Latest on Four Small Nuclear Reactors

Idaho Samizdat has the latest on NuScale, Babcock & Wilcox mPower, Hyperion Power Generation and Toshiba 4S from the American Nuclear Society Winter Meeting

Hyperion Takes Steps to Speed to Market Within Four Years

Hyperion Power Generation (HPG) uranium nitride fuel burns would begin before the end of the year. He said that Los Alamos National Laboratory, from whom Hyperion has licenced some of the technology, has researched uranium nitride. It said that the Russian military has used uranium nitride fuel and the lead-bismuth coolant.

* HPG plans to rely on the supply chain for producing the first units.
* HPG is looking to find six launch customers, some of which would run a prototype, including customers based in the US and UK. Letters of intent have been signed
* in order to have operating units within four years, HPG is considering building its first pilot units in facilities that do not require approval from a nuclear regulator, such as US Department of Energy facilities, or military facilities.
* HPG has signed up TetraTec as the architect-engineer-constructor, supported by Chamberlain.

Hyperion Power Generation More Technical Details

Nuclear Engineering International:
Although the Hyperion Power Generation had originally been aiming to create a TRIGA reactor burning uranium hydride, it has decided for reasons of speed-to-market to focus on commercialising a liquid-metal-cooled fast reactor instead.

The Hyperion Power Module has a core of 24 assemblies of a metal fuel, uranium nitride, that is 20% enriched set in HT-9 cladding tubes. Flowing around the pins is liquid lead-bismuth eutectic coolant. Quartz is used as a radial reflector. A gas plenum is at one end of the 2-3m long fuel pins.

Two sets of boron carbide control rods keep the reactivity of the core under control. One set of 12 control rods advance about 0.5mm/day to moderate the reaction. A second set of 6 shutdown rods close to the centre of the reactor would automatically drop into the core in case of an accident. The centre of the core is hollow. Inside that void space marbles of boron carbide would be dropped in case of an emergency.

The hot (500 degrees C) coolant transfers its heat through an intermediate heat exchanger to another lead-bismuth loop, through another intermediate heat exchanger to a tertiary circuit with an undisclosed fluid, and then through a third heat exchanger to water (at about 200 degrees C). The reactor is not only designed to deliver electricity, but also process heat or co-generation. Hyperion Power president and CEO John ‘Grizz’ Deal told NEI that the configurations of the secondary and tertiary circuit would depend on the reactor’s uses.

The reason why the 70MWt reactor has a relatively low electrical efficiency of 36%, or 25MWe, is because the steam loop does not run through the inside of the reactor, for simplicity and safety.

B & W mPower

* mPower small reactor, a 125 MW LWR design that is still being completed on the drawing boards in Lynchburg, VA.

* The reactor will use 5% enriched uranium in fuel rod assemblies which are similar in design to those used in 1,000 MW plants.

* At a hypothetical price of $3,000/Kw, a single unit would cost $375 million

* One of the intended uses of the mPower reactor is to “repower carbon-intensive plants where the transmission and distribution infrastructure is already in place. (coal to nuclear ? )

* First units could be received by customers by 2018 and that the reactor can can be shipped by truck and rail to a customer site and installed below grade by skilled trades without complex training.

* three years from signed contracts to operational units

Rod Adams has more info on the mPower

Nuclear Engineering International has more info on mPower

B&W boasts that when the mPower goes on the market in 2012, each 125MWe reactor would be made in a factory, cost about half a billion dollars firm fixed price, and could be built and installed, in multiples of two or four reactors, in only three years.

mPower – main data

Reactor type: Integral PWR
Power: ~125MWe, ~400MWt
Reactor coolant:

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