Generation II & III

Proud of our involvement with Generation II&III, thanks to trusted partnerships with major vendors

AP600/AP1000 and European Passive Plant Engineering

We have provided a significant contribution to Generation III+ plants, playing a major role in the development of the AP600 plant participating to the Licensing and FOAKE Programs, as Westinghouse Partner.
We contributed to the most critical activities for the development of the AP600 design, including:

  • Computer Codes for Safety Analyses purpose; 
  • Preparation of transient Analyses for the licensing documentation; 
  • Reactor Coolant System  (RCS) Design including the sizing and definition of the main components (e.g., Pressurizer);
  • Definition of the performance of Passive Core Cooling System Design (PXS) and in particular of the Passive Residual Heat Removal System and Core Make Up Tanks;
  • Passive Containment System design including containment design basis analyses and licensing support,
  • Plant Layout and preliminary studies for modularization ,
  • Piping Stress Analysis

One of the major contribution of Ansaldo Nucleare and Italian Industry is related to the Experimental Testing Support that includes the design and construction of several test facilities (e.g. SPES, VAPORE) to assess the behavior of the passive safety features of the AP600 and, subsequently, the AP1000 TM. We also initiated the development and design of the Westinghouse AP1000TM plant since the very beginning of the program, from the first component sizing, experimental testing and safety analyses, to the detailed design of systems, structures and components up to the realization of the construction drawings.
Under contracts with Westinghouse we provided Engineering Services for the detailed design of the AP1000 TM Plant for China and US.
Our Activities include, among the others:

    • Accident analyses for Licensing Documentation (e.g., Design Control Document and Probabilistic Risk Assessment)
    • Structural Modules Design (Inside Containment, e.g. CA01, CA02, CA03, CA04, CA05)
    • Containment Internal Structures Design (Basemat, Floors:CA30s & CA50s, Steel Frames: SPLs & CH)
    • Fuel Transfer Tube design
    • Shield Building Roof Integrated Design 
    • Shielding and Radiation Analyses
    • Safety and Thermal Hydraulic Analyses
    • ASME CL. 1 (e.g., DVI lines) Piping Stress Analysis and Leak Before Break

As Westinghouse Industrial Partners, we established with the support of several European Utilities the European Passive Plant (EPP) Program. The goal of the program was to develop a passive PWR plant design to meet European Utilities requirements and being licensable in Europe. In this frame Ansaldo Nucleare has been involved in the assessment of the EPP plants (EP1000 and AP1000TM) against the  European Utilities Requirements (EUR).  The EPP program also provided contribution to the definition of the AP1000TM proposed for the UK market. We have provide the licensing support, detailed engineering and component design and manufacturing (i.e. Primary Steel Containment Vessel, Passive Residual Heat Removal Heat Exchanger) for the very first Westinghouse AP1000TM nuclear power plant at Sanmen, and today, we are focusing to those AP1000TM plants being considered for construction in the UK, Europe, and elsewhere around the world.


Cernavoda Construction


Since the end of the cold war, Eastern Europe has seen a steep increase in the demand for energy, and nuclear power has been a  key energy source to help meeting this rapidly growing need. In Romania, the  Cernavoda generation II nuclear power plant safely produces around 20 per cent of the country's electricity. The power plant currently has two operational units both using CANDU 6 technology and plans are in place for future expansion. By harnessing this nuclear power, Romania has reduced its greenhouse gas emissions by over 10 million tonnes each year.  The power plant was designed by Atomic Energy of Canada Limited in the 1980s, and was contracted during the Communist era. The initial plan was to build five units but the project was stopped with the five units at different completion stages.

Our solution

In 1990, we formed a consortium with Atomic Energy of Canada Limited AECL to enter into a new contract, taking on the responsibility to manage the completion of the Cernavoda Unit 1. The Plant was successfully completed and began operating at full power in 1996.  Cernavoda 1 has had record capacity factors of 90 percent since 2005. In 2006, this unit supplied almost 10per cent of Romania's electricity demand.

Continuing our alliance with AECL, Cernavoda Unit 2 was completed in 2007.  The plant is essentially the same as Unit 1, but  several improvements were introduced to optimize the thermal cycle and increase reliability and operation.  Among the most important modification it's worth to note the design, procurement, installation and testing of the DCS a modern state-of-the-art Distributed Control System for the Balance of the Plant.  

Present and future

As of today, we continue to provide design and maintenance services to the two Cernavoda Units to ensure safe, reliable and economic energy generation.

We are ready and we also look forward to participate to the completion of Unit 3 and 4 of the Cernavoda Plant.


Innovative Components

Our vision is to provide the clients with innovative design solution and engineered components and equipment to increase the safety and reliability while reducing, at the same time, the overall risk associated with the Nuclear Installation. Following this vision, we have been at the forefront for the development of innovative components for both PWR and BWR nuclear power plants.

 AP1000TM Steel Containment Vessel

The AP1000TM Containment Vessel is a freestanding cylindrical steel vessel, 40 meters in diameter and almost 70 meter high, with elliptical top and bottom heads

We designed the Steel Containment Vessel for the very first AP1000TM unit ever built (Sanmen Unit 1) and also provided support to the manufacturing activities at the Haiyang State Nuclear Power Equipment Manufacturing Company (SNPEMC) workshop and to the construction activities at the site.

AP1000 Passive Residual Heat Removal Heat Exchanger

The Passive Residual Heat Removal Heat Exchanger (PRHR HX) is the component of the passive core cooling system whose function is to remove the core decay heat for any postulated non-loss of coolant accident event, where a loss of cooling capability via the steam generators occurs.

The component is classified as ASME NC, Class 1 and shall withstand a Safe Shutdown Earthquake.

SBWR Isolation Condenser and Passive Containment Cooling Heat Exchangers
Isolation Condenser and PCCS-HX were designed to passively operate and extract heat from the SBWR primary system and by the containment system respectively.  The two Nuclear Classified, ASME-N, heat exchangers were designed, manufactured and tested by Ansaldo Nucleare. 



We are participating to the Mochovce completion project since 2008. This project immediately follows the successful completion, on time and on budget, of the Cernavoda Unit 2 in 2007 and represent the most tangible rewards and confirmation of Ansaldo Nucleare capability to act, in partnership with other major companies, as a credible and effective EPC contractor.

We provide specialized services in support to ENEL/Slovenske Elektrarne (SE) for the proper execution of engineering, quality assurance, planning and erection of the Mochovce 3 & 4 Units.

Ansaldo Nucleare main role is to support the client's Engineering and site project management team by coordinating and supervising the activities carried out by external Main Contractors in charge of the realization of the Conventional and Nuclear Islands assuring the respect of all the Quality, Functional and Physical requirements and interfaces.