Alternative for lithium in Deuterium-Tritium fusion power

[FTM1000]

Is there alternative ways for producing Tritium for fusion power plants other than using lithium?. In the wiki article about fusion power I read that Deuterium-Deuterium fusion produce Tritium so I wonder if this can be used as a way to produce tritium for Deuterium-Tritium fusion power plants in case there is a problem with lithium resources. Is Deuterium-Deuterium fusion even possible with current technology?.

 

[mfb]

D-D fusion is much harder to achieve than D-T. We don't even have D-T fusion at levels useful for a power plant.

 

[FTM1000]

D-D fusion is much harder to achieve than D-T. We don't even have D-T fusion at levels useful for a power plant.

so D-D fusion is impossible with current technology or it is so problematic that we can't even do it to harvest tritium in a way that will be useful for D-T fusion power plants?. technological advancement might make D-D fusion a source for tritium for D-T fusion power plant without needing to figure out how to produce energy from D-D fusion?.

 

[anorlunda]

You don't need fusion to produce tritium. At one time, it was produced in bulk to make glow-in-the-dark watch hands.

https://en.wikipedia.org/wiki/Tritium#Production_history

According to a 1996 report from Institute for Energy and Environmental Research on the US Department of Energy, only 225 kg (496 lb) of tritium had been produced in the United States from 1955 to 1996.[15] Since it continually decays into helium-3, the total amount remaining was about 75 kg (165 lb) at the time of the report.[15][3]

Tritium for American nuclear weapons was produced in special heavy water reactors at the Savannah River Site until their closures in 1988. With the Strategic Arms Reduction Treaty(START) after the end of the Cold War, the existing supplies were sufficient for the new, smaller number of nuclear weapons for some time.

The production of tritium was resumed with irradiation of rods containing lithium (replacing the usual control rods containing boron, cadmium, or hafnium), at the reactors of the commercial Watts Bar Nuclear Generating Station from 2003–2005 followed by extraction of tritium from the rods at the new Tritium Extraction Facility at the Savannah River Site beginning in November 2006.[16][17] Tritium leakage from the rods during reactor operations limits the number that can be used in any reactor without exceeding the maximum allowed tritium levels in the coolant.[18]

 

[mfb]

so D-D fusion is impossible with current technology or it is so problematic that we can't even do it to harvest tritium in a way that will be useful for D-T fusion power plants?. technological advancement might make D-D fusion a source for tritium for D-T fusion power plant without needing to figure out how to produce energy from D-D fusion?.

It is possible to get some fusion, but not in relevant quantities with existing or planned reactors.
If we can use D-D fusion we can just leave the tritium in the plasma or put it back in (if it is kicked out), it will easily fuse with another deuterium nucleus.

You don't need fusion to produce tritium. At one time, it was produced in bulk to make glow-in-the-dark watch hands.

Not enough. A 1 GW (electric) power plant would need about 200 kg per year. All the tritium the US produced in 40 years could power a single reactor for a single year. Fusion power plants have to produce their own tritium, there is no other practical source for such a large amount.

 

[anorlunda]

Not enough. A 1 GW (electric) power plant would need about 200 kg per year.

Thank you @mfb. You are a valuable source of key numbers when we need them.

 

[Astronuc]

Is there alternative ways for producing Tritium for fusion power plants other than using lithium?. In the wiki article about fusion power I read that Deuterium-Deuterium fusion produce Tritium so I wonder if this can be used as a way to produce tritium for Deuterium-Tritium fusion power plants in case there is a problem with lithium resources. Is Deuterium-Deuterium fusion even possible with current technology?.

There is no practical alternative to lithium for tritium production. Other reactions are possible, but they require more energy input.

Adding to what mfb stated above, I found a comment on one of my textbooks (Robert A. Gross, Fusion Energy, John Wiley & Sons, 1984) that a 1 GW (thermal) reactor would consume about 140 grams of T per day, or 51.1 kg T/year. So a larger plant (~1 GWe) with an efficiency of about 0.34 would require ~150 kg/yr, which is in the ballpark of 200 kg indicated by mfb. In 1981, T cost about $9000/g. Also, 1 g of T represents about 9600 Ci.

D-D fusion would be ideal, however, whereas D-T fusion achieves a peak at a plasma temperature of ~ 50 keV (~58 million K), D-D doesn't achieve comparable activity until beyond 1000 keV (11.6 billion K). D-He³ has a peak reactivity of about 300 keV (3.5 billion K), but one has to content with greater radiation losses. Also, higher plasma temperature, the plasma density has to decrease for a given pressure. The plasma pressure is limited by the magnetic field strength. So even if fusion can be demonstrated scientifically, there are numerous engineering challenges.

 

[Astronuc]

https://en.wikipedia.org/wiki/Tritium#Production_history

The production of tritium was resumed with irradiation of rods containing lithium (replacing the usual control rods containing boron, cadmium, or hafnium),

The statement from Wikipedia is inaccurate. Rod containing lithium do no replace control rods. Rather lithium contain rods are place in assemblies that do not sit under control rods, or are rather in uncontrolled locations. They basically behave as burnable absorbers, which would have boron if they were used for reactivity control. Watts Bar uses Westinghouse fuel, in which some fuel rods have ZrB₂ coating on the fuel pellets (so-called IFBA, for integral fuel burnable absorber), which has been used for a little over 3 decades now.

Control rods do use silver-indium-cadmium (AIG) or boron in the form of B₄C, but not Hf, since Hf can absorb hydrogen from the coolant (hydrogen diffuses through stainless steel) and swell. In PWRs, control rods sit out of the core, with the tips located in just above the plenum region. They are not used in the core during full power operation, although some PWRs (B&W types) have been designed to use axial power shaping rods, but those would have a moderate (grey) absorber, e.g., Inconel, instead of Hf or B. As far as I know, most if not all B&W plants stopped using APSRs.