Monday, October 20, 2008

Natural Radiation

by Marcel F. Williams

Humans exist on a planet and within a universe that is naturally radioactive. In fact, humans and all other plant and animal species that live and breed on Earth are also inherently radioactive.

Since the birth of the cosmos, the earth has been subjected to an endless hailstorm of cosmic radiation. These potentially deleterious ionizing particles consist of highly accelerated protons, electrons, and neutrons originating mostly from other stars in our galaxy.

Our planet of evolutionary origin is also radioactive due to naturally occurring radioactive elements in the earth's crust such as: potassium-40, uranium-238, thorium-232, and rubidinum-87, and radium-226. In fact, the radioactive decay from uranium, thorium, and potassium may be responsible for 45 to 90% of the earth's internal heat source which is the source of earthquakes, volcanoes, mountain building, hot springs, and continental drift.

On average, humans receive 0.4 mSv (40 millirems) of cosmic radiation. People also receive about 0.5 mSv (50 millirems) of terrestrial radiation. We also inhale about 1.2 mSV (120 millirems) of radiation from radon gas annually.

The human species is also internally radioactive due to the potassium in our bones which exposes our tissues to 0.4 mSv (40 millirems) of ionizing radiation. So being in constant proximity to other human beings increases one's exposure to ionizing radiation.

So if you lived with at least one other person in your house, you would receive 0.4 (40 millirems). That's more than ten times as much radiation as you would receive by living near a nuclear facility. If you lived in California and moved to Colorado, you would receive 45 times as much ionizing radiation as you would living next to a nuclear power facility.

Ionizing Radiation Levels (annual):

0.39 (mSv) Annual human internal radiation due to radioactive potassium

0.35 mSv Annual exposure to cosmic radiation in the state of Louisiana

1.20 mSv Annual exposure to cosmic radiation in the state of Colorado

0.30 mSv Annual exposure to terrestrial radiation in the state of Texas

1.15 mSV Annual exposure to terrestrial radiation in the state of South Dakota

0.07 mSv Annual radiation exposure to while living in a stone, brick, or concrete building

0.03 mSv Annual radiation exposure while living near the gate of a nuclear power plant

0.01 mSv Annual USA dose from nuclear fuel and nuclear power plants

1.15 mSv Annual radiation exposure while working at a nuclear power plant

2.0 mSv Annual human internal radiation due to radon

1.0 mSv Annual Limit of dose from all DOE facilities to a member of the public who is not a radiation worker

5.0 mSv Annual USA NRC limit for visitors

20 mSv Annual (averaged over 5 years) is the limit for radiological personnel such as employees in the nuclear industry, uranium or mineral sands miners and hospital workers

50 mSv Annual highest dose which is allowed by regulation of occupational exposure. Doses greater than 50 mSv annually arise from natural background levels in several regions of the world but do not cause any discernible harm to local populations.

500 mSv Annual USA NRC occupational whole skin, limb skin, or single organ exposure limit

Ionizing Radiation Levels (acute):

0.o5 mSV One round-trip to Paris-New York

0.46 mSv off-site exposure to the Three Mile Island core meltdown accident

2.2 mSv Average dose from upper gastrointestinal diagnostic X-ray series

50 mSv Lowest dose at which there is any evidence of cancer being caused in adults

100 mSv USA EPA acute dose level estimated to increase cancer risk 0.8%

500-1000 mSv Low-level radiation sickness due to short-term exposure

Persons working at a nuclear facility are normally exposed to 1.15 mSv (115 millirems) annually. This would be the equivalent of living in the state of Ohio where Americans there are exposed to an equivalent amount of cosmic and terrestrial radiation and below that of states like Colorado, Wyoming, and Utah where one receives a lot more background radiation.

If you lived near the gate of a nuclear reactor and never left the house, you would be exposed to 0.03 mSv (3 millirems) of radiation annually from that nuclear facility. However, you would receive 0.07 mSv (7 millirems) of radiation if you were living in a stone, brick, or concrete building. So you would receive more radiation from your house than from living near the gate of a nuclear facility.

But what about a nuclear meltdown?

Thanks to the fact that US reactors are housed in huge protective containment structures, the nuclear meltdown at Three Mile Island exposed nearby residents to only 0.46 mSv of acute radiation. That's nearly five times lower than receiving a gastrointestinal medical X-Ray and more than 100 times below the level of cancer causing radiation. But the new generation of nuclear reactors such as the AP1000 and GE's ESBWR have core damage frequencies at least 100 to 1000 times lower than current reactors such as the LWR at Three Mile Island. But, again, even if a meltdown did occur, the public would be protected by the containment structures which are also designed to withstand an impact from a jet plane.

Americans are exposed to natural radiation from cosmic and terrestrial radiation ranging from as low as 0.75 mSv (75 millirems) to as high as 2.25 mSv (225 millirems). And Americans are exposed to an additional 2.0 mSv (200 millirems) of radon gas on average. Yet living near the gate of nuclear power facility would only expose them to 0.03 mSv (3 millirems) of radiation. And even consistent contact with a family member would expose you to another 0.4 mSv (40 millirems) of radiation annually. So the idea that a dramatic increase in nuclear power would expose humans to a dramatic increase in ionizing radiation is clearly not supported by the scientific evidence.

References and Links

1. G. Olah, A. Goeppert, and G. Prakash, (2006) Beyond Oil and Gas: The Methanol Economy, Wiley-VCH Verlang, Weinheim, Germany

2. Ionizing radiation (Wikipedia)

3. Economic Simplified Boiling Water Reactor

4. Martin D. Ecker, and Norton J. Bramesco (1981) Radiation: All you need t know about to stop worrying...or to start, Vintage Books, New York

5. Radiation and Life

A New Papyrus Publication

Wednesday, October 15, 2008

The Cost of Non-Carbon Dioxide Polluting Technologies

by Marcel F. Williams

Today America and the world finds itself at the dawn of an energy, economic, and environmental crisis.

Carbon dioxide and methane gas pollution from the fossil fuel economy is causing the melting of the polar ice caps and a gradual rise in sea levels that could threaten our coastlines and, in some cases, threaten the existence of entire nations. More violent and extreme weather patterns are also believed to be caused by increasing global temperatures.

The importation of foreign oil is causing the US to send more than $700 billion annually to foreign nations. That's $700 billion dollars a year that is going to other nations instead of being invested right here in the USA. The oil imports do not include the $60 billion a year that the US military spends on protecting the flow of oil from the Persian Gulf, essentially a $60 billion a year subsidy to the international oil industry by the US tax payers.

Increasing population and economic growth could also cause an electricity shortage in the US and in many other nations in the near future.

So what do we do?

Energy re-industrialization through nuclear and renewable energy technologies would appear to be the most logical solution to the problems of our energy, the environment, and our economy. Energy re-industrialization through through non-carbon dioxide polluting technologies could not only solve our future energy and environmental problems but could also create tens of millions of jobs in practically every region and community in America.

Cheap base load energy is essential for a growing economy while affordable peak load energy helps to supplement base load capacity during periods of high energy demand. Cheap hydrogen through water electrolysis also requires low priced base load electricity. Hydrogen is an essential ingredient for the production of synthetic hydrocarbon fuels such as gasoline, diesel fuel, aviation fuel, and methanol.

While the shift towards electric vehicles and plug-in-hybrid electric automobiles could help the US wean itself off of foreign oil, it will also increase the demand for non-carbon dioxide polluting electricity in order to avoid increasing greenhouse pollution from electric power generating resources.

In our current fossil fuel dominated economy:

coal cost 2.4 cents per kwh

natural gas cost 6.8 cents per kwh

oil cost 9.6 cents per kwh

Amongst non-carbon dioxide polluting energy technologies:

hydroelectric cost 0.85 cents per kWh

nuclear cost 1.68 cents per kWh

garbage incineration (non-subsidized) cost 4.0 cents per kWh

wind (non-subsidized) cost 4.35 to 6.56 cents per kWh

solar thermal (Sunny climate) cost 6 cents per kWh

home photovoltaic (Sunny climate) cost 37.78 cents per kWh

home photovoltaic (Cloudy climate) cost 83.13 cents per kWh

commercial photovoltaic (Sunny climate) cost 27.49 cents per kWh

commercial photovoltaic (Cloudy climate) cost 60.47 cents per kWh

industrial photovoltaic (Sunny climate) cost 21.41 cents per kWh

industrial photovoltaic (Cloudy climate) cost 47.11 cents per kWh

With hydroelectric sources in the US already fully exploited, only nuclear power has the capacity to replace coal as our primary source for base load electricity in the future. While new nuclear power facilities are likely to generate electricity at a higher price than current nuclear reactors, this may be somewhat mitigated by the continued reduction in the cost of electricity from current nuclear facilities as more of these existing sites reach the point where they've paid off their amortized capital cost, leaving only the cost of labor and fuel. However, the building of large clusters of new nuclear power plants in centralized nuclear parks could dramatically reduce capital, labor, security, and fuel transportation cost in the future.

Although significantly higher priced than nuclear, the incineration of urban biowaste could add additional base load capacity in practically every community in America. The off-peak production of methanol via base load water electrolysis synthesized with carbon dioxide flue gas from biowaste incinerators could produce methanol and oxygen to power peak load power plants. Methanol can even be used by current natural gas electric power plants with cheap modifications. The fluctuating load capacity of wind and solar thermal could also be backed up by synthetic methanol.

Eventually, the emerging aerocarbon extraction devices could utilize base load electricity to produce all of our hydrocarbon transportation, industrial chemical, and peak-load fuels once these devices become fully commercialized.

However, the extremely high cost of photovoltaic technologies would appear to regulate these technologies to only marginal aspects of our energy economy in the near future. While solar enthusiast and the wealthy may continue to place these extremely expensive devices on their rooftops, the best place for solar photovoltaics will probably be in remote communities that have very little access to alternative sources of electricity.

References and Links


2. Solar Photovoltaic Electricity Price Index
October 2008 Survey Results

3. 6 Cents Per kWh: World's Largest Solar Project Unveiled

4. Cost of Wind: American wind energy association


6. The Value of the Benefits of U.S. Biomass Power

7. Municipal Waste Combustion

8. U.S. Nuclear Power Plants Set Record Highs
For Electricity Production, Efficiency in 2007

9. Nuclear Power:Economic Alternative for Baseload Electricity

10. Industry Leader Cites Value of Nuclear Power Plants to California’s Mix of Energy Sources

A New Papyrus Publication

Thursday, October 9, 2008

Fueling our Nuclear Future

by Marcel F. Williams

One frequent argument against the expansion of commercial nuclear power is the the claim that our planet is simply running out of the nuclear material to power the world's nuclear reactors. So any future expansion of the commercial nuclear power industry would simply be out of the question.

Uranium ore

Nuclear power produces approximately 20% of the electricity in the US and represents approximately 6% of the world's energy consumption. Uranium currently sells at below $35 per kilogram on the world market. But it is estimated that there are approximately 5.5 million tonnes of proven uranium reserves at a cost below $130 per kilogram. With the resurgence of nuclear power, however, it is estimated that the exploration for new uranium sources would increase total reserves to more than 16 million tonnes. The current world demand for uranium is 65,000 tonnes per year. So there should be enough uranium to supply current global nuclear power facilities for 246 years.

Countries with the most abundant uranium supplies

But if nuclear power were required to supply the world's total energy needs, 1.1 million tonnes of uranium would be required annually. So these terrestrial uranium reserves could only power our planet for less than 15 years. And even reprocessing spent fuel would only extend the nuclear fuel supplies to no more than 20 years.

However, there are alternatives to terrestrial uranium.

The world's oceans contain more than 4 billion tonnes of uranium in seawater. That's enough to power our entire planet for more than 3600 years or over 5000 years if spent fuel is also utilized. Japanese uranium from seawater demonstration projects estimate that marine uranium could be extracted at a cost of $135 to $250 per kilogram. Current world uranium prices are less than $35 per kilogram but expected to rise as uranium demand rises as new power plants are built around the world. But since uranium fuel only represents about 5% of the total cost of the energy produce by a fission power plant, that would only increase the total cost of energy via nuclear power by 14 to 31 percent which would still make the cost of nuclear electricity significantly lower than coal and natural gas. New laser uranium enrichment techniques, however, could dramatically lower total fuel cost which could, in theory, wipe out the increase in cost of using seawater uranium since enrichment represents 30% of the cost of nuclear fuel.

Yellow cake extracted from seawater

So even if our future global society used three times as much energy as we use today, marine uranium and spent fuel could provide more than 1600 years of energy. Of course the contribution of renewable energy systems (hydroelectric, wind, solar, and biomass) could stretch uranium supplies even longer.

But even without marine uranium, breeder technologies could power our global society at three times the current level for 700 years using terrestrial uranium. Nuclear breeding technologies such as fast neutron reactors or ADS accelerator reactors could increase fuel supplies by a factor of 140 since fissile uranium 235 only represents about 0.7% of natural uranium. In light water reactors (LWR), approximately 70% of the uranium 235 is converted into energy while another third comes from the conversion of plutonium into energy which is created as a by product of the neutron irradiation of uranium 238. Breeder technologies could give the world a 500,000 year supply of nuclear power or a 166,000 year supply at three times current energy use levels. However, the oceans are constantly being replenished with uranium from the worlds rivers, depositing over 32,000 tonnes of uranium annually. Since breeder technologies would only require less than 24,000 tonnes of uranium annually, marine uranium could power our entire society at three times the current level essentially-- forever!

Thorium is another alternative to terrestrial uranium. There is at least 3 times as much terrestrial thorium 232 as there is terrestrial uranium 238. Neutron bombardment within a reactor can convert fertile thorium 332 into fissile uranium 233. And there is at least 3 times as much terrestrial thorium 232 as there is uranium 238. So terrestrial nuclear fuel sources could power our global society at three times the current level for approximately 2800 years.

A CANDU heavy water reactor could have an 80% conversion rate if it utilized fissile uranium or plutonium inside of a thorium blanket. A modified CANDU heavy water reactor that uses thorium fuel enriched with fissile uranium 235, plutonium 239, or uranium 233 can produce as much fissile fuel as it utilizes. An ADS accelerator reactor could also breed uranium 233 from thorium. For every kilogram of plutonium burned in a thorium breeder, approximately 2.73 kilograms of uranium 233 could be produced, more than 8o% of a reactors total fissile fuel requirements. Combined with the 30% of reprocessed uranium 235 from spent fuel, an ADS could supply all of a reactors fuel needs through uranium 238 and thorium 232. However, it might by easier and cheaper just to gradually replace third generation reactors with thorium and uranium burning ADS reactors.

Japanese companies currently lead the world in uranium extraction from sea water technology. But, in my opinion, the next US administration should set the goal for the commercial extraction of uranium from sea water within 10 years time. The US should also set the goal of having a functioning full scale ADS accelerator thorium breeder online within a decade with the goal of having commercial ADS reactors online within 20 years time. The same goal should be set by the Canadian government for the CANDU thorium breeder reactor.

Such policies should insure a smooth transition from our current terrestrial uranium, third generation, nuclear economy to a more diverse nuclear economy that includes current reactor technology, fast neutron reactors and ADS breeder reactors along with a more diverse fuel supply that includes terrestrial uranium, uranium from seawater, and thorium.

References and Links

1. G. Olah, A. Goeppert, and G. Prakash, (2006) Beyond Oil and Gas: The Methanol Economy, Wiley-VCH Verlang, Weinheim, Germany

2. How long can Uranium last for nuclear power? 5 billion years at double current world electricity usage.

3. World Uranium and Thorium Supplies

4. Supply of Uranium: WNA

5. How long will nuclear energy last?

6. Plutonium

7. Burn Up the Nuclear Waste

8. Mixed Oxide Fuel (MOX)

9. Costs of Reprocessing Versus Directly Disposing of Spent Nuclear Fuel

10. Japan's large scale uranium from seawater and superconductiong wire plans

11. The Cost of Recovering Uranium from Seawater

12. Uranium recovery from Seawater

13. Confirming Cost Estimations of Uranium Collection from Seawater:
Assessing High Function Metal Collectors for Seawater Uranium

14. A Guide Book to Nuclear Reactors (A.V. Nero, 1979) University of California Press

15. Operation of CANDU power reactor in thorium self-sufficient fuel cycle


17. Is thorium the nuclear alternative?

18. Accelerator Driven Sub-critical Nuclear Reactors for Safe Energy Production and Nuclear Waste Incineration

19. Laser enrichment could cut cost of nuclear power

20. Accelerator Breeder Nuclear Fuel Production

Blog Archive


Popular Posts