Olkiluoto 3 1,600MW Nuclear Power Plant, Finland

Construction of the Finnish Olkiluoto 3 1600MWe nuclear power plant has has been delayed again; this time the plant is scheduled for completion by 2010 at the earliest. This, the fifth Finnish nuclear reactor, is an EPR (Evolutionary Power Reactor) Pressurised Water Reactor and is being constructed by a consortium formed by Areva and Siemens.

The EPR is the only third-generation reactor currently under construction in the world, and Olkiluoto 3 will be the first third-generation type to come on line. Studies for another reactor are being discussed.

The overall project cost was €3.2bn. In 2006, the levelling concrete for the base of the main buildings was to be poured and construction started on the APC (Air Plane Crash) Shell.

EPR PRESSURISED WATER REACTOR

The EPR is the direct descendant of Areva’s N4 and KONVOI reactors. The pressurised water in the primary system is used as a moderator to slow down the neutrons, allowing a nuclear reaction to occur in the core, and transfer the heat generated during the reaction to the steam generators.

The EPR has four steam generators – one for each of the four heat removal loops making up the primary system. Steam generators are heat exchangers. They receive heat from the nuclear reactor on their primary side, and deliver heat to the non-nuclear part of the facility on their secondary side. There is a leak-tight separation between primary and secondary sides. The secondary heat produces steam to power the turbine which generates electricity.

The turbine building houses the equipment that transforms the steam produced into electricity: the turbine, the alternator and the transformer, which is connected to the grid. During a power blackout, diesel generators housed in two separate buildings supply electricity to the safety functions.

REDUNDANT SAFETY SYSTEMS

The reactor containment building has two walls: an inner pre-stressed concrete housing internally covered with a metallic liner, and an outer reinforced concrete shell, both 1.3m thick. The outer shell covers the reactor building, the spent fuel building and two of the four safeguard buildings (the other two safeguard buildings are in a different location).

The containment building houses the reactor coolant system, made up of the reactor vessel, steam generators, pressuriser, and reactor coolant pumps. Inside the containment there is an area where any of the molten core escaping from the reactor vessel during a core meltdown would be collected, retained and cooled.

The major safety system consists of four sub-systems or "trains". Each train is capable of performing the entire safety function independently. There is one train in each of the four safeguard buildings, separated from each other by the reactor building to prevent simultaneous common-mode failure of the trains.

The control room is in one of the safeguard buildings, protected by the outer shell. The computerised control room allows operators full control over all parameters important for plant operation.

Projected service life is 60 years, compared with a 40-year service life for other power reactors.

AREVA HEADS CONSTRUCTION CONSORTIUM

A consortium formed by Areva and Siemens signed the contract for the turnkey construction with TVO. Areva is supplying the nuclear island, the Digital Control System and the first fuel core, and civil works. It is also supplying parts of balance of plant comprising access building, waste building and an EPR simulator. As leader of the consortium, Areva is coordinating the overall project, including functional and technical integration of the complete plant.

Siemens PG is building the turbine island and supplying the turbine generator set. That includes engineering and design, procurement and delivery of electro-mechanical equipment, turbo-generator protection and control system, civil works, erection and commissioning.

A significant part of the civil construction and erection work has already been subcontracted. A large amount (47%) was awarded to companies in Finland directly, but companies from abroad often engage Finnish sub-suppliers, too. TVO is responsible for the overall project management and licensing process with the Finnish Safety Authority STUK.

In October 2006, the EC launched a formal investigation on the French government's €570m loan guarantee for Olkiluoto-3, asking whether it broke EU rules on state aid. In December 2006, Areva reportedly took a charge of €500m for extra costs because work on the reactor was 18 months behind schedule. Areva remarked in response that it was the first reactor of its kind.

Around 600 people work at the site, with up to 3,000 during peak times.

NUCLEAR POWER IS MAJOR FINNISH ENERGY PROVIDER

Nuclear power is the largest source of energy in Finland, accounting for 25% of the energy produced. The country’s internal natural resources are limited, while the consumption per inhabitant is high (15,600kWh), and growing at an annual rate of over 2% per year. Nearly 70% of the energy used must be imported. This major constraint threatens the country’s energy independence and economic balance.

Finland used 84.9 billion kWh of electricity in 2005, and demand is continuing faster than in the other Nordic countries. In the last 10 years, consumption has increased by an average of 2.6% a year, and is expected to reach 94.2TWh in 2010 and 103.3TWh in 2020.

Industry is the largest consumer of electricity because Finland has a large energy-intensive industry, and increased production raised the industrial power demand by 3.8%. In 2005, Finnish industries used about 52% of all electricity.