- Nuclear installations in Germany
- Safety in nuclear energy
- Legal bases
- Licensing and supervision
- Safety philosophy
- Precautions and emergency response
- National committees
- International co-operation
- Reportable events
- Reporting procedure
- Incident registration centre
- International Nuclear Event Scale (INES)
- Reportable events in nuclear installations
- Reports on reportable events
- Shutdown and decommissioning
- Nuclear accidents
- What is nuclear waste management?
- Design approvals of transport packages
- Interim storage facilities
- What are interim storage facilities?
- Licensing of interim storage facilities for nuclear fuels
- Central interim storage facilities
- Decentralised interim storage facilities
- Interim storage facilities for radioactive waste with negligible heat generation
- Federal custody of nuclear fuels
- What is nuclear waste management?
- Foundation and development
- President of the BfE
- Laws and regulations
- Frequently applied legal provisions
- Handbook nuclear safety and radiation protection
- 1A Nuclear and radiation protection law
- 1B Other laws
- 1C Transport law
- 1D Bilateral agreements
- 1E Multilateral agreements
- 1F EU law
- 2 General administrative provisions
- 3 Announcements of the BMU and the formerly competent BMI
- 4 Relevant provisions and recommendations
- 5 Nuclear Safety Standards Commission (KTA)
- 6 Key committees
- Annex to the NS Handbook
- A 1 English translations of laws and regulations
- Dose coefficients to calculate radiation exposure
- Legal Basis
- BfE Topics in the Bundestag
Fuel elements contain the nuclear fuel of a reactor in their fuel rods. The fissile materials contained in nuclear fuel (such as uranium-235) can be fissioned in a controlled, physical process. This releases thermal energy which is subsequently converted in the nuclear power plant into electrical power by means of turbine and generator.
Uranium and MOX fuel elements
- Uranium fuel elements and
- Mixed-oxide (MOX) fuel elements.
Since plutonium always generates anew from the uranium-238 during reactor operation, pure uranium fuel elements contain plutonium over time, too. This is also fissioned and thus contributes to energy production.
In German nuclear power plants, MOX fuel elements are always used together with uranium fuel elements.
In a reactor loaded with MOX fuel elements, the core contains about two- to five-times as much plutonium as a reactor core loaded with uranium fuel that has been in operation for a longer period of time. Besides, after a certain period of operation, the MOX core has clearly higher contents of so-called transuranium elements such as neptunium, americium and curium.
Behaviour in the event of a core melt
Correspondingly to the higher contents of plutonium, neptunium, americium and curium in the MOX fuel elements, larger amounts of these materials are released in the event of a core melt and may be discharged into the environment. In that case, plutonium, neptunium, americium and curium are available as dust particles or are bound to dust particles.
To a substantial extent, all these materials are only released from the melt at temperatures clearly above ca. 2,000˚C. In the event of a core melt accident, the effects on the environment are determined by the composition of all the radioactive materials in the nuclear reactor at the time of accident (inventory) and by the share being released. In most accident courses, the differences between a uranium core and a MOX core play only a minor role in terms of effects on the environment.
State of 2018.02.09