Radioactive waste emits greenhouse gases

Environmental impact of nuclear power plants

In a nuclear power plant, despite all the technical precautions, the smallest amounts of radioactive substances can either get directly from the fuel rods or through the action of neutrons on the primary coolant and from there into the waste water or exhaust air system of the plant.

Therefore, the following are carefully monitored:

  • The release of radioactive substances via the sewer and the exhaust chimney (emissions)
  • The entry of radioactive substances into vegetation, soil and water (immissions)


Water contaminated with radioactive substances (e.g. laundry wastewater or laboratory wastewater) is collected in the nuclear power plant, cleaned and, if possible, reused within the facility. If necessary, the treated wastewater can be drained off via a river inlet (receiving water) without endangering people or the environment. The residues (such as evaporator concentrates or ion exchange resins) that arise during the purification of the power plant water are solidified and brought into a form suitable for final disposal.

Exhaust air

The exhaust air from nuclear power plants is primarily cleaned with mechanical filters (e.g. fiber materials or wet scrubbers) in order to largely remove the radioactive substances transported with dust and very fine particles (aerosols). Radioactive gases from nuclear fission require special treatment. They are effectively retained in large activated carbon filters. For the radiation exposure of the population through the release of radioactive substances with the exhaust air (air path) and the wastewater (water path) from nuclear power plants, we apply very low limit values, which are based on the fluctuation range of natural radiation exposure.

The radiation exposure actually caused by nuclear power plants is less than 0.5% of the average natural radiation exposure to which everyone is constantly exposed.

  • Limit value for the effective dose equivalent for air and water path: 0.3 mSv / year
  • Actual radiation exposure in the vicinity of nuclear power plants is less than: 0.01 mSv / year

For comparison:

  • Average natural radiation exposure: 2.4 mSv / year
  • Average medical radiation exposure: 1.5 mSv / year

(mSv = millisievert)

Comparison with coal-fired power plants

In contrast to coal-fired power plants, nuclear power plants emit no chemical pollutants, dusts containing heavy metals and no CO2 from. They also do not consume oxygen. In addition to natural radioactive substances, a coal-fired power plant (1300 MW) emits the following pollutants per year via the exhaust air:

  • Sulfur dioxide (SO2): 3,500 tons / year
  • Nitrogen oxides (NOx): 5,500 tons / year
  • Dusts containing heavy metals (including arsenic): 300 tons / year
  • Carbon dioxide (CO2): 10,000,000 tons / year

Modern cleaning systems for the flue gases have already been taken into account.

Heat dissipation

As thermal power plants, nuclear power plants have a thermal efficiency of less than 40 percent.

The rest of the primary energy used is released into the environment in a controlled manner as waste heat at a low temperature. With fresh water cooling, due to the multiple effects on the ecology of the river (receiving waters) from which the cooling water is taken, severe restrictions apply to the inlet temperatures as well as to the removal and return of the cooling water. The introduction of heat into the receiving water is continuously monitored. The main cooling water of nuclear power plants is therefore now usually re-cooled with cooling towers.

Effects of cooling towers

The cooling tower impacts can

  • affect the local meteorological conditions,
  • lead to pollution from air pollutants in the environment,
  • cause regional climate changes.

Measurements in the vicinity of the cooling towers installed at power plants in Germany and abroad have shown that power plants with wet cooling towers do not have any significant meteorological effects.