The failure of cooling systems at Fukushima has already been classified by the International Atomic Energy Agency as the third worst incident in nuclear history after Chernobyl and Three Mile Island.
Many pixels have been lit over this issue already, much of which follows the predictable splits along socially conservative and liberal politics one might imagine. Nuclear power is perhaps the ultimate conservative political device because of its long lead times in construction and decommissioning and unique reliance on state legitimacy through various legislative and political provisions. Thus, a few points need to be reiterated in the face of patronising calls for 'an informed public' and rallying cries by pro-nukes to unmask 'liars'.
1. Expertise in nuclear physics does not equate to expertise in radiation dispersion. At the level of philosophy of science, all the greatest excesses of Western Science are embodied in nuclear physics: true representations of nature, an ignorant and/or irrational public that must be disciplined; in short, epistemology where 'just the facts' must first be known, then people can form a rational opinion about the topic.
But nuclear physics is not nuclear engineering and nuclear engineering is not radiation science.
Damage at Fukushima may thus far be confined to reactor core and containment structures but they don't exactly have a camera in there, and there are a number of risks that must be honestly dealt with. Many nuclear advocates have bet the proverbial farm on the integrity of containment, and a full meltdown seems unlikely. (for that scenario, see Joe Romm).
It's worth noting here that once highly radioactive cesium and iodine elements are released into the environment, entirely separate bodies of knowledge are needed to deal with their movement. Because such releases are relatively rare, knowledge about the movement of radiation through the atmosphere, soils, plants and animals is basically a form of bricolage. Field testing radiation leakage models would hardly pass any Ethic Committee, so risk management of public health radiation is based on extrapolations and models that deserve public scrutiny. We're in the terrain of what Bruno Latour calls 'matters of concern', rather than 'matters of fact' here (see. eg. The Union of Concerned Scientists)
This isn't to say science should be suppressed or excluded - it's indispensable to eventually addressing those matters of concern: For example, Ben Sandilands has noted that:
This morning there was an elevated radiation level emergency declared at the Onagawa nuclear plant, which comprises three reactors, and is 120 kilometres from the NE outskirts of Tokyo, compared to about 240km for the nearest Fukushima plant. These fluctuations at Onagawa are now attributed to fallout from the Fukushima “releases” which is not comforting to those in Tokyo or elsewhere in Japan but is an inevitably that adds to the far more visible and immediate aftermaths of the tsunami.Yeah, sorry - once this has happened, Barry Brook's credentials are no better than mine.* [Update: here's his latest update]
2. Nuclear institutions have a poor record of disclosure. One of the reasons earlier incidents were so damaging was that authorities were incredibly secretive about what was happening. Nuclear physics brings with it a completely impoverished sociology of trust: people are assumed to either hold or not hold information about a topic. The only role of science is to fill any perceived void there. This is the 'deficit model' of scientific citizenship.
In reality, as much key science studies work has shown, this 'deficit model' is an ideological fiction. Local publics have sophisticated models of trust about science and technology built from many sources - they parse the interests behind official reports of incidents in a rational manner.
Brian Wynne's classic study of Cumbrian Sheep farmers after the Chernobyl disaster exemplifies the need to be attentive to local specifics. The main point from that study was that the Sellafield nuclear reprocessing plant was nearby and a bunch of accidents were covered up. As a result, local farmers held little trust of nuclear authorities. When the Chernobyl meltdown occurred, authorities used a set of crude models to determine how long it would take the radioactive elements to decay around local farms. They basically messed this up, using models that assumed a dry soil, rather than wet clay. In the meantime, the stories fed to farmers were revised, information withheld and they were basically screwed around.
The bottom line is that regulatory science should (but for obvious institutional reasons rarely does) have a dose of humility.
3. Energy policy is a political matter: Nuclear scientists might dream of a linear process from 'science to society' (energy 'too cheap to meter' from the 'peaceful atom'), but energy policy is not just a logical problem to be solved according to a set of mathematical principles. Planning requires these, but they're not sufficient. Nuclear power carries with it the authority of science, but requires the social legitimacy of democratic institutions. For better or worse, Sweden placed a moratorium on further nuclear power plants following the (US) Three Mile Island incident. Such decisions must be respected if made in a fair way.
Nuclear power plants have political consequences insofar as they are part of inflexible technological networks with incredibly long lead times, incorporating mining, reprocessing, disposal and electricity transmission. This is of course a criticism that could be made against other energy technologies. It is only by suppressing the political consequences of nuclear engineering (of which there are many! - this post hasn't even mentioned weapons proliferation) that one can claim an expert 'unbiased'. And that's a recipe for a debilitated public sphere.
Some notable Science and Technology Studies Scholarship on nuclear issues:
Gabrielle Hecht's brilliant 2008 book The Radiance of France
Brian Wynne's classic 1996 study May the sheep graze safely?
*There's an interesting SSK case study on nuclear power advocacy and disciplinary training. Flannery and Barry Brook are both geologists and deal with extremely long time scales in their daily work. Thus a few thousand year half-life is a proverbial blink.