Top scientists back nuclear power

[oracle]

Top scientists back nuclear power (http://news.bbc.co.uk/2/hi/uk_news/2743515.stm)

The UK will be unable to cut greenhouse gas emissions without new nuclear power stations, the country's top science academy has warned.

The Royal Society has urged the government to show "political courage" in its forthcoming White Paper on energy, and make a clear decision on the future of nuclear power.

Without nuclear energy, Britain would have to rely increasingly on fossil fuels, leading to increasing carbon dioxide emissions and the catastrophic consequences of global warming, it said

Britain currently gets about a quarter of its energy from nuclear power, but its 16 stations will reach the end of their working lives in about 30 years, and there is a moratorium on building new ones.

The warning came in a joint statement from the Royal Society's president, Lord May of Oxford, and vice-presidents Professors David Wallace, Patrick Bateson, John Enderby, and Julia Higgins.

"In the short to medium term, it is difficult to see how we can reduce our dependence on fossil fuels without the help of nuclear power," they said.

The scientists said growth in renewable energies such as wind, wave, and solar power would not be fast enough to make up for the loss of capacity resulting from a phasing-out of nuclear power.

As it is, they said, the UK's carbon dioxide emissions have risen over the past two years.

...


Click here to read more (http://news.bbc.co.uk/2/hi/uk_news/2743515.stm)

[DesertFox]

The hypocritical Left will demonstrate FOR nuclear power when they see the money to be made in it. They're just a little slow on the uptake.

As usual.

[DoctorDoom]

As long as the anti-newkewlar know-nothings are given credibility, and their media cat's-paws fawn obsequiously over them, the development of the next generation of nuclear power stations will be stalled.

The no-nukes are not interested in clean, safe, abundant power. If they were, they'd be pushing for more nukes. Their aim has always been an energy-deficient society. The fact that they are on record opposing windmills, hydopower, solar, biomass et al is proof of their intentions.

Here are two very frank statements from early leaders in their neo-Luddite movement. The quotes are from the 70s, but they have not deviated one tiny bit from their stated goals.

"It would be little short of disastrous for us to discover a source of clean, cheap, abundant energy because of what we might do with it. We ought to be looking for energy sources that don't give us the excesses of concentrated energy with which we could do mischief to each other."
-- Amory Lovins, Mother Earth News, 11-12/77

"In fact, giving society cheap abundant energy at this point would be the equivalent of giving an idiot child a machine gun."
-- Paul Erlich, Not Man Apart (Friends of The Earth), Vol 5, No. 18, Sept 1975

They are typical arrogant liberal elitists who believe that what they think is best for us MUST be forced upon us for our own good. Nukes represent the sort of clean, abundant energy that they want to deny us, and they'll lie shamelessly to terrify the scientifically uninformed public into rejecting new plants.

[MaximumSam]

The only real issues with nuclear power are a meltdown, which I think is mostly an overblown threat, and what to do with the waste. that is a problem, because right now the waste sits in drums onsite. I don't know of the progress on the Yucca Mountain site, although it may not be a full proof solution.

[DoctorDoom]

The threat of a meltdown is egregiously overblown. It assumes the simultaneous failure of two or more redundant safety systems resulting in a LOCA (Loss Of Coolant Accident). This results in an immediate cessation of the nuclear chain reaction, but the residual decay of short half-life radioisotopes in the fuel rods creates enough heat to cause the rods to melt.

The LOCA at Three-Mile Island 2 was as bad as any accident in the US will ever be, and improvements in safety systems were effected following that event. What was the final toll at TMI? A: zero deaths, zero injuries, insignificant radiation leakage and a big cleanup bill. Since the US technology is standard in all western nuclear facilities, the likelihood of another event even approaching TMI in severity is minimal.

Before anyone asks, the RBMK-1000 reactors at Chernobyl are totally unlike western reactors. They are graphite-moderated, and the design results in a positive void coefficient. This means that a loss of coolant increases the nuclear reaction. Even so, the accident was a result of a totally unauthorized experiment by the operators that included deliberately locking out the safety systems.

The events at Chernobyl could not happen at any western reactor because of the design differences and the laws of physics.

<hr>
Re the waste at the nuke sites, the LLRW (Low-Level Radioactive Waste – tools, rags, gloves, etc.) is trucked out and buried at one of a number of LLRW disposal sites. The HLRW (High-Level Rad Waste – the spent fuel rods) is retained at the sites in cooling ponds where the short-half-live isotopes burn themselves out.

Re Yucca Mountain, the objections to it are solely political, and result from the culpable ignorance of nuclear technology that I decried above.

Yucca Mountain Project (http://www.ocrwm.doe.gov/ymp/index.shtml)

[MaximumSam]

The events at Chernobyl could not happen at any western reactor because of the design differences and the laws of physics.


I agree.

Re Yucca Mountain, the objections to it are solely political, and result from the culpable ignorance of nuclear technology that I decried above.


Well, that's not quite true. One of the biggest issues with Yucca is that the high level waste will sit there for years, and likely outlast whateevr it is kept in. This can present a large problem, since there is at least some evidence that a leak could get into the groundwater table. also, some people think there could be volcanic activity at the site, but I don't know much about that.

[DesertFox]

Sam, any reason you know of to think we can't insulate against leakage? It's a straightforward problem of engineering.

Ain't been volcanoes in Colorado for upwards of two eons.

[RayChuang]

Sam,

Actually, there are safe ways to store nuclear waste so it is not so dangerous.

First, fuse the radioactive waste with glass at high temperature and turn them into glass balls. The glass will effectively absorb most of the radiation anyway, so waste in this form has a tiny fraction of the radiation of normal unprocessed nuclear waste.

Second, store this stabilized waste in disused salt mines and/or salt domes in areas that used to have a lot of crude oil to pump out. People used to make a "dig" against the Bush family by saying "send the waste to Texas" until nuclear engineers announced that salt domes over pumped-out oil deposits in Texas are among the best ways to store nuclear waste, since the salt acts as an excellent radiation absorbant.

[DoctorDoom]

[ QUOTE ]
Well, that's not quite true. One of the biggest issues with Yucca is that the high level waste will sit there for years, and likely outlast whateevr it is kept in. This can present a large problem, since there is at least some evidence that a leak could get into the groundwater table. also, some people think there could be volcanic activity at the site, but I don't know much about that.

[/ QUOTE ]
Point 1: after about 500 years, the waste will be less radioactive than the original uranium ore.

Point 2: reactor fuel rods consist of ceramic pellets of uranium dioxide (UO₂) fuel encased in sealed Zircaloy-4 tubes.

[ QUOTE ]
LWR fuel pellets are fabricated by compacting and then sintering the powdered oxides and then grinding the pellet to size. The powder is usually compacted and sintered to around 95% of its theoretical maximum density to provide void space for fission gases. The resulting ceramic pellet is similar to other ceramics, like those used for dishware and mugs.

The uranium in LWR fuel is enriched to between 1.6% to 4.5% uranium 235 (U235), with the remaining uranium being almost exclusively the isotope uranium 238 (U238). When at power, neutrons generated in the reactor core are absorbed by the U235, producing fission reactions where the U235 nucleus becomes unstable and breaks into two smaller fragments (called fission products) and a couple of neutrons. The fission fragments are radioactive, and therefore go through a series of decay processes, creating daughter species. In general the fission products remain trapped in the crystaline structure of the ceramic pellet, and thus the pellet material provides the first barrier to fission product release. However, some of the daughter species are noble gases, and these species tend to diffuse through the crystaline pellet material and into the fuel rod gas space.

[snip]

Fuel rods are made by stacking fuel pellets inside a Zircaloy cladding tube. The tube is then evacuated, backfilled with helium to around 3 atmospheres pressure and sealed at each end by weld plugs as seen in Fig. 2. The Zircaloy cladding tube contains the gaseous fission products released from the fuel, and provides the second barrier to fission product release.

Large amounts of heat are generated in LWR fuel during reactor operation, primarily from kinetic energy deposited in a short distance by the high-energy fission products (83%). A typical BWR fuel rod generates around 44 kW/m (13.4kW/ft) of heat. Because the thermal conductivity of UO2 is relatively low, a large temperature gradient exists from the center of pellets to their surface, giving pellet surface temperatures around 650°C (1200°F) and centerline temperatures around 1260°C (2300°F). These temperatures are well below the melting temperature of UO2 2800°C (5072°F), but because the nonuniform temperature causes the center material to expand more that the surface material, the pellets normally crack under power. Thus in spent fuel, the pellets are usually cracked and broken.

[/ QUOTE ]
Physical Description of LWR Fuel (http://cnwm.berkeley.edu/reports/RE94-0001/)

This is the nature of the fuel rods that constitute HLRW. The fuel is embedded in ceramic material, which is insoluble in ground water. Ancient glass found in running water demonstrates the immunity of glass and ceramics to water.

3. There is no ground water in the Yucca Mountain project. The water table is 800 to 1000 feet below the storage area. And, the area is subject to a maximum of about 6" of rain per year.

4. One method for interring the waste is to remove the pellets from the rods and encase them in concrete-filled steel drums. This provides two more barriers between the ceramic pellets and the outside world.

5. Concerning possible volcanic activity...

[ QUOTE ]
To assess the possibility of future volcanic activity in the Yucca Mountain area, the U.S. Department of Energy relied upon careful evaluation by some of the world’s foremost experts in such fields as volcanology, geophysics, and geochemistry.

Their studies started with extensive analysis of the location, age, and volume of past volcanic activity in the Yucca Mountain area. Using the data from these studies, along with information from studies of both modern and ancient volcanoes throughout the world, the scientists performed a volcanic hazard analysis.1 This analysis evaluated the likelihood of magma entering the potential repository area. The analysis also evaluated the possibility of magma intersecting the repository and erupting up through the mountain’s surface. A panel of independent external experts continues to provide the DOE with ongoing advice about volcanic hazards. This will help ensure that a sound technical basis is presented in future licensing interactions with the U.S. Nuclear Regulatory Commission.

Could a future volcano disrupt a repository at Yucca Mountain?

Using their extensive studies of the Yucca Mountain region, experts estimate the chance of a volcanic event disrupting the proposed repository to be about one in 63 million per year. This equals about 0.0000016 percent chance per year that a volcano will disrupt the repository. Put another way, it means there is about a 99.9999984 percent chance per year that a volcanic event will not disrupt the repository.

1. Probabilistic Volcanic Hazard Analysis for Yucca Mountain, Nevada (U.S. Department of Energy, CRWMS M&amp;0 1996)

[/ QUOTE ]
Understanding the potential for volcanoes at Yucca Mountain (http://www.ocrwm.doe.gov/factsheets/doeymp0341.shtml)

6. Concerning heat generated by waste decay...

[ QUOTE ]
Engineers call this process thermal loading

When radioactive elements decay, one result is heat. Because it will contain waste packages with many tons of decaying spent nuclear fuel and high-level radioactive waste, the underground repository proposed for Yucca Mountain will generate heat for thousands of years.

Engineers with the Yucca Mountain Project call the amount of heat generated by this radioactive decay within a particular area a "thermal load." The number, size and contents of the waste packages placed in the repository will help determine the actual concentrations of heat within the facility. How these waste packages are arranged will determine which parts of the repository will become hottest. Many packages placed closely together will concentrate considerable heat nearby. This is similar to how heaping the coals in a grill at the center focuses more intense heat there than at the edges. Placing these same packages farther apart - a low thermal load - results in lower temperatures over a greater area.

Scientists consider heat management to be an essential design element for a repository. This is because the way heat moves through a repository could affect its rock floors and walls, and therefore the facility’s ability to do its job. Each possible arrangement comes with its own potential advantages and disadvantages. Scientists have conducted extensive underground and laboratory tests of the man-made materials and the rock at Yucca Mountain to determine which method of spacing will best contribute to the safe disposal of highly radioactive materials there.

[/ QUOTE ]
Managing Heat in a Repository at Yucca Mountain (http://www.ocrwm.doe.gov/factsheets/doeymp0204.shtml)

7. Concerning gas and fluid movement through rock...

[ QUOTE ]
At the Exploratory Studies Facility at Yucca Mountain, workers have excavated a series of four test alcoves on the right side of the tunnel. Here, scientists will try to understand how air, water, and other gases move through layers of rock within Yucca Mountain.

The tests conducted within these alcoves will help researchers determine whether Yucca Mountain is a suitable site for disposal of high-level radioactive waste. Understanding how water or gases behave in the natural environment within Yucca Mountain is crucial to this task. For example, one of the components of spent nuclear fuel is radioactive carbon dioxide (14CO2). Scientists need to understand how this gas and other fluids travel naturally through the layers of thick volcanic rock at Yucca Mountain.

[/ QUOTE ]
A study of how fluid moves through rock (http://www.ocrwm.doe.gov/factsheets/doeymp0006.shtml)

Fact sheets on the YMP are available here.

Fact Sheets - Alphabetical (http://www.ocrwm.doe.gov/factsheets/alphafact.shtml)

Last point: the exposure of uncontained nuclear waste to the environment is well known because of a group of 15 reactors in South Africa which operated for years with no waste containment or safety features, and with the waste products directly exposed to ground water.

[ QUOTE ]
Deep under African soil, about 1.7 billion years ago, natural conditions prompted underground nuclear reactions. Scientists from around the world, including American scientists, have studied the rocks at Oklo. These scientists believe that water filtering down through crevices in the rock played a key role. Without water, it would have been nearly impossible for natural reactors to sustain chain reactions.

The water slowed the subatomic particles or neutrons that were cast out from the uranium so that they could hit-and split-other atoms. Without the water, the neutrons would move so fast that they would just bounce off, like skipping a rock across the water, and not produce nuclear chain reactions. When the heat from the reactions became too great, the water turned to steam and stopped slowing the neutrons. The reactions then slowed until the water cooled. Then the process could begin again.

Scientists think these natural reactors could have functioned intermittently for a million years or more. Natural chain reactions stopped when the uranium isotopes became too sparse to keep the reactions going.

What happened to the nuclear waste left at Oklo?

Once the natural reactors burned themselves out, the highly radioactive waste they generated was held in place deep under Oklo by the granite, sandstone, and clays surrounding the reactors’ areas. Plutonium has moved less than 10 feet from where it was formed almost two billion years ago.

Today, manmade reactors also create radioactive elements and by-products. Scientists involved in the disposal of nuclear waste are very interested in Oklo because long-lived wastes created there remain close to their place of origin.

[/ QUOTE ]
Oklo: Natural Nuclear Reactors (http://www.ocrwm.doe.gov/factsheets/doeymp0010.shtml)

Conclusion: the objections to Yucca Mountain are political, not scientific. And, any natural disaster that unearthed this buried waste would be of sufficient magnitude that no one would have enough free time to worry about it.

[MaximumSam]

That's a lot of good information. However, it doesn't solve the main problem - we are collecting all of long lasting waste and putting it in a single place. I suppose that politics are the main problem, since I think Yucca is still probably preferable to leaving it on site near towns and cities. However, it is difficult not to sympathize with people in Nevada who could be threatened.

In a study to be published in the July issue of Environmental Geology, physics research associates John B. Davies and Charles Archambeau present their conclusions on what might happen if a significant earthquake struck the Yucca Mountain area. It is the first study to assess the impact of an earthquake on the area's groundwater levels.

Using computer modeling based on geological data, historical quakes and results from about 20 test wells, they showed that a magnitude 5 or 6 earthquake could raise the water table between 450-750 feet at the storage site. Because the repository would be only 600 to 800 feet above the present water table, "flooding could be expected to occur," they write.

The water table below the Yucca Mountain site is unusually deep, about 1,500 feet below the surface, Davies said. But within a six-mile area north of the proposed storage facility the groundwater level rapidly rises to a more normal depth of about 600 feet.

The reason for this abrupt change in the water table is a cause for concern, Davies said.
Davies and Archambeau believe that the presence of open fractures underneath Yucca Mountain has allowed the water table to descend to unusually low depths, and that closed fractures to the north have resulted in a more normal water table level. The danger is that an earthquake of sufficient magnitude could cause the open fractures underneath the Yucca Mountain site to squeeze shut, forcing the water upward into the storage facility.

"If water hits the storage area it could cause a rapid corrosive breakdown of the containers and allow the plutonium to leak into the water table and the atmosphere," Davies said.
Historical evidence exists for earthquakes causing groundwater to squeeze upward and even erupt from the surface, the authors said, citing the magnitude 7 quake at Idaho's Borah Mountain in 1983 and the 7.3 quake at Montana's Hebgen Lake in 1959. Both quakes occurred in areas subject to similar geological forces as Yucca Mountain.


http://www.antenna.nl/wise/475/4711.html

Furthermore, there are plenty of risks in the shipment itself.

Splitting uranium-235 atoms in a nuclear reactor creates intensely radioactive elements known as fission products, such as cesium, strontium, and plutonium. When spent nuclear fuel is removed from the reactor core, it is about one million times more radioactive than when it was loaded. A typical rail cask of high-level nuclear waste contains more than 200 times the long-lived radiation (cesium and strontium) than the atomic bomb dropped on Hiroshima. If unshielded, the average cask of nuclear waste destined for Nevada delivers a lethal dose of radiation in 2 minutes to a person standing 3 feet away.

http://www.mapscience.org/faq_whatisit.php

We will have thousands of shipments moving this stuff across the country. While there are plenty of natural risks associated with that, the terrorist risk will also be high.

All in all, there is certainly a scientific argument that putting all of our waste in Yucca mountain may be unwise - after all, this is a very large scale project involving long-lasting dangerous waste. We simply don't know all the ramifications of putting waste in Yucca, which should make us pause on how to going for more nuclear power. However, I do think the benefits outweight the costs.

[Dash_Riprock]

Let's just store the stuff in Ohio.

[DesertFox]

In Columbus. The law school there.