The Sri Lankan Energy Crisis
and Reducing Climate Change
A Report by Roger O. Smith
Introduction
The future for generating energy from fossil fuels: coal, oil and gas, is becoming increasingly problematic. Environmental factors alone dictate that all countries have to look for alternative clean energy. The nuclear option with Uranium is a possibility but the dangerous nuclear waste disposal problem of plutonium and its handling, final processing, transporting and storing the waste products all under tight security, are not going away, but increasing with each new reactor built..
Happily, we have a clean, cheap and plentiful nuclear fuel alternative using Thorium. This has the huge advantage that it is energy rich: it is a dense energy source giving high grade electric power, with high thermodynamic efficiency, and it is a mineral widely available in Sri Lanka, unlike Uranium.
Having a Fukushima, Chernobyl or Three-Mile Island – type accident is not possible due to the fact that the Thorium process has to be activated continuously to keep it going; this is the opposite to Uranium-fuelled reactors which have to be constantly kept under control. Further, Thorium reactor products cannot be converted to weapons grade material and so, are of no interest to terrorists. But, due to historical reasons, this favourable alternative, although tried and tested successfully at the Oakridge Research Laboratory, Tennessee, USA, has been totally neglected and unexploited for its available benefits.
This report suggests that Sri Lankan authorities should investigate all aspects and requirements for using this new technology, and to set aside the necessary recourses, firstly in scholarship and learning, and initiate the task of acquiring the necessary knowledge and science which will enable proper and well founded decision-taking on the future of nuclear energy in Sri Lanka. The first decisions on concept design are the most crucial as costs get locked in and set the direction of the life-cycle costs in total.
However, it seems inevitable that such technical assessments and crucial decisions need to be taken at some point in the future due to the intractable nature of the problem of atmospheric pollution versus energy production.
The First Steps
The first requirement is for Sri Lanka to acquire a body of scientific knowledge in the fertile processes of Thorium reaction involved, and the associated nuclear chemistry required for keeping the process productive and not poisoned by its own waste products.
The whole chain of steps through which the raw Thorium is mined, cleaned, placed in the reactor with the Fluoride salts, through its life in the reactor, right to the final resting place of the waste products, should be understood.
This whole sequence of events needs to be investigated, including the requirements of a final resting place to allow the waste products 10 years to pass for 83% of the material to become harmless and the remaining 17% to about three hundred years to pass for it to become harmless, too..
THORIUM
Thorium is freely available for extraction in the North of Sri Lanka.
It is chemically distinct so that it can be readily separated and cleaned. It is only a slightly radioactive metal (actinide). Its colour is silvery-white in its pure form, but becomes black as Thorium Dioxide (ThO2 or Thoria).
Boiling point:
Its boiling point is 5061 K (8650oF)
Melting point:
It has the highest melting point of any oxide at (3573K)
It has the widest liquid range of any element.
Density is 11.72 gr/ cc
It decays as alpha emission.
Atomic number is 90. Atomic weight: 232.0381
The material is relatively abundant, being four times more abundant than Uranium238. It is an attractive, energy-dense source of fuel.
The Liquid Fluoride Thorium Reactor (LFTR) design
– a type of nuclear reactor where the nuclear fuel is in a liquid state, suspended in a molten fluoride-based salt and uses a separate fluid stream for the conversion of Thorium to fissionable fuel to maintain the nuclear reaction. The nuclear reactor core is in liquid form and has a completely passive safety system (i.e., no control rods). The size is small relative to Uranium reactors.
DESIGN:
The (LFTR) design is characterized by :
Operation at atmospheric pressure.
High operating temperatures (>>600K)
Chemical extraction of Protactinium-233 and reintroduction of its decay chain product Uranium 233
Thermal spectrum runs slightly above breakeven,
– Closed power conversion. USA uses: Brayton Cycle.
In sum, it is the mixing or joining forces of the Nuclear power industry and the Nuclear processing industry, which technologies usually occupy separate grounds of influence..
Nuclear Chemistry Design
This is not complex and can be fairly easily understood when explained. The Thorium fuel is “Fertile” and in the reaction produces Uranium 233.
During operation there must be continuous chemical processing to get rid of (sequester) the intermediate products from the core – and that is a special industrial chemical process not a nuclear technology process.
The Liquid Fluoride Thorium Reactor (LFTR) design has a lot of support, by specialists who propose this to be the best design for ease of operation, economy of operation, etc.
Because Thorium reactors operate at 500-600oC, and liquid fluoride salts are mildly corrosive, special Nickel-based stainless steel will be needed for the containers, pipework and valves and fittings.
In parallel with this will be the need to learn the complexities of handling both very hot materials and nuclear radiating materials, but this high working temperature allows energy turbines to operate at higher efficiencies.
Major advantages include: significant reduction in nuclear waste, (producing no transuranics and near 100% fuel burn up), inherent safely, weapon proliferation resistant, and high power cycle efficiency – a new era of nuclear fuel.
The size of the reactor is small, it could almost be mobile. Costs are smaller due to the ease of access to raw Thorium, and the smallness of size of the whole reactor system. There is low maintenance and long life and little risk to people working on site. There is low vapour pressure and at room temperature the fluids become solid. There is no radiation released, there is simple heat removal. There is reduced contamination, it produces less permanent waste, and gives good reactor control. Valuable by-products can be extracted – rare earths, Bismuth, and other useful elements.
Alternative designs:
Proponents have put forward for consideration a variety of seventeen designs and configurations of reactors. They are being evaluated for costs and efficiencies and assessments made of their good aspects and their drawbacks.
OVERALL SCENARIO FOR
MOLTEN SALT REACTORS
Information gained from You Tube film clips:
1) The Liquid Fluoride Thorium Reactor – what Fusion wanted to be…
2) An unbiased look at Molten Salt Reactors
3) LFTR Chemical Processing .. u0026 Kirk Sorensen
The hard facts are that:
1) Coal supplies cannot last for more than 70- 100 years more at most, with the price rising as demand exceeds supply.
2) Reactor grade Uranium is in short supply, also with the price rising.
3) Of 440 standard Uranium reactors around the world, many are 25-30 years old – coming to the end of their working life and need to be replaced.
4) Climate Change is increasingly making itself felt and forecasts can only be for continuing deterioration due to existing levels of CO2 being continuously added to in the atmosphere. Not to mention the more serious problems associated with the release of methane gases – a more harmful gas – arising from several sources.
5) Many (thousands) of new sources of electric power generation need to be built to meet increasing demand. But the waste Plutonium 239 (the Satan Stuff) material has also to be carried around each country by lorry with police escort at each stage, as: converted, recovered, stored, processed, and formed into blocks for storage. The security of transport problem becomes an impossible nightmare.
The positive strengths to Thorium Power generation are:
1) Thorium is quite abundant on the planet – 100 time more than Uranium 238, therefore supplies will last thousands of years.
2) Cleaning or refining the Thorium is not a difficult process.
3) It is not highly radioactive having a very slow rate of isotope decay. There is little danger from radiation poisoning. It can be safely stored in the open, unaffected by rain. It is not harmful when ingested.
4) Power generation is quite different and processing is a lot less complex.
5) It is ‘fertile’ not fissile: the thorium has to be kick-started with a source of Neutrons – fissile materials to get it started.
6) It is “Fail – Safe”. It has walk-away safety. If the reactor overheats, cool drain plugs unfreeze and the liquid drains away to storage tanks below. There can be no “Chernobyl/ Fukoshima” type disasters.
7) It is not a pressurized system, it works at atmospheric pressure.
8) As long as reactor temperatures are kept around 600oC there are little effects of corrosion in the Hastalloy metal tanks, vessels and pipe work.
9) No-where is there a stage where material can be stolen and converted or used as a weapon. The waste products have a half- life of 300 years, not the millions of years for Plutonium.
10) Production of MEDICAL ISOTOPE Bismuth 213 is there to fight cancer. The nastiest cancers can be cured with this Bismuth 213 as Targetted Alpha therapy.
11) A hydrogen generation unit can be added.
Thorium! The Way Ahead!
Roger O. Smith, 7/4/2017