Adam,
You certainly picked the right
text -- especially the part about the fuel microspheres being the primary
containment structures:
The fuel consists of graphite pebbles about the size of a tennis ball (60 mm diameter), inside of each of which are about 10,000 individual ceramic-coated fuel microspheres about 0.9 mm in diameter. The ceramic coating will not melt at the highest temperature able to be reached by the fuel, so that each individual tiny fuel sphere is designed to contain the radioactivity within it under all accident conditions, thereby obviating the need for any other barriers (such as a containment) to keep radioactivity from the environment in upset conditions.
...............but the antis are once again playing cynically on the ignorance and fear of the public, in their efforts to discredit this (and other) new reactor designs. This type of blatant deception is standard practice by the likes of Sierra Club, quoted in the NYT article:
"There are many safety problems with this reactor," said Carl Pope, the executive director of the Sierra Club. "It's not safe, and it's certainly not clean. It has already failed once, in Germany.
"And this pebble-bed facility is not going to have a containment shell. It will be a terrorist target just sitting out there waiting for someone. This is just not sensible."
................Of course they know full well that the expensive containment shell of today's reactors is designed for the specific purpose of airtight containment of high-pressure radioactivity-contaminated steam in the event of a reactor loss-of-coolant accident (LOCA) -- after all, this is the very fact they have played on since 9-11, pointing out disingenuously, that the containment domes were not designed specifically for resistance to external impacts by airliners.
By contrast, the PBMR does not need that type of airtight
containment.
Protecting against impact is a much simpler
task than building a large, hermetically sealed pressure-retaining structure.
A gravel dike piled up against the sides of a building, for example, would do the trick very economically. The size of such a dike (or alternative low-cost protection) can be reduced by installing the reactor partially below grade -- the approach actually chosen by the designers of PBMR.
The antis also play on the fear that the PBMR fuel is largely graphite, a combustible material (as we've seen in the Chernobyl disaster -- a fact they only forget when it comes to estimating radioactive releases due to LOCAs in LWRs). Of course they conveniently ignore the fact that its physically impossible for the PBMR core to explode like Chernobyl and expose its fuel to oxygen, needed for burning -- another case of their cynical reliance on the public's ignorance of chemistry. Even if the PBMR steel pressure vessel or primary loop piping were to develop a leak, there would be (surprise !) helium going outside -- not air going in (unless of course the antis have discovered of a way for flow to go against the pressure gradient...).
They have the gall to talk about what's "sensible" ?? Aaaaarrrrgh !!!
Jaro