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XYLENE POWER LTD.

SUSTAINABLE NUCLEAR POWER

By Charles Rhodes, P.Eng., Ph.D.

INTRODUCTION:
Due to rapid accumulation of carbon dioxide in the Earth's atmosphere mankind must increasingly rely upon nuclear energy for reliable base load power.
 

PETROLEUM:
The average world petroleum consumption rate in 2014 was about 84,950,000 barrels per day. Combustion of this oil yields an average thermal power of:
84,950,000 barrels / day X 158.987 lit / barrel X 38.2 MJ /lit X 1 day / 24 h X 1 h / 3600 s
= 5,971,379 MJ / s
= 5,971,379 MWt
 

NATURAL GAS:
The claimed average world natural gas production rate in 2010 was about:
(4359 X 10^9 m^3 / year) X (10.2 kWh / m3) X (1 year / 8766 hr) X (1 hr / 3600 s)
 
= (4359 X 10^3 m^3 / year) X (10.2 kWh / m^3) X (1 year / 8.766 hr) X (1 hr / 3.6 s)
 
= 1,408,909 MWt

However, the claimed average natural gas based electricity production rate in 2014 was:
3,422,313 MWe
which indicates that either the actual natural gas production rate in 2014 was four fold higher than in 2010 or the natural gas based electricity production rate in 2014 was lower than claimed.
 

COAL:
The average world coal production rate in 201___ is claimed to be about:
7823 X 10^6 tonnes / year X 1000 kg / tonne X (24.6 MJ / kg black coal) X 1 year / 8766 hr X 1 hr / 3600 s
 
= 6,098,239 MWt

The claim is that this coal was primarily used to produce 4,220,853 MWe of electricity, which indicates that either the average coal heating value is above 24.6 MJ / kg or the actual coal tonnage produced is higher than claimed or the actual coal sourced electricity production is lower than claimed.
 

NUCLEAR:
The average world nuclear electric power production is about 257,000 MWe.
 

HYDRO:
The average world hydro-electric power production is about 300,000 MWe
 

WIND:
The average world wind energy energy production is about 57,000 MWe
 

TOTAL PRIME ENERGY PRODUCTION:
Thus the total annual prime power production is:
(5,971,379 MWt + 1,408,909 MWt + 6,098,239 MWt) + (257,000 MWe + 300,000 MWe + 57,000 MWe)
= 13,478,527 MWt + 614,000 MWe

Note that the average fossil fuel thermal output is almost 2 kWt per person on Earth. Assume that the average nuclear power plant operates at a thermal efficiency given by:
(electricity output) / (reactor thermal power output) = 0.33
 

PRESENT REQUIREMENT:
Then as a minmimum displacement of the present fossil fuel consumption requires new nuclear reactors with about:
13,478,527 MWt (0.33) / (257,000 MWe) = 17.3 times the present functional nuclear reactor capacity.

Note that this estimate inherently assumes that in both motive power and general heating applications one kWhe can replace 3 kWht.
 

PROJECTED REQUIREMENT:
Hence with allowance for 2 X load growth due to increasing population and increasing per capita 3rd world energy requirements the installed world nuclear reactor capacity needs to increase by about 40 fold over the next 60 years. Viewed another way, the operational world nuclear reactor capacity must double about every 11 years. This estimate will likely be too low because it does not take into account the projected increase in per capita energy requirements for desalination of water for agricultural purposes.

A major constraint on the FNR production rate is availability of sufficient plutonium to start FNRs. It will be ironic if present attempts to prevent nuclear weapon proliferation via using plutonium as fuel in water cooled reactors lead to extinction of mankind due to insufficiency of plutonium for starting future FNRs.

At this time there is complete failure of planning authorities to face this basic nuclear capacity expansion issue.
 

RENEWABLE ENERGY CONSTRAINTS:
Most renewable energy is seasonal. Rivers consistently run much higher in the early spring than in the late summer. In Ontario average wind generation in the summer is half as much as in the winter. In northern Canada solar energy is non-existant in the mid winter. Thus, contrary to misleading claims by "environmentalists" it is impossible to totally replace fossil fuels with renewable energy without massive seasonal energy storage. The only seasonal energy storage technology that makes any sort of financial sense is hydraulic storage in major river valleys and lakes.

A recent agreement between Ontario and Quebec that allows Ontario access to some of the hydraulic enegy storage in Quebec is clearly a step in the right direction, but relying on such an agreement instead of proceeding with a Fast Neutron power Reactor (FNR) prototype is simply foolish procrastination because the total available hydraulic energy storage in Quebec is nowhere near sufficient to meet the Ontario requirement for displacement of fossil fuels.

An issue that many people fail to grasp is that average world hydro electric power production will likely plateau at about 400,000 MWe and due to balancing constraints that plateau will effectively clamp average grid connected wind power production at about 200,000 MWe. Some additional wind power could in principle be used for production of electrolytic hydrogen for liquid hydrocarbon synthesis. However, the economics of wind generation exclusively for hydrogen production are extremely adverse because none of the power generated earns premium income by assisting in meeting the uncontrolled electricity peak load. Hence, to economically displace fossil fuels almost all of the present fossil fuel supplied 13,478,527 MWt must come from nuclear energy. There is further energy required for water desalination, synthetic hydrocarbon processing, expanded concrete production and steel production that is not included in the fossil fuel energy total. Displacement of fossil fuels will require at least a 40 fold expansion in world wide installed nuclear reactor capacity. In Ontario the installed nuclear capacity must be increased about 10 fold.
 

NUCLEAR CAPACITY PROJECTIONS:
In Ontario replacing the present fossil fuel consumption while allowing for a modest increase in Ontario population over the next 60 years requires about a 10 fold increase in functional nuclear power capacity. To put this matter in perspective, if we adhere to the present OPG/NWMO nuclear waste disposal methodology, which presently contemplates two Deep Geologic Repositories (DGRs), in reality after 60 years 20 DGRs will be required and after 300 years at least 100 DGRs will be required. Clearly the present OPG/NWMO nuclear waste disposal plan is not sustainable. There are certain radio isotopes such as Ca-41, Cl-36, Ni-59 and C-14 where there is no alternative disposal solution other than permanent containment within a DGR. With respect to these long lived low atomic weight isotopes the most important long term safety measure is to do all necessary to avoid their production.

For most of the remaining radio isotopes there are disposal alternatives that potentially cost a lot less in terms of both dollars and environmental pollution than the present plan by OPG and the NWMO and that should be pursued. For most shorter lived radio isotopes a DGR should be designed as an interim storage facility rather than as a permanent storage facility.

The entire nuclear energy cycle, including both electricity production and nuclear waste disposal, must be made sustainable.

A potential long term limit on sustainability of fission nuclear power is formation of long lived inert gas radio isotopes. The problem with inert gases is that it is almost impossible to physically isolate them from the atmosphere for long periods of time. If the entire world is powered by fission nuclear power over time the accumulation of inert gas radio isotopes in the atmosphere may be an issue. The inert gas isotopes that are are anticipated to be problematic are:
ISOTOPEHALF LIFE
Ar-39269 years
Ar-4233 years
Kr-812.1 X 10^5 years

The number of these radioactive inert gas isotope atoms formed per kg of Pu fissioned must be determined. The Kr-81 concentration in the atmosphere will be an indication of the cumulative fission nuclear power production on Earth.
 

DGR REQUIREMENTS:
Any Deep Geologic Repository (DGR) design that is not consistent with long term nuclear power sustainability is not the right design. The DGR concept that is presently contemplated by the NWMO and OPG is not sustainable and hence is not acceptable. Achievement of safe sustainability requires ongoing DGR accessibility. The requirement for ongoing accessibility determines the type of rock in which the DGR should be located and the elevation of the DGR storage vaults with respect to the elevation of the surrounding water table. There must be an adequate provision for future changes in the water table elevation with respect to the DGR elevation. For example, the Niagara escarpment, which is about 100 m high, is only 12,000 years old. Hence as a minimum the DGR vault must be at least 100 m above the present water table.

If dilution of radio isotopes is relied upon as a means of reducing nuclear waste toxicity, and if a DGR open period is 60 years, over 10,000 years the required number of DGRs will increase by a factor of:
(10,000 years / 60 years / DGR) X 40 = 6666 DGRs
causing the average background radiation contribution due to long lived isotopes in DGRs, which may be considered acceptable with two DGRs, to increase by almost four orders of magnitude. Hence dilution of nuclear waste is neither an acceptable nor a sustainable method of reducing nuclear waste pollution. The NWMO/OPG safety case for the proposed Bruce DGR is simply not sustainable.
 

FUEL RECYCLING:
One of the present complexities of the nuclear power industry is the need for multiple reactor types for efficient use of uranium. Natural uranium consists of about 99.3% U-238 and about 0.7% U-235. The most efficient way to use all the potential energy contained in natural uranium is to use the fuel in a succession of different reactor types.

First the natural uranium oxide is used to fuel a heavy water cooled and moderated CANDU nuclear reactor. This step consumes part of the U-235 and converts a portion of the U-238 into Pu-239 and also produces high neutron cross section fission products and trans-uranium actinides. It is then necessary to separate the lower atomic weight fission products from the higher atomic weight trans-uranium actinides and to convert the uranium oxide fuel into metallic fuel.

Then the metallic fuel is used in a liquid sodium cooled fast neutron reactor. This reactor fissions the existing plutonium and converts part of the U-238 into new putonium. Periodically the fuel is removed and low atomic weight fission products are extracted and placed in isolated storage for 300 years. The weight of fission products removed is replaced by an equal weight of more U-238.

This fuel recycling methodology improves the energy yield of natural uranium over 100 fold and reduces the future requirement for long term nuclear waste storage more than 1000 fold. However, due to the technical complexities governments are reluctant to embrace fuel recycling technologies.

Thorium (Th-232) may also be bred into U-233 for use in CANDU reactors. However, a major problem with the thorium fuel cycle is that fission of U-233 does not provide enough spare neutrons to economically consume the existing inventory of CANDU spent fuel. Another problem with the thorium power cycle is that it lends itself to production of concentrated U-233 and hence nuclear weapon proliferation.
 

MAJOR ISSUES WHICH MUST BE FACED:
1. Safe and economical interim storage of the present inventories of spent fuel and other nuclear waste. In this respect recent events at Fukushima Daiichi have clearly demonstrated that the existing inventories of radio toxic materials should be moved to a dry storage location that is high above the local water table;

2. Change in nuclear reactor design from slow neutrons to fast neutrons so that the prime energy source is the plentiful uranium isotope U-238 instead of the much les abundant uranium isotope U-235;

3. Recycling of spent CANDU and other spent water moderated reactor fuel to convert the highly radio toxic long lived trans-uranium actinides into short lived radio isotopes that rapidly decay into non-toxic low energy stable isotopes. This recycling process extracts 99% of the potenial energy from the nuclear fuel instead of only 1% as presently realized with CANDU and other water moderated reactors;

4. Recycling of irradiated nuclear reactor materials such as zirconium to both reduce the cost of new nuclear reactors and to minimize the mass and volume of radio toxic material in storage;

5. Recovery of tritium/helium-3 for sale to third parties to earn income, to reduce the mass and volume of radio toxic material in storage and to provide helium-3 which is required for detecting illicit shipments of fissionable material;

6. Development of safe, economic, accessible and reliable storage for radio isotopes with half lives less than 30 years such that after 300 years the stored material, storage containers and storage space can all be reused;

7. Development of a safe, economical and reliable methodology for concentration, isolation and storage of long lived low atomic weight isotopes such as C-14, Cl-36, Ca-41, Ni-59, Se-79 and Sn-126 that have no present or foreseeable future value. The storage methodology should recognize that dilution is not a solution to pollution and that these isotopes are highly mobile in water. eg Dry storage in double wall stainless steel-porcelain containers;

8. Modification of nuclear reactor designs to minimize future production of long lived low atomic weight isotopes such as Cl-36 and Ca-41 which form water soluble chemical compounds;

9. Modification of nuclear generating station designs to reduce use of concrete by siting the reactors at higher elevations to avoid tsunami and flood risks and by use of liquid sodium primary coolant to avoid the problem of potentially having to contain radio active steam;

10. Use of natural draft cooling towers instead of direct lake water cooling to reduce cooling water requirements, to allow siting reactors at higher elevations with respect to cooling water bodies and to minimize reactor impact on marine species;

11. Change in nuclear reactor design to separate mechanically stressed components from neutron stressed components to extend facility life, to reduce reactor maintenance costs and to reduce formation of neutron activated decommissioning waste.

12. Large scale deployment of helium-3 based neutron detectors to prevent illicit transport of fissionable material.
 

Unfortunately, the present NWMO and OPG plans for the Bruce DGR fail to address all of the aforementioned issues. The present NWMO and OPG plans are implicitly based on three false assumptions which are fashionable but which have no basis in fact.
 

FALSE ASSUMPTIONS BY NWMO/OPG:
1. The first false assumption is that future nuclear reactors will be assembled by skilled tradesmen using the same methodology as was used four decades ago for assembly of CANDU reactors.

2.The second false assumption is that non-accessible burial of unprocessed long lived nuclear waste below the water table is a sustainable activity and that this activity is acceptable to the Canadian population;

3. The third false assumption is that the electricity rate payers are indifferent to:
a) the cost of DGRs,
b) the cost of labor in nuclear reactor construction and
c) the cost of expensive and non-recycled nuclear fuel and nuclear reactor materials.
 

INVALID CONCLUSIONS FLOWING FROM FALSE ASSUMPTIONS BY NWMO/OPG:
1. For worker safety the materials used in nuclear reactor construction need to initially be non-radioactive;

2. When a nuclear reactor reaches the end of its useful working life its radio active components are not recyclable;

3. All radioactive waste material should be permanently consigned to a DGR;

4. The DGRs should be inaccessible after closure and hence should to be located far below the surrounding water table.

5. The rock surrounding a DGR should be soft and inherently unstable to the point of being self sealing as with limestone or salt;

6. The DGRs should rely primarily on the character of the surrounding rock to minimize the rate of diffusion of water soluble material from the DGR into the surrounding environment;

7. Dilution of radio toxic material is considered by NWMO/OPG to be an acceptable solution to pollution.
 

I suggest that the aforementioned implicit assumptions by NWMO/OPG are all wrong and hence the related conclusions are also all wrong.
 

CORRECTED ASSUMPTIONS AND RESULTING CONCLUSIONS:
1. I have worked on development of advanced microprocessor based equipment control systems and on the design of liquid sodium cooled fast neutron reactors, as described at www.xylenepower.com/FNR%20Design.htm and adjacent Nuclear related web pages. The OPG assumption that the cores of new nuclear reactors will be assembled by skilled tradesmen is not valid because during the last thirty years there have been major advances in robotic assembly technology and because during the same period a sufficient inventory of radioactive material has accumulated to justify radioactive material recycling. Canadian robotics were used to assemble the International Space Station. Robotics are now widely used in automotive assembly. By comparison the assembly of a fast neutron reactor is a relatively simple task.

2. With robotic assembly it does not matter if the reactor materials and fuel components are initially radio active. Fast neutron reactor fuel bundles are intended for robotic assembly;

3. Hence neutron irradiated chromium, iron, uranium, plutonium, zirconium, and trans-uranium actinides can all be recycled.

4. Hence the DGRs should remain permanently accessible to permit on-going safety inspections, risk mitigation and material recycling. The DGRs will make extensive use of robotic technology developed by and for the hard rock mining industry;

5. In order to inexpensively exclude water from an accessible DGR the elevation of the DGR storage vaults should be high above the local water table and the DGR should be gravity drained and naturally ventilated;

6. In addition to reliance on the quality of the surrounding rock the nuclear waste stored in the DGR should be further isolated from the environment via long life engineered containers (> 10,000 years) where the contents of each container are uniform. Achieving that objective requires improved waste sorting at the reactor sites using gamma ray spectrometers and may require significant radio chemistry;

7. The DGR should have internal gravity drainage to sumps and should provide ongoing access for remote monitoring, risk mitigation and material recycling. The sump overflows must be gravity drained.

8. The DGR storage vaults should be about 400 m below grade to provide certain containment of long lived radio isotopes through numerous glaciations;

9. The DGR should be formed in stable high density granite to provide a combination of durability, water exclusion, and safe access for thousands of years;

10. Recycling of spent CANDU fuel involves trans-uranium actinide fission in a fast neutron reactor. As compared to the present CANDU process the spent fuel toxicity lifetime is reduced 1000 fold and the energy per kg available from natural uranium is increased 100 fold;

11. The fast neutron reactor fuel cycle allows for major material, labor and DGR cost savings for the benefit of the electricity rate payer;

12. Recent political polls indicate that at least one third of the Ontario voters are opposed to the projected electricity price increases related to wind generation and its required supporting energy storage and transmission costs and are seeking electricity price mitigation;

13. Contrary to claims by the NWMO there is no evidence that any permanent "receptive community" in Canada is in favor of high level non-accessible nuclear waste burial in that community. The majority of witnesses from the Bruce area before the Joint Review Panel are opposed to the present NWMO/OPG Bruce DGR plans.

14. Any location that is naturally sufficiently dry for safe long term storage of long lived nuclear waste does not have sufficient ground water to support a permanent community.
 

SPECIFIC CLAIMS:
1. As fossil fuels are phased out part of the energy requirements that fossil fuels presently meet must be met by synthetic hydrocarbon fuels made using nuclear energy;

2. As a result of this increased dependence on nuclear energy the public will become less tolerant of present technical incompetence and wasteful practices at OPG and the NWMO;

3. The public will insist, if only as a cost saving measure, that materials such as iron, chromium, zirconium, and uranium that contribute significantly to the overall cost of nuclear energy, be recycled both to save money and to reduce the radioactive material inventory. Hence for both worker safety and cost reduction nuclear reactor modules will be robot assembled;

4. The informed public will demand fission of trans-uranium actinides to prevent long term pollution of drinking water;

5. In the future mankind will have no practical alternative to liquid metal cooled fast neutron reactors operating with U-238 for fossil fuel displacement, due to depletion of the U-235 resource. Note that the deuterium-tritium-helium-lithium fusion fuel cycle is also a liquid metal cooled fast neutron process.

6. The only known aneutronic energy source is the (H-1) - (B-11) process, but there are serious questions as to whether that process can ever yield enough power gain to be useful as a practical energy source.

7. The relatively high coolant temperature of a liquid metal cooled fast neutron reactor allows efficient heat dissipation via evaporation of water instead of by direct lake or sea water cooling, and thus greatly reduces the impact of nuclear power on marine species.

8. Nuclear reactor designs should be modified to minimize formation of C-14, Ca-41, Cl-36 and Ni-59;

9. With respect to existing CANDU reactors reasonable efforts should be taken to recover tritium/helium-3 for use in prevention of nuclear weapon proliferation.
 

POTENTIAL NUCLEAR WASTE STORAGE LOCATION:
From a geophysical perspective by far the best nuclear waste storage location in Canada is Jersey Emerald. Jersey Emerald is a 5 million square foot naturally dry depleted Canadian hard rock mine with about 10 km of main access truck tunnels, 12 foot to 60 foot high internal storage vaults and geology that is uniquely suitable for storage of radio isotopes and/or other highly toxic material. The Jersey Emerald workings are 200 m to 600 m below grade but are more than 300 m above the surrounding water table. The lower portions of Jersey Emerald are in extremely dense water tight granite. Jersey Emerald was a critical source of zinc, lead and tungsten during WWII but was closed in 1972 due to low commodity prices. Today Jersey Emerald is likely the most safe and secure facility in North America for nuclear material storage.

In 2013 Jersey Emerald and the surrounding property and mineral rights were available for purchase at a price that was a tiny fraction of the projected cost of the Bruce DGRs.

In August 2013 both the NWMO and OPG failed to even inspect Jersey Emerald when it was available to them, free and clear, complete with 4000 hectares of assembled surrounding property, including both surface and mineral rights, for $67.5 million. For an estimated additional $100 million NWMO/OPG could have acquired an additional 16,000 hectare exclusion zone, giving NWMO/OPG title to everything within an 8 km radius of Jersey Emerald. The failure of both NWMO and OPG to place a $2 million dollar purchase deposit on the Jersey Emerald property prior to December 13, 2013 will likely go down in Canadian history as the worst ever management decision relating to nuclear power. This matter is indicative of the gross incompetence and/or corruption within the executives of both OPG and the NWMO.
 

This web page last updated January 24, 2017.

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