Mochovce 3&4 construction

Mochovce 3&4 Project Completion (01/10/2015)
  • one of the three projects of nuclear power plants currently under construction in Europe
  • the largest private investment in the history of Slovakia
  • 2/3 of works on site is performed by Slovak companies
  • 90% of the population around power plant is in favour of the completion of Units 3&4
  • each unit will have 471 MWe output
  • annual production of two units will save over 7 million tonnes of CO2 emissions
Mochovce 3&4 project progress: Cummulative man-hours

Construction progress at Mochovce NPP units 3&4

1st quarter 2015

  • Insulation of tanks for the emergency feedwater system.
  • Erection of horizontal and vertical cable trays in the turbine hall of unit 3 +9.6 m.
  • Erection of ventilation in the ancillary building continued.
  • Pipelines and pumps for boron concentrate were added.
  • Erection of stainless steel lining of the spent fuel pool.
  • Demineralized water system was installed for turbogenerator TG41.
  • Erection of the steam separator in the turbine hall of unit 4 continued.
  • Pipelines and valves for residual heat removal were erected in the turbine hall of unit 3.
  • Welding of stainless steel lining of the spent fuel pool.

2nd quarter 2015

  • Erection of 688 anchoring plates in unit 3 and 1 588 plates in unit 4.
  • 386 out of 396 rooms in the reactor building were prepared for the erection of technology in unit 3.
  • Hydrotests concerning the fire water lines on the conventional island of unit 3 were completed. Installation of smoke detectors in the I&C rooms was completed as well.
  • In the conventional part of unit 4, construction test of emergency demineralized water tank was carried out. 

3rd quarter 2015

  • Construction test and hydrotest of the tank (emergency feedwater system for steam generators).
  • Construction works were carried out following the erection of fire flaps and freon pipelines in two rooms.
  • In the ancillary building, 140 rooms out of 155 were prepared for the erection of technology.
  • Functional tests of the cooling water system were carried out.
  • The construction of anti-aircraft barriers continued.
  • Concrete works in the common diesel generator station continued.
  • We delivered a new TG32 turbogenerator for unit 3.
  • Hydrostatic tests of the sealing of the spent fuel pool lining were carried out.
  • Completion of Full Scope Simulator site acceptance testing.
  • Commencement of functional tests of medium voltage switchboards at Mochovce Power Plant Unit 3.
  • Unit 3 Control Rooms (main control room, emergency control room, common control room) assembled for start of Commissioning activities.
  • Start of Mochovce 3&4 operators training at the Full Scope Simulator; following the completion of licensing process for operators training by the Nuclear Regulatory Authority of the Slovak Republic.
  • Submission of "Pre-Operational Safety Analysis Report" to the Nuclear Regulatory Authority of the Slovak Republic. The document is the key for authorization of Fuel Loading to Unit 3.
  • Unit 3 Main Control System: 90 % of internal cabling of Unit 3 Main Control System (total: 9.000 cables) completed.
  • Unit 3 Nuclear Island: Civil Readiness of over 90 % of NI rooms needed for Unit 3 Commissioning. Instrumentation room (1 out of 3) with impulse lines, penetrations impulse lines and racks completed. The room is ready for the installation of the instruments. Radioactive waste treatment piping installed.
  • Reactor hall civil works completed which is the first step towards Strict Clean Conditions required for Reactor internals works.
  • Unit 3 Conventional Island: First phase of 6kV busbars commissioning completed. Mechanical completion of the main systems (non-essential and essential service water, main steam, feed-water, condensate, high and low pressure air systems). Up to 100 km of main cable trays erected (100 %).
  • As of the end of 2014, the Unit 3 was 81% and the Unit 4 was 63% completed.
  • Civil readiness of Unit 3 Nuclear island critical rooms.
  • Completed the Detailed Design of Unit 3 Anchoring Plates.
  • Start of mechanical erection activities in the Nuclear island critical rooms.
  • TG31 and TG32 Final assembly, bearing closing, turning gear installation, insulation assembly.
  • Completion of Mechanical Erection of Unit 3 Main Steam and Feedwater systems.
  • Individial tests of Unit 3 LV/MV Cabinets.
  • Unit 3 – Distributed control system power up.
  • Full Scope Simulator
    • Application Software Installed and Tested;
    • Site Acceptance Tests.
  • Refurbishment of hermetic cable penetrations at the Units 3&4.
  • Fire protection lining and painting in auxiliary nuclear building
  • Civil readiness for foundations under pipe bridge
  • Concrete floor drainage in room A217
  • Transport and assembly of 7th section of spent fuel pool in Unit 4
  • Installation of instrumentation and control system cabinets
  • Welding of stainless-steel lining floors on Unit 4 in A201/2, A301/2
  • Grouting activities - works under the tripods of primary circuit of Unit 4
  • Assembly of penetrations on the shaft no. 1 of Unit 4
  • Concreting of floors and vertical elements in the vent stack
  • Modernization of main circulation pump 3, 6
  • Refurbishment of main circulation piping
  • Erection of diagnostic system on steam generator 6
  • Welding of support ring under core basket
  • Erection of removable part of main circulation pump 2-6
  • Three stand supports straining of main circulation pumps 1-6
  • Transport of frames and pumps of sprinkler and low pressure emergency injection system
  • Erection of bellows
  • Blowing through the steam generator 1
  • Commissioning of 110 kV back-up electric source
  • Concreting of Unit 3 reactor postament
  • Installation of 400kV electric switch yard
  • Fresh nuclear fuel storage prepared for technology installation
  • Assembly of all four steam turbines of Units 3 & 4 completed
  • Safe Enterprise certificate for SE-MO34 site
  • Refurbishment of internal walls of vent stack;
  • Refurbishment of roof of nuclear auxiliary building;
  • Refurbishment works of condensate tanks on the roof of auxiliary nuclear building;
  • Seismic reinforcement of reactor building;
  • Seismic reinforcement of internal walls of auxiliary nuclear building;
  • Refurbishment of internal walls of connecting bridge;
  • Installation of earthing networks of vent stack;
  • Civil readiness of the emergency room in a simulator building;
  • Hydrotest of spent fuel pool of Unit3 (shaft No. 1);
  • Grouting of mechanical equipments (primary coolant pumps);
  • Civil readiness for refurbishment of reactor upper block;
  • Refurbishment of hermetic and non-hermetic zone in reactor building (Unit 3,4);
  • Foundations for pipe bridge; 
  • Refurbishment of external walls of auxiliary nuclear building;
  • Internal seismic reinforcement of connection bridge;
  • Erection of fire protection lining in auxiliary nuclear building;
  • Concreting works on postament of unit 3;
  • Heavy concreting on postament of Unit 4;
  • Reinforcement on postament of Unit 4 around shaft no.1;
  • Concreting works around reactor pit of Unit 3;
  • Erection and welding of main circulation piping in the steam generator box;
  • Reactor pressure vessel of unit 4 transport and placement (2-3/12/2011);
  • First turbine of Unit 3 installation (December 2011).
  • Seismic reinforcement of reactor building roof;
  • Seismic reinforcement of external structures of reactor building;
  • Seismic reinforcement of steel structures of the turbine hall;
  • Erection of new bridge crane in turbine hall;
  • Refurbishment of turbines supports;
  • Seismic reinforcement of internal steel structures of auxiliary nuclear building;
  • Refurbishment of steam generators (unit 3);
  • Refurbishment of 250t crane in the reactor hall;
  • Reinforcement of roads, corridors and slabs for the reactor pressure vessel transport;
  • Refurbishment of auxiliary structures for transport of reactor pressure vessel;
  • Refurbishment of external walls of vent stack;
  • Refurbishment of cooling towers;
  • Reactor pressure vessel of unit 3 transport and placement (3-4/9/2010);
  • Refurbishment of anchoring structures of steam generators (unit 3);
  • Refurbishment of bubble condenser (unit 3);
  • Refurbishment of external walls of reactor building;
  • Removal of old moisture separators and reheaters (unit 3);
  • Refurbishment of hermetic penetrations;
  • Refurbished rooms in reactor building, number of rooms ready for mechanical erection:
    • Unit 3: 328 out of 353;
    • Unit 4: 197 out of 239.
  • Main nuclear island contracts, EPCM contract for the conventional island and main I&C Engineering contract were signed and activities have started;
  • Contractors' mobilization works completed (site services, site offices, ...);
  • Evaluation of existing components;
  • Refurbishment of reactor hall roof;
  • Seismic reinforcement of the external walls of the reactor building.
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


Main suppliers

Stavebné práce: Inžinierske stavby Košice

Mechanické systémy: Škoda JS, ENSECO, VUJE

Elektrické systémy a prístroje: PPA

Systém kontroly a riadenia: Areva / Siemens

Ostatní dodávatelia: ASE, Rolls-Royce, GSE

Stavebné práce: ZIPP

Mechanické systémy: Škoda Power, Modrany Power

Elektrické systémy a prístroje: ČKD, PPA, Energo & Schneider, Brush SEM, Techimp