- Asked 2/21
- 2081 Shrawan · 6 marks
- 2078 Kartik · 6 marks
Thermal versus nuclear power plant
Short answer
Thermal plants burn coal/oil/gas, have moderate availability (70–85%), can follow load, emit CO₂ and pollutants, and have high fuel cost. Nuclear plants use uranium, have high availability (85–90%), run best at constant base load, emit almost no CO₂ but produce radioactive waste, and have very high capital cost but low fuel cost.
Compare thermal power plant with nuclear power plant on the basis of availability, grid connectivity, easiness to control, environmental effect, cost factors and so on.
Both thermal (coal/oil/gas fired) and nuclear plants produce steam to run a steam turbine–generator. They differ in the heat source: combustion of fossil fuel in a boiler versus nuclear fission in a reactor.
Comparison
| Basis | Thermal power plant | Nuclear power plant |
|---|---|---|
| Fuel | Coal, oil, gas; large quantity | Uranium-235, plutonium; very small quantity |
| Fuel availability | Widely available; transport of bulk coal needed | Limited suppliers; strict international control |
| Availability (plant) | About 70–85%; boiler outages | About 85–90%; long refuelling outages every 12–24 months |
| Grid connectivity | Units 100–800 MW; can be near load centres | Large units 600–1600 MW; away from populated areas; needs a strong grid |
| Easiness to control | Moderate load following; slow start (hours) | Best run at constant base load; control by control rods is complex |
| Starting time | Few hours | Long (many hours to days) |
| Efficiency | About 30–40% | About 30–35% (lower steam temperature) |
| Environmental effect | CO₂, SO₂, NOx, fly ash, thermal pollution | Almost no CO₂; radioactive waste, risk of radiation accident |
| Capital cost | Moderate | Very high (reactor, shielding, safety systems) |
| Running (fuel) cost | High | Low |
| Cost factors | Fuel price dominates | Capital, decommissioning and waste disposal dominate |
| Space | Large (coal yard, ash pond) | Smaller for same output, but large exclusion zone |
| Maintenance | Boiler, ash handling, coal mills | Highly skilled, radiation-safe procedures |
| Life | About 25–30 years | About 40–60 years |
Remarks
- Thermal plants are flexible and cheaper to build but costly to run and polluting.
- Nuclear plants are clean in CO₂ terms and cheap to run, suited only for steady base load in large grids.
- Nuclear power is not practical for Nepal due to small grid size, cost, lack of fuel and expertise, and seismic risk.
✓ Answer checked by Claude Opus 5.5 (high effort)
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