Heavy Metal Nuclear Power

Heavy-Metal Nuclear Power

Could an unconventional coolant enable reactors to burn radioactive waste and produce both electric power and hydrogen?

Heavy Metal Reactor

..in the operation of a standard reactor (in this context the standard reactor was called a burner), while the 235U fissioned, there was also present in the fuel rods a large quantity of 238U. Many of the neutrons produced during the reactor's operation were absorbed by the 238U nuclei to produce plutonium.

In this way one can indirectly use the energy in 238U as well as 235U. If we remember the percentages of these isotopes found in nature (99.3% 238U and 0.7% 235U), we see that there is more than 100 times as much 238U in the earth as 235U. If the burner reactor could, theoretically, satisfy the world's energy needs for decades, the breeder reactor potentially could do so for thousands of years.

The boiling point of Pb-Bi (1670o C) is higher than that of sodium (883o C), and this means the reactor can operate at a higher temperature than the sodium-cooled reactor. This makes the reactor more efficient in producing electricity.

The high boiling point of Pb-Bi also reduces the risk a loss-of-coolant accident. Since the Pb-Bi reactor operates at a temperature far below the boiling point of the coolant, it is unlikely, in the event the reactor overheats, that the coolant will suddenly and rapidly boil away. In contrast, the sodium-cooled reactor operates close to the boiling point of sodium.

Heavy elements are best at absorbing radioactivity; lead is commonly used for shielding from x-rays as well as radioactivity.

One important reason for reconsidering the heavy-metal reactor at this time is its possible use in solving the problem of nuclear waste. ... If transuranics and 238U are placed in a heavy-metal reactor, they will fission, and contribute to the production of electricity. At the same time, they will gradually be converted into fission fragments. The problem of storing relatively short-lived fission fragments is one of safeguarding a site for a period of several hundred years.

The heavy-metal reactor, thus, may provide a way to utilize the energy in the world's 238U reserves, and simultaneously reduce the problem of radioactive waste to a level that appears more manageable than it has up till now.