Renewable Energy Ping
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Posted on 05/19/2008 5:59:37 AM PDT by Straight Vermonter
Save-for-later bump.
IMO, anything that gets rid of the iconic massive smoke stacks is going to do alot for deflecting NIMBYism.
Pretty hot and pretty fast --- conventional gas turbines would rip themselves apart at that speed. And they must be way out on the edge of material sciences to have a rotating device that can deal with those temperatures. I wonder what their design looks like.
In the more usual open-cycle gas turbine, the turbine exhaust would exit to the atmosphere. But the PBMR runs in a closed loop, so the helium leaving the turbine first passes through a recuperator to transfer some of its heat, then into a pre-cooler and on to the low-pressure compressor.
I wonder why not run exhaust through a heat recovery steam generator and make it a combined cycle operation. Must have something to do with core physics.
Not a bad idea if it can be done.
I read an article a few years ago on pebble reactors; it had a great graphic on the operation of the reactor. Wish I had saved it. Also, I heard that the chinese are big on these reactors.
As are Americans, Europeans and others --- but nobody is 'big' on them at this point --- just very interested in the concept. That is all the pebble bed is right now, a concept with a lot of research and testing going on. Until one is actually built and operated, and we see if it can deliver on the 'concept', it's not something we should pin our hopes on.
Previous gas cooled reactor designs had very disappointing operating results. Hopefully, this one works out better, but as I said, even on the turbine side, the temps and speed they are talking about are significantly greater than anything we have done in the past and not a trivial challenge.
I had heard that the chinese were actually building them....?
bump
Ping back at cha.
bump
Stated in the article ... they have a small PB test reactor in development, so do the Japanese. But that's a far cry from a commercial sized station. There is still a long way to go and a lot of unknowns to discover.
The development and subsequent manufacture of the reactors is being carried out by Pebble Bed Modular Reactor (Pty.) Ltd. in South Africa, with participation by teams from Eskom (South Africa's state-owned utility), Westinghouse from the U.S., Mitsubishi Heavy Industries of Japan, and Nukem of Germany. ---------------- Snip... ---------------------------------- The high-temperature, gas-cooled reactor projects now under way include not only the South African effort, but also the General Atomics GT-MHR unit, a high-temperature test reactor in Japan and a 10 MWt pebble bed reactor in China. -----------------------------------------------------
Of those projects, the South African PBMR is the one closest to commercial testing and manufacturing. Recently, the U.S. Department of Energy awarded a $3 million first-phase engineering contract to PBMR Ltd. for the Next Generation Nuclear Plant at the Idaho National Laboratory. There is widespread interest in PBMR, and many in the world's electric power community will wait to see test results in the coming years from the first unit.
“Me Magazine.”
I thought it was a more egocentric version of “Us” until at the end of the article it dawned on me that it stood for “M.E.”
< }B^)
Renewable Energy Ping
Please Freep Mail me if you'd like on/off
No control rods.
Good explanation! Thanks.
"By the 1990s, the demand for helium by the private sector was ballooning..."
The Chinese plan to use it to make hydrogen.
IMHO, reprocessing is key to the long-term viability of nuclear power.
Not true. Read the Wikipedia article (which I read after I posted).
Not true. There may be a shortage of CHEAP helium, but there's plenty of helium to be had. The US has been lucky compared to the rest of the world in that it does(did?) have a high-helium natural deposit. The rest of the world gets helium as a by-product of the manufacture of liquid oxygen and liquid nitrogen. The atmosphere isn't going to run out of helium anytime soon.
Good to know, any idea of the price differential?
The article did not say we would run out but more specifically, there was going to be an issue about cost effective use of MRI machines.
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