You are not logged in.
Do they know something we don't? Yep...if you use free prison labour to build nuclear reactors you can build them more cheaply...
Seriously, take a look at this projection from BP:
https://www.bp.com/content/dam/bp/busin … -china.pdf
The analysis states "Nuclear increases by 7.3% p.a. from 2017 to 2040, and China accounts for 37% of global nuclear power generation in 2040. Renewables expand rapidly, rising by8.5% p.a. to 2040, and accounting for 26% of global renewables by then" - so renewables are growing at a faster rate than nuclear. Do you think that means they know something else?
Yes. The Chinese have a lot of legacy coal plants, with capital cost long paid off. The only costs are fuel and operating labour. Trouble is, Chinese coal production has peaked; coal prices are rising and air pollution in China kills a couple of million people per year. Although winfd and solar plants are not cheap, it makes economic and societal sense to build them and use the coal plants as backup power plants. This reduces fuel consumption and pollution, which outweighs the wasted operating costs.
The trouble will come when the coal plants reach the end of their lives and need replacement. Building a few wind turbines to reduce coal consumption in an old plant is one thing. But building a state of the art coal powerplant to function as dedicated backup is quite another. At a stroke, it doubles the cost of power. So renewables make sense as a short-term strategy, but not so well in the long run, because two power plants are needed instead of one. If storage is used, make that 2.5 power plants. Not many countries can afford that. Which is why the Chinese are building nuke plants as quickly as they can. You only need one nuke plant to produce a GW of power. No need for backup. No one ever escapes the second law of thermodynamics.
Last edited by Calliban (2019-11-05 16:08:53)
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
Offline
Wind energy will continue to decline in cost but the reductions will not be as steep as with solar.
I believe that already it could well be economic in some parts of the USA now to have PV plus methane storage, at least for daylight hours. Last time I looked at this I was getting a figure of about 20 cents per KwH for methane manufactured from air and water using PV in the best locations. The problem may be that in the SW USA there is not already a methane infrastructure as in Western Europe and some parts of the USA.
louis wrote:Do they know something we don't? Yep...if you use free prison labour to build nuclear reactors you can build them more cheaply...
Seriously, take a look at this projection from BP:
https://www.bp.com/content/dam/bp/busin … -china.pdf
The analysis states "Nuclear increases by 7.3% p.a. from 2017 to 2040, and China accounts for 37% of global nuclear power generation in 2040. Renewables expand rapidly, rising by8.5% p.a. to 2040, and accounting for 26% of global renewables by then" - so renewables are growing at a faster rate than nuclear. Do you think that means they know something else?
Yes. The Chinese have a lot of legacy coal plants, with capital cost long paid off. The only costs are fuel and operating labour. Trouble is, Chinese coal production has peaked; coal prices are rising and air pollution in China kills a couple of million people per year. Although winfd and solar plants are not cheap, it makes economic and societal sense to build them and use the coal plants as backup power plants. This reduces fuel consumption and pollution, which outweighs the wasted operating costs.
The trouble will come when the coal plants reach the end of their lives and need replacement. Building a few wind turbines to reduce coal consumption in an old plant is one thing. But building a state of the art coal powerplant to function as dedicated backup is quite another. At a stroke, it doubles the cost of power. So renewables make sense as a short-term strategy, but not so well in the long run, because two power plants are needed instead of one. If storage is used, make that 2.5 power plants. Not many countries can afford that. Which is why the Chinese are building nuke plants as quickly as they can. You only need one nuke plant to produce a GW of power. No need for backup. No one ever escapes the second law of thermodynamics.
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
Offline
Well if its the cost to the consumer that matters than 20 cents for an equal quantity of energy means that I will stick with my high level of power from the electric company thats selling it for 9 cents. So what is the costs for energy in any form?
capital investment
https://en.wikipedia.org/wiki/Cost_of_e … _by_source
consumer cost are not as easy is is more varied with local and type of source with many companies subsiding there cost to the consumer with cheaper sources so as to maximize there profits while still charging more for the connection to the pole supply.
The investment for the consumer if you have the funds when compared to what you get currectly take a long time to pay off and to equalize out to a net zero for comparison over time.
Offline
For SpaceNut ... this item is hard for me to place, so if you want to move it please do.
The article is about Bill Gates funding research to make carbon fiber out of coal, even though the title is about his attempt to fund nuclear reactors.
I'm hoping kbd512 will be interested to see this line of research, because he has posted on numerous occasions about the economic value of pure carbon, for manufacture of a wide range of valuable products.
I ** really ** like the idea of finding a better use for coal than burning it, and hope this initiative succeeds in the marketplace.
https://www.yahoo.com/news/nuclear-vent … 56952.html
(th)
Offline
Went looking for KBD512 posts as that was the use of carbon in nano tube applications, topics found listed next but still looking for the post which is way newer..
Carbon nano tube straw for fuel transfer to space
Physics transfers fuel inside carbon nano tube - fuel into space
Capillary action in a carbon nanotube???
Colonizing / terraforming small asteroids
CNT Flywheels vs Batteries for Energy Storage
Power to Ammonia for Energy Storage
If I recall the post was in regards to carbon capture and use in creating fibers for frames and body parts for vehicles under a fuel cell topic.
Need to check for CNT as well since its being used as the abbreviation
big post with links for CNT by kbd512 in the topic Technology needed for Mars which is the one we remembered along with this one Fuel Cell Development, Application, Prospects
Offline
For SpaceNut .... First, thanks for finding all those neat links about Carbon as it relates to the idea (still in research) of making useful products out of coal.
Here is another link which is a stretch for this topic, but there ** is ** a connection to many posts in this forum in the past year (and likely before)
The article reports on research indicating that progress with pulsed lasers is moving in the direction of a capability to transmute elements, and thus could be used to detoxify nuclear waste. We have a forum contributor whose ID has a French aspect who's been writing recently about transmutation for manufacturing purposes, so this new capability might be of interest.
The specific technique described is to apply a laser pulse to knock a proton out of a nucleus. I find that concept to be surprising at first reading, but perhaps it shouldn't be, because something like that already happens when a massive particle such as a neutron enters a nucleus.
The difference (as I understand it) is that the arriving object would be a photon of sufficient energy to achieve transmutation.
In any case, I am looking forward to comments that may show up here in the forum, as contributors have time to evaluate the article.
https://www.yahoo.com/finance/news/nobe … 00349.html
(th)
Last edited by tahanson43206 (2019-11-05 22:12:48)
Offline
Wind is a very plausible energy creator in just the correct location but there are those that do not want it arguing its killing birds, they are noise makers and yes they are unsightly. Some have gone to no end to block the building of of these large windmill farms and have gone to the point of purchasing land adjecent to property such that they are not letting current sites expand.
I was reminded about the Groton wind Farm that can be seen as you drive north on route 95 setting high on the hillside turning out 48-megawatt with Annual net output 144 - 158 GWh....with nearly none lowering the energy cost to NH residents.
https://en.wikipedia.org/wiki/Wind_powe … _Hampshire
Offline
Kilopower: NASA’s Offworld Nuclear Reactor
Offline
Chinese nuclear reactor proposal could power 10 International Space Stations
https://www.space.com/chinese-nuclear-r … e-stations
Chinese officials haven't explained yet why they want all that space power.
The Chinese project was first begun in 2019 as part of "a strong Chinese interest in developing nuclear power for use in space," SpaceNews said.
China's media is state-controlled; in 2021, the South China Morning Post reportedly announced that a prototype nuclear design was completed for space power.
The country is highly experienced in using nuclear power during space missions, with the Chang'e 3 moon lander, for example, using a plutonium-powered nuclear generator to survive the frigid, two-week lunar night.
Last week, NASA announced 13 candidate landing regions for future Artemis missions to the Moon. For comparison, I add landing sites proposed by CAST scientists for China's future lunar landing missions in this figure. Data from a paper published in 2020
https://twitter.com/CNSpaceflight/statu … 1511185408
What else to use perhaps a small reactor, cooled by some inert gas? or a lithium cooled reactor type structure feeding a thermoelectric converter like on an RTG. Some thermal output could be used for heating on Mars?? SP-100 (Space reactor Prototype) was a U.S. research program for nuclear fission reactors usable as small fission power systems for spacecraft. It was started in 1983 by NASA, the US Department of Energy and other agencies.
http://www.allacronyms.com/SP-100/Space … _prototype
Safe affordable fission engine (SAFE) were NASA's small experimental nuclear fission reactors for electricity production in space. Most known was the SAFE-400 reactor concept intended to produce 400 kW thermal and 100 kW electrical using a Brayton cycle closed-cycle gas turbine. The fuel was uranium nitride in a core of 381 pins clad with rhenium. Three fuel pins surround a molybdenum–sodium heatpipe that transports the heat to a heatpipe-gas heat exchanger. This was called a heatpipe power system
https://archive.today/20130121120848/ht … ience6.htm
Nuclear Reactors and Radioisotopes for Space
https://archive.ph/kQjNG
Radioisotope power sources have been an important source of energy in space since 1961.
Fission power sources have been used mainly by Russia, but new and more powerful designs are under development in the USA.After a gap of several years, there is a revival of interest in the use of nuclear fission power for space missions.
While Russia has used over 30 fission reactors in space, the USA has flown only one - the SNAP-10A (System for Nuclear Auxiliary Power) in 1965.
Early on, from 1959-73 there was a US nuclear rocket program – Nuclear Engine for Rocket Vehicle Applications (NERVA) – which was focused on nuclear power replacing chemical rockets for the latter stages of launches. NERVA used graphite-core reactors heating hydrogen and expelling it through a nozzle. Some 20 engines were tested in Nevada and yielded thrust up to more than half that of the space shuttle launchers. Since then, "nuclear rockets" have been about space propulsion, not launches. The successor to NERVA is today's nuclear thermal rocket (NTR).
Another early idea was the US Project Orion, which would launch a substantial spacecraft - about 1000 tonnes - from the earth using a series of small nuclear explosions to propel it. The project was commenced in 1958 by General Atomics and was aborted in 1963 when the Atmospheric Test Ban Treaty made it illegal, but radioactive fallout could have been a major problem. The Orion idea is still alive, as other means of generating the propulsive pulses are considered.
The United Nations has an Office for Outer Space Affairs (UNOOSA)* implements decisions of the Committee on the Peaceful Uses of Outer Space (COPUOS) set up in 1959 and now with 71 member states. UNOOSA recognises “that for some missions in outer space nuclear power sources are particularly suited or even essential owing to their compactness, long life and other attributes” and “that the use of nuclear power sources in outer space should focus on those applications which take advantage of the particular properties of nuclear power sources.” It has adopted a set of principles applicable “to nuclear power sources in outer space devoted to the generation of electric power on board space objects for non-propulsive purposes,” including both radioisotope systems and fission reactors.
*UNOOSA has the dual objective of supporting the intergovernmental discussions in the Committee and its Scientific and Technical Subcommittee (S&T) and Legal Subcommittee, and of assisting developing countries in using space technology for development. In addition, it follows legal, scientific and technical developments relating to space activities, technology and applications in order to provide technical information and advice to Member States, international organizations and other United Nations offices.
Radioisotope systems – RTGs
So far, radioisotope thermoelectric generators (RTGs) have been the main power source for US space work for over 50 years, since 1961. The high decay heat of Plutonium-238 (0.56 W/g) enables its use as an electricity source in the RTGs of spacecraft, satellites, navigation beacons, etc and its intense alpha decay process with negligible gamma radiation calls for minimal shielding. Americium-241, with 0.15 W/g, is another source of energy, favoured by the European Space Agency, though it has high levels of relatively low-energy gamma radiation. Heat from the oxide fuel is converted to electricity through static thermoelectric elements (solid-state thermocouples), with no moving parts. RTGs are safe, reliable and maintenance-free and can provide heat or electricity for decades under very harsh conditions, particularly where solar power is not feasible.
The importance of such power sources was illustrated by the European Space Agency's Rosetta mission, which successfully landed the Philae probe on comet 67P/Churymov–Gerasimenko in 2014. Equipped with batteries and solar panels, the position in which Philae came to rest on the comet's surface – shielded from the Sun's rays by cliffs – meant that the lander was unable to make use of solar energy and was only able to send 64 hours' worth of data before its battery power ran out.
So far 45 RTGs have powered 25 US space vehicles including Apollo, Pioneer, Viking, Voyager, Galileo, Ulysses and New Horizons space missions as well as many civil and military satellites. The Cassini spacecraft carries three RTGs providing 870 watts of power from 33 kg plutonium oxide as it explores Saturn. It was launched in 1997, entered Saturn’s orbit in 2004, and is expected to function until at least 2017. Voyager spacecraft which have sent back pictures of distant planets have already operated for over 35 years since 1977 launch and are expected to send back signals powered by their RTGs through to 2025. Galileo, launched in 1989, carried a 570-watt RTG. The Viking and Rover landers on Mars in 1975 depended on RTG power sources, as does the Mars Science Laboratory Rover launched in 2011. Three RTGs (each with 2.7 grams of plutonium-238 dioxide) were used as heat sources on the Pathfinder Mars robot lander launched in 1996, producing 35 watts. Each produced about one watt of heat. (The 10.5 kg Pathfinder rovers in 1997 and the two Mars Rovers operating 2004-09 used solar panels and batteries, with limited power and life.)
The latest plutonium-powered RTG is a 290-watt system known as the GPHS RTG. The thermal power for this system is from 18 General Purpose Heat Source (GPHS) units. Each GPHS contains four iridium-clad ceramic Pu-238 fuel pellets, stands 5 cm tall, 10 cm square and weighs 1.44 kg. The Multi-Mission RTG (MMRTG) uses eight GPHS units with a total of 4.8 kg of plutonium oxide producing 2 kW thermal which can be used to generate some 110 watts of electric power, 2.7 kWh/day. It is being used in the large mobile Mars Science Laboratory – the rover Curiosity, which at 890 kg is about five times the mass of previous Mars rovers. Another one is due to be launched in 2020.
The Stirling Radioisotope Generator (SRG) is based on a 55-watt electric converter powered by one GPHS unit. The hot end of the Stirling converter reaches 650°C and heated helium drives a free piston reciprocating in a linear alternator, heat being rejected at the cold end of the engine. The AC is then converted to 55 watts DC. This Stirling engine produces about four times as much electric power from the plutonium fuel than an RTG. Thus each SRG will utilise two Stirling converter units with about 500 watts of thermal power supplied by two GPHS units and will deliver 130-140 watts of electric power from about 1 kg Pu-238. The SRG and Advanced SRG (ASRG) have been extensively tested but have not yet flown. NASA plans to use two ASRGs for its probe to Saturn's moon Titan (Titan Mare Explorer – TiME) or that to the comet Wirtanen, though these missions have been postponed in favour of the Mars InSight mission in 2016. In November 2013 NASA said it was halting development of the ASRG due to budget constraints and the fact that it had enough Pu-238 for MMRTGs. It also said that production of Pu-238 was being ramped up to 1.5 kg/yr, though this has yet to become evident. Since the 1990s the USA has relied on Russian supplies of Pu-238 produced at Mayak, and has bought 16.5 kg of it. However, Russia no longer produces or sells it.
Russia has developed RTGs using Po-210, two are still in orbit on 1965 Cosmos navigation satellites. But it concentrated on fission reactors for space power systems. China’s Chang’e 3 lunar lander apparently uses RTGs with Pu-238.
Americium-241 can be used for RTGs. It has about one-quarter of the energy of Pu-238, but is cheaper and readily available from clean-up of aged civil plutonium stocks such as in the UK. It also has a longer half-life – 432 years instead of 88 years. However it has much higher gamma activity (8.48 mSv/hr/MBq at one metre is quoted) and has been disregarded for that reason. However the European Space Agency is setting out to use it and is paying for Am-241 recovered from the UK’s civil plutonium by the National Nuclear Laboratory to be used for its RTGs.
As well as RTGs, Radioactive Heater Units (RHUs) are used on satellites and spacecraft to keep instruments warm enough to function efficiently. Their output is only about one watt and they mostly use Pu-238 – typically about 2.7g of it. Dimensions are about 3 cm long and 2.5 cm diameter, weighing 40 grams. Some 240 have been used so far by USA and two are in shut-down Russian Lunar Rovers on the moon. Eight were installed on each of the US Mars Rovers Spirit and Opportunity, which landed in 2004, to keep the batteries functional. China’s Chang’e 3 lunar rover Yutu apparently uses several RHUs.
The Idaho National Laboratory's (INL) Centre for Space Nuclear Research (CSNR) in collaboration with NASA is developing an RTG-powered hopper vehicle for Mars exploration. When stationary the vehicle would study the area around it while slowly sucking up carbon dioxide from the atmosphere and freezing it, after compression by a Stirling engine. Meanwhile a beryllium core would store heat energy required for the explosive vaporisation needed for the next hop. When ready for the next hop, nuclear heat would rapidly vaporise the carbon dioxide, creating a powerful jet to propel the craft up to 1000 metres into the 'air'. A small hopper could cover 15 km at a time, repeating this every few days over a ten-year period. Hoppers could carry payloads of up to 200 kg and explore areas inaccessible to the Rovers. INL suggests that a few dozen hoppers could map the Martian surface in a few years, and possibly convey rock samples from all over the Martian surface to a craft that would bring them to Earth.
Both RTGs and RHUs are designed to survive major launch and re-entry accidents intact, as is the SRG.
and
Fission systems – heat
For power requirements over 100 kWe, fission systems have a distinct cost advantage over RTGs.
The US SNAP-10A launched in 1965 was a 45 kWt thermal nuclear fission reactor which produced 650 watts using a thermoelectric converter with ZrH moderator and operated for 43 days but was shut down due to a voltage regulator (not reactor) malfunction. It remains in orbit.
The last US space reactor initiative was a joint NASA-DOE-Defence Dept program developing the SP-100 reactor – a 2 MWt fast reactor unit and thermoelectric system delivering up to 100 kWe as a multi-use power supply for orbiting missions or as a lunar/Martian surface power station. This was terminated in the early 1990s after absorbing nearly $1 billion. The reactor used uranium nitride fuel and was lithium-cooled.
There was also a Timberwind pebble bed reactor concept under the Defence Dept Multi-Megawatt (MMW) space power program during the late 1980s, in collaboration with DOE. This had power requirements well beyond any civil space program.
Between 1967 and 1988 the former Soviet Union launched 31 low-powered fission reactors in Radar Ocean Reconnaissance Satellites (RORSATs) on Cosmos missions. They utilised thermoelectric converters to produce electricity, as with the RTGs. Romashka reactors were their initial nuclear power source, a fast spectrum graphite reactor with 90%-enriched uranium carbide fuel operating at high temperature. Then the Bouk fast reactor produced 3 kW for up to 4 months. Later reactors, such as on Cosmos-954 which re-entered over Canada in 1978, had U-Mo fuel rods and a layout similar to the US heatpipe reactors described below.
These were followed by the Topaz reactors with thermionic conversion systems, generating about 5 kWe of electricity for on-board uses. This was a US idea developed during the 1960s in Russia. In Topaz-2 each fuel pin (96% enriched UO2) sheathed in an emitter is surrounded by a collector and these form the 37 fuel elements which penetrate the cylindrical ZrH moderator. This in turn is surrounded by a beryllium neutron reflector with 12 rotating control drums in it. NaK coolant surrounds each fuel element.
Topaz-1 was flown in 1987 on Cosmos 1818 & 1867. It was capable of delivering power for 3-5 years for ocean surveillance. Later Topaz were aiming for 40 kWe via an international project undertaken largely in the USA from 1990. Two Topaz-2 reactors (without fuel) were sold to the USA in 1992. Budget restrictions in 1993 forced cancellation of a Nuclear Electric Propulsion Spaceflight Test Program associated with this.
Development of a small fission surface power system for the moon and Mars was announced by NASA in 2008. The 40 kWe system could utilise one of two design concepts for power conversion: The first, by Sunpower Inc., of Athens, Ohio, uses two opposed piston engines coupled to alternators that produce 6 kilowatts each, or a total of 12 kilowatts of power. The second, by Barber Nichols Inc. of Arvada, Colorado, is for development of a closed Brayton cycle engine that uses a high-speed turbine and compressor coupled to a rotary alternator that also generates 12 kilowatts of power. NASA itself will develop the heat rejection system and provide the space simulation facility. In mid-2012 NASA reported successful tests of power conversion and radiator components of this 40 kWe system, which is based on a small fission reactor heating up and circulating a liquid metal coolant mixture of sodium and potassium. The heat differential between this and the outside temperature would drive two complementary Stirling engines to turn a 40 kWe generator. Some 100 square metres of radiators would remove process heat to space.
In December 2014 NASA’s Glenn Centre announced progress with its 4 kWt/1 kWe KiloPower project, using high-enriched uranium powering a heatpipe system and Stirling engine to generate electricity. NASA appealed to the US National Nuclear Security Administration (NNSA) to let it proceed. Following successful proof-of-concept testing carried out at NNSA's Nevada National Security site in 2012 in collaboration with NASA, critical experiments using the core are due to be carried out in fiscal 2017 under the Department of Energy's Criticality Safety Program working with NASA. The optimum fuel for the reactor would be an HEU alloy with 7% molybdenum. A beryllium oxide reflector would surround this, with eight heat pipes between the fuel and the reflector.
Fission systems – space propulsion
For spacecraft propulsion, once launched, some experience has been gained with nuclear thermal propulsion systems (NTR) which are said to be well developed and proven. Nuclear fission heats a hydrogen propellant which is stored as liquid in cooled tanks. The hot gas (about 2500°C) is expelled through a nozzle to give thrust (which may be augmented by injection of liquid oxygen into the supersonic hydrogen exhaust). This is more efficient than chemical reactions. Bimodal versions will run electrical systems on board a spacecraft, including powerful radars, as well as providing propulsion. Compared with nuclear electric plasma systems, these have much more thrust for shorter periods and can be used for launches and landings.
However, attention is now turning to nuclear electric systems, where nuclear reactors are a heat source for electric ion drives expelling plasma out of a nozzle to propel spacecraft already in space. Superconducting magnetic cells ionise hydrogen or xenon, heat it to extremely high temperatures (millions °C), accelerate it and expel it at very high velocity (eg 30 km/sec) to provide thrust.
Research for one version, the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) draws on that for magnetically-confined fusion power (tokamak) for electricity generation, but here the plasma is deliberately leaked to give thrust. The system works most efficiently at low thrust (which can be sustained), with small plasma flow, but high thrust operation is possible. It is very efficient, with 99% conversion of electric to kinetic energy.
Heatpipe Power System (HPS) reactors are compact fast reactors producing up to 100 kWe for about ten years to power a spacecraft or planetary surface vehicle. They have been developed since 1994 at the Los Alamos National Laboratory as a robust and low technical risk system with an emphasis on high reliability and safety. They employ heatpipes* to transfer energy from the reactor core to make electricity using Stirling or Brayton cycle converters.
* a heatpipe is a heat transfer device combining thermal conductivity with phase change. At the hot end a liquid vapourises under low pressure and at the other end it condenses, releasing its latent heat of vapourisation. The liquid then returns to the hot end, either by gravity or capillary action, to repeat the cycle. (If using gravity, they are sometimes called two-phase thermosiphons, but capillary ‘pumping’ using surface tension is the main mechanism used.)
Energy from fission is conducted from the fuel pins to the heatpipes filled with sodium vapour which carry it to the heat exchangers and thence in hot gas to the power conversion systems to make electricity. The gas is 72% helium and 28% xenon.
The reactor itself contains a number of heatpipe modules with the fuel. Each module has its central heatpipe with rhenium-clad fuel sleeves arranged around it. They are the same diameter and contain 97% enriched uranium nitride fuel, all within the cladding of the module. The modules form a compact hexagonal core.
Control is by six stainless steel clad beryllium drums each 11 or 13 cm diameter with boron carbide forming a 120 degree arc on each. The drums fit within the six sections of the beryllium radial neutron reflector surrounding the core, and rotate to effect control, moving the boron carbide in or out.
Shielding is dependent on the mission or application, but lithium hydride in stainless steel cans is the main neutron shielding.
The SAFE-400 space fission reactor (Safe Affordable Fission Engine) is a 400 kWt HPS producing 100 kWe to power a space vehicle using two Brayton power systems – gas turbines driven directly by the hot gas from the reactor. Heat exchanger outlet temperature is 880°C. The reactor has 127 identical heatpipe modules made of molybdenum, or niobium with 1% zirconium. Each has three fuel pins 1 cm diameter, nesting together into a compact hexagonal core 25 cm across. The fuel pins are 70 cm long (fuelled length 56 cm), the total heatpipe length is 145 cm, extending 75 cm above the core, where they are coupled with the heat exchangers. The core with reflector has a 51 cm diameter. The mass of the core is about 512 kg and each heat exchanger is 72 kg.
SAFE has also been tested with an electric ion drive.
A smaller version of this kind of reactor is the HOMER-15 – the Heatpipe-Operated Mars Exploration Reactor. It is a15 kW thermal unit similar to the larger SAFE model, and stands 2.4 metres tall including its heat exchanger and 3 kWe Stirling engine (see above). It operates at only 600°C and is therefore able to use stainless steel for fuel pins and heatpipes, which are 1.6 cm diameter. It has 19 sodium heatpipe modules with 102 fuel pins bonded to them, 4 or 6 per pipe, and holding a total of 72 kg of fuel. The heatpipes are 106 cm long and fuel height 36 cm. The core is hexagonal (18 cm across) with six BeO pins in the corners. Total mass of reactor system is 214 kg, and diameter is 41 cm.
In the 1980s the French ERATO program considered three 20 kWe turboelectric power systems for space. All used a Brayton cycle converter with a helium-xenon mix as working fluid. The first system was a sodium-cooled UO2-fuelled fast reactor operating at 670°C, the second a high-temperature gas-cooled reactor (thermal or epithermal neutron spectrum) working at 840°C, the third a lithium-cooled UN-fuelled fast reactor working at 1150°C.
In 2010 the Russian government was to allocate RUR500 million (about US$170 million) of federal funds to design a space nuclear propulsion and generation installation in the megawatt power range. In particular, SC Rosatom is to get RUR 430 million and Roskosmos (Russian Federal Space Agency) RUR 70 million to develop it. The work will be undertaken by N.A. Dollezhal NIKIET (Research & Development Institute for Power Engineering) in Moscow, based on previous developments including those of nuclear rocket engines, but beyond that the design envisaged is not known. Russia's Energia space corporation started work in 2011 on standardized space modules with nuclear-powered propulsion systems, initially involving 150 to 500 kilowatt systems. A conceptual design in 2011 is being followed by the basic design documentation and engineering design. The idea now being pursued by Russia's Keldysh Research Centre is to use a small gas-cooled fission reactor aboard the rocket to turn a turbine and generator set and thereby produce electricity for a plasma thruster. The reactor unit should be developed about 2015, then life-service tests are planned for 2018. The first launches, are envisaged for about 2020.
The Director of Roskosmos says that development of megawatt-class nuclear space power systems for manned spacecraft is crucial if Russia wants to maintain a competitive edge in the space race, including the exploration of the moon and Mars. The project will require funding of some RUR 17 billion ($540 million). Energia earlier said that it is ready to design a space-based nuclear power station with a service life of 10-15 years, to be initially placed on the moon or Mars. It is also working on a concept of a nuclear-powered space tug, which could be used for launching satellites.
Project Prometheus 2003
In 2002 NASA announced its Nuclear Systems Initiative for space projects, and in 2003 this was renamed Project Prometheus and given increased funding. Its purpose was to enable a major step change in the capability of space missions. Nuclear-powered space travel will be much faster than is now possible, and will enable manned missions to Mars. (See section below.)
One part of Prometheus, which is a NASA project with substantial involvement by DOE in the nuclear area, was to develop the Multi-Mission Thermoelectric Generator and the Stirling Radioisotope Generator described in the RTG section above.
A more radical objective of Prometheus was to produce a space fission reactor system such as those described above for both power and propulsion that would be safe to launch and which would operate for many years with much greater power than RTGs. Power of 100 kW is envisaged for a nuclear electric propulsion system driven by plasma.
The FY 2004 budget proposal was $279 million, with $3 billion to be spent over five years. This consists of $186 million ($1 billion over 5 years) building on FY 2003 allocation plus $93 million ($2 billion over five years) towards a first flight mission to Jupiter - the Jupiter Icy Moon Orbiter, expected to launch in 2017 and explore for a decade. However, Project Prometheus received only $430 million in 2005 budget and this shrank to $100 million in 2006, most of which was to compensate for cancelled contracts, so it is effectively on hold.
In 2003 Project Prometheus successfully tested a High Power Electric Propulsion (HiPEP) ion engine. This operates by ionizing xenon with microwaves. At the rear of the engine is a pair of rectangular metal grids that are charged with 6,000 volts of electric potential. The force of this electric field exerts a strong electrostatic pull on the xenon ions, accelerating them and producing the thrust that propels the spacecraft. The test was at up to 12 kW, though twice that is envisaged. The thruster is designed for a 7 to 10-year lifetime with high fuel efficiency, and to be powered by a small nuclear reactor.
Radiation in space
The 2011-12 space mission bearing the Mars Science Laboratory - the rover Curiosity, measured radiation en route. The spacecraft was exposed to an average of 1.8 mSv/day on its 36-week journey to Mars. This means that astronauts would be exposed to about 660 mSv on a round trip. Two forms of radiation pose potential health risks to astronauts in deep space. One is galactic cosmic rays (GCRs), particles caused by supernova explosions and other high-energy events outside the solar system. The other, of less concern, is solar energetic particles (SEPs) associated with solar flares and coronal mass ejections from the sun. One way to reduce the crew exposure would be to use nuclear propulsion, reducing the transit time considerably.
The radiation dose on the International Space Station orbiting Earth is about 100 mSv over six months.
Last edited by Mars_B4_Moon (2022-09-01 14:14:29)
Offline
NASA’s space-worthy nuclear reactor could be ready to fly by 2022
https://bgr.com/science/nuclear-reactor … kilopower/
Optimism Grows For U.S. Space-Nuclear Potential
https://aviationweek.com/defense-space/ … -potential
Chinese nuclear reactor proposal could power 10 International Space Stations
https://www.space.com/chinese-nuclear-r … e-stations
PM-3A Design and Construction: Rapid Pace to Fulfill a Need
https://atomicinsights.com/pma-design-c … fill-need/
On March 3, 1962, the U.S. Navy activated the PM-3A nuclear power plant at the station. The unit was prefabricated in modules to facilitate transport and assembly. Engineers designed the components to weigh no more than 30,000 pounds (14,000 kg) each and to measure no more than 8 feet 8 inches (2.64 m) by 8 feet 8 inches (2.64 m) by 30 feet (9.1 m). A single core no larger than an oil drum served as the heart of the nuclear reactor. These size and weight restrictions aimed to allow delivery of the reactor in an LC-130 Hercules aircraft. However, the components were actually delivered by ship. The reactor generated 1.8 MW of electrical power and reportedly replaced the need for 1,500 US gallons (5,700 l) of oil daily.Engineers applied the reactor's power, for instance, in producing steam for the salt-water distillation plant. As a result of continuing safety issues (hairline cracks in the reactor and water leaks), the U.S. Army Nuclear Power Program decommissioned the plant in 1972.
https://books.google.com/books?id=wwoAA … ks&pg=PA35
Conventional diesel generators replaced the nuclear power station, with a number of 500 kilowatts (670 hp) diesel generators in a central powerhouse providing electric power. A conventionally fueled water-desalination plant provided fresh water.
Offline
No signs of what the kilowatt reactor would fly on or when it would.
Offline
tahanson43206,
The primary reason we don't turn coal into CNT is all the unwanted inclusions of other elements in the fiber, such as Sulfur or metallic compounds, which weakens the fibers or renders them unusable. Some applications require great strength, others don't, and a handful of applications like batteries may actually be able to use certain impurities to enhance electrical energy storage, for example. Generally speaking, all advanced fiber-based technologies attempt to achieve very uniform chemical and mechanical properties in order to assign specific uses to those fibers with repeatable results. For example, if we set out to make Kevlar, then we don't want other chemical compounds or elements included in our Kevlar fibers, because those tend to either weaken the fiber or make it less functional for a given use case.
Metals are somewhat different, with respect to impurities. If selectively added / uniformly distributed into the base metal / added in the correct proportions, the "impurities" serve to improve or add to the properties of the base metal. Recall that all metals are crystalline structures. Specific impurities can be used to enhance desirable attributes of the base metal, in order to make it stronger (grain boundary reinforcement) or more corrosion resistant (stainless), adjust its service temperature upwards (super alloys like Inconel), more electrically conductive (alloying with Copper or Silver), make it tougher and less brittle at higher levels of hardness (why Chromium for hardness and Vanadium plus Molybdenum are frequently added to gun barrel steels or other highly stressed steel components such as power transmission shafts and gearing or tools subjected to hard use, like cutting tools) and why we use a variety of additives for Titanium parts (not enough hardness of the pure base metal and pure Titanium becomes too brittle if you do try to harden it to the degree required for something like an aircraft landing gear or actuator or engine mount or bolts), easier to forge or cast or machine (make it easier to chip). This is why we forge 2024 Aluminum, but cast A319 Aluminum, even though both are using a Copper-based primary alloying metal. You wouldn't forge A319. 2024 also contains some Magnesium and Manganese that A319 doesn't. Beyond that, I think there's a limit to the amount of Zirconium and Titanium that a 2024 forging can have. Long story short, there are very specific properties that make one alloy more suitable for casting or forging or machining. You could technically cast 2024, but probably wouldn't if cost was an issue. 2024 is normally formed into sheets or plates. A319 comes in ingots that are melted down and cast into a hot mold. Different casting techniques and heat treatment specifications drastically affect the strength and uniformity of the finished parts.
The huge but very uniform castings now used in the Tesla Model 3 chassis are stupidly expensive to purchase the equipment to make, but then very cheap to operate and crank out large quantities of exceptionally high quality and high strength parts (the casting process is done and over with in seconds). If you're going to make millions of something, then buying the equipment Tesla purchased makes a lot of sense. If you're only going to make one or a handful of parts, then such expense and complexity would be absurd. You'd machine a block or billet of Aluminum instead, providing equivalent or better strength to the high-tech castings that Tesla uses. Forgings make the most sense for simple parts geometry, very high strength requirements, and large numbers of manufactured parts, such as connecting rods or pistons or gun barrels, aircraft engine mounts, wing spars or boxes, etc. Powdered metallurgy is used for moderate strength requirements and very large production runs, such as the GM connecting rods on LS-platform truck engines.
I have no clue what the logic was behind the Titanium rods used in the Corvette LS engines, probably higher revs and faster acceleration from much lighter parts, with acceptance of significant service life limitations. Chevy doesn't care how much it costs for a customer to replace them, so long as Chevy isn't paying for it, and the vehicle still accelerates faster than their competitor's sports car models. Titanium connecting rod service life in race engines is below 100 hours before replacement, but it's 40% lighter than a 4340 forging for equivalent strength. Titanium would never be something I'd use in a factory street car engine or aircraft engine or marine engine. You can spend infinite money on an engine, but components built to last are made from certain materials and used in specific ways. Basically, any continuous duty high output engine needs forged 4340 connecting rods and a forged 4340 crankshaft. There are other alloys that will work, but all are more expensive or less suitable for that use case. Billet is not stronger than a good forging, but it's possible to economically make one-off parts by carving blocks or bars of steel or Aluminum. That's for ultimate durability and high-output. Similarly, you would opt for a fully counter-weighted crankshaft if ultimate durability was desired. LS-based engines omit the center counterweights to save on production costs, but this introduces bending stresses that will lead to premature failure if pushed too hard. You'd also want a high degree of crank pin overlap with the main bearing journals for ultimate durability. A casting may be just fine for a low-output engine with enough meat to overcome the lower strength of the part. Lots of light duty engines use cast parts to save money. It's not "bad", it just has real limitations that must be respected.
Anyway, some of our most advanced metallurgy involves combining ceramics or fibers with metals under a vacuum or inert gas so that oxidation at the high temperatures required to liquefy the metal don't ruin the fiber, which can withstand very high temperatures, but only in non-oxidizing atmospheres. CNT is merely highly ordered Carbon, and Carbon readily combines with Oxygen at elevated temperatures (reacts / combusts), same as Hydrogen, so at the temperatures required to melt steel, any CNT fiber exposed to such temperatures within an oxidizing or "normal Earth" atmosphere would transform the CNT into ordinary CO2. CNT withstands about 750C in "normal air", but in a vacuum can withstand 2,800C. Steel melts between 1,350C and 1,550C, so to reinforce a steel sheet / plate pressure vessel using CNT fabric, you need to process the metal under either a hard vacuum or under Argon or other inert gas to displace any Oxygen. The CNT would do some of the same things that alloying metals would do, but unidirectional CNT tape, much like unidirectional Carbon Fiber tape is used to reinforce existing metal pressure vessels by wrapping it over a much thinner / lighter metal liner, would also mightily resist any attempt to "deform outwards" under internal pressure contained by a pressure vessel so-constructed. The CNT is protected from Oxygen by the steel, so a thin / lightweight but high-temperature-capable pressure vessel is achievable. It would even be "bullet resistant" to some degree. The extremely high tensile strength of the emedded CNT fiber holds the shape / resists deformation at elevated temperatures because the metal protects the fiber from oxidation.
For example, you could make a thinner and therefore lighter but unnaturally strong reactor pressure vessel by embedding CNT or BNNT into a steel alloy, if that fabrication process was carried out in a vacuum. The CNT or BNNT fiber would serve the same function as the various precipitates or alloying metals used in conventional steel alloys. Since the tensile strength of the fiber is sky-high, a very thin pressure vessel could be produced, leaving more mass for radiation shielding, which would ultimately reduce costs by requiring less metal, less fuel to transport it, etc.
Offline
https://www.msn.com/en-us/news/world/ne … 0d9f2843e1
Indiatimes
View Profile
New Nuclear Energy Reactor Designed By Utah Professor Is Smaller, Safer And Economical
Monit Khanna - 12h agoNew Nuclear Energy Reactor Designed By Utah Professor Is Smaller, Safer And Economical
© Provided by IndiatimesResearchers from Brigham Young University have developed a new system for safe nuclear energy production, reveals a report by KSL.
© Provided by Indiatimes
To the unaware, standard nuclear reactors use a light-water reaction, where uranium atoms are split to create energy, with the remaining products radiating massive amounts of heat.
They're stored in solid fuel rods and water is run through the rods to keep everything cool enough. If there’s not enough flow of cooling water, rods can overheat and can risk the meltdown of the entire nuclear facility.
However, in the new system developed by researchers, radioactive elements are stored in molten salt instead of fuel rods. While the idea isn’t the latest, it’s a newer version with novel features.
Matthew Memmott, professor and nuclear engineering expert at BYU explains, "Instead of trying to trap uranium inside a zirconium alloy rod, and then putting that inside of a big pressure vessel, and then putting that inside of containment where you're trying to mechanically keep things in place in case something goes wrong. Instead, what you do is you dissolve the fuel directly into a salt that's melted or a molten salt."
According to Memmott, salt fuses to the dissolved fuel chemically, "Instead of having to try and trap the fuel inside mechanically, where these mechanical failures could fail or melt, now we have the salt itself chemically bonding that fuel. Right away, we have a system that's impossible to melt down. There's nothing to melt, and it's not likely to cause any release problems because there's no pressure and there's nothing to push it out,” Memmott added.
Moreover, the molten salt nuclear reactor design not just eliminates dangerous nuclear waste, but also turns its byproducts into expensive commodities which can be harvested from the salt and sold.
For instance, Molybdenum-99 costs $30 million per gram and can only be brought from the Netherlands. It is used in around 20 million medical imaging procedures and scans every year, and this can be extracted easily using Memmott’s design.
Memmott claims that they can go to that salt and apply specific electrochemistry to extract pieces one at a time or even groups at a time. So the so-called waste, which is essentially a mix of uranium and other components can be pulled out and separated and sold, till the point there’s no nuclear waste to be disposed of.
Another aspect of Memmott’s design is that it’s smaller compared to other nuclear reactors. Normal reactors are built over one square mile to reduce the risk of radiation. With its core being around 30 feet by 30 feet. Memmott’s reactor is just four feet by seven feet. And since there’s no risk of meltdown, it doesn't need to have such a large surrounding zone. And despite its size, it can power 1,000 American homes.
Moreover, their approach is extremely affordable too -- costs just three cents per kilowatt hour -- which according to Memmott is the cheapest electricity production source in existence.
Keep visiting Indiatimes.com for the latest science and technology news.
Related video: Nuclear power is an important source of low-carbon energy: World Nuclear Association
This report was posted in the India Times.
If there are other reports on this specific design, please post them!
Can anyone in the NewMars community comment upon the 3 cents per KWH estimate?
(th)
Offline
Rolls-Royce gets British government funding to develop miniature nuclear reactor for space. Topics like Cold-Fusion might seem like fringe science more scifi like topics but the tech is closer every year.
Thorium’s Long-Term Potential in Nuclear Energy: New IAEA Analysis
https://www.iaea.org/newscenter/news/th … a-analysis
Nuclear fusion: The one relationship Russia and the West just can’t break
https://www.politico.eu/article/the-one … raine-war/
The €44 billion project aims to test nuclear fusion
World's largest nuclear fusion reactor promises clean energy, but the challenges are huge
https://www.abc.net.au/news/science/202 … /102050226
Efficient, clean power from nuclear fusion could be available in 30 years: political advisor
https://www.globaltimes.cn/page/202303/1286842.shtml
CEA spins off two companies for SMR development
https://www.world-nuclear-news.org/Arti … evelopment
Offline