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Nuclear reactors are seen emotionally as risky due to a few major accidents, but new technologies are coming which will potentially reduce the risks associated with it dramatically.
Commercial reactors have used the same fuel for decades: small pellets of uranium dioxide stacked inside long cylindrical rods made of a zirconium alloy. Zirconium allows the neutrons generated from fission in the pellets to readily pass among the many rods submerged in water inside a reactor core, supporting a self-sustaining, heat-producing nuclear reaction.
Trouble is, if the zirconium overheats, it can react with water and produce hydrogen, which can explode.
To reduce this risk,
[m]anufacturers such as Westinghouse Electric Company and Framatome are hastening development of so-called accident-tolerant fuels that are less likely to overheat—and if they do, will produce very little or no hydrogen. In some of the variations, the zirconium cladding is coated to minimize reactions. In others, zirconium and even the uranium dioxide are replaced with different materials. The new configurations could be slipped into existing reactors with little modification, so they could be phased in during the 2020s.
Core testing of some of these options is already underway and would have to be successful and regulatory hurdles overcome. Additionally, some of the options actually improve efficiency (and consequently cost-effectiveness) of plants. Sadly, 'Too cheap to meter' remains well off the table.
Modern plants, such as are being deployed by Russia both at home and abroad, now include
“passive” safety systems that can squelch overheating even if electrical power at the plant is lost and coolant cannot be actively circulated. Westinghouse and other companies have incorporated passive safety features into their updated designs as well.
Alternative cooling approaches not subject to hydrogen generation, such as Molten Salt (e.g. liquid sodium) and Helium are being tested and deployed. And very small modular reactors are being developed at the Idaho National Laboratory (the Russian state-run company Rosatom is making small reactors as well.)
a group of Western states has entered a tentative deal with NuScale Power in Oregon for a dozen of its modular reactors.
Mortality rates for various power generation methods in the U.S. shows nuclear power with a 50x lower mortality rate per unit power generated than the next safest option (hydroelectric) and 100,000 times lower rate than Coal, which provides much of the U.S. base power generation in its stead.
Still, nuclear power remains stalled in the U.S. and is being phased out in other countries such as Germany, leaving primarily Russia and China, both of which are deploying nuclear power aggressively, as the primary markets and beneficiaries of these new technologies.
(Score: 0) by Anonymous Coward on Friday July 05 2019, @02:11PM (5 children)
So, for it to explode you need oxygen, right? But, the oxygen from the water reacted with the zirconium, forming a zirconium oxide, right? So why are reactors not build anairobic? They don't need oxygen for the nuclear reactions. The hydrogen could be collected and used in other applications.
(Score: 1) by nitehawk214 on Friday July 05 2019, @02:48PM (2 children)
I think the issue is the reactors buildings and containment vessels are huge and people need to go into them for maintenance purposes. Maybe if we can have a fully robotically operated reactor, we could fill it with helium.
"Don't you ever miss the days when you used to be nostalgic?" -Loiosh
(Score: 4, Insightful) by HiThere on Friday July 05 2019, @04:12PM (1 child)
Not Helium. Nitrogen if that would work, otherwise Argon or Neon. Helium is much too expensive to use where you don't need it...and using it for party balloons is criminal waste. It's NOT a renewable resource.
Javascript is what you use to allow unknown third parties to run software you have no idea about on your computer.
(Score: 3, Funny) by RandomFactor on Friday July 05 2019, @11:10PM
Fusion. It solves everything.
В «Правде» нет известий, в «Известиях» нет правды
(Score: 4, Informative) by RS3 on Friday July 05 2019, @04:01PM
> So why are reactors not build anairobic?
In fact, some (most?) are- they fill the buildings with nitrogen.
Trouble is, when water gets heated enough, and by neutron flux / fission, it splits apart, forming much more free O2 than can be joined with zirconium atoms. The O2 and H2 rejoin later on, which is why the Fukushima buildings blew apart (but the reactor vessels did not).
(Score: 2) by driverless on Saturday July 06 2019, @04:50AM
Another, even bigger problem, is that no new research into safer reactors is ever going to be deployed except in countries like China. The rest of the world is still running unsafe, 1950's-technology reactors because no-one wants to build new ones, but we also can't shut down the old unsafe ones because there's no easy replacement source of power, the Reactor Curse. On the one hand this is kinda neat, but OTOH we'll never see it used in reactors because of the Reactor Curse.