Q What is a SMART energy system?
SMART stands for Small Modular Adaptable Reactor Technology. It belongs to a class of small reactors which are generically referred to as a "nuclear battery". A nuclear battery is a small, modular reactor which is not refuelled on site, nor is the spent fuel (nuclear waste) stored on site. When the fuel in a nuclear battery is consumed, the entire reactor module (which contains the spent fuel) is removed as a sealed unit and shipped to a processing facility. A new, freshly fuelled reactor module is installed to replace it.
A SMART. energy system consists of a SMART nuclear reactor module to produce steam which is used to drive a turbine that is connected to an electrical generator. Additionally, turbine exhaust steam can be recovered for space heating or upgraded and used for industrial processes. (For a pictorial display see the top animation icon at http://www.animatedsoftware.com/environm/nukequiz/nukequiz_one/nuke_parts/reactor_parts.swf)
Q How much power does it produce?
The reactor module is identical for all SMART energy systems. Initially SMART will be offered at a fixed power rating of 5 megawatts electric (MWe), and will have a measure of load following capability. Later models will be offered at power levels between 500 kWe and 10 MWe, depending on the customer's needs. The balance of plant modules such as turbo-generators and condensers can be sized for maximum efficiency and minimum cost. When operating in the steam only mode, SMART would be capable of producing 25 megawatts thermal, or about 72 million BTU/hr of steam heat.
Q Is it safe?
Yes. All nuclear reactors, worldwide, must be licensed by safety authorities before they can be built or operated. In Canada, the organization charged with this responsibility is the Canadian Nuclear Safety Commission. Before a nuclear reactor design can be licensed, built or operated it must meet rigorous safety standards that have been developed during more than 45 years of nuclear power production in Canada. Nuclear energy is among the safest forms of energy production in the world today.
Q Is there any possibility that radiation could leak out of a SMART reactor?
Because the SMART reactor uses TRIGA® fuel, all radiation producing fission products stay contained within the fuel, even at temperatures well above normal. The fuel is further clad with a stainless steel sheath and immersed in radiation absorbing water. The water is contained in a thick pressure vessel that is surrounded by a radiation shield. Finally, the reactor core is installed below ground, which acts as the final layer of complete radiation shielding. It is extremely improbable that a significant radiation leak could occur from a SMART reactor.
Q What is TRIGA® fuel and why is it so special?
The free neutrons in the reactor have too much energy and must have their energy reduced, or moderated, in order to sustain the energy producing chain reaction in the nuclear fuel. In conventional reactors a separate moderating material such as water or graphite surrounds the fuel bundle. With TRIGA® fuel the moderator is incorporated directly into the fuel. As a result, when the fuel reaches a higher than normal temperature (but still well below its maxim structural temperature) the reactivity of the fuel abruptly ceases and the chain reaction stops in about 3 thousandths of a second. By its very design the power produced by TRIGA® fuel is inherently self-limiting thereby preventing any possibility of a fuel overheat, or reactor runaway. Some research reactors use this self-limiting property of TRIGA® fuel as the primary means of power control. TRIGA® fuel was developed in 1958 as an ultra safe and self-limiting fuel and has been used in over 60 reactors worldwide for more than 50 years. For more information on TRIGA® fuel technology see “TRIGA 50 Years Of Success” .
Q How much does a SMART energy system cost?
The cost of a SMART energy system depends on a number of factors. The power output of the reactor and mode of operation, i.e. electrical, steam, or co-generation, will dictate the size and complexity of the balance of plant modules and hence the cost. It is more instructive to look at the cost per kilowatt-hour (kWh) of the electricity produced. The target cost for the 5 MWe SMART is 20¢ per kWh. In time, volume production and design refinements will bring this figure down. Dunedin Energy Systems will operate on a Build – Own – Operate (BOO). business model whereby SMART energy systems are constructed, owned, operated, and decommissioned by Dunedin Energy Systems under a power supply contract to the customer. This will substantially reduce up-front capital requirements and relieve the customer of many of the tasks involved in new technology adoption and integration.
Q Is a SMART energy system complicated to run?
A SMART energy system is a highly automated system with automatic controls, monitoring and load following capability. As a steam centred system, it will require a 1st Class Power Engineer to be on duty at all times. It is intended that the SMART nuclear reactor will be licensed to be operated with minimal staffing and remote monitoring of nuclear systems, so long as a Licensed Nuclear Operator (LNO) is available to be on site on short notice.
Q Does a SMART energy system produce air pollution or greenhouse gasses?
No. A nuclear reactor produces virtually none of the emissions that cause smog, acid rain, or greenhouse gasses. All reaction products remain within the nuclear fuel. The Canadian Energy Research Institute has found that the mining and fuel production, operation and waste disposal of nuclear plants produces just 1.8 grams of CO2 per kilowatt hour (g/kWh) compared with 540 g/kWh for natural gas fired generation and 1,050 g/kWh for coal fired generation. (Source: Comparative Life-Cycle Assessment of Electricity Generation in Ontario, CERI 2008). Replacing diesel generation with a SMART 1000 reactor operating for 10 full power years will displace the combustion of over 23 million litres of diesel fuel and eliminate the production of more than 65 million kg of CO2
Q Does the SMART reactor use a lot of water? Will it need those huge cooling towers?
No. Although the SMART reactor needs to reject waste heat like any thermal power plant, because of its small size, waste heat rejection can be accomplished with air cooled condensers which do not require a supply of cooling water.
Q How often does the SMART reactor have to be refueled?
The refuelling schedule of a SMART nuclear battery will depend on its rated power and capacity usage. A 5 MWe SMART can run for about 17 years at full power on one fuel load. Since electrical loads vary, a capacity factor of 80% may be more representative of actual use. In this case the reactor would would exhaust it's fuel in about 19 to 20 years
Q How is the SMART reactor refueled?
The SMART reactor is not refueled on site, rather the entire reactor core module is removed as a sealed unit and returned to a central processing facility for refurbishment and refueling. At the same time, the spent core is replaced with a fully fueled replacement core module, much like changing the batteries in a flashlight. There is no fresh or spent fuel stored at the operating site.
Q What about the nuclear waste?
Before all the nuclear fuel is consumed, the fission products (the waste) build-up in the fuel and make it inefficient at producing heat. At this point the fuel is said to be "spent", and thus the nuclear "waste" is actually only partially used fuel that still contains much of the nuclear energy. The spent fuel is not removed from the SMART nuclear battery, but rather the entire reactor module, which contains the spent fuel is removed as a sealed unit. The reactor module is then sent to a processing facility where the spent fuel can be recycled back into fresh nuclear fuel.
Q What if my power needs increase?
The modular design of SMART energy systems means that additional reactor units can be readily integrated into the system, allowing power output to grow along with your power requirements.
