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Samurai-Sword Maker May Cool Nuclear Revival
NobleSavage sends a story from Bloomberg about Japan Steel Works Ltd., a company that still makes Samurai swords, and how it may control the fate of the global nuclear-energy renaissance. "There stands the only plant in the world, a survivor of Allied bombing in World War II, capable of producing the central part of a nuclear reactor's containment vessel in a single piece, reducing the risk of a radiation leak. Utilities that won't need the equipment for years are making $100 million down payments now on components Japan Steel makes from 600-ton ingots. Each year the Tokyo-based company can turn out just four of the steel forgings that contain the radioactivity in a nuclear reactor. Even after it doubles capacity in the next two years, there won't be enough production to meet building plans."
This article is from 2006. Surely there's more recent news, even about this topic?
New nuclear build is not going to grind to a halt because this plant can't keep up.
"Physics is to math as sex is to masturbation." -R. Feynman
And the reason why the CANDU was designed was because it runs on natural, unenriched uranium. It had nothing to do with the design of the pressure vessel. When the first CANDU's were being built, the US was still manufacturing PWR pressure vessels and there was no problem in that area.
The problem here is not wanting to stick with currently proven designs, but the hideous cost of certifying a new design. It is so expensive to re-certify a project after a design change people really don't want to do it often.
The certification process probably makes the design safer, but it also disincentives innovation in ways that would horrify someone used to the rapid pace of consumer electronics.
On the other hand, the kind of reliability standards we see on consumer electronics would horrify me if they ever happened be applied to a nuclear facility or an airplane.
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I think the article confuses the reactor vessel with the containment vessel.
A reactor vessel is a large-room-sized steel vessel, that holds the fuel and steam transfer pipes and so forth and is subjected to huge internal pressures in normal operation.
A containment vessel is the building-sized concrete structure that gives many reactors buildings their impressive dome shape. It is only important in the case of an accident, when it might be subjected to pressures on the order of an atmosphere or so. It is intended to hold in or contain any radioactive materials released after an accident has occurred.
Interestingly enough, in light of his demonization by anti-nuclear factions, it was Edward Teller who was largely responsible for insisting on containment vessels, a nice simple brute-force protection measure.
Every reactor has a reactor vessel, but not all reactors have containment vessels. Some reactors, such as Chernobyl, and, in the United States, GE boiling-water reactors such as the one in Plymouth, Massachusetts have very ordinary-looking block-like buildings rather than containment domes. These reactors are designed to "suppress" pressure in an accident rather than "contain" it, by the use of engineered mechanisms that open valves at the right time and direct steam through big tanks of water, cooling it down and condensing it.
"How to Do Nothing," kids activities, back in print!
That's incorrect. The US Military admitted there were 'some unknown dangers' associated with DU after Dr. Doug Rokke (US Army Physicist) got cancer and is suffering numerous other ill effects from radiation poisoning whilst leading efforts to clean up the radiation after the first Iraq war. He also has explained that the US Military actively suppressed a WHO study which showed DU has the same effects as normal uranium on the human body. I only know because his brother, General Irving Rokke was the Dean of my college and I got to speak with him. I also learned about how the US and UK have been pressed about the issue numerous times in the UN and have used their comfy chairs on the UN Security Council to veto any sort of punitive action.
So.. it's less toxic than one of the world's most famous deadly poisons
That's really reassuring.
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Nuclear reactor pressure vessels are a real problem. Most of the larger ones are in fact built up from welded sections. This isn't an easy welding job, and inspection of welds is a big headache. Several Japanese nuclear plants have had problems with cracks in pressure vessel welds, although in internal reactor components welded to the shell, not the shell itself. So making the pressure vessel and its internal support structures from one big forging makes a better product.
The environment of a reactor pressure vessel is tough. First, there's "embrittlement". Neutrons are constantly blasting apart the atoms in the pressure vessel, and over a period of years, this structural damage adds up. Then there's corrosion. There have been major corrosion problems requiring reactor shutdowns from carbon dioxide and boric acid corrosion inside the pressure vessel. Remember, this is a steam pressure vessel; at steam temperatures and pressures, minor corrosive effects at room temperature become big problems.
High quality welding of thick steel sections is a tough problem. Many approaches have been tried. The general idea is to make a V-shaped notch and fill it in during the welding process. Doing this in a way that's no weaker than the surrounding material is hard. Electric arc welding under an inert gas is the usual approach. Electron beam welding and laser welding have been tried. Then there's the problem of approach angle - welding on a vertical surface is not easy. Quality control requires X-rays, ultrasonic tests, and regulators that aren't corrupt.
So there's much to be said for building the pressure vessel as one big forging. Of course, then there's the problem of delivering a 550-ton object to the job site. There are companies that can do that, if you can find them a clear path from a seaport.
Sword making technology is relevant to the making of big forgings. Swords are built-up forgings. This is unusual in modern metalworking; most modern forged objects, like tools, are banged out in one piece by equipment much larger than the thing being manufactured. Big pressure vessels are built-up forgings; the scale requires it. In Japan, it's considered a good doctoral thesis in metallurgy to improve on sword making technology. So smart people are still thinking about the technology of built-up forgings. Nobody else bothers much.
Here's a US NRC fact sheet. on pressure vessels, and a similar European document.