Showing posts with label peak load. Show all posts
Showing posts with label peak load. Show all posts

Tuesday, April 28, 2015

The Production and Utilization of Renewable Methanol in a Nuclear Economy


10.7 MWe rated methanol electric power plant at Point Lisas, Trinidad (Credit: Mendenhall Technical Services)
Terrestrial and off-shore nuclear power plants could safely and economically provide all of the base load electricity requirements for future carbon neutral  industrial economies. The additional-- peak load-- electrical demands for an industrial region could also be supplied by carbon neutral methanol electric power plants-- if nuclear electricity was also utilized to produce renewable methanol derived from biowaste and waste water resources

Methanol (CH3OH) is, of course, the simplest alcohol, producing only carbon dioxide (CO2) and water after combustion with oxygen. The production of methyl alcohol through the pyrolysis of carbon based materials and their distillation has been known since the time of the ancient Egyptians. Modern techniques of methanol production utilize pyrolysis to produce syngas (synthetic natural gas),  a gaseous mixture of consisting of carbon monoxide, carbon dioxide, and hydrogen  that is then converted into methanol.

Since approximately 65% to 75% of the CO2 content is wasted during the  synthesis of  syngas into to methanol, introducing additional hydrogen into the synthesis process could potentially increase the production of methanol by three to four times. Sources of carbon neutral hydrogen could, therefore, be produced through nuclear, hydroelectric, wind, and solar electric power through the electrolysis of water.

Plasma arc pyrolysis plants, a commercial technology that's already in existence,  could be used for the conversion of urban and rural biowaste (garbage and sewage) into syngas.  Additional hydrogen can be added to the mix through the production of hydrogen through the electrolysis of water at an electrolysis plant. The syngas and additional hydrogen can then converted into  methanol at a  alcohol methanol synthesis plant.

Diagram of a methanol biowaste complex for the production of methanol and electricity.

Carbon neutral sources of electricity could come  from nuclear, hydroelectic, wind, and solar power plants.  Because the sun doesn't always shine and the wind doesn't always blow, wind and solar facilities only offer intermittent supplies of carbon neutral electricity to the electric grid.  While hydroelectric power plants can supply carbon neutral electricity to the grid 24/7, this renewable energy source  has already reached its maximum capacity in the US and can actually supply less power to the grid during periods of drought-- as is currently the occurring in drought stricken California.

Nuclear power plants, on the other hand, can supply carbon neutral electricity to the grid 24 hours per day.  Except during periods of refueling (once every three years), current light water nuclear power plants in the US have an electrical capacity exceeding 90%. Nuclear power currently produces about 20% of America's electricity supply. But there is currently enough room-- at existing US nuclear sites--  to increase nuclear power production  in the US by at least four to five times the current nuclear capacity without the need to add new locations within the continental US. This could easily be done by gradually adding the next generation of Small Modular Reactors (SMR) to existing sites over the next twenty to thirty years.

A methanol complex using carbon neutral electricity from nuclear and renewable energy could produce methanol from the pyrolysis of urban and rural garbage and sewage-- solving the problems of urban and rural refuse while also producing clean energy. The production of hydrogen from the electrolysis of water could substantial increase methyl alcohol production. Domestic sources of carbon neutral methanol could then be used to fuel methanol electric power plants during peak load demands.  The production of electricity from a methanol electric power plant could be further increased if the waste oxygen from the production of hydrogen were  utilized during fuel combustion instead of air which contains only 20% oxygen and  80% nitrogen. 

While the CO2 produced from a methanol electric  power plant could be exhausted into the air without increasing the net amount of CO2 in the Earth's atmosphere, the waste carbon dioxide from the  flu gas could also be recycled.   Post combustion and pre- combustion CO2 capture facilities can collect 85 to 90% of CO2 from flu gas. And power plants that used oxygen can capture as much as 90 to 97% of the CO2 produced from flu gas. Pumping the waste CO2 into the methanol synthesis plants could nearly double  the production of  renewable methanol if even more hydrogen is added to the mix.

Any excess production of methanol from a methanol electric complex would be a valuable commodity that could be exported. Exported methanol could be used  for the base load production of electricity in areas with no access to nuclear power or it could be converted into gasoline or dimethyl ether for trucks and automobiles. Methanol would also be of value to industrial chemical companies.
 
TVA’s, Sequoyah Nuclear Plant (Credit TVA).

Despite the accidents at Fukushima and Chernobyl, terrestrially based commercial nuclear power are still the safest source of electricity production ever invented. But floating commercial nuclear reactors deployed several kilometers off marine coastlines or even deployed far out into the ocean could enhance nuclear safety even further.

The Earth's oceans, of course,  are certainly no strangers to nuclear power. There are over 140 nuclear powered ships and submarines roaming the Earth's oceans and seas  with more than 12,000 reactor years of marine operations  accumulated since 1954. 

More than 100 million Americans currently  live within 80 kilometers of a commercial nuclear reactor. But undersea electric cables more than 1000 kilometers away from coastlines  are possible.   Floating nuclear power facilities  could be deployed more than  300 kilometers from an American coastline while still being within the US's  200 nautical mile (370 kilometer) exclusive coastal economic zone.  Such floating reactors could, therefore, be deployed far beyond the 80 kilometer exclusion zone recommended by the United States during the height of the  Fukushima nuclear accident.

Of course, a Fukushima type of incident would be impossible for a floating nuclear facilities located in the open ocean since water  is a natural coolant for light water reactor fuel. Ocean waters would serve as an infinite heat sink for fissile material-- essentially making nuclear meltdowns impossible for floating reactors  placed below the water level. Floating nuclear reactors placed dozens of  kilometers offshore would also be immune to potential damage from earthquakes and tsunamis.

The safety of floating nuclear facilities from potential harm from terrorist or other hostile political groups could be enhanced by naval security from  US Coast Guard or other US government authorized security forces. Potential damage to the reactor from a  torpedo could also easily be prevented with an extensive network of  torpedo nets surround the nuclear power facilities.

But, again, even if an attack on a floating nuclear facility was successful, the ocean water would immediately prevent any melting of the nuclear material to occur.  Water also acts as a natural radiation shield. Just a few meters of water can  reduce ionizing radiation to harmless levels of exposure near the radioactive material.



Japanese Methanol Tanker (Credit: SHIN KURUSHIMA DOCKYARD CO)

Ocean Nuclear power plants could also be remotely deployed, more than a thousands of  kilometers away from coastlines for the production of electricity. Methanol powered ships could transport garbage from coastal towns and cities to floating biowaste pyrolysis, water electrolysis,  and methanol synthesis plants remotely powered by underwater electric cables from Ocean Nuclear Power plants just a few kilometers away. The methanol could then be shipped to coastal towns and cities all over the world for the production of electricity or for conversion into gasoline or dimethyl ether for diesel fuel engines.

First Methanol Fueled Ferry (Credit Stena Line)

Combined with nuclear and renewable energy, renewable methanol fueled peak load power plants  could finally end the need for  greenhouse gas polluting coal and natural gas power plants in the US and in the rest of the world.


Thursday, February 26, 2009

The Nuplex Solution

by Marcel F. Williams

In 1982, the United States Congress passed a law requiring the Department of Energy to find a suitable site to construct a disposal facility for the radioactive spent fuel from commercial nuclear reactors. In 2005, 52,000 tonnes of spent fuel was being held at nuclear power and military facilities in the US. And it is estimated that by 2015, the nation's nuclear power facilities will be storing over 75,000 metric tons of spent fuel on site. There are laws preventing the expansion of nuclear power within several States in the US until a final storage solution is found for the radioactive spent fuel accumulating at current commercial nuclear reactor sites. And to fund such a permanent storage facility, nuclear utilities have paid nearly $30 billion in fees and interest to a Federal “nuclear waste fund”.

Nuclear Energy Institute map of stored radioactive waste from the commercial and military nuclear industry

Eventually, Yucca Mountain became the Department of Energy's solution to the nations nuclear waste problem. Over 2 billion dollars has been spent studying the Yucca Mountain area in Nevada with an additional 5 to 6 billion dollars to finish the facility by 2010. But there has been strong political and environmental opposition to storing spent fuel at the Yucca Mountain facility. Harry Reid, Senator from Nevada and the current leader of the US Senate, strongly opposes Yucca Mountain as a repository for the nation's nuclear waste material. And President Barack Obama ran in opposition to utilizing the Yucca Mountain facility for radwaste deposition during his campaign for president.

So it now seems unlikely that the Yucca Mountain facility in Nevada will be utilized for the deposition of the nation's spent fuel. And the Nuclear Energy Institute has reportedly recently advanced the idea that President Barack Obama convene a blue ribbon nuclear waste commission to find an alternative to burying radioactive power plant fuel at Yucca Mountain.

Despite that fact that there are tens of thousands of tonnes of spent fuel now residing at US commercial nuclear power plants, it should be noted that only 3 or 4% of that spent fuel is actually radioactive waste. After enriched uranium is utilized in a nuclear reactor for fuel, 96% of the remaining mass is in the form of the original fertile uranium 238 with a residual component of fissile uranium 235 composing about 0.83% of the total uranium content. This percentage of uranium 235 is down from its original 3% as fuel, but still higher than the 0.71% natural concentration of uranium. An additional 1% of the spent fuel is in the form of fissile plutonium 239. And the rest is in the form of fission products and minor actinides. Since the uranium and plutonium can be recycled and utilized for fuel, only 3% or 4% of spent fuel can actually be considered as radioactive waste material.

Spent fuel cask stored on site

Spent Fuel Composition

95.6% uranium (0.83% of which is U-235)
2.9% stable fission products
0.9% plutonium (about two thirds fissile plutonium)
0.3% cesium & strontium (fission products)
0.1% iodine and technetium (fission products)
0.1% other long-lived fission products
0.1% minor actinides (americium, curium, neptunium)

So instead of the Federal government using the 30 billion dollars given to them by the utilities to simply throw away the spent fuel, I propose that the Federal government use that money along with additional Federal investment funds to dispose of 96% of the spent fuel by recycling the fissile material and converting it into clean energy.

I propose that a Federal Nuplex Corporation should be established in order to fund the construction of Federal Nuplexes in every State that is currently storing spent fuel at their nuclear power facilities and for every State willing to take in spent fuel from other states.

I envision Federal Nuplex facilities as consisting of:

1. Temporary storage areas for spent fuel cask recently imported from nuclear power facilities within the state

2. On site spent fuel reprocessing facilities to extract uranium and plutonium fuel on site utilization

3. On site uranium enrichment facilities to fabricate uranium fuel for on site reactors

4. 8 to 40 on site nuclear reactors capable of using the recycled uranium and plutonium fuel for base-load electricity production

5. Long term storage cask for housing the reprocessed radioactive spent fuel fission products and minor actinides from nuclear reactors

6. Adjacent site synfuel production facilities for the production of carbon neutral gasoline, methanol, diesel fuel, jet fuel, dimethyl ether, hydrogen, oxygen, and ammonia for the transportation and industrial chemical industry

7. Off site (up to 80 kilometers) methanol-oxygen cogeneration and trigeneration power facilities for the production of peak-load electricity

8. On site storage facilities for radioactive waste from hospitals and radioactive research facilities

A State's spent fuel could be transported by rail to the Federal Nuplex facility located within the state. The residual nuclear waste produced after reprocessing would be stored on site for a few hundred years until either transmutation or final out of state deposition. On site reactors could also be decommissioned on site after energy production from a Nuplex has finally ceased. The safest and most economical way to decommission a reactor facility would be to allow the irradiated components of the facility to decay over the coarse of 100 to 200 years. So if you assume that several reactors would be gradually added to a nuplex over the course of the next 30 or 40 years and that these reactors will continue to operate for at least 60 to 80 years then Nuplex facilities would probably not be completely decommissioned and removed from its site until at least 300 years from now, or not until the 24th century. So any residual radioactive waste could remain on site at secured Nuplex facilities for a few hundred years until the material is eventually transmuted into shorter lived elements or permanently deposited in deep sea beds or in some extraterrestrial environment in the 24th century.

Spent fuel cask being transported by rail

A typical Nuplex could contain perhaps four AP 1000 light water reactors plus four ACR 1000 heavy water reactors. The recycled plutonium and uranium could be used inside of a thorium blanket inside of an ACR reactor to reduce plutonium production while producing more uranium 233. A Heavy Water Reactor utilizing thorium could in theory have an 80% conversion ratio or above almost to the point of being self-sustaining. The AP 1000 Light Water Reactor could use the recycled and enriched uranium to produce power or the plutonium as MOX, or the plutonium in a mixture of a thorium-uranium blanket






Federal Nuplexes would contain between 8 to 40 reactors. Concentrating so many reactors at one site could substantially reduce the capital cost of the power facility due to economies of mass production and large concentrated facilities could also reduced labor and security cost. Each Nuplex would also produce thousands of permanent jobs. But because of the heat island effect, it may be necessary to limit the number of nuclear reactors at a site to ten or less. However, if waste it is dissipated by locating several cooling ponds and dry cooling towers in all directions, several kilometers off site, then this effect could be mitigated. Alternatively, the heat island effect could be mitigated by utilizing the waste heat for seawater desalinization, greenhouse and hydroponic agriculture, or aquaculture.

Because the Federal government would be reprocessing domestic spent fuel on Federally protected facilities, there should be no danger of nuclear proliferation. Additionally, the export of Nuplex produced synfuels to other countries for electric power production, transportation, and industrial chemicals would enable foreign nations to benefit from the production of nuclear energy without the need for nuclear facilities or nuclear material.

Federal Nuplexes would eliminate the need for long term storage of spent fuel at commercial nuclear reactors sites. They would also substantially reduce the volume of spent fuel produced by the commercial nuclear industry while also substantially increasing the amount of nuclear energy produce for base-load electricity and synfuel production. As the Secretary of Energy Steven Chu has already noted, nuclear power plants already produce 100 times less radioactive material than coal power facilities. Nuplexes could furter reduce radwaste production by more than 1000 times relative coal power production. Finally, Federal Nuplexes would allow regional utilities to increase the number of reactors on existing sites without the long term trouble of managing and storing spent fuel.

References and Links

1. Waste Management in the Nuclear Fuel Cycle

2. Short & Long Term Solutions for Nuclear Waste

3. Experts Weigh In On How The U.S. Should Handle Its Commercial Nuclear "Waste"

4. Public Power & the Future of Nuclear Energy


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

6. Green Freedom: A concept for producing carbon-neutral synthetic fuels and chemicals, Los Alamos Labs, November 2007 F.J. Martin and WL Kubic,

7. Gasoline from Air and Water

8. A Guidebook to Nuclear Reactors: Reactors, Fuel Cycles, The Issues of Nuclear Power
Anthony V. Nero Jr.


9. Nuclear Decommissioning

10. Technology and Policy Instruments for Mitigating the Heat-island Effect

11. Coal Ash Is More Radioactive than Nuclear Waste


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