There is a good Wikipedia article on fossil fuel power stations that quotes references from the international atomic energy agency for the radioactivity of the coal power stations. In summary, the old unfiltered power stations use to to kick out up to 5200 kg of uranium a year (34 kg of U235). For perspective, in 1982 all of the coal power stations produced 155 times the radiation released by the Three Mile Island incident (which is compatible to the scale of the Fukushima station incident to date. 5 out of 7). This would be less than what the coal stations in China are producing, and more that stations that filter the smoke of particulates.

That gives the mass of material, but what is more important is the dosage of radiation which depends on proximity and duration. It also depends on if the source has been irradiated to start the chain reaction to increase the number of decay events (kilograms of highly enriched uranium 235 can be carefully handled before being irradiated with neutrons and be well with in an acceptable dosage.) To give you radiation dosages there is a great pictorial representation put together by the geek comic strip xkcd, which employed the help of a senior reactor operator to make the chart and provide the references (Yes, a comic with references). This has been the most comprehensive and digestible way I have seen this information handled.

Well that depends on how you look at it. Burning coal produces CO₂ and that will tend to warm up the Earth's atmosphere will many consequences such as rising sea level and coastal flooding. Also some coal is Sulfur rich and the sulfur can react and produce different kinds of air pollution and cause sulfuric acid to form ACID RAIN which can affect ecosystems. Radioactive products are also harmful... so it is really an issue of the following:

For generating a certain quantity of energy by coal or by nuclear, which overall process is less harmful?This question can not be answered unless ALL the possible consequences are accounted for, and that is not easy.

Define "worse". Pollution released from coal fired power plants is not radioactive, so it is not as bad to the individual person as actual radioactive material that broken nuclear plants emit. However, radioactivity only hurts people at an individual level, not altering the entire environment the way that greenhouse gasses and other forms of pollution that coal-fired power plants do. So while coal-fired pollution is less likely to give you cancer, it's more likely to change the weather.

From Helen, Biophysics
click-here

The major pollutants caused by burning coal are (in order) carbon dioxide, sulfur dioxide, nitrogen oxides, and carbon monoxide. Chemical "scrubbers" are used to get trap much of the harmful chemicals. There are some other more harmful materials released, but they are in lower concentrations. While rising carbon dioxide levels is a major concern for the world right now, it is not a toxic gas. The concern with the power plant in Japan is radioactive materials. A substance that is radioactive is unstable and emits particles from its nucleus. These emissions can cause irreversible damage to DNA resulting in cancer or genetic defects. The radioactive material being released is worse than what is released from coal plants, it is just in much lower volumes.