Why not use the kinetic energy of the tides for energy

[KF]

Originally posted by: Peter
It's been done ... here in Augsburg we have a handful of small power plants (gas burners) spread across the city, producing electrical power, and at the same time feeding heat to the surrounding households through pipes.

The soviets have been doing that on a much bigger scale, as some may recall from a recent, particularly cold winter, when it was reported that the system had failed and Moscow was freezing inside and out.

Interesting to know what goes on outside the US, Peter. Thanks.

From here in America, it seem that people outside the US have a rather constricted view of what goes on the US. Pehaps your newspapers inform you what a bunch of insular jerks Americans are? For instance, your observation that Americans are wasteful is not unknown in the US. In fact, you hardly hear anything else in US newspapers or TV or anywhere else. It goes on and on 'til you are sick of it. No politician in office or running for office leaves the spotlight without pontificating on how important it is to conserve. He probably needs to to get elected. It is actually people that will state a dissenting view that are the beleagered, downtrodden and intimidated. But it is true nevertheless that Americans overwhelmingly do not actually behave in accordance with the professed value of conservation, don't think they should have to, and have no intention of ever doing so. That is the saving grace of Americans

Sometime back -I don't know if it was the '30s, '40s, or '50s - downtown Detroit (near where I live) had the sidewalks heated in winter to melt the snow. The heat came from the spent steam of an ordinary (coal) electric power plant that was downtown. I am told the power plant also sold steam for heating buildings. I am told this was fairly common in the US. That disappeared long ago. I gather the reason was that the price of direct heat went below what the power plant charged.

In outstate in Michigan, and other US states, nuclear power plants back in the '50s and '60s similarly used to heat the sidewalks of the business areas in winter with the waste heat from the spent steam as a "freebee" to demonstrate the benefits of ultra-cheap nuclear power. That disappeared long ago as the anti-nuke activists put a stop to it. (As I understand it, there was no direct connection to the innards of the reactor, and no radiation.) Now, that otherwise unusable heat is disappated in gargantuan cooling towers that resemble unearthly chimneys. They have to get rid of that heat somehow to maintain the low temperature point which keeps the efficiency of the cycle high. (Carnot)

However, I think this is different than running a motor in your own home rather than using the fuel directly for heat, and getting the benefits of that motor and the heat as well. I never heard of that one before.

I have heard people wonder why we need to run refrigerators in our homes when it is cold outside, but I never saw a workable, commercial system to do that either.

 

[BrownTown]

Using "waste heat" for usefull purposes is something that is done in many places, but its uses are limited. The problem of course is that power plants are usually built away from populated areas, so you can't go piping steam all the way to the city. However, many chemicals plants use waste heat from nearby power plants. The heating in alot of colleges is also done this way, I beleive alot of militay bases are the same way. Basically if you have to have somewhere for the steam to go that is realitively close.

 

[Steve]

Originally posted by: KF
Plutonium's toxicity.

http://members.tripod.com/~Arnold_Dion/Daghlian/accident.html

 

[Peter]

Originally posted by: KF The inherently safe operation of nuclear power plants will never get any air play. It's boring. There is no one to accuse falsely. There is nothing to scream about. If cheerful, calm and serious people are not as insistant as the wackos, the wackos will prevail.

As long as the "calm" people come up with good looking statistics that obfuscate the scale of the disaster when a nuclear plant actually DOES go boom, the wackos as you call them do have a point.

Maybe you've forgotten or successfully ignored, but yes it happens, and it already has.

http://en.wikipedia.org/wiki/Pripyat,_Ukraine
http://www.chernobyl.in.ua/en/chapter_1/1

Even we here in Bavaria, easily 1000 kilometers UPWIND of the Chernobyl site, still are advised to eat only limited amounts wild mushrooms and deer, because radiation levels are still biologically relevant. It's been 20 years.

 

[MrPickins]

Originally posted by: sm8000

Originally posted by: KF
Plutonium's toxicity.

http://members.tripod.com/~Arnold_Dion/Daghlian/accident.html

A critical mass of any fissionable material is toxic, of course.

But, how often is it stored that way other than in the reactor core?

 

[Calin]

Originally posted by: BrownTown
yeah, but evenutally breeder reactors will be needed since the current reactors wast 99% of the fuel. Fortunately this radioactive "waste" can be reused in breeder reactors. ITs kinda funny that everyone is trying to get rid of their nuclear waste, but with a different reactor it suddenly turns into valuable fuel. I'm sure like everything else in the world this will come around when it becomes economically feasible, when Uranium prices start going way up people might decide that it makes mroe sense to use all the Uranium and not jsut the very rare U235 isotope.

Not to rain on your parade, but the radioactive "waste" is composed from irradiated components of the nuclear reaction chamber - these could be radioactive enough not to be disposable thru any other means, and could be very big.

 

[BrownTown]

I was reffering to the spent fuel, not the decomiisioned reactor chamber. I am reffering to the ability to extract more energy from the fuel, eventually it will still have to be discarded, but the more energy you get out the less waste you have in the end. Also, the decommisioned pressure vessel is considered "low level" waste and is not as gangerous as the "high level" fuel waste. They usually jsut bury them in concrete in a low level waste dump.