Energy From Thorium Discussion Forum

Thorium MSR Workshop at UNIST, Ulsan, South Korea
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Author:  Kirk Sorensen [ Jan 28, 2013 5:55 pm ]
Post subject:  Thorium MSR Workshop at UNIST, Ulsan, South Korea

I flew to Seoul, South Korea for a workshop at the Ulsan National Institute of Science and Technology (UNIST) on the subject of thorium molten-salt reactors. I arrived Monday night and took a taxi from Gimhae International Airport in Busan to the Lotte Hotel in Ulsan, and being incredibly jet-lagged I pretty much collapsed into bed immediately after I got there.

The next day those of us who would speak at the conference were picked up by one of the university staff and driven to the UNIST campus. First we assembled in a conference room and spoke with some of the faculty there, and then we had a tour of the campus with a particular focus on their laboratory equipment.

We had a Korean-style lunch with the vice president of UNIST, Dr. Mooyoung Jung, where he expressed his interest in molten-salt reactors and his hopes that there would someday be a molten-salt research reactor on the UNIST campus. Dr. Jung had gotten the book "SuperFuel" from one of his colleagues and read it cover to cover. He was very excited to meet Rick Martin and also happy to meet me. We enjoyed a delicious and varied Korean lunch for about an hour and talked about how Korea needs a new nuclear technology. Many of them consider light water reactors too dangerous after Fukushima. There is also a strong concern about proliferation and Dr. Jung thinks that thorium will go a long way towards reducing international fear on this topic.

They have big ambitions for UNIST and want it to be top-ranked in the world, so they need something to differentiate themselves from the competition, and LWR and LMFBR technology does not differentiate them. I brought up industrial participation. I brought up Hyundai Heavy Industries and what this could mean to their shipbuilding industry, to have MSRs powering their ships and a corps of students from UNIST who knows the technology. He told me that he had already been thinking the same thing.

The researchers and faculty at UNIST are just getting introduced to MSR technology. One of their faculty is an engineer expert in LWR technology and had lived in Idaho Falls and in Oak Ridge. He knew all about LWR technology so I drew analogues with LWR subsystems and he began to understand things quickly. I asked him if he had ever heard about it in the time he lived in Oak Ridge---no.

Contrary to what I might have thought, the Shanghai conference had nothing to do with their decision to have this workshop. Most of them heard were just hearing about the Chinese work. The workshop was largely precipitated by some key people reading Rick's book and are thinking about global and local developments from Fukushima and proliferation.

After lunch the speakers and attendees for the conference assembled in Hyundgong Hall in the main Administration Building. The speakers and topics for the first day were:

Dr. Jerome Serp, CEA (France), "Molten Salt Reactor system in GIF 2009-2012 Status"

Prof. SeKee Oh, Aju University (Korea), "LWR-MSR Symbiosis: AMBIDEXTER-NEC"

Richard Martin, Pike Research (USA), "Thorium Power: the Year Ahead"

Dr. Victor Ignatiev, KIAE (Russia), "Molten salt actinide recycler and transforming system with and without thorium support: new configurations and developments"

Author:  Kirk Sorensen [ Jan 29, 2013 12:18 am ]
Post subject:  Re: Thorium MSR Workshop at UNIST, Ulsan, South Korea

The conference started Tuesday afternoon, January 29, 2012, at 2pm. It was held in the Kyungdong Hall in the Main Administration Building of UNIST.

Professor Dong-Seong Sohn gave introductory remarks. He said that they at UNIST think that "thorium MSR is the technology for tomorrow". He said they hope for collaboration with each of the people in attendance. He also mentioned that there are large heavy industries in the Ulsan area.

Then we all gathered on stage and took a big group picture.

The first speaker was Dr. Jerome Serp from CEA (the French Atomic Energy Commission). He mentioned that MSR is one of the six reactors in the Gen-4 program. France and the Joint Research Center (European Commmission) signed the Memorandum of Understanding in 2010. Russia and the US are permanent observers. This year, China joined the pSSC as an observer. The reference concept in the steering committee is the molten-salt fast reactor. This is a fluoride-fueled reactor with no moderator elements and a simplified fuel cycle. He also mentioned that they are studying the molten-salt-cooled reactor as part of GIF. He mentioned Ignatiev's work on MOSART but says that Ignatiev (who is here) will say more about it later. He also described the salt-cooled reactor and describes it as "the molten salt reactor that the US is working on." The main results since 2009 include 1) physical studies of neutronic and thermo-hydraulic coupling models and feedback coefficients, 2) safety analysis that is different than solid-fuel reactors and initiating events, 3) materials studies that show that controlling the U4+/U3+ ratio leads to tremendous reductions in corrosion. They have also tested a new alloy that replaces molybdenum with tungsten. 4) salt properties and thermodynamic modeling, 5) salt reprocessing in the new fast spectrum reactor versus the thermal spectrum--the required reprocessing rate goes down. 6) Forced Fluoride for Experiment Research molten salt loop where they are testing freeze plug concepts. In a fast spectrum reactor this becomes more challenging than in a thermal spectrum reactor.

He stated that we are in a viability phase stretching til 2017, then a performance phase til 2025, and then after 2025 the data will be available to decide continue the development of the molten salt reactor system. He mentioned that the Chinese anticipate 2017 for the salt-cooled reactor and 2020 for a 2 MW test MSR.

Author:  Kirk Sorensen [ Jan 29, 2013 12:56 am ]
Post subject:  Re: Thorium MSR Workshop at UNIST, Ulsan, South Korea

The next speaker was Prof. Se Kee Oh of Ajou University speaking on LWR-MSR synthesis. What should be the next generation nuclear? Sustainability, economics, safety and reliability, and proliferation resistance and physical protection. How to realize these in a design? Enhance fuel utilization, reduce the burden of nuclear waste, reduce the lifecycle cost and financial risks, and have an extremely low core damage frequency by having inherent and passive safety features. His concept is AMBIDEXTER-NEC (Advanced Molten-salt Break-even Inherently-Safe Dual-Function, EXcellenTly-Ecological Reactor Nuclear Energy Complex). He started developing the concept in 1997 and versions continued in 2006 and 2009. Essential principles of the design:

DUPIC-based NaF-ZrF4 molten salt fuel
Erbium-doped graphite moderator
Thermal-Fast hybrid reactor
Integral Reactor System module
On-power Continuous Recharge of Fuel
Continuous Reconditioning of Fuel-salt

NaF-ZrF4 is cheap compared to FLiBe and has no tritium generation. The core has a hexagonal lattice of graphite with central fuel channels and a central region with no moderator (for fast burning).The primary heat exchanger is on top of the reactor graphite assembly. The reactor is 250 MWt and made of Hastelloy. Core inlet and outlet temps are 566 and 704 C. The fueling plan begins with DUPIC and extends it into fluorination and addition of NaF-ZrF4. Essentially all uranium is removed by fluorination before introduction into the reactor.

His conclusions: AMBIDEXTER should be well-suited for Gen-4 due to sustainability, safety, proliferation transparency, and economics.

Author:  Kirk Sorensen [ Jan 29, 2013 2:10 am ]
Post subject:  Re: Thorium MSR Workshop at UNIST, Ulsan, South Korea

Rick Martin, author of "SuperFuel", spoke about "Thorium Power: The Year Behind and the Year Ahead". He introduced thorium, then Alvin Weinberg and some of his statements. He described the MSRE and how the fast-breeder reactor effort killed it. He then started to talk about the events of the last year, beginning with the efforts of Bryony Worthington to promote thorium in the UK. But he stated that the publication of a governmental report in the UK was a great disappointment, damning with faint praise the potential of thorium. Norwegian efforts for solid-fueled thorium reactors went forward however, supported by a number of other organizations. He mentioned that the new prime minister of Japan is reconsidering the use of nuclear power in their society, and that there were several Japanese efforts in the molten-salt reactor area. Australia is lifting its ban on uranium exports to India, and there was a Czech-Australian MSR effort started last year.

China has been the heart of new efforts in thorium, however, under the auspices of the Shanghai Institute of Applied Physics.

Author:  Kirk Sorensen [ Jan 29, 2013 7:44 pm ]
Post subject:  Re: Thorium MSR Workshop at UNIST, Ulsan, South Korea

Victor Ignatiev spoke next, but unfortunately by this point my jet-lag had rendered me unable to take notes and nearly unable to stay awake.

After this talk my jet-lag had caught up with me so badly that I asked to be excused from the dinner appointment and returned to the hotel where I quickly fell asleep about 6pm.

Author:  Kirk Sorensen [ Jan 29, 2013 7:45 pm ]
Post subject:  Re: Thorium MSR Workshop at UNIST, Ulsan, South Korea

The second day of the Thorium MSR conference at UNIST in Ulsan, South Korea included the following talks:

Dr. Ritsuo Yoshioka, ITMSF (Japan), "Thorium Molten-Salt Nuclear Energy Synergetic system (THORIUM-NES)"

Kirk Sorensen, Flibe Energy (USA), "Liquid-Fluoride Reactor for Power Generation and Desalinated Water"

Prof. Dong-Seong Sohn, UNIST (Korea), "Preliminary Plan for Thorium MSR Technology Development in Korea"

The conference began at 9:45am with a talk from Dr. Ritsuo Yoshioka of the International Thorium Molten-Salt Forum in Japan. He recited the advantages of thorium MSR, including minimized transuranic production, proliferation resistance, and fuel abundance. Molten salt is a transparent fluid similar to water, and he showed a video of him melting frozen LiCl-KCl salt in a test tube. He showed another video of pouring molten-salt, which looks exactly like water in the video, into a circular dish. The salt was LiCl-KCl-CsCl with a melting point of 300C.

Their THORIMS-NEC concept anticipates an electric power station (FUJI-MSR), a fissile breeding facility (AMSB) to generate new uranium-233 using spallation neutrons from an accelerator, and a chemical processing facility. Spent LWR fuel would also be fed into the THORIMS-NEC regional center and its plutonium would be used to start thorium reactors. The AMSB would use a 1 GeV, 200-300 mA proton accelerator to strike a spallation target and generate neutrons that would convert thorium to U-233. The MSR FUJI looks just like the ORNL-4541 one-fluid reference design.

He says that people ask why are so there so many advantages, what are the disadvantages? The materials are challenging. Is MSR safe against a Fukushima-type accident? Yes, for many reasons, including no fuel failure and no core meltdown in MSR. No overpressure, no water, no hydrogen generation from cladding failure. Gaseous fission products are not released. Dangerous radionuclides are chemically trapped in the molten-salt fuel.

Critical calculations were done with SRAC2006 code and the JENDL 3.3 nuclear data library using the ORIGEN2 depletion code. Fuel salt circulation effects are small and static calculations are used. Many of these details were presented at the Indian conference earlier this month. The conversion ratio is held at 1.0 over thirty years of operation, and there is no graphite replacement during this time. Plutonium can be used to start the reactor as well. The graphite fraction will be 0.67 in this design rather than the 0.88 graphite fraction in the ORNL one-fluid MSBR design. This is made possible by the flat "eta" profile of uranium-233, which stays above two in all neutron spectra.

In summary the FUJI design can achieve self-sustaining operation, burn plutonium and minor actinides, and with AMSB huge numbers of MSRs can be started.

Then he turned to a discussion of the Chinese reactor program and some of the plans that they had discussed at the Shanghai conference last October. He also talked about the Indian MSR conference earlier this month at BARC.

Author:  Kirk Sorensen [ Jan 29, 2013 7:47 pm ]
Post subject:  Re: Thorium MSR Workshop at UNIST, Ulsan, South Korea

My talk began with an introduction to the thermodynamic incentives associated with reactors operating at higher temperatures, namely, that more of the thermal energy can be converted to useful shaft work. But the goal of higher temperatures is limited so long as one is using steam-turbine-based power conversion systems (Rankine cycles) and this is an incentive to develop and use gas-turbine-based power conversion systems (Brayton cycles).

Today's combustion-based gas turbines can be very compact because they have no heat transfer surfaces. Enthalpy is deposited in the working fluid (air) volumetrically through the combustion process. Of course, that requires that the working fluid be air, that the inlet pressure be atmospheric, and that fuel be supplied and combustion products (including CO2) rejected. For a nuclear-heated gas-turbine, at least one heat transfer structure (the gas heater) will be required. If we were to use a fluid other than air and go to a closed-cycle turbine, then at least two heat exchangers will be required (a gas heater and a gas cooler). Further improvements in efficiency are possible by increasing the number of heat exchangers (regenerators, intercoolers, and reheaters) but each of these complicate the turbine and make it larger.

Steam turbines are also often complex and have many heat exchangers, but the nature of their thermodynamic cycle is that waste thermal energy must be rejected at low temperature (and very low absolute pressure). Increasing the temperature at which thermal energy is added to the cycle is also challenging because of limitations on the thermal flux from the uranium dioxide pellet, across the cladding, and into the water coolant.

So how can one build a nuclear reactor that can take advantage of the gas turbine? Consider a two-by-two matrix, with pressure on the x-axis and temperature on the y-axis. Liquid metal and molten-salt coolants operate at low pressure, while water and gas coolants operate at high pressure. Gas and molten-salt coolants operate at high temperature, while water and liquid-metals (to some degree) operate at lower temperatures. Thus molten-salt coolants embody both desirable attributes of high temperature operation and low pressure operation. The use of water coolant in today's reactors contribute directly to the large containment structures that house a reactor vessel that is relatively small in comparison--the containment structure must hold the water that would flash to steam in the event of a loss of coolant.

Fluoride salts, on the other hand, would not need containment structures that are much larger than the reactor vessel. They would not require the expensive fabrication of nuclear fuel nor would they involve complicated refueling procedures in the reactor. F-Li-Be, as a fluid, is transparent and impervious to radiation damage, and also has a high volumetric heat capacity, which is a basic yardstick that determines reactor size. Because molten-salts are undamaged by radiation, they can attain much higher fuel consumption relative to today's solid-fueled reactors, contributing to effective fuel use. The reactor concept that we intend to pursue involves a fuel salt passing through a lattice of moderator material (graphite) where it picks up enthalpy from the fission reactions that take place within it. After leaving the moderated core structure the reactor, fission stops in the fluid and enthalpy increase stops. The fuel salt passes through a primary heat exchanger, transferring enthalpy to the coolant salt. The coolant salt passes outside of the containment structure and heats the gaseous working fluid of the Brayton-cycle gas turbine, which then drives the turbine generating electrical power.

Thorium is three times more abundant than uranium and only a small fraction of uranium is currently consumed in today's reactors. The thorium fuel cycle involves the creation of Th-233, then Pa-233, then fissile U-233. The delay involved in the decay of Pa-233 means that it is impossible to release the total energies of thorium at any given moment. The processing scheme of the reactor involves fluorinating the blanket salt that surrounds the core, extracting the uranium that has formed therein as UF6. Then that UF6 is reduced to UF4 in a stream of fuel salt by contacting it with H2. The HF product of the reduction is then electrolyzed to recreate the reactants, F2 and H2. Fuel salt is processed in a similar scheme but also included distillation of the carrier salts.

Another advantage of the thorium fuel cycle is its vastly reduced production of transuranic materials, since as the thorium-232 passes through the U-233 and U-235 steps it is mostly fissioned. In the uranium fuel cycle by contrast, most of the fuel is U-238 and that only needs to absorb a single neutron to produce transuranic material (plutonium). Each cubic meter of earth contains about the equivalent of 2 cc of thorium, whose energy content in a LFTR is greater than tens of cubic meters of crude oil. This leads to an incredible energy return on energy invested (EREOI).

A variety of companies are proposing to build small modular reactors, but most of these are water-cooled reactors and only Flibe Energy is proposing to build a liquid-fluoride reactor. The advantage of thermal spectrum reactors over fast spectrum reactors is that reaction cross sections are orders of magnitude larger in the thermal spectrum than the fast spectrum, and uranium-233 has sufficient performance in the thermal spectrum to sustain breeding and net conversion of thorium into fissile uranium-233. Considering a 2x3 matrix with the thermal and fast spectra on the y-axis and the three different fuel options (thorium, U-235, U-238/plutonium) on the x-axis, there are really only three feasible and attractive options of the six possible. Mapping these six options against the 2x2 matrix of coolants mentioned earlier further reduces the 12 possibilities down to only about five, with the thermal-spectrum liquid-fluoride reactor occupying an attractive corner of the design space.

In the United States, it is the responsibility of industry to propose and develop nuclear power plants, and to provide a supporting business case.

From a safety perspective, in a pressurized-water reactor, if pressure is lost and emergency cooling is not provided to the core, the fuel can melt, breach the cladding, and release radioactivity and potentially breach the reactor vessel. In molten-salt reactor reactors, a freeze plug that melts in the event of an accident drains the liquid fuel into a passively cooled drain tank structure.

Nuclear power will be necessary to provide the energy that the population of the future needs while reducing the environmental impact of today's energy generation. Some contemporary writers consider nuclear power dead, but I disagree based on the energy density of nuclear fuel and the potential for newer, better, more efficient designs. Many design principles were proven by the operation of the Molten-Salt Reactor Experiment in the United States at Oak Ridge National Lab from 1965 to 1969. It was a technological triumph, but Nixon's Atomic Energy Commission was focused on the sodium-cooled plutonium fast-breeder reactor and funding for Weinberg's molten-salt reactor development work was cut. The funding profile for the fast-breeder was always greatly in excess of the molten-salt work. But in 1974 the Indians detonated a nuclear bomb that made nuclear proliferation an issue in the 1976 presidential campaign, and President Ford banned the reprocessing of nuclear fuel. This was the end of the road for the fast-breeder reactor in the United States, but no one revisited the decision to cancel the thorium-fueled molten-salt reactor. Why?

For years, small groups around the world have continued to push for and hope for the development of molten-salt reactors. There are even more reasons to develop it now, particularly the issues of global warming and the unattractiveness of low-carbon alternatives. Without better nuclear power the developing world will turn to coal. But with thorium one could hold their lifetime energy needs in the palm of their hand. The US has a great deal of thorium in storage in Nevada.

The reactor under design by Flibe Energy is analogous to the two-fluid molten-salt breeder reactor design proposed by ORNL in 1967, but with modification for gas-turbine power conversion. The reactor would be located below-ground and would produce not only electrical power but a variety of valuable byproducts, including desalinated water.

There is an opportunity now to take a leadership position in the development of this important technology. The development of energy from thorium, I am convinced, will be the greatest technological advance of the twenty-first century.

Author:  Kirk Sorensen [ Jan 29, 2013 9:30 pm ]
Post subject:  Re: Thorium MSR Workshop at UNIST, Ulsan, South Korea

Dr. Dong-Seong Sohn then spoke briefly about a preliminary plan for thorium MSR technology in Korea.

He said that they need a future energy system with inherent safety and no spent fuel storage problem. He says that they cannot consider reprocessing as an option at the current time, under the current political administration. Proliferation resistance is a very sensitive issue, and the potential of almost no plutonium production in the thorium fuel cycle is very desirable. Higher efficiency and better economics are strongly desired, as well as very high fuel utilization. A reactor of small size, perhaps one that could power a high-speed super tanker, would be desirable.

In preparing for the development of MSR technology, there would be a need to setup the necessary tools and systems, such as reactor physics codes, thermal-hydraulics codes. There would also be testing for basic properties--materials compatibility, major safety feature testing, degradation of salts, and test for liquid fuel performance. They don't have any experience with liquid fuel, and desire testing.

A feasibility study would consider various possibilities. Thermal vs. fast, transmuter vs. self-sustainable, liquid-fuel vs. solid-fuel. The eventual reactor chosen should have inherent safety, no spent fuel storage problem, proliferation resistance, and small size. A three year plan would setup the tools and testing, execute the feasibility study, and continue on into development in the third year.

Author:  Kirk Sorensen [ Jan 30, 2013 7:15 pm ]
Post subject:  Re: Thorium MSR Workshop at UNIST, Ulsan, South Korea

After the workshop presentations ended, another group picture was taken and we adjourned briefly before reconvening in another room where we had a panel discussion. Dr. Sohn led the discussion and the matter at hand was how to devise the best system for Korea to go forward with. We brought up the currently severe restrictions on reprocessing, and he also brought up the concerns about proliferation that are amplified by North Korean activities in the last few years.

Several of us, particularly Dr. Ignatiev and myself, put forward the opinion that it would be very difficult to implement the full advantages of the LFTR if reprocessing of all types was off the tables. Rather, an enriched-uranium-fueled, once-through style MSR was really the only possible option. There was also a discussion of fast spectrum versus thermal spectrum and I put forward a number of the advantages of thermal spectrum operation as I saw them, including the fact that there would be no possibility of recriticality in the drain tank(s) in the thermal spectrum design, and that the operating inventory would be much much lower. Of course, the advocates of fast spectrum MSR that were present hastened to point out the issues with graphite replacement.

There was also a fairly lively discussion of the relative advantages of steam turbine versus gas turbine power conversion systems. I brought up the issue of tritium trapping in steam turbine systems but the immaturity of the gas turbine versus the steam turbine was a valid counterargument.

The panel discussion was not terribly long and Dr. Sohn was a very gracious host.

Author:  Kirk Sorensen [ Jan 30, 2013 7:23 pm ]
Post subject:  Re: Thorium MSR Workshop at UNIST, Ulsan, South Korea

After the panel discussion we boarded a bus and drove to Hyundai Heavy Industries, in the southern area of Ulsan. This is the world's largest shipyard, and I had been looking forward to this trip the entire time. We were greeted by a company representative and escorted into the Asan Memorial Center, which commemorates the founder of Hyundai, Chung Ju-yang, in 1950. They first showed us a film about HHI which is also available online. Chung was nicknamed "Asan" and the entire first floor of the building was a museum of his life and the accomplishments of Hyundai. I wished many times that I had been allowed to take pictures, for it was truly incredible. They had detailed scale models of many of the ships, factories, and facilities that Hyundai had build around the world. The culmination of the museum was a detailed miniature scale model of the "Hyundai kingdom" that we were currently in the middle of. It is the area around the Hyundai shipyards where tens of thousands of Hyundai employees live, work, and enjoy recreation. It reminded a bit of Walt Disney's original vision of EPCOT as an integrated center of living, working, and recreating.

We left the Asan Building and boarded the bus again for a driving tour of the shipyard. I have never seen anything quite like it. There were dozens of enormous ships under construction. There were container ships being assembled in huge sections. I saw bronze propellers at least 20 feet in diameter resting on their sides in a fabrication facility. I saw two huge floating oil drilling platform ships that were nearly complete, one for a company called Noble and another for Dolphin Drilling. I saw more container ships for Hapag-Lloyd, and everywhere, sections of new ships coming together. In one of the huge drydocks I could see the keel of a new ship being laid. We drove up a hill and looked out over the shipyard. They told us that there were thirty ships under construction, and that last year they completed sixty ships, sold for $30 billion.

And strangely, incongruously, there was a single windmill on the end of a piece of land in the midst of the shipyard, not spinning, perhaps representing some corporate attempt to "look green".

As we drove back through the shipyard, we had to stop as three "Titan" transporters, each carrying a huge section of a ship, drove past us at just a few miles an hour. Our host told us that the drivers of the transports are some of the best paid employees in the shipyard.

We thanked our hosts profusely and the trip to the shipyard was an incredible experience. JJ Abrams ought to film his next "Star Trek" movie there!

Author:  Kirk Sorensen [ Mar 17, 2013 1:28 pm ]
Post subject:  Re: Thorium MSR Workshop at UNIST, Ulsan, South Korea ... 01304.html ... 0315F.HTML

Author:  Cthorm [ Oct 23, 2013 5:49 pm ]
Post subject:  Re: Thorium MSR Workshop at UNIST, Ulsan, South Korea

I don't know why it took me 6 months to find this post. Thanks for the full rundown Kirk. I hope UNIST has the backing it needs to see this through. I particularly like your vision of a UNIST 'merchant marine corps' running ship-based MSRs...what sort of output would be required on one of those very large container ships? 250 MWe seems high.

Author:  jagdish [ Oct 26, 2013 3:14 am ]
Post subject:  Re: Thorium MSR Workshop at UNIST, Ulsan, South Korea

The French unmoderated MSR concept appears to be the most simple. NaF-ZrF4 looks like a good, low cost selection for the salt. Uranium appears to be a good selection for core fuel due to fast fission bonus from U-238. Large amounts of U-238 are stored in DU, reprocessed uranium and in stored SNF, mostly from LWRS.
Thorium's main attraction is being the source of U-233, the best fissile isotope. This should ensure its place in the blanket.It should best be used in a metal form for easy electrolytic extraction of Th and U-233. This should also get rid of the problem of getting the thorium in liquid form. U-238 and U-233 could later form a good core fuel combination.

Author:  macpacheco [ Feb 09, 2014 1:11 am ]
Post subject:  Re: Thorium MSR Workshop at UNIST, Ulsan, South Korea

Cthorm wrote:
I don't know why it took me 6 months to find this post. Thanks for the full rundown Kirk. I hope UNIST has the backing it needs to see this through. I particularly like your vision of a UNIST 'merchant marine corps' running ship-based MSRs...what sort of output would be required on one of those very large container ships? 250 MWe seems high.

Your generic medium sized ships wouldn't be the pioneers, because most don't have a fixed routes. It won't be easy to convince every port in the world with an anti-nuclear crowd to let it dock.

In the iron ore carrying fleet, the largest ships will dock to no more than a half a dozen ports in their lifetime. Most ports just can't take them. Oil supertankers are a little more flexible, cause oil terminals are easy to construct half a mile from shore (just need means to dock and huge oil pumps) but even then, there aren't too many oil terminals in the world that can take the monster tankers. The largest container ships are like the ore carrying fleet, some will do the same route throughout their lifetime.

I found 110k HP for maximum power output of a super oil carrier, so around 100MW thrust on the propeller, or 200MWt with 50% brayton cycle losses on a LFTR. But typical power settings are around half max power, due to better fuel economy and lower wear and tear. So just matching max power but having no significant longevity issue from half power to max power would do.

Really large container / oil / grain ships are the size of an aircraft carrier, but while a carrier can go 40 kts, civilian ships go 13 kts cruise due to fuel costs. Assuming essentially free thorium / U233 as fuel, I believe ship operators would like to go faster, but much above 20kts makes little sense. So the 250MWt sounds very sensible, perhaps a 300MWt might be ideal as long as the output can be throttled down to 30% without shutting down.

International maritime shipping is extremely competitive. If LFTRs succeed in taking the 300k ton plus super ship category for being significantly cheaper, in time medium sized (150k tons and up) will be forced to migrate or be priced out of the market. If a new LFTR powered ship costs just a little less than a conventional ship over 20 years, but can speed up 50% without fuel cost penalties, just the time saved can make the ship at least 25% more economical to operate.

It will be funny seeing oil supertankers being nuclear powered. One can dream.

Author:  E Ireland [ Feb 09, 2014 9:03 am ]
Post subject:  Re: Thorium MSR Workshop at UNIST, Ulsan, South Korea

If fuel costs for the reactor are essentially zero the only thing that matters is capital cost.

At which point they will want to go as fast as possible so they can make more trips.

IN other words, 35 knots.

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