Britain to have boiling water reactors

The move by Hitachi to take on the Horizon Nuclear Power project marks a shift in technology direction for the UK, which had been set to replace older gas-graphite reactors with pressurized water units. Industry said the broadening of scope was "good news for the UK supply chain."

Generation I and II units from the UK's former national nuclear program were based on graphite-moderated cores cooled by carbon dioxide. A project in the 1990s to compliment these with a tranche of ten pressurized water reactors resulted in just one, Sizewell B.

In the UK's current push for nuclear power it has been up to private investors to make technology choices, not the government. Based on discussions with vendors and utilities, the first two designs to go through the Generic Design Assessment (GDA) process have both been pressurized water reactors: the Areva EPR and Westinghouse AP1000. Hitachi's move today to purchase Horizon and put forward its boiling water technology means that will also become an option after another round of GDA, sure to begin soon.

UK trade body the Nuclear Industry Association (NIA) said the addition of boiling water technology in the UK would broaden the range of supply chain opportunities. NIA chief executive Keith Parker called the deal, "good news for the UK supply chain, for jobs in the nuclear sector, and for the wider economy." The UK could supply up to 60% of the value of the first unit with the figure increasing for subsequent units, according to Hitachi and government.

Hitachi said it will work with Babcock International and Rolls-Royce to "plan and deliver" the new build program. Rolls-Royce said it would explore with Hitachi how it could offer support through its manufacturing, engineering and technical services. It would also like to develop opportunities in nuclear instrumentation and control.

Advanced Boiling Water Reactor (ABWR)

This is a modular design, for which large sections of the reactor building can be assembled in a factory, complete with wiring and components, before being shipped to site and lifted into place. Hitachi wants to "transfer" this technology and establish a module factory in the UK. The company promised "significant investment in training engineers, construction teams and operating staff for the plants." It is to work with local colleges and universities to develop training programs, which will "create a strong and permanent base of nuclear skills in the UK that also have a global demand."

The development of the ABWR design was unique, and has led to an unusual situation where it can be offered by three different companies. ABWR was co-developed by Toshiba and GE, which then worked with Hitachi to construct the first two units in the late 1990s. GE and Hitachi went on to form joint ventures of their nuclear businesses, resulting in two daughter firms: GE-Hitachi and Hitachi-GE. Both those joint ventures can build ABWR, as can Toshiba, although its version differs in some technical respects due to intellectual property issues.

Horizon has been purchased by the main Hitachi corporate entity and the share of resulting work between Hitachi and GE's two joint ventures is yet to be announced. GE told World Nuclear News: "It's very exciting day for our joint venture partner, Hitachi. While the project is in its earliest days, we look forward to supporting them."

There are four operable ABWR units in Japan, while two more are under construction. Two more are being built in Taiwan and two planned for Lithuania, although another project for two has been shelved in the USA. The design is already licensed in Japan and the USA. It can run on a full-core of mixed-oxide (MOX) nuclear fuel.

Hitachi cited the construction times of the four Japanese ABWRs, which varied between 36.9 and 43.2 months.

Researched and written
by World Nuclear News