Nuclear Energy as a Viable Option

Yukon Energy Charrette

Background Paper

Prepared by:

Dr. Chary Rangacharyulu Department of Physics and Engineering Physics

University of Saskatchewan Saskatoon, Saskatchewan

S7N 5E2 Chary.r @usask.ca

February 2011

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Nuclear Energy as a Viable Option Chary Rangacharyulu Dept. of Physics and Engineering Physics University of Saskatchewan Saskatoon, SK, Canada, S7N 5E2 Chary.r @usask.ca Since the advent of artificial nuclear transmutations and later discovery of nuclear fission, nuclear processes have found wide range of applications in medicine, material science and engineering and also as a source of energy. Currently, there are 439 reactors operating in 30 countries around the world, which produce around 374 GWe, nearly 20% of the world’s electricity. In Canada, we draw about 16% of electricity from nuclear sources while the Province of Ontario gets nearly 50% of its electricity from nuclear power. During the last 15 years or so, the world has seen a drastic increase in thirst for energy. Several countries are being reclassified from developing type to those of developed ones. China and India with nearly one third of world’s population are leading the pack. Many other countries are following the trend. The world nuclear association (http://www.world-nuclear.org) reports that the demand for electricity is expected to increase from 16.5 PWh (1PWh is one million GWh) in the year 2007 to 28.94 PWh in 2030 amounting to about 75% increase in energy needs. It is anticipated that nuclear energy will be a major piece of the energy puzzle. A few reasons for the continuing usage of nuclear electricity are given below:

i) a reliable source of energy- currently nuclear reactors operate at more than 90% capacities

ii) it is not expensive, at a cost of less than a few cents per kWh

iii) The fissile 235U material supply is expected to last for about 100 years. The fissionable 238U is about 99.3% of naturally occurring uranium, which will last for several thousands of years. Still there is untapped energy in thorium.

iv) It is one among the cleanest energies with greenhouse gas emissions of 5-30 gCO2 eq/kWhe, comparable to the emissions associated with wind, solar or biomass energies and much less than coal or oil sources. (see fig. 1)

v) Needless to say, nuclear energy is a steady supply unlike the intermittent wind and solar energies.

Radiation hazards: The opponents of nuclear power cite radiation hazards of nuclear power. In some circles, “nuclear energy” is a thing to be scared about and be

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avoided at any cost. Some people go to extremes to say that there is no safe levels of radiation. They themselves readily accept X-ray examinations, PET/CT scans, or radiation therapies and take transatlantic or transpacific flights to choice destinations. They are not aware, or ignore the fact, that we are continually bombarded by radiation that passes through or interacts in our bodies. The cosmic rays coming from outside of our planet are composed of several species of radiation such as high energy muons, photons and neutrinos. There is no human contribution to this phenomenon. In addition, we ourselves are sources of radiation as we have carbon and calcium in our bodies. It was reported that the average worldwide exposure is 3 milli Sieverts, nearly 80% of which is from natural sources of radiation, while about another 20% is due to medical exposure. All other sources contribute less than 1%. The nuclear power plant related exposures are less than 0.01% (M.J. Crick, 2008, United Nations Scientific Committee on the Effects of Atomic Radiation, Proceedings of 12th Congress of International Radiation Protection Association). The table below lists various sources and levels of radiation we come across in our daily lives. They are comparable to or higher than the radiation levels one encounters in the operations of nuclear power facilities. All these radiations are well below the permissible limits suggested by the health physics and radiation safety agencies.

Source of radiation Amount

(micro Sieverts) Sleeping next to your spouse for one year 5 Watching TV at an average rate for a year 10 Natural background radiation for a year 10 A chest X-ray 20-100 A 10-hr Trans-Pacific Airplane trip 50 Cosmic rays at Sea level 250 K-40 in our bodies (half-life =1.3 billion years) 300 Near a nuclear plant <50

Nuclear safety: One often cites safety and likelihood of accidents as a major concern against the nuclear power plants. If at all, the evidence shows that they are much safer than other energy sources or industries. The reason is the “defense in depth” strategy that nuclear safety regulatory agencies insist upon. Right at the outset, nuclear power plant designers provide the specifications on the prevention of accidents, detailed monitoring philosophy of the operations and planned courses of action if some components of the system malfunction. The defense in depth approach comprises of

i) a quality design and construction of the facility ii) equipment to ensure smooth and straightforward operational procedures

and control systems to eliminate human errors

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iii) Electronic and computer monitoring systems which continually test, detect and display any abnormal conditions of the components

iv) Multiple layers of redundant control and safety systems to minimize the damage to the system in case of malfunctions and prevent release of radioactive materials to the surroundings

v) provisions to confine the effects of fuel damages, if any.

The site licensing process takes several years as the regulatory agencies seek the operators to provide the technical and financial details of construction, operations and decommissioning of nuclear facilities. Their approval is a must before the providers can move forward. It should be mentioned that nuclear power plants were first built in late 1940s, when the modern-day modular, computer based electronic monitoring and control systems were unheard of. In the present times, the thermal, pressure, radiation etc. sensors are quite effective. Multitudes of diverse sensors are easily implemented. Also, control systems to effect corrective actions are easily incorporated. They provide a detailed, on-going report of the functioning of systems not only to the operator but to other stake-holders such as supervisors, management as they wish. A common concern is that, in case of a mal-function or an accident at a reactor, hazardous radiations will be released to the environment. The nuclear technology responded to this concern by implementing three physical barriers between the fuel and its surroundings. The fuel is made as pellets which are inserted in fuel rods, which are placed in a pressure vessel, which in turn is enclosed in a robust concrete containment structure. As of February 6, 2011, 14386 reactor-years of world wide experience in producing civil nuclear power. By March Yukon meeting, this number would exceed 14410 reactor-years as there are about 439 reactors operating in the world. Every calendar day is just over one reactor year. The number speaks itself for the safety records of nuclear reactors. It may also be of interest to note that, now, there are about 20 nuclear power plants within 200 km radius of Paris, France. To close this section, it may be worth pointing out that there is no risk-free human endeavor. While a fatal accident is not something that we can take lightly and be complacent, it is useful to compare accidents of nuclear energy facilities with some other resources. The table below shows such comparison: (http://www.world-nuclear.org/info/inf06.html, Data from Paul Scherrer Institut, in OECD 2010. * severe = more than 5 fatalities).

Summary of severe* accidents in energy chains for electricity 1969-2000 OECD Non-OECD

Energy chain Fatalities Fatalities/TWy Fatalities Fatalities/TWy Coal 2259 157 18,000 597

Natural gas 1043 85 1000 111 Hydro 14 3 30,000 10,285

Nuclear 0 0 31 48

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Radioactive waste: Another major concern is the long-lived nuclear waste. First, it must be pointed out that the waste from nuclear power plants has been around for more than half a century, since the first nuclear reactors went into operation in 1950s. While they are safe in the short term, one does not overlook the need for a permanent solution. To put it in proper context, we must recognize that the radioactive waste is not solely due to nuclear power plants but it comes from various other uses of nuclear radiation in scientific research, medical and agricultural applications. The International Atomic Energy Agency (IAEA, Vienna, Austria) is an agency which serves as the international authority on nuclear matters. Among various things it does, it sets standards and references for technology, research, education and safety as well as security. The general classification is exempt waste (EW), very short lived waste (VSLW), very low level waste (VLLW), low level waste (LLW), Intermediate level waste (ILW), and high level waste (HLW). Figure 2 is a depiction where the half-life of the radioactive substance (x-axis) plotted against the activity concentrations (y-axis). The waste corresponding to higher activities and longer time scales are more and more hazardous. Fortunately, the long lived activities are not voluminous. In countries with nuclear power, the radioactive waste is less than 1% of total industrial toxic waste. The high level radioactive waste is about 3 cubic meters (~105 cubic feet) per one terawatt hour operation. This means that one thousand high power reactors together produce less than one small cubicle volume of high level waste per hour. Long term storage of the radioactive waste in geological repositories is one of the possible options to address this issue. Scientific and technological research of radioactive waste treatment is on-going at several laboratories. Some suggest that we must not consider the nuclear residues as waste, but try to harness them for various applications. When this may not be feasible, there is still option to convert the activities of thousands of years or longer half-lives to those of short-lived ones of few years or less. All these ideas are based on artificial transmutations, the basic principle of nuclear power generation. This area of research has not yet been fully developed but several groups around the world are paying attention to these possibilities. Nuclear Proliferation or Terrorism: Some people express concern of the possible nuclear terrorism and the fear that nuclear bombs might fall in the hands of terrorists. First, we note that, from among the 192 United Nations’ member countries, all but four countries are signatories of non-proliferation treaty of nuclear weapons. In comparison, the number of countries who did not sign the treaties against biological and chemical weapons is about 20 and 16, respectively. Also, it must be recognized terrorist groups can easily and routinely develop chemical and biological weapons but nuclear weapons are beyond their expertise, out of reach and inaccessible.

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It is of interest to note that the high level radioactivity with very long half-lives is due to the fission products and transuranic elements, which is very small in volume. With the new reactor technologies, this waste is reduced from an original 50 cubic meters in the first generation reactors to about 3 cubic meters of the current generation for 1 TWh reactor operation. It is expected that this would be less than one cubic meter in the next generation of reactors. The extended lives and recycling of fuel will leave less materials for destructive purposes. Small reactors: USA and Russia had long standing experience of small reactors of a few MWe to several tens of MWe for military purposes. The reactors were workhorses which operated for more than 35 years for uninterrupted service. Several small reactors were built as research reactors to serve as intense neutron sources. The thermal power of these reactors varies from a few kW to a few MW. General Atomic in USA sold several TRIGA reactors of a few MW power to universities and research centers in USA and elsewhere. In Canada, Chalk River was the home of reactors since late 1940s. Also, research reactors dubbed as SLOWPOKE of a few kW power were built for Dalhousie University, École Polytechnique, Univ of Alberta, University of Toronto, Royal Military College and Saskatchewan Research Council. These are turn-key operation units. McMaster university is the home of a research reactor of 5 MW. The NRX and NRU research reactors at Chalk River were of 25 MW and 200 MW powers, respectively. Built in 1940s and 1950s, they put Canada on the world map of research in nuclear science and technologies. Currently, there are several small reactor manufacturers offering output powers in the ranges of about 10-125 MWe. At least some of them offer units which need no refueling for several years. This is a very attractive option since it

a) ensures uninterrupted power supply for a very long period b) eliminates the concerns of spent fuel accumulations on site and so forth. One can conceivably procure a few modular units operating in parallel

configurations to increase the output powers over time. It is possible to distribute them over a geographical region to minimize the transportation losses and associated costs. Given that the radioactive wastes are coming down to about 1m3/TWh, a 100 MWh will produce less than 30 m3 in 30 years of operation.

The table below lists a few small reactors in advanced stages of development.

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Table: Small-medium reactors with development well advanced (from http://www.eoearth.org/article/Small_nuclear_power_reactors). Model name Power Type Manufacturer

(MWe)

CAREM 27 PWR CNEA & INVAP, Argentina KLT-40 35 PWR OKBM, Russia MRX 30- 100 PWR JAERI, Japan IRIS-100 100 PWR Westinghouse-led, international SMART 100 PWR KAERI, S. Korea NP-300 100-300 PWR Technicatome (Areva), France VK-300 300 BWR Atomenergoproekt, Russia PBMR 165 HTGR Eskom, South Africa, et al GT-MHR 285 HTGR General Atomics (USA), Minatom (Russia) et al BREST 300 LMR RDIPE (Russia) FUJI 100 MSR ITHMSO, Japan-Russia-USA 4S 10/50 MSR Toshiba, Japan NuScale 45 PWR NuScale, USA mPower 125 PWR Babcox & Wilcox, USA HPM 25 MSR Hyperion, USA The above list is not exhaustive. It is to illustrate that there a few systems to choose from. The small modular reactors were originally designed to power nuclear submarines, as stand-alone units in remote settings. Thus, they are very attractive option for the Canadian geography. It is somewhat unfortunate that Canadian nuclear industry did not pursue this line of development. However, with the experience of small research reactors and the CANDU systems and more recent advanced reactors, it will not be too long before they can become important players, if they choose to move in this direction. Galena Nuclear Reactor: A 4S reactor of 10MWe is being considered for Galena, Alaska. They seem to have the business plan and decommissioning strategy in place. At this time, the licensing process is still in works, which may take another couple of years and one may expect the 4S to become operational in the year 2015 or later. The entire facility fits in an area of less than 0.5 acre, with nuclear island being below ground level. The slow regulatory process seems to be the cause of this delay. Figure 3 shows a sketch of the 4S reactor. It has a neutron reflector as the only one moving part in the system. This underground system is designed to function even in an earth-quake prone environment, devoid of pressurized water cooling system. Yukon option: Currently, the Yukon energy profile consists of about hydro (76MWe), diesel (50MWe) and wind (0.8MWe) for a total of about 128 MWe. Along lines of projected world trends, we might expect that the energy needs of Yukon will be somewhere between 180-230 MWe by the year 2030. If we assume constant hydro production and no diesel in the energy mix, Yukon will be short of 100-150 MWe by

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the year 2030. Renewables such as wind and solar cannot, by themselves, make up for this energy gap. Clearly, nuclear energy can play an important role. The options are a distributed system of multiple reactors spread out over Yukon. This may not be very economical since the costs do not increase linearly with output power. However, the costs of energy transportation, losses etc must be assessed before one can draw conclusion. Since the modular reactors are being commercialized only now, it is difficult to put an exact figure for the cost of one kWh. The estimates vary from about $0.05 - $0.10 per kWh, implying an over all cost of $15-30M per 1 MWh over a period of 30 years. One may thus expect a 10MW reactor to cost about $200 M over its life of about 30+ years. It is important to realize that construction (licensing, building, reactor construction) are major portions of the costs and they are upfront, initial investment. Currently, Toshiba is designing a 50MWe reactor in addition to the one of 10 MWe. If such reactor becomes available, it may be of interest to Yukon. However, the refueling cycle of a 50 MWe reactor is not specified. Hyperion Power, with head office in Santa Fe, New Mexico, is developing a Hyperion Power Module (HPM) capable of delivering 25 MWe. They have completed a first formal meeting with the Nuclear Regulatory Commission of USA (NRC) in December 2010. The characteristics of this compact system are shown in Figure 4. The artist’s conception is sketched in figure 5. NuScale is a 45 MWe reactor design based on water cooling system. Its refueling cycle is 24 months. The design anticipates future possibilities of larger power outputs by adding more modules to the first delivery. They are in the process of licensing by NRC. (http://www.nuscalepower.com/). It seems advantageous to find a site or sites to accommodate 2 or 3 nuclear reactors of about 50 MWe each and start planning for one reactor to meet immediate needs. Within 10 years or so, one can reassess the energy needs forecast and revise the plan. Canadian Nuclear Safety Commission (CNSC, http://nuclearsafety.gc.ca/eng/), successor of the Atomic Energy Control Board, is the Canadian counterpart of the NRC. Thety report to the Minister of Natural Resources. One may not expect miracles with regard to licensing speed. It maybe prudent to think it will take 5-10 years, more likely 10 years to get to the construction phase. This may not be seen as a hopeless case, as the increasing demand for energy will not happen over night. As Yukon continues to expand the mining industry, each of which with its own energy needs, nuclear batteries are an attractive option. In view of the long lead times required for licensing, one must begin these considerations in the early stages of projects. The CNSC is aware of the concerns

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about delays and they are working to streamline the procedures. There are three major steps before the CNSC renders its decision on licensing. They are i) submission of an application, ii) environmental assessment and iii) licensing technical assessment. Extensive consultations with all stakeholders are carried out during all phases of licensing process. Concluding remarks: It is important to remember that we should not put all eggs in one basket. It is essential to identify all possible sources of energy, evaluate relative merits of those sources in view of the geographical features and the profiles and needs of industrial, business and residential clientele and arrive at possible mix of a few of those options as the best possible solution for the communities. While renewables can play increasing role, it is inconceivable that renewables alone would suffice to meet the energy needs of modern societies. However, it goes without saying that in energy economy, a principle of conservation based on “waste not, want not” philosophy must be the guiding one. We suggest that Yukon may consider nuclear energy as a substantial portion of its energy mix along side the renewable energy options. This will ensure a stable base supply of affordable and relatively clean energy for the rural communities. With the increasing focus on modular reactors, an improved technology originally designed for military purposes, the nuclear option looks attractive for electrical and thermal energy needs such as power and desalination of sea water, mining operations, heat and steam generation etc. Some useful resources: http://world-nuclear.org http://www.cna.ca/ Canadian Nuclear Association http://www.new.ans.org/ American Nuclear Society http://www.iaea.org/ International Atomic Energy Agency http://www.euronuclear.org/ European Nuclear Society http://www.world-nuclear-news.org/ http://www.world-nuclear-university.org/ http://nuclearsafety.gc.ca/eng/ Canadian Nuclear Safety Commission http://www.cns-snc.ca/home Canadian Nuclear Society

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Fig. 1. This figure shows that the full chain GHG emissions from nuclear electricity are very low compared to conventional energy sources such as coal. They are also lower than emissions from some renewable energies. Adopted from R. Dones, T.Heck and S. Hirschberg, report to Swiss Federal Office of Energy , Paul Scherrer Institut, Villigen, Switzerland, Annual Report (2003).

Fig. 2 Conceptual illustration of radioactive waste classification scheme of International Atomic Energy Agency (IAEA, Vienna, Austria) safety standards. Adopted from the IAEA Pub.1419_web.pdf (2009)

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Fig. 3 Cross sectional sketch of the 4S (super safe, small and simple) reactor of Toshiba planned for Galena. It has U-Zr alloy as the fuel enriched to less than 20%. It employs liquid sodium coolant (melting point: 980C and boiling point: 883 0c) http://www.toshiba.co.jp/nuclearenergy/english/business/4s/introduction.htm

Fig.4 Specifications of Hyperion Power Module (HPM) of Hyperion Power with Head office in Santa Fe, New Mexico. The system will be underground linked to the turbines above ground.

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Fig.5 HPM layout as it is connected to the external turbine, power grid etc. The system is built underground at a depth of about 10 meters. http://www.hyperionpowergeneration.com/product.html