Electric Nuke?


A nuclear reactor, for instance the Toshiba 4S, is basically a very expensive and complex water boiler (picture 1 and 2). Many water boilers use electric heating elements. Imagination gone wild: Would it be possible to build an "Electric Nuke", and would it be as efficient as a real nuclear reactor? Please read on, it is only short read with a lot of pictures.  ;-)

Picture 1 Main specifications Toshiba 4S
Toshiba 4S nuclear plant The active nuclear core of the 50 MWe version is 120 cm in diameter and 250 cm high.

The maximum temperature of the nuclear fuel element's cladding is 610 Celsius.

The coolant (sodium) is heated to 510 Celsius.

The steam it produces has a temperature of 415 Celsius and a pressure of 10.5 MPa. The steam is used to power a turbine generating 50 MW.

(Sources: Under The Hood With Duncan Williams - Toshiba 4S, Toshiba 4s reactor for Galena Alaskaaris.iaea.org).

Picture 2 How the Toshiba 4S works
Simplified flowchart of an Toshiba 4S small modular nuclear reactor
Pump (A) pumps liquid sodium through the nuclear core (B) and through the steam generator (C). After it passed through the steam generator it is pumped again into the nuclear core (B), and starting the next liquid sodium cycle.

Simultaneously, pump D pumps feed water through the steam generator, where it is heated by the liquid sodium and turns into super heated steam.

The super heated steam drives power turbine (E). When the steam leaves the power turbine (E), it goes through the condensor (F), turning steam back to feed water. The feed water is again pumped through the steam generator (C). Starting the next feed water cycle.
 

How does the Electric Nuke work?


Picture 3 How the Electric Nuke works
Simplified flowchart of the Electric Nuke Apart from the use of an electric furnace, the same as the Toshiba 4S. Pump (A) pumps liquid sodium through tubes fitted in the electric furnace (B) and through an steam generator (C). After it passed through the steam generator, it is pumped again into the electric furnace (B), and starting the next liquid sodium cycle.

Simultaneously, pump D pumps feed water through the steam generator, where it is heated by the liquid sodium and turns into super heated steam.

The super heated steam drives power turbine (E). When the steam leaves the power turbine (E), it goes through the condensor (F), turning steam back to feed water. The feed water is again pumped through the steam generator (C). Starting the next feed water cycle.


Note: the electric furnace consists of 10 furnaces like the one in picture 4. Why 10 furnaces, the nuclear core would fit in a single furnace? The brochure does not state the maximum load weight and also there would be more room between the tubes, so the hot air can move more easily move between the tubes and get a faster and uniform heat distribution. A bit like the load in picture 5.

Picture 4 Main specifications Thermconcept electric furnace
236 kW 1280 Celsius Thermconcept electric furnace Inner dimensions: width 140 cm x height 140 cm x depth 400 cm
Inner volume: 7840 litres
Power: 236 kW
Maximum temperature: 1280 Celsius

Heated from five sides (from both sides, rear wall, door and bottom), uniform temperature distribution in furnace chamber.

Source: click here for brochure, go to page 24.

Picture 5

View inside an electric furnace

Efficiency


In this setup the Electric Nuke should be able to heat the same volume of liquid sodium, to the same temperature as the Toshiba 4S, and therefor produce the same volume of super heated steam with the same temperature as the superheated steam produced by the Toshiba 4S. Consequently, it could drive the same type of steam turbine and generator, generating the same power (50 MW).

The combined power requirements of the ten electric furnaces is 2360 kW. There is more piping over a longer distance so more pumping power is required. How much is hard to estimate at this tage, but setting the total power requirement to 10 MW (electric furnaces + pumps) is a safe estimate. This would mean the Electric Nuke should be able to deliver 40 MW to the consumer.

Note: Because the temperature in the Electric Nuke is hotter, it might be able to heat the liquid sodium to a higher temeperature, which means hotter steam = more energy. This could balance out the extra energy needed for the pumps.