In the previous post, I had signed out saying that I preferred nuclear fusion to the solutions being bandied about. Nuclear fusion, even though it has the N-word, and even though it IS a radioactive waste emitter, still trumps as a better energy source. Since I am not a nuclear physicist, so please feel free to correct me if I have made a mistake, but from the literature I have read, I have become convinced that nuclear fusion is the fuel of tomorrow.
First, the statistics. The total water on earth is about 326 million trillion gallons. And lets assume that we will go for the deuterium cycle. Going for the deuterium-deuterium cycle has several advantages.
- We do not have to perform tritium enrichment from lithium, which is not a very widely available metal. And as Li-ion batteries gain in prominence, lithium is increasingly expected to become dearer.
- The emitted radiation spectrum is softer, and can be more easily contained than the deuterium-tritium cycle.
However, the energy yield for deuterium-deuterium cycles are 68% less than that for the deuterium-tritium cycle. Higher pressure and temperature conditions are also needed, making it technologically challenging in the first place, but because of the wider availability of deuterium, more sustainable in the long run. Deuterium is an isotope of hydrogen and while the normal, garden variety hydrogen is devoid of neutrons, deuterium on the other hand contains a neutron in addition to the proton and the electron. Tritium is another isotope of hydrogens with two neutron compared to deuterium's one. Deuterium, tritium and hydrogen are almost chemically indistinguishable from each other, so wherever you collect a naturally available sample of hydrogen, expect to find some deuterium atoms in place of hydrogen. Thus water can be an excellent source of deuterium, with 5000 lires of water containing approximately about a liter of D20. Since the total water available on earth is about 326 million trillion gallons, we thus get 65200 trillion gallons of D2O approximately. Even at 10% efficiency the deuterium-deuterium fusion cycle gives 2000 GJ of energy per liter of D2O. At 100 times the current global energy consumption, fusion sources should last us out at least 10000 years. The average person in developed countries consumes around 10 times the energy of an average Indian, and as advanced technologies make processes increasingly fuel efficient, a 50000 year timeline for fusion to last us out is neither an impractical or improbable idea.
The main bone of contention for environment groups is radiation. First of all remember that the process of fusion itself does NOT produce radioactive wastes. However due to neutron radiation being emitted the material surrounding the fusion core would become radioactive. However quoting Wikipedia,
"The half-life of the radioisotopes produced by fusion tend to be less than those from fission, so that the inventory decreases more rapidly. Unlike fission reactors, whose waste remains radioactive for thousands of years, most of the radioactive material in a fusion reactor would be the reactor core itself, which would be dangerous for about 50 years, and low-level waste another 100. Although this waste will be considerably more radioactive during those 50 years than fission waste, the very short half-life makes the process very attractive, as the waste management is fairly straightforward. By 300 years the material would have the same radioactivity as coal ash."
In fusion the chance for catastrophic accidents like the Three Mile Island incident is inherently low. Fusion requires delicately calibrated and difficult to achieve conditions of heat, magnetic field and pressure to happen, and a slight change would just kill the reaction. Similarly after the reactor is stopped, the heat production stops immediately, unlike fission where the background reactions would continue for hours, generation heat. The plasma is burnt in near-optimal conditions, so any disruptions or accidents would actually cause the reaction to cool down or cease, instead of heating up. The fusion reactor is loaded with very small amounts of fuel thus making it inherently more safer, than the fission reactor.
And the benefits?
- Energy deficiency a problem of the past.
- Energy significantly cheaper
- Nobody controls the oceans. So nobody controls the deuterium supply. No more oil embargoes or future "Iraq"s over oil.
- Run cars on electricity, the technology for this is now remarkably developed, with electric cars available in the market. No more pollution too. Deuterium production will generate hydrogen too. Hydrogen technology too is developed enough to be put into production reality.
- The problem of potable water can be translated to a problem of energy. So a sweet goodbye to water woes.
- And last but not the least, another sweet goodbye, this time to petro-dollars, which would translate to a goodbye to terrorism, especially of the Salafist kind.
The good news is that several multi-billion dollar projects are underway to exploit fusion as a power source, like ITER, Joint European Torus or the National Ignition Facility. For future world peace and prosperity, we need fusion. Investing in fusion research is thus a must for us now. If due to distorted notions of political correctness or due to an irrational fear of anything nuclear, we do not seize this moment, then neither the history nor our environment will ever forgive us.
