AE Mochovce

In the south of Slovakia, between the towns of Nitra and Levice, there are located four VVER 440/V-213 pressurised water reactors units of the Mochovce NPP.

Mochovce NPP on-line virtual tourUnit 1 supplies electricity to the power grid since the summer of 1998, and Unit 2 since the late 1999. Their gross power output was up-rated from 440 to 470 MW per each unit. Each Mochovce NPP unit generates over 3,000 GWh of electricity annually, which represents approximately 11% of Slovakia's electricity consumption.

Construction of Units 3 and 4 was suspended in 1992 and re-started in November 2008.

Mochovce units are one of the youngest VVER 440/V-213 type units. That's why they benefit from the latest technological improvements that were implemented at the plant. International expert teams have agreed that, once the safety measures are in place, the plant complies with all the international standards and nuclear safety levels, assessing its reliability as extremely high.

Since late 2008 the two operating units at Mochovce NPP have uprated power output to 235 MWe per turbogenerator, ergo the total installed capacity of units 1 and 2 in Mochovce NPP stands at 940 MWe. In 2009, the plant managed to generate over 7 TWh of electricity during a one year period for the first time in its history. This represents approximately one quarter of the overall annual electricity consumption in Slovakia.

20000BC: Inhabited by humans, stone axe found 20 000 BC
Inhabited by humans, stone axe found
1 259 AD
First written mention of a settlement called Mohi
1 259 AD: First written mention of a settlement called Mohi
1 981: Start of construction works at Mochovce – ground works 1 981
Start of construction works
at Mochovce NPP – ground works
Start of construction works on Mochovce NPP unit 1 and 2
Start of construction works on Mochovce NPP unit 3 and 4
Replacement of the instrumentation and control system
Halt of the construction works
Re-start of conrtruction works on unit 1 and 2
Commissioning of Mochovce NPP unit 1 and 2 1998
Commissioning of unit 1

Commissioning of unit 2
Enel acquired 66 % of Slovenské elektrárne
Unit 1 and 2 installed output increased to 107%
Start of the Mochovce NPP 3&4 completion project
Commissioning of NPP Mochovce
units 3 and 4
Green field 2100
Green field
Number of units 2
Reactor type VVER 440/V 213 - tlakovodný
Reactor heat capacity 1 471 MWt
Reactor rated output 440 MWe
Self-consumption 35 MW (8 % menovitého výkonu)
Unit efficiency 32%
Reactor pressure vessel
- internal diameter 3 542 mm
- wall thickness 140 + 9 mm
- height 11 805 mm
- weight (less internals) 215 150 kg
- material legovaná Cr-Mo-V oceľ
Primary circuit
- number of cooling loops 6
- coolant flow rate 42 600 m3/h
- operating pressure 12,26 MPa
- reactor output coolant temperature 297,3 °C
- reactor input coolant temperature 267,9 °C
- core temperature drop 29°C
- overall volume 242 m3
- number of operating fuel assemblies 312
- number of control fuel assemblies 37
- total fuel assemblies 349
- core fuel weight 42 t
- fuel used UO2
- medium fuel enrichment 4,87 % U235
Steam-generator 6 per unit
- PG type V-213
- amount of steam generated 450 t/h
- steam output pressure 4,61 MPa
- steam output temperature 255 °C
- feed water temperature 222 °C
- weight 169 t (less suspensions)
Turbo-generator 2 per unit
- ŠKODA type 220 MWe
- number of stages 1 high-pressure, 2 low-pressure
- rated rotational speed 3 000 rpm
- generator rated apparent output 250 MVA
- terminal voltage 15,75 kV
- rated current 3 x 9 500 A
- amount of cooling water 35 000 m3/h
- maximum cooling water temperature 33 °C
Emergency systems
(a) Passive:  
4 hydro-accumulators 70 m3 each
of which:  
- water volume 40-50 m3
- nitrogen volume 20-30 m3
barbotage tower  
- overall barbotage well capacity 13 800 m3
- 4 capture chambers for gases with a capacity 16 140 m3
- 12 barbotage throughs 1 380 m3
(b) Active:  
high-pressure system  
- pump capacity 65 m3/h
- outlet pressure 13,5 MPa
low-pressure system  
- pump capacity 800 m3/h
- outlet pressure 0,72 MPa
- pump capacity 380-520 m3/h

Monitorovacie staničky v okolí AE MochovceNuclear power plants emit no greenhouse gas to the atmosphere, in this way NPPs annually contribute to CO2 emission reduction by 15 million tonnes in Slovakia.

Nuclear power plants hence contribute significantly to the obligation to reduce emissions of harmful greenhouse gas to the atmosphere.

Mochovce NPP meets all international requirements and that the operation impact is minimal.

Water required for cooling is taken from a water dam built on the nearby Hron river, which ensures sufficient supply of water even in extremely dry climate conditions. The impact of the discharged waters on the quality of the Hron river water, fauna and flora is negligible.

Emissions to the atmosphere and effluents to the hydrosphere are regularly measured and assessed in the 15-km area around the plant. There are 25 monitoring stations of the tele-dosimetry system, which continuously monitor the dose rate of gamma radiation, activity of aerosols and radioactive iodine in the air, soil, water and food chain (feed, milk, agricultural products). The volume of radioactive substances contained in liquid and gaseous discharges is considerably lower than the limits set out by authorities.


  • WANO Peer Review Follow-Up


  • WANO Peer Review Mission (2009) Review of 9 areas:maintenance, operation, technical support, operational experience, radiation protection, chemistry, training and qualification, organisation and management, and emergency preparedness


  • OSART Follow-Up Mission – review of condition of equipment or recommendations from 2006


  • OSART mission


  • IAEA Mission within the IPPAS programme


  • Follow-Up WANO Review Mission


  • Peer Review of the Mochovce NPP during the WANO mission


  • IAEA IPSART Mission focused on the probabilistic safety analysis report of the Mochovce NPP


  • WENRA Mission – after review of parts of the safety analyses, the safety standards of the installation are comparable with power plants already operated in the Western Europe


  • The RISKAUDIT Consortium reviewed safety of the Mochovce NPP within the PHARE project.


  • Meeting of IAEA experts confirmed that no risks related to the NPP reactor pressure vessel in Mochovce were identified.


  • IAEA Mission – review of safety measures in the Mochovce NPP:verification of NPP safety measures in Mochovce
  • IAEA Mission within the WATRP programme – review of operation safety at radioactive waste management in the Mochovce site
  • Environmental impact assessment – study prepared by AEA Technology in July – August
  • IAEA Mission – review of seismic safety in Bohunice and Mochovce NPPs.The Mission evaluated basic data and compared them with recommendations defined in the IAEA Safety Guide 50-SG-S1 related to positioning of NPPs.
  • RISKAUDIT Consortium mission (Consortium of IPSN and GRS organisations ensuring works for national regulatory authorities in France and Germany) focused on evaluation of NPP safety measures in Mochovce and verification of design safety


  • IAEA Mission – pre-OSART:focused on verification of readiness of the operator to commission and operate

Občianska informačná komisia MochovceCivic Information Committee (CIC) Mochovce is an independent information channel to transfer information between the Mochovce NPP and the population living in its vicinity. Its establishment by Mochovce NPP was based on good practice from some world countries where similar committees had been established on the basis of voluntariness or legislation.

The purpose of the Committee consisting of representatives of the public who are active and known in the public and social life is to transfer qualified and current information by its independent members to the public in compliance with strategic objectives and goals of Slovenské elektrárne in the field of informing public and in compliance with the Act on Free Access to Information.

CIC was established by Mochovce Director as of January 1, 2005 with the aim to carry on an open dialogue with the public on peaceful use of nuclear energy, and taking into account the right of citizens to be informed truly and immediately of all aspects of operation of nuclear power plants, safety and impact of the power plant on the environment by delegated representatives of the citizens, and to improve the quality of informing the public.