How does the national electricity system work?
The Hungarian energy system – similar to those of other European countries – consists of numerous market segments. The electricity is generated by various power plants and in Hungary the biggest one is the Paks Nuclear Power Plant with its four power units producing approximately a half of the domestic electricity. In addition, the system comprises coal-fired and gas-fired power plants (these can be readjusted for oil-firing), biomass-based power plants and a few water and wind power plants as well. Electricity generated by these power plants and an additional imported volume is purchased by MVM Hungarian Electricity Ltd. The process is supervised by MAVIR Hungarian Independent Transmission Operator Company Ltd., which deals with the distribution of electricity that is further delivered by local electricity providers to small consumers. Industrial consumers, however, purchase electricity in the competitive market and not from local electricity providers, rather mainly from electricity trading companies which, in their turn, purchase the greater part of their electricity from the MVM electricity trading company, while a smaller quantity can be procured directly from import.
Why is a nuclear power plant needed in Hungary?
It is needed in order to provide for the possibility of generating the cheapest, clean and safe electricity in the country.
Why are nuclear power plants necessary, given that you often hear that we should rather use renewable energy sources for producing the required energy?
No country is capable of satisfying its energy demands using only one single energy source. Thus each country strives to achieve the most favourable combination of different sources, i.e. the so-called energy mix. There are some countries where, due to geographical conditions, the defining role would be played by water energy, while in the case of coastal states the use of wind energy will be higher than the average. There are some countries which can cover their natural gas demands required for energy production from own exploitation; however, many countries rely on nuclear-based energy generation. As far as Hungary is concerned, renewable energy sources (wind, water, solar, geothermal, biomass) are not available in sufficient quantities and we would not be able to generate the required volume of energy using traditional fossil fuel carriers, so it is necessary for nuclear energy to be involved in the production process.
Why cannot we replace nuclear power plants with a renewable energy source?
On the one hand, it is not possible since renewable energy sources do not assure continuous and demand-relevant electricity generation; on the other hand, the electricity generated with the help of renewable energy sources is much more expensive compared to that produced by nuclear. Naturally, with respect to the environment and sustainable development it is necessary that the renewable energy sources should be used to the maximum possible extent. However, we have to be realistic.
Is the nuclear power plant environmentally safe?
Yes, it is, since it does not emit carbon dioxide, sulphur dioxide and nitrogen oxides leading to the greenhouse effect and thus does not contribute to global warming and formation of acid rains.
Is nuclear energy cheap?
Yes, it is. The nuclear power plant generates the country’s cheapest electricity, which is characterised by price stability.
What happens to the radioactive waste?
The operation of the nuclear power plant involves the production of a relatively small quantity of radioactive waste. The waste products are collected, handled and supervised until their final disposal. For the purpose of final disposal of radioactive waste with low and medium activity, the underground facilities of the National Radioactive Waste Repository in Bátaapáti were commissioned in 2012. Research activities pertaining to the prospective storage of radioactive waste with high activity are carried out in Mecsek, in the region of Boda. Spent nuclear fuel is not considered as waste and at present it is stored in a special facility next to the plant’s site (for a defined period of time, 50 years). Later this nuclear fuel can be reprocessed and recycled or can be placed in the storage for radioactive waste with high activity.
There was an accident in Paks in 2003 that was qualified as a Level 3 accident. Should we be afraid of similar accidents in the future?
Along with international organisations, the safety of nuclear power plants is regularly inspected by the national nuclear authority of the given country. In Hungary the tasks related to nuclear oversight are carried out by Hungarian Atomic Energy Authority (HAEA). Safety of nuclear power plants is regulated by extremely strict requirements, including periodical inspections which are performed in Paks as well. However, there can occur incidents that require the intervention of the authorities. Nuclear incidents and accidents are handled in accordance with a 7-level international scale (International Nuclear Event Scale – INES), which determines actions and information provision depending on the potential extent of an accident. The accident in Paks in 2003 happened during the course of operation involving the cleaning of fuel assemblies in the storage pool near the reactor. Notwithstanding the fact that it was accompanied by increased attention on the part of the public, the accident did not lead to radioactive emissions and had no impact on the plant’s safety. The accident was assigned Level 3 according to the above-mentioned scale. The accident’s consequences were eliminated, damaged fuel assemblies were removed and the concerned power unit is operating at full power.
In the case of nuclear power plant incidents, the level assigned to the event is always indicated. What does this scale mean and what are the existing levels?
The demand for the improvement of information provision in respect of nuclear incidents gave grounds for the OECD section dealing with nuclear issues and IAEA (International Atomic Energy Agency) to elaborate an International Nuclear Event Scale. Three levels are applied in the case of incidents and four levels are applied in the case of accidents.
We have heard that with many nuclear power plants a power uprate has been implemented. A similar programme has also been implemented in Paks. What were the essentials of this programme?
Four power units of Paks Nuclear Power Plant operating VVER-440 reactors were put into operation between 1982 and 1987. Based on the operational experience gained, by the year 1994 the power plant had carried out a full-scale re-evaluation of the plant’s safety. As a result of the ‘Safety Enhancement Measures’ programme implemented during 1996–2002, the safety level of the power units of Paks NPP was brought into conformity with the safety level of Western nuclear power plants of a similar age. Owing to the modification of the turbine and reconstruction of the secondary circuit, the original electric power of 400 MW was gradually increased to 470 MW through an efficiency increase. A further efficiency increase could be achieved by the increase of reactor thermal power, which was demonstrated as feasible by international experiences. Due to cautious supporting activities and comprehensive reconstructions, the nominal power of the four power plant units was gradually increased to 500 MW; after the completion of the last reconstruction, starting from 2009 all four units have been operating at the 500 MW power level, bringing the plant’s overall capacity to 2000 MW.
What does service life extension mean?
According to the regulations, the use of the plant’s equipment and operation of power units is allowed as long as it is safe and economically efficient. In the case of Paks Nuclear Power Plant, beyond the originally designed 30-year service life, the extension means another 20 years of operation, naturally with the observation of safety requirements.
Is service life extension safe?
Yes, it is. The safety level corresponds to that of Western power units of the same age. In its everyday practice, the power plant broadens its knowledge base and implements international experiences with the help of safety enhancing measures. Power units have been safely operating for more than 20 years and the primary condition in the process of service life extension is to guarantee that the nuclear power plant’s safety will not be reduced.
What are the international trends?
International experiences and technical examinations carried out at other nuclear power plants in the world demonstrate that the service life of these power units can be safely extended.
What does ageing management mean at Paks Nuclear Power Plant?
Continuous inspection of structural materials and scheduled replacement of ageing equipment, plus planned preventive maintenance of other equipment.
Will the plant have a sufficient number of well-trained personnel?
An integral part of the HR policy implemented by the nuclear power plant is the establishment of a close relationship with secondary and higher educational institutes to ensure the availability of a pool of appropriate candidates.