delays & Cost Overruns → It was launched in 2007, but its first plasma is expected only by 2033.
• High Costs → With a budget of over €18 billion, it is called the most expensive science experiment ever.
• Tritium Shortage → ITER will require large amounts of tritium, which is hard to produce.

📌 EAST’s success is important for ITER, as it validates many of the technologies that ITER will use.

6. Alternative Fusion Approaches

Scientists are also exploring other ways to achieve fusion besides Tokamaks.

🔹 1. Stellarator:

• A different type of magnetic confinement reactor.
• More complex design but does not need external current.

🔹 2. Laser Fusion (Inertial Confinement Fusion):

• Uses powerful lasers to compress a small fuel pellet (Deuterium & Tritium) until fusion occurs.
• The National Ignition Facility (NIF) in the US achieved fusion ignition in 2022, producing more energy than was put in.

📌 Which method will be successful in the future remains uncertain, but fusion energy is closer than ever before.

1. Which of the following statements about nuclear fusion is correct?

(a) Nuclear fusion releases energy by splitting heavy atomic nuclei.

(b) Fusion requires extremely high temperatures to overcome the electrostatic repulsion between atomic nuclei.

(c) Nuclear fusion produces long-lived radioactive waste, making it environmentally hazardous.

(d) Fusion energy is already being commercially used for electricity generation.

✅ Answer: (b) Fusion requires extremely high temperatures to overcome the electrostatic repulsion between atomic nuclei.
📌 Explanation:

• Fusion is different from fission → It combines two lighter nuclei instead of splitting heavy ones.
• Fusion requires high temperatures (above 100 million °C) to overcome repulsion between positively charged nuclei.
• Fusion does not produce long-lived radioactive waste (unlike fission).
• It is not yet commercially viable, as existing reactors (like EAST) are still in experimental stages.

2. Consider the following statements regarding nuclear fusion and nuclear fission:

1. Both processes release energy, but fusion generates significantly more energy per reaction than fission.
2. Fusion requires the presence of heavy elements like uranium, whereas fission works with lighter elements like hydrogen.
3. Unlike fission, fusion does not produce greenhouse gases or long-lived nuclear waste.

Which of the above statements is/are correct?

(a) 1 and 3 only

(b) 2 only

(c) 1 and 2 only

(d) 1, 2, and 3

✅ Answer: (a) 1 and 3 only
📌 Explanation:

• Statement 1 is correct → Fusion releases more energy per reaction than fission (which is why it powers the Sun).
• Statement 2 is incorrect → Fission uses heavy elements like Uranium & Plutonium, while Fusion uses lighter elements like Hydrogen isotopes (Deuterium & Tritium).
• Statement 3 is correct → Fusion is cleaner, as it does not produce greenhouse gases or long-lived radioactive waste.

3. What is the primary challenge in making nuclear fusion a viable energy source?

(a) Limited availability of Uranium and Plutonium

(b) Extremely high temperatures required for fusion to occur

(c) Difficulty in controlling chain reactions in fusion

(d) High greenhouse gas emissions from fusion reactors

✅ Answer: (b) Extremely high temperatures required for fusion to occur
📌 Explanation:

• Fusion requires extreme temperatures (100 million °C or more) to make atomic nuclei collide and fuse.
• Uranium & Plutonium are not used in fusion (option a is incorrect).
• Fusion does not have chain reactions like fission (option c is incorrect).
• Fusion does not produce greenhouse gases (option d is incorrect).

4. In the context of nuclear fusion, what is the role of a tokamak reactor?

(a) It uses chemical reactions to generate energy.

(b) It uses a magnetic field to confine and control superheated plasma for fusion reactions.

(c) It generates electricity using conventional steam turbines.

(d) It is designed for the controlled splitting of heavy atomic nuclei.

✅ Answer: (b) It uses a magnetic field to confine and control superheated plasma for fusion reactions.
📌 Explanation:

• Tokamaks (like EAST & ITER) use powerful magnetic fields to confine plasma, preventing it from touching the reactor walls.
• They do not use chemical reactions (option a is incorrect).
• They are still experimental and not yet producing electricity (option c is incorrect).
• Fission reactors split atomic nuclei, not fusion reactors (option d is incorrect).

5. The International Thermonuclear Experimental Reactor (ITER) is significant because:

(a) It aims to achieve nuclear fission energy at a large scale.

(b) It will be the first fusion reactor to generate net energy.

(c) It uses a laser-based system instead of magnetic confinement.

(d) It is the world’s first commercially operational fusion power plant.

✅ Answer: (b) It will be the first fusion reactor to generate net energy.
📌 Explanation:

• ITER is an international project aiming to produce more energy from fusion than is required to sustain the reaction.
• It focuses on fusion, not fission (option a is incorrect).
• It uses a magnetic confinement system, not lasers (option c is incorrect; laser-based fusion is tested in the U.S. at NIF).
• It is still under construction and will not be commercially operational for decades (option d is incorrect).