2 Renewable sources

2.1 Solar energy

The Sun. One of the millions stars of our galaxy that has an enormous deal in enabling our existence. It is the centre of our planetary system and the cause of the life circle. It provides us with water and air circulation, it is the irretrievable source of light and heat. It is still the truth that the Sun as the bases of the renewable sources is the only source of energy that the humankind can fully depend on. Solar energy is able to provide us with everything without risk and pollution, such as heat for our homes, electricity for the electrical appliances and also the fuels for machines.

In fair weather there is solar radiation with the power of 1000 W on one square meter of the earth surface. It is then changed to heat and chemical energy. It is just the one divided from two milliards from the global energy that is radiated by sun to the universe, but it is enough for existence of life and a great store. Radiation that falls down on the Earth is 1000 times bigger than the energy that is produced in our power stations all over the world per year.

There is 950 - 1100 kW.h.m2 of radiation per year in Slovakia. There is 8760 hours in one year. The Sun shines according to regions for 1300 to 1900 hours. Three quarters of this radiation is present during the summer months.

Pct. 2. Solar radiation in Slovakia at horizontal surface in kW.h.m2 in summer months

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2.1.1 Sorts of solar radiation

Direct solar radiation: It is the radiation when the sky is clear that falls down directly on the surface.

Efficiency of the collector depends on the angle of the incidence of light.

Diffuse solar radiation: During cloudy weather there is discontinuous radiation and the rays fall on the collector indirectly.

Reflected solar radiation: Surroundings of each building reflect solar radiation. Also these rays fall down

discontinuously.

Global solar radiation: This radiation is summarisation of the direct and diffuse radiation. During fair

sky it reaches the value 1000 W per m2. During cloudy sky the value declines to 80 to 100 W per m2.

2.1.2 Different ways of exploitation of the solar energy in households

We talk about active and passive exploitation of solar energy according to the way it is used. It can be either in its original form or by the technical means.

a) Passive exploitation • Those are architectural solutions where the solar - 2 -

Pct. 3. Scheme of solar radiation

Pct. 4. Solar collector

radiation is used directly to heat room. For example: the windows situated to south, winter gardens.b) Active exploitation • collectors for heat production • barrier-layer photocells for production of electrical energy • heating pumps for exploitation of the heat from the environment, air, water or soil.

2.1.3 Solar collectors

Solar collectors are the main and the most important equipment in solar heating systems. Those are the means that absorb global solar radiation on their surface and transform it to thermal energy. Their exploitation is scheduled to production of warm utility water with the possibility of nother heating.

Correct orientation of the solar collector is very important. The greatest amount of the energy radiates from south, so we will get the best result, when we orientate the collector southwards. When we orientate it slightly westwards (about for 8 - 15 degrees), we can use the energy of setting sun as well. The collector is the most efficient when the rays fall on it in 90 degrees angle. When we use the summer sun,

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SOLAR SYSTEMS

ACTIVE

transformation of solar radiation to heat by the

means of collectors

PASSIVE

transformation of solar radiation to electrical

energy

Liquid

transformation of solar energy to heat by convenient architectural design of the building

air

by barrier-layer photocell

in solar - thermal way

the collector should be located flatly. In winter steep location is more convenient. Optimal declension for all year’s service is 45 degrees. 2.1.4 The types of solar collectors

Liquid collectorsThey transform solar radiation caught by absorber to thermal energy. It is then

concentrated in liquid cooling medium that transports it to the place of consumption.

Flat collectorsTheir frontal area is the same size as absorbing one. They are used for low-

thermal systems (to 100˚C). They are the most widespread collectors for their acceptable price, good parameters and effortless use. Their effectiveness is about 70%.

Concentric collectorsTheir reflexive area concentrates the radiation to smaller absorbing area. They

reach higher temperature than flat collectors do and they are also more difficult and expensive. Their efficiency is up to 90%.

2.1.5 Photoelectric cells

Photoelectric cells are based on inner photoelectric phenomenon that we can see in semiconductors. If semiconductor diodes are subjected to radiation of convenient wavelength, there is at the attachment point of semiconductors P and N a potential stoppage. Its potential is several tens of Volts. In the area of adapter there is electrostatic field, which stops transmission of major charge carrier.

When we connect two parts of diodes (P and N), there is no current in the circuit, because there is no energy yet. The current arises when the light falls down to the area of adapter. During this impact of photons of convenient energy the couple of charge carrier, electron, and a gap arise. These carriers go through adapter, which is open for them. Part P loses electrons and it is charged positively. Part N loses gaps and it gains negative potential. New photoelectric voltage Uf invokes a current in outer electric field. Exploitation of photoelectric cells is quite effective. They reach the efficiency of 20%. It is assumed that in the future photoelectric cells will be placed in the cosmos as stabile satellites in height of 35 000 km above the Earth. Their power will be 5000 MW and they will produce direct current. Microwaves in cosmic room will transport electric energy. Their frequency will be 2450 MHz. Or the laser rays will transmit the energy.2.2 Wind energy

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Wind energy is kinetic energy of air. It is the indirect form of solar energy. Solar rays heat the earth surface from region to region with different intensity. This is the cause of thermal and pressure differences. Approximately 2% of the energy from sun are transformed constantly to air circulation. To utilise the wind energy in electrical energy we need mean speed of the wind greater than 4-5 m. s-1 (in the height 10m). It is truth that in the height to 650 m. over the sea level the mean speed of the wind is small (about 2,5 m.s-1). Optimal speed of the wind is 12 m.s-1. When this margin is overcome, the wind power must be reduced and the part of this energy is not used.

Wind power stations can economise the fuel, but hardly can they replace other sources of energy, as the customer wants to have the electric power whenever he needs it. However it can become an important complementary source.Wind power stations are built for generating electrical energy. Rotary power of the wings of the wind power station is transported by actuator mechanism to generator, where electric energy is produced. Power of the wind is not constant, the main factor is the speed of air circulation. Energy gained from the wind equals the cube of the wind speed. If we build the wind power station at the place, where the average wind speed is 6 m.s-1 instead of 3m.s-1, we can get 8 times greater amount of energy. That is why the place where we locate the power station has the crucial influence on the efficiency of the all of appliance. Diameter of rotor, the height of tower, power of generator, efficiency of aerodynamic, mechanic and electrical transformation, power characteristics and economy of the appliance are the other crucial factors when we build the wind power station. From every square meter of the surface that is covered by rotor we can get 600 - 900 kWh. of electrical energy per year. The best windy conditions are in winter that is why it is effective to combine windy power station with solar collectors.

Annual energy Average speed of Expenses of - 5 -

Pct. 4. Windy turbine

Type of locality production wind ( m.s-1 ) production inkW.h ( Sk )

Poor 330 – 420 5,5 4,3 – 6,2Available 550 – 690 6,5 2,5 – 3,7 Good 850 – 1050 7,5 2,2 – 2,5Very good 1200 – 1540 8,5 1,6 – 1,9

Ideal windy power stations can theoretically exploit approximately 59% of wind energy. It is possible because of thermodynamic features of air circulation. The biggest exploitation is possible to be reached with two - three laminated rotors. To absorb the wind energy in the most effective way by the rotor, the head of the power station called gondola is situated in revolving way on the mast. Windy wheel or an electric motor serves to direct the axis of rotor in the drift of the wind.

2.3 Water energy

2.3.1 The energy of water circulation

This kind of energy is a typical example of renewable sources. Water sources are similarly to traditional sources bound to the specific area and they are also limited, but they are constantly supplemented and renewed.

Energy of the water has its origin in solar energy. Solar radiation causes

evaporation from seas, oceans, rivers, streams and pools. By cooling vapours above the surface there is condensation followed by rainfalls. By this way the potential

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energy of the water in clouds is changed to kinetic energy of watercourses, oceans and seas. We transform this energy to mechanic energy then for actuation of water turbines and production of electrical energy.

Except for great water buildings there are also small water power stations (SWPS). Running of SWPS should be economically favourable. The amount of produced electrical energy influences fall and overflow, therefore these data are very important in our choice of the area.

2.3.2 Turbines used in SWPS

Banki’s turbine It is the same pressure turbine with twice bigger overflow of revolving wheel. It is available for the falls from 1m to 50m, it’s economically favourable mainly from 4m‘s fall. Pelton’s turbine It is the same pressure turbine available for falls above 30m. Serial centrifugal pumps can be cheaper in reserve course.

Francis’s turbine It is gauge pressure turbine for almost whole extent of overflows and falls in SWPS. The installation of new turbines in SWPS is recommended from 10m falls and rather big overflows. There are also great powers then. Kaplan’s turbine It is the basic classical gauge pressure turbine excellently regulated. It is used for fall from 1m to 40m, overflows 0,1 to several m3.s-1. It is convenient for SWPS in dams and rivers.

2.3.3 Energy of the sea - 7 -

Machine room of water power stationSpiral chamberPressure feederJointed absorber - steelJointed absorber - concrete Circular wheelDead front wheelGear boxGeneratorFirm clutchFlexible clutchPct. 5. Model of the water power station

We call all the water matter on the Earth surface the World Sea or ocean except for the water of rivers and lakes, underground water, water bound in minerals, biosphere and vapours in atmosphere.

The area of World Sea is approximately 361,18 mil. km2. Total capacity of water was calculated. It is 1138 millions km3. The middle depth of oceans and seas reaches about 3790 m. If all the water overflowed across the Earth surface, it would reach the height about 2200m. Nowadays modern equipment is able to exploit energy of seawater movement. The great energy is hidden in surf waves. Also sea currents and energy of thermal gradient of depth could be used. The sea is the resource of different materials that can be important for energetic purposes, for example uranium and deuterium. Also coal, mineral oil and gas could be mined from sea bottom. There is 97,2% of world’s water resources, 39,8 trillions of salt and almost all the minerals in oceans and seas.

2.3.4 Energy of waves

All the water matter of world oceans is constantly moving not only on its surface, but also in the deepness. According to the direction of water elements the movements are divided to vertical, which change the sea level, and horizontal, which are made of local or over oceanic current systems. It was calculated that we could gain from current energy up to 342 mld. MJ of electric energy. Energy could be obtained by classical equipment of water power stations or by unusual modern methods. An Englishman Christopher Cockerel came up with one of them. The fundament of his project is made of three part balks; pontoons that float on the sea surface and are anchored to sea bottom (picture 6). Wave movement is transported to water motor linked with alternator for production of electric energy.

Japanese had another interesting proposal. It comes out from regular increase of hydrostatic pressure according to water column of rising waves. At such a principle small power station is based. It supplies reflectors of lighthouses on the island Aschika nearby Tokyo.

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Pct. 6. Cockerell’s floating balks

Norway is planning a great exploitation of sea waves. According to Noriform centre the waves distanced 20 naval miles in front of their seashore have the mean power 23,7 kWm-1. From the 2500-km long Norwegian shore we could gain about 600 TWh of electric energy. It is the same amount as is produced in nowadays power stations on Earth.

Sea waves change when they move. If they slap the sea bottom, their height and length will change, but period will be the same. Length and speed is reduced with lowered depth. If the depth of water equals the half of length of wave, or it is less, the shape will change as well. Its height will rise and it will break. The place, where the wave is broken, is called breaker. The power of surge during thunderstorms is about 30 tm-3 of water. For example in France the surge waves threw 3,5 t heavy rocks over 7m high breaker and they moved for 20m 65t heavy concrete block

2.3.5 Energy of sea currents

25 main oceanic currents have been studied on Earth for energetic purposes The Golf current is the most important. It influences the climate in North America, Greenland, Europe and Africa.

The best exploitation of this current is between Florida and cape Hatteras in the USA. The average current speed is 3,2 km/h in low levels here and 8,8 km/h below the surface. Each second 70 millions m3 of water flow in that area. At the cape area 100-km wide current turns towards east and is directed to Europe. From 1 m2 of water we could gain approximately 0,8 kW of electric power. Total theoretical power of Golf current in that places is about 25 000 MW. In the USA the idea appeared that digging American peninsula Florida could turn the Golf current to the north. It would markedly heat the shore. It would never get to Europe. If it were carried out, the temperatures in Western Europe would fall down to -40*C and the climate would be similar to one at Labrador or Alaska.

2.3.6 Spring and tide

As man realised the constant circulation of water, he revealed the mystery of spring and tide. The oldest way of exploitation was carried out in tidal mills in the 13-th century. There are still remnants of those mills on the French and Italian shores. Isaac Newton, English physicist, explained the periods of spring and tide. It is by gravity of the Sun and the Moon, while the force of the Moon is 2,3 times stronger. The oldest tidal power station is Dee Hydrostation with the power 635 kW in England. It was built before the First World War in 1913. After that new design ofpower stations followed, which would solve the only problem; irregularity of spring and tide. By exploitation of tidal energy it would be possible to obtain 7,2 to 11,8

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billions MJ per year. It is not a small amount, because today 108 up to 126 billions f global energy is produced. San Jose, Secure Bay (Australia), South Korea and the area of Normandy are the convenient areas for exploitation of tidal energy.

2.4 Geothermal energy

Geothermal energy, inside heat of the Earth, is only the part of energy of our planet. It is manifested either mechanically (earthquakes, folding of the mountain ranges) or thermally (volcanoes, geysers and warm springs).

It has bee verified that heat course from the inside of the Earth to its surface reaches 26 TJs-1, that is 820 trillions J. If we covered all the nowadays and future energetic consumption of humankind by this energy, the temperature would fall down by only 1 degree C for 40 millions years.

The core of the Earth is created by fiery material from melted metals. It is under the pressure of about 350 thousand MP. This material is closed in the globe, which is 300 km in diameter. Around the core there is a coat made of melted iron and nickel. Between the coat and solid earth’s crust there is 2900-km wide thick layer of fiery minerals. Their temperature when they near the surface is about 1000 degrees C. Land consists of lighter rocks with Si and aluminium.

When we consider the exploitation of geothermal heat, the temperature rises with the depth; for every 30m it is 1 degree C. In 3km bellow the surface it is approximately 100*C and in 60km it is theoretically up to 1800*C. The Earth radiates as much heat per 1 year as would be gained from 30 mld. of the highest quality coal. It is one half of the world’s resources of natural fuels.

Three types of geothermal power stations are used in practise.

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Pct. 7. Cross-section of the planet

The first typeIt exploits thermal energy of vapours and gases coming out from the earth.

Operation as well as building of this type is cheap. Power does not overcome 3 MW. 15 -20 kg of vapour is used for 1 kWh of electrical energy.

The second typeIt is used in the regions with corrosion elements. Vapour is cleaned in

separators and then it is lead towards the turbine. The vapour exploitation is 15 kg per 1kWh.

The third typeIt is the combination of previous two. It is used when vapour does not cause

corrosion, but it contains bor. acids and ammonium salts. The exploitation is 10 kg per 1 kWh.

Resources of subterranean warm waters are enormous, for example in west Siberia there is ocean under the ground. Its area is twice bigger than Mediterranean Sea. It contains 1 mld. km3 of hot water from 100 to 150 *C. There is more energy than we would use by burning all the coal, mineral oil and gas plus exploitation of wind and water courses.

2.5 Thermonuclear energy

So far we know two ways of gaining thermal energy from nuclear reaction:

The first wayFission of heavy element’s atoms - uranium and plutonium.

The second way Connection of some lighter element’s atoms in very high temperatures. It is thermonuclear reaction.

The first way is used peacefully. The second way is useless, because we cannot regulate the reaction. If we succeeded in that, thermonuclear reaction would be abundant source of energy.

What does it really mean the thermonuclear reaction? It is exoteric reaction of the synthesis of two atom’s nuclei. It is carried out in very high temperatures. The substances are heated to tens of millions degrees C and they perfectly ionise. In

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following plasma the medium value of energy of elemental thermal motion reaches several kilo electron volts. According to Maxwell’s theory there is a group of elements, which energy is sufficient for synthesis of light atom’s nuclei while the great amount of heat is relieved. As soon as this amount of energy is relieved spontaneous thermonuclear reaction may occur. It is similar to the Sun or stars.

In hydrogen bombs there is merging of isotopes of hydrogen and lithium in a one millionth of second. Uncontrolled and non-stationary thermonuclear reaction is carried out. It destroys everything living by its effect in 100 km‘s circle.

The most effective fuel for thermonuclear reactors is deuterium. Its resources would last for several 100 millions years of exploitation on the Earth. Directed thermonuclear reaction is simple. Atoms of heavy hydrogen are transformed to plasma. Nuclei and electrons are separated there and then merged in heavier nuclei of helium. Much more energy is relieved there than during the nuclei fission and there is no radioactive radiation.

3 Sources of energy in Slovakia

3.1 VOJANY POWER STATION

The power station is placed in the Slovnaft factory area in Vojany. It provides for convenient transit and trade services, because of its position near borders with Ukraine, Hungary and Poland. It is connected with European railway network as well as large scaled railway network. It has got its own trailers.

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Pct. 8. European railway

Installed capacity of the Vojany Power Station is 1,320 MW, which is 21.5 percent of the capacity of the Slovak Electric, Plc.

Vojany Thermal Power Station consists of two plants: - TPS Vojany I (EVO I) - TPS Vojany II (EVO II)

EVO I Installed accomplishment : 660 MWBoiler number : 6Fuel : T bitumonous coal (anthracite)Boiler : One- drumm boiler with natural circulation With powder heating and melt firePower output : 355 t/hOutput pressure of steam : 13,6 MpaConstruction : Start in 1961Putting into service : During 1966

Coel is imported from Ukraine and Russia with an integrated set of wagons to the TPS. A wagon can carry 65 tons of coal. The LHV ( Lower Heat Value ) is app. 25 GJ per ton of fuel.

EVO II Installed accomplishment : 660 MWBoiler number : 6Fuel : heavy heating oil and natural gas Boiler : One- drumm boiler with natural circulation With oil or gas heatingPower output : 355 t/hOutput pressure of steam : 13,6 MpaConstruction : Start in 1968

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Putting into service : During 1973-1974

Liquid fuel (the heavy oil) of the LHV of 39.5 GJ per ton is bought in a free market from both domestic production (Slovnaft), and abroad. Gaseous fuel (Natural gas) of the LHV of 35GJ per 1000 is taken from the interstate gas pipeline BRATSTVO from Russia.

3.2 MOCHOVCE NUCLEAR POWER PLANT

Mochovce Nuclear Power Plant is situated in the Southeast of Slovakia, near the town of Levice, on the area of the former village of Mochovce. The course of construction was influenced by various factors – the crucial once turned out to be the change of instrumentation and control system concept and system of funding. After a complicated period of halted construction in 1991 to 1995 ( when ways of further funding and public confidence in the uncompleted construction were sought ), the Slovak Government endorsed a model of the units 1&2 completion and funding on 5 September 1995.

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Pct. 9. Sight of nature around Nuclear power plant in Mochovce.

3.2.1 ELECTRICITY GENERATION, OPERATION & NUCLEAR SAFETY

The principle of a nuclear power plant generation is similar to the one of a fossil-fuel burning plant. The only difference is the source of heat. In thermal power plants, the source of heat is a fossil fuel (coal, gas), while nuclear power plants use a nuclear fuel (natural or enriched uranium). There are four reactor units on he site of Mochovce NPP. One WWER 440 reactor unit generates annually approximately 3 billion kWh in average – that is about 10% of the total energy demand of Slovakia. The plant operation daily preserves about 46 wagons of coal that would have to be burnt in a thermal power plant to generate the same electrical capacity. The fuel in form of fuel assemblies is placed in the reactor pressure vessel, where chemically treated water runs through channels in fuel assemblies and removes heat generated in the fission reaction. The water passes from the reactor at the temperature of about 2970C and flows through a hot branch of the primary loop into a heat exchanger – the steam generator. Running through a bundle of steam generator tubes water transfers its heat to 2220C secondary circuit water. Cooled primary water primary water gets back to the reactor core.

The secondary circuit water evaporates in the stem generator and the steam is transported through a steam collector onto turbine blades. The turbine shaft rotates the generator which produces electricity. After the energy is transferred to the turbine, the steam condenses in condensers and passing through heaters returns back to the steam generator in a liquid state. The mixture is cooled in a condenser by the third cooling circuit. The water in this circuit is cooled by air flowing from the bottom to the top of a cooling tower ( “a chimney effect” ). The airflow takes the steam and a small drops of water and forms steam clouds above the cooling towers. Electricity generation in nuclear power plants in Slovakia is controlled by the energy dispatching centre normally at the base load, because the operation is the most economical at full power. Nuclear plants operate in campaigns once a year the reactor is shut down for refuelling. The fuel used in the reactors is uranium dioxide (UO2) enriched with fissionable isotope of uranium U – 235 whose average enrichment in a fuel assembly is 3.82%. The fuel enrichment gradually decreases as the reactor operates and therefore it must be replaced with fresh fuel after a certain period of time. After the end of the

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campaign one fourth of the fuel is removed and fresh fuel is transported in special containers to an intermediate spent fuel storage where it will be stored for 50 years. The systems and components of the power plant are inspected during the refuelling outages and maintenance is done to ensure failure – free operation in the coming campaign. Each reactor unit has it owns control room where the operation process is controlled by a group of consisting of the reactor unit supervisor, primary circuit operator and secondary circuit operator. The staff has all the necessary information on parameters and plant status available at the control room. The human factor is one of the most important for the safe and reliable operation of nuclear plant. Therefore a considerable attention is paid to continuous staff training and education training and refreshment training programmes have been worked out for every position which ensures staff development. There is a full – scope simulator of the power plant technological process located on the site. The simulator is a replica of the control room. The operational staff passes through regular training courses at the simulator and trains activities in various standard as well as non-standard situation. Elimination of a failure due to a human factor is the most important contribution to safety enhancement and the overall power plant safety. The nuclear safety is immeasurable, impalpable and omnipresent. It depends greatly on the human knowledge and consciousness. It is a process that never ends. Every year a significant amount of money is invested in its enhancement. The general task of nuclear safety is to protect employees, population and the environment by the formation and maintenance of an effective protection against leakage of radioactive substances into the environment. The basic requirements of nuclear safety are : control of the fission reaction, entrapment of radioactive materials and heat removal.

There is a series of safety systems installed at the power plant. The purpose of the systems is to shut and cool the reactor in safe manner in any conditions. The safety systems have 200% back-up, i.e. each system consists of three identical independent systems out of which one is sufficient to prevent an accident. The systems are located in separated areas and each of them has an independent source of electrical power supply. The level of nuclear safety is also conditioned by a strong safety culture, the responsibility of the power plant staff and the independent inspection of the observance nuclear safety rules. The radiation protection of the power plant staff and the population of the nuclear safety. The main goal of the radiation protection is expressed by the ALARA (As low as reasonably achievable) principle , i.e. to insure that the radiation exposure inside and outside the power plant be as low as reasonably achievable with consideration economic and social factors.

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All international audits in various aspects have so far confirmed that the nuclear safety and technical level of Mochovce NPP are of the very highest level among all WWER 440/V-213 units. Mochovce NPP has become a referential power plant for updating and enhancing of other units of the same type in the Central and Eastern Europe. It is an outstanding example of putting Eastern and Western technologies together, as well of broad international co-operation.

3.2.2 BASIC DATA OF MOCHOVCE NNP

General: Number of units: 4Type of reactor: VVER/V-213 pressurized water Reactor thermal power: 1,375 MWtReactor nominal power: 440 MWeOwn consumption: 35 MWUnit efficiency: 32%

Reactor pressure vessel Internal diameter: 3,542 mm

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6

5

4

3

2

1

Pct. 10. Split reaction of uranim.

Wall thickness: 149 mmHeight: 11,805 mmMass: 215,150 kgMaterial: alloyed Cr-Mo-V steel

Primary circuit: Number of cooling loops: 6Coolant flow rate: 42,600 m3/hWorking pressure: 12,26 MpaCoolant temperature at reactor outlet: 297,30CCoolant temperature at reactor inlet: 267,90CTotal volume:242 m3

1. UPPER BLOCK2. PROPULSION OF REGULATION CASSETTES3. COVER OF PRESSURE VESSEL4. BLOCK OF SAFETY PIPES5. EXIT GAP6. ENTRANCE GAP7. ACTIVE ZONE8, 9. PRESSURE VESSEL OF REACTOR10, 11. PIT, BOTTOM OF THE PIT Reactor core Number of working fuel assemblies: 312Number of control fuel assemblies: 37Fuel mass in the core: 42 metric tonsFuel used: UO2

Fuel enrichment: 3,3 – 3,6 – 4,0 % U235

Steam generator – 6 pcs per unitType: PGV - 213Volume of steam generated: 450 metric tons per hourOutlet steam pressure: 4,61 MpaOutlet steam temperature: 2550CFeedwater temperature: 2220CMass: 169t (suspensions excl.)

Gas discharges

Discharge Value Size

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10

11

9

8

Pct. 11. Scheme of reactor VVER 440/V – 213 installated in NNP.

Noble gases 4,1.1015 Bq/yearIodine 6,7.1015 Bq/yearAerosols 1,7.1015 Bq/year

Liquid discharges

Discharge Value SizeTricium 1,2.1013 Bq/yearCorrosion & fission products 1,1.109 Bq/year

3.3 THE GABČÍKOVO HYDROELECTIC PROJECT

The Gabčíkovo Project was originally designed and constructed as a part of the Hydro – electric System Gabčíkovo – Nagymaros located on the Danube river downstram of Bratislava. Bratislava, the capital city of the Slovak Republic, lies close to the borders with Austria and Hungary. The highways, railways, airways and the international Danube water – way secure and ideal interconection between these countries.

The multipurpose hydroelectric project was built together with Hungary, according to an interstate Treaty signed in 1977. When the Gabčíkovo Project was completed to about 90%, Hungary stopped to fulfill its treaty obligations in 1989 and tried to terminate the Treaty in 1992. Czechoslovakia had no other choice in its endeavour to save the investment ant to prevent significant economic and environmental damage as to introduce a temporary

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solution, called Variant C, diminishing the size of the reservoir damming the Danube at Čunovo, on Slovak territory and setting the Project in operation. One of the most significant goals of the multipurpose Gabčíkovo Project, is the protection against floods, which caused several times catastrophes on the Danubean region. In addition, the project secures in its section full navigability throughout the whole year, and produces yearly about 2.4 billion KWh of electric energy, what represents approximately 10% of the annual consumption of the Slovak Republic. Besides these main goals, the Project stabilises the riverbed of the Danube, improves the water regime of its interior delta and creates also good conditions for enhancement of water – sports and recreational use of the newly created water surfaces and of the surrounding territory. The Gabčíkovo Project was put into operation in October 1992, with an installed capacity of 720 MW in 8 turbine / generator sets. The monitoring results confirm that the environmental parameters of the whole influenced area did not become worse, or that they were even improved. The same applies for the quality of the ground water, while increasing the capacity of wells. The system of side arms on both sides of the Danube was, in the pre – dam state, 10 to 11 months in year without water supply. The take – off structure from the power canal at Dobrohošť, allowing permanent watering, or even an artificial simulation of floods on the left side, when necessary. For the watering of the right Hungarian) side, there serves an overflown dam in the Danube at Dunakiliti, built after a long discussion in 1995. Both the Slovak and Hungarian Republics agreed in April 1993, to present their dispute to the international Court in the Hague, mutually formulating questions to be answered. The verdict has been delivered on 25 th September 1997. in its judgement, the Court found :

● That Hungary was not entitled to suspend and subsequently abandon, in 1989 its part of the works in the dam Project, as laid down in the treaty signet in 1977 by Hungary and Czechoslovakia and related instruments.

● That Czechoslovakia was entitled to start, in November 1991, preparation of an alternative provisional solution (called

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“Variant C”), but not to put that solution into operation in October 1992 as a unilateral measure.

● That Hungary’s notification of termination of the 1977 Treaty and related instruments on 19 May 1992 did not legally terminate them (and that they are consequently still In force and govern the relationship between the Parties).

● That Slovakia, as successor to Czechoslovakia became a party to the Treaty of 1977.

According to this verdict, Hungary and Slovakia must negotiate in good faith the achievement of the objectives of the Treaty 1977. In accordance with the relevant provisions of the Treaty, there has to be established a joint operational regime on all structures, including the Čunovo structures and the accounts for construction and operation have to be settled. Each Party must compensate the other Party for damage caused by its conduct. The ability of man to harmonise his interest with the needs of the nature has been fully reflected in the Gabčíkovo Project. The demand of sustainable development was in this case completely fulfilled.

4 ADDITIONS

4.1 Coverage of energetic consumption in Slovakia in year 1998 and 1999

4.2 Emissions of bad waste products that are shed every year by power plants with the output of 1000 Mwe

Power plant Acid gas Oxide sulphur Oxide - 21 -

nitrogenCoal 1 600 70 25Gas 920 0 15Oil 1 300 32 14Wood singe 1 320 1 7Nuclear* 50 3 1

*The nuclear pow.pl. don´t spread any dangerous gas. The numbers mean the construction.

4.3 Comparison of social hazard by nuclear and thermal power plants on GWe/year

Nuclear power plant Thermal power plant

Source of hazard Mortality Events not ending

with death Source of hazard MortalityEvents not ending with

death

Uranium-mining 0,2 4,6-14,0 Coal-mining 0,9 84

Manipulation 0,001 0,76-2,3 Coal cleaning

(accidents)0,06 3,0-5

Produce of energy 0,01 1,7-5,1 Coal-transporting

(accidents)0,24 3,1

Transportation 0,01 0,06-0,18 Power plants

(accidents)0,13 5

Overall 0,22 7,0-20 Overall 1,3 96

4.4 Comparisn of consumption of fuel and production of garbage by running nuclear and coal power pl. with the same output

 

Nuclear power plant

1000 Mwe

Coal powerplant

1000 MweConsumption of fuel in year (t) 35 2000000*Consumption of oxigen by combustion (t) 6 200 000Emission of Nox (t) 40 28 000Emission ofCO2 (t) 6 600 000Emission of SO2 (t) Negligible 57 000Other gas (t) 2 000

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Hard garbage(t) 415 000Highly active garbage(t) 10Low active garbage (t) 400Mediumly active garbage (t) 600

*bituminous coal. In the case of brown coal it is consumted 4-6 mil.ton.4.5 Consumption ofenergy in Slovakia in yers

1998 and 1999 for redeemable and not redeemable sources

Indexes Unit of mesurement Power plant

Nuclear Coal Gas Watter Wind Sun***

Standard output of power plant MWe 400-1400 300-1000 50-250 10-600*

0,1-10** 0,1-0,5 0,001-0,010

Consumption of area m2/MWe 630 2400 1500 265000 1700000 100000

Consumption of material (beton ,steel,

glass, plastic)kg/MWh.r 90 50 50 535 255 355

Time needed to cover energy consumted by

constructionMonths 2,2 3,4 3,4 2-3,0 8,0-16 80-240

Coefficient of investment cost DM/kWe 2700 2000 6000-

12000 4000 20000

Expenses of generation for

el.energyDM/kWh 0,1 0,15 0,13-0,27 0,3 1,8-3,0

Comparisn of some indexes at construction of power plants of several types

* Big watter pow.pl.** Small watter pow.pl.*** Fotovoltaic pow.pl

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4.6 Nuclear reactors in Slovakia - condition to 1.1.2000

Commercial nuclear reactors in Slovakia

El. power plant A-1 V-1 V-2 MochovceBlock 1 2 1 2 1 2 3 4

Begin of construction 1958 1972 1972 1976 1976 1981 1981 1981 1981

Begin of commercial construction 1972 1978 1980 1984 1985 1998 1999 ? ?

End of commercial construction 1977 2006 2008

Condition Type of reactor PWR PWR PWR PWR PWR PWR PWR PWR

Technical mark of reactor KS-150 V-230 V-230 V-213 V-213 V-213 V-213 V-213 V-213

Thermal performance of reactor (MW) 560 1375 1375 1375 1375 1375 1375 1375 1375

Pure electric performance of block

(MWe)150 408 408 408 408 408 408 408 408

-Reactor out of running-Reactor in run-Reacor under constructionA-1, A-2, V-2 – Jaslovske Bohunice nuclear power plant

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