Coal power vs. Nuclear: How clean? How safe?

[Una_Persson]

*Originally posted by magdalene *
Hail, King and Queen of Coal:

Ugh…I’m not sharing the throne with a man…

Do environmental health effects depend on the “kind” of coal that is burned? Anthracite, what did you find in Polish plants? It seems that this debate has been largely based on efficient, well-run plants in the U.S. and U.K. However, in Central and Eastern Europe, it’s my understanding that they burn “brown” coal for heating energy, with disastrous consequences.

The Polish plants I visited burned a variety of coals, esp. from the Silesia region. They included Anna, Boleslaw Smialy, Brzeszcze, Budryk, Debiensko, Knurow, Krupinski, Murcki, Sosnica, Wujek, and Ziemowit. I don’t think any of these coals, based on the coal quality samples I saw, would be brown coals, also known as lignites in the United States. The Polish plants burned coals that had sulfur contents ranging from 0.62% to 1.25% - not too bad overall, and Btu contents of 8754 to 11,391 Btu/lbm. So definitely not brown. Now, some German plants do burn brown coal, as do many other plants in central Europe, and other ones in Poland. Brown coal has a poor heating value and yields a poorer combustion efficiency. Thus, more of the coal must be burned to produce the same electrical output.

Maybe this should be a completely separate thread, but I wanted to ask what you know about “brown” coal and what the environmental consequences might be for a population exposed to emissions over the long term, in terms of air-pollution related illnesses such as athsma. What is the difference between “brown” coal and what we burn in the U.S.?

Brown coal very closely resembles what is burned in some Texas coal power plants, and plants in North and South Dakota. And in Mexico as well. Brown coal in Europe is closest to what we call lignite here in the US. It is a coal with very poor heat content, very high ash, often high moisture, and sometimes high sulfur. US lignites often have a very high sodium content, which makes it difficult to burn them without building up deposits in the furnace called slag, which decrease the efficiency of the furnace (think of them as hard-water deposits on the furnace, if you like). As to long-term health effects, well, I will let others answer you better I think.

[Una_Persson]

*Originally posted by hibernicus *
They certainly do. At the station I know best, we’ve moved from coal with 2.2% sulphur content to coal with 0.8% S. That’s a 64% reduction in SO[sub]2[/sub] straight away. Also fuel nitrogen and fuel ratios will vary.

Well…this is a dangerous assumption here. Sure the sulfur content is less, but on a (mass sulfur)/(energy) basis what is it? Does the 2.2% sulfur coal have the same heating value as the 0.8% sulfur coal?

[Cerowyn]

*Originally posted by douglips *
**True. I was using Chernobyl in an attempt to get nuclear power to look as bad as possible. I have heard nuclear engineers on the radio talk about how the Chernobyl design and other Soviet design is so inherently unsafe that you’d never get a license for it in the US or Europe. This implies to me that we will never have a disaster like Chernobyl except in the former USSR. Hopefully we’ll never have such an accident again, but by taking the highest estimate possible for the event, and adding more deaths on top of it, I was hoping for decent approximation.
**

A friend of mine, who did most of a Ph.D. in sub-partical physics and worked in the Canadian nuclear industry for some time, suggests that Three Mile Island was an example of everything possible going wrong, and everyone doing the wrong thing in a boiling water nuclear reactor accident, shy of actual deliberate sabotage. Perhaps using emission and health impact statistics from that accident would be more realistic.

[Bobort]

*Originally posted by Cerowyn *
**

*Originally posted by douglips *
**True. I was using Chernobyl in an attempt to get nuclear power to look as bad as possible. I have heard nuclear engineers on the radio talk about how the Chernobyl design and other Soviet design is so inherently unsafe that you’d never get a license for it in the US or Europe. This implies to me that we will never have a disaster like Chernobyl except in the former USSR. Hopefully we’ll never have such an accident again, but by taking the highest estimate possible for the event, and adding more deaths on top of it, I was hoping for decent approximation.
**

A friend of mine, who did most of a Ph.D. in sub-partical physics and worked in the Canadian nuclear industry for some time, suggests that Three Mile Island was an example of everything possible going wrong, and everyone doing the wrong thing in a boiling water nuclear reactor accident, shy of actual deliberate sabotage. Perhaps using emission and health impact statistics from that accident would be more realistic.
**

About Chernobyl: It is true that the major cause of the Chernobyl accident was the extremely (I would almost go so far as to say criminally) bad design of the RBMK reactors. Since the accident, the Russians have upgraded the remaining RBMK units to fix some of the design flaws that directly caused the Chernobyl catastrophe, but most of the really egregious flaws remain such as the lack of a containment structure and the positive temperature coefficient of reactivity. The NRC would absolutely not grant a facility license (10CFR50) to any reactor like the RBMK.

About Three Mile Island: It is certainly possible for worse accidents to happen at US reactors than TMI in terms of radiological releases to the environment or personal injury. If I remember correctly, the theoretical maximum offsite dose from TMI was 80 milliRem (to put that into perspective, the average dose from natural background radiation is ~1 milliRem/day). That’s not a dose I would lose any sleep over. That said, It’s hard to imagine a Chernobyl-scale accident happening at an American-style PWR or BWR plant. (by the way, TMI was a pressurized water, not a boiling water reactor)