-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
Nuclear power
- Thread starter eledille
- Start date
-
- Tags
- Energy Environment Policy
I was talking the other day with someone who was responsible for the environmental permitting of a pumped-storage facility built in the 70s. I asked, "could you get that facility permitted today?" He just laughed.
If it's built in connection with a hydro-power plant, and both the upper and lower reservoirs are fresh water, there are no environmental concerns beyond allowable water-level change per hour. (And the newest research here is showing that fish are a lot more resiliant against water-level changes than previously thought.)
Within existing regulations here, the potential for pumped hydro is around 5 TWh and 16 GW. I'm sure that if the US systematically looked at the potential, they would find more than they think. Or they could rely on Canada's ample opportunities for pumped hydro.
Within existing regulations here, the potential for pumped hydro is around 5 TWh and 16 GW. I'm sure that if the US systematically looked at the potential, they would find more than they think. Or they could rely on Canada's ample opportunities for pumped hydro.
(nudging back towards topic....) The pumped storage units here in New England were built because there were so many nuclear units planned that their collective output would exceed overnight load in the region -- they had to put the power somewhere!
William13
Active Member
For those wondering how a nuclear reactor really works, there is a lot of very good info available on the net about the CANDU reactor.
Nuclear reactor overview, exemplified with the CANDU reactor.
For the technically oriented who want to see all the equations: CANDU Reactor Physics. This is a 160-page account of the processes that are going on inside of a real nuclear reactor, including how every aspect of behaviour can be predicted using physics and math. Basic calculus and a little physics is required to understand all of it, but the most difficult mathematics is simple differential equations. Highly recommended if you like this sort of thing.
On a page linked to in the first document is an essay about the future need for energy and why a large proportion of that must come from nuclear power. While I don't necessarily agree with all of his opinions, I think he has got the broader picture right. When you realize that the only way to get the population growth under control is education and a reasonable chance of an acceptable quality of life, you start to appreciate the magnitude of the task ahead of us.
Nuclear reactor overview, exemplified with the CANDU reactor.
For the technically oriented who want to see all the equations: CANDU Reactor Physics. This is a 160-page account of the processes that are going on inside of a real nuclear reactor, including how every aspect of behaviour can be predicted using physics and math. Basic calculus and a little physics is required to understand all of it, but the most difficult mathematics is simple differential equations. Highly recommended if you like this sort of thing.
On a page linked to in the first document is an essay about the future need for energy and why a large proportion of that must come from nuclear power. While I don't necessarily agree with all of his opinions, I think he has got the broader picture right. When you realize that the only way to get the population growth under control is education and a reasonable chance of an acceptable quality of life, you start to appreciate the magnitude of the task ahead of us.
Last edited:
Actually, France has such a high proportion of nuclear power that they have had to develop load-following reactors. When a reactor has just received a new load of fuel, reactivity is very high and it can quickly respond to demand. But as control rods are withdrawn, they leave the core first at either top or bottom, and this causes total reactivity to increase, but also causes uneven neutron density and fuel burn. The French developed "gray" control rods that capture neutrons less efficiently. Possibly neutron absorbtion varies along the control rod too (speculation). Anyway, this allows them to run newly charged reactors in a load-following mode. As reactivity decreases with increasing fuel burnup the reactor becomes more and more sluggish, and is eventually reallocated to base load generation.
Latest estimates by TEPCO for cleaning up the Fukushima Daiichi plant run up to 1000bn Yen, or $126bn. Several thousand people were evacuated, with unclear perspective to return to their homes. Eating produce from the soil or fish from the seas around Sendai is discouraged. I wonder how you call that cheap and safe.
You have a point in that Japan has a limited choice of alternatives right now. Granted it takes decades to turn a nation's energy sector.
But IMO not starting now will bring you to the point where you have to - at some point in the not-so-distant future, and at unfavorable conditions.
Remember that when mining coal you chop the tops of mountains off, put giant scars in the earth, and let all sorts of nasties out in the environment And this doesn't even count all the nasties you get when burning (more radioactives released into the environment than nuclear) the coal for power.
When extracting NG you release a LOT of NG straight into the atmosphere. When fracking you cause earthquakes and ruin water supplies.
When drilling for oil you run the risk of destroying something the size of the Gulf of Mexico!
Yes the Fukushima Daiiichi was tragic. It will be extremely costly. But having one accident every 25 years (between Chernobyl and Fukushima Daiichi) that cost turns out to be not all that great. And remember that Chernobyl wasn't all that safe, and Fukushima Daiichi had a earthquake and tsunami (sure they go together) double failure. And it apparently wasn't built all that well for the location (generators on low ground and centralized).
Thanks for linking that thread here, Doug. All said and done over there. My point is that the financial aspects of the triple meltdown continue to mount, whereas here in Germany the turn to renewable energy ("Energiewende") is discussed mainly under financial aspects. You can buy several GW of wind and solar power for $126bn. The opponents keep making up numbers to show that green energy is way too expensive. Death tolls of the different power generation methods are not discussed - yet. That would be the way to insanity, as the public is willingly accepting the death tolls of street traffic, smoking, drug abuse, etc.
He did not call it "cheap and safe". He wrote "cheapest and safest". The difference is enormous, "cheapest and safest" indicates that there are risks and costs, but that these are lower than those of the alternatives. "Cheap and safe" is an unrealistic absolute, and unfortunately no such technology exists. You need to ask "how cheap and how safe", and compare the alternatives.
The cost you qoute and the decision to return the evacuees are completely dependent on what level of radioactivity is considered safe. The fact is that no rigorous scientific study has ever been able to link chronic radiation exposures below 100 mSv per year to loss of health or life, despite huge effort by many different teams, over a sixty year time period. The evacuations at both Fukushima and Chernobyl were based on an assumption called "The linear no-threshold model" (LNT) which has zero factual basis. The reality is that how the dose-response curve looks below 100 mSv/year remains unknown, and many well respected scientists in the field of radiobiology consider the linear no-threshold hypothesis unlikely to be true, or even falsified. See for example "Radiation and Reason" by professor Wade Allison.
Let's assume the LNT is valid anyway. Radiation safety must be seen in relation to other safety standards. Protecting the public to the fullest possible extent from danger A, while dangers B and C are routinely causing loss of health or life orders of magnitude larger makes no sense. As an example, consumption of wild freshwater fish larger than 1 kg is officially restricted in Norway because of high mercury content due to pollution from coal power, primarily from the UK, Denmark and Germany. Mercury is extremely toxic and stays in the environment forever. The dose-response of mercury is well known, and indicate that intake of freshwater fish should be limited to once per month with a total ban for pregnant women. Recent studies indicate that fish as small as 200g are poisonous. This means that pollution from coal power has made unfit for human consumption an entire class of healthy food that has been a part of Norwegian diet since the ice age. This situation is far, far worse than the situation that prompted evacuation at Fukushima and even Chernobyl! I haven't even mentioned particles, uranium emissions, arsenic, strip mining, waste volume or CO[sub]2[/sub].
How do you propose getting rid of coal and nuclear at the same time? Natural gas also produces far too much CO[sub]2[/sub], let's eliminate that too.
Scenario: Winter in Europe. Long nights and cloud cover has cut solar output to 7% of nominal. As often happens in the winter, there is no wind and there hasn't been any for a week anywhere in Europe. Another week of still air is forecast. Average wind production is below 10%. This is a realistic scenario, it's happened before and it will happen again. Germany needs around 12 TWh per week, more in the winter.
How do you propose generating the missing 20 TWh during those two weeks, and at what cost?
Last edited:
NuclearPowered
Member
Buy it from France and turn the other way. :wink: Germany can say what they want, not many people in the industry believe they will follow through with it.
Thanks for your careful post, eledille. Good point not to mix "cheap" with "cheapest" resp. "safe" with "safest", and my apologies to jerry33 for mis-quoting.
To start with the scenario "Germany is an island, missing 20TWh within 2 weeks". That's a continuous load of 60GW (in average) over 336 hours - quite a realistic value for today's power curve:
To replace the grey (conventional) power generation capacity would require some 60GW of natural gas burning combined cycle gas turbine (CCGT) plants. Usual large-scale plant size is 0.4GW so we need 150 of them. Today's installed capacity is 25GW. Typical efficiency is 60% so we need to feed them with 33TWh of natural gas during that two dark winter weeks. The German natural gas network features 47 storage units, holding a total of 24b cubic meters today. 1m³ NG = 10kWh so total stored energy is 240TWh, well in excess of that required 33TWh.
IMO the problem of storing variable power output of renewable energy sources like wind and solar has been solved. The technology is there - now it's time for deployment, scale up, and explore efficiencies of scale.
A 6MW demonstration plant for methane synthesis from surplus electrical power goes online in 2013. Planned efficiency is 60%. If we assume that during 50 week's time, these plants operate for 20% of the time (when surplus power is generated) to cover these 2 dark weeks per year, the required synthesis generation capacity is 33TWh in 10 weeks, equaling 20GW natural gas output and 33GW electrical power input. A whopping 5500 plants will do the job. :scared:
This back-of-envelope calculation neglects any possibilities of further efficiency increases, better power demand management, or vehicle-to-grid services. The vast costs of doubling the NG power generation capacity and of erecting 5500 methane synthesis plants should drive enough research and investment in these topics, should France or Norway stop trading electric power with us :biggrin:
To start with the scenario "Germany is an island, missing 20TWh within 2 weeks". That's a continuous load of 60GW (in average) over 336 hours - quite a realistic value for today's power curve:
To replace the grey (conventional) power generation capacity would require some 60GW of natural gas burning combined cycle gas turbine (CCGT) plants. Usual large-scale plant size is 0.4GW so we need 150 of them. Today's installed capacity is 25GW. Typical efficiency is 60% so we need to feed them with 33TWh of natural gas during that two dark winter weeks. The German natural gas network features 47 storage units, holding a total of 24b cubic meters today. 1m³ NG = 10kWh so total stored energy is 240TWh, well in excess of that required 33TWh.
IMO the problem of storing variable power output of renewable energy sources like wind and solar has been solved. The technology is there - now it's time for deployment, scale up, and explore efficiencies of scale.
A 6MW demonstration plant for methane synthesis from surplus electrical power goes online in 2013. Planned efficiency is 60%. If we assume that during 50 week's time, these plants operate for 20% of the time (when surplus power is generated) to cover these 2 dark weeks per year, the required synthesis generation capacity is 33TWh in 10 weeks, equaling 20GW natural gas output and 33GW electrical power input. A whopping 5500 plants will do the job. :scared:
This back-of-envelope calculation neglects any possibilities of further efficiency increases, better power demand management, or vehicle-to-grid services. The vast costs of doubling the NG power generation capacity and of erecting 5500 methane synthesis plants should drive enough research and investment in these topics, should France or Norway stop trading electric power with us :biggrin:
Report: Zero Carbon Options: Seeking an economic mix for an environmental outcome
From bravenewclimate.com: This post concerns a new report, written unpaid by energy and climate experts, comparing a hybrid solar/wind and a nuclear solution to replacing two Australian coal power stations.
It's due to be released 5. December. They promise it's rigorous. It's about two Australian coal plants, but as a case study it is applicable anywhere, and the Australians are dumping that CO[sub]2[/sub] into my atmosphere.
The authors have donated their time for free, and the design bureau has done the same. The launch has been successfully funded through crowd funding, but ideally they would like more funding to be able to film the launch and distribute more copies.
From bravenewclimate.com: This post concerns a new report, written unpaid by energy and climate experts, comparing a hybrid solar/wind and a nuclear solution to replacing two Australian coal power stations.
It's due to be released 5. December. They promise it's rigorous. It's about two Australian coal plants, but as a case study it is applicable anywhere, and the Australians are dumping that CO[sub]2[/sub] into my atmosphere.
The authors have donated their time for free, and the design bureau has done the same. The launch has been successfully funded through crowd funding, but ideally they would like more funding to be able to film the launch and distribute more copies.
Last edited:
Similar threads
