Page 41 - Energize December 2022

TECHNICAL

Nuclear power has suffered several setbacks in the past few decades and has been Build costs are the real costs
hamstrung for many years by real or perceived problems, which have all been used as incurred, and these can vary from
excuses for not going nuclear; the most common challenges and concerns facing nuclear project to project. A single plant of new
are safety, cost, build time and nuclear waste disposal. design or first-off of a new technology is
likely to be subject to cost overruns, as
Safety experienced by several recent projects,
Safety concerns are fear-driven. Nuclear incidents at Three Mile Island, Chernobyl and whereas a fleet of standardised mature
Fukushima have resulted in extreme safety regulations. Although two of the incidents design plants is likely to have a much
were subsequently ascribed to human error, nuclear power should not be vulnerable lower unit cost. This has been shown in
to such circumstances. The conflict in the Ukraine has also raised fears about nuclear countries with a large ongoing nuclear
safety. It is a fundamental requirement of any power plant that it should not be possible build program.
to compromise safety by human error. Increased safety requirements have affected both Another critical factor is how NPPs
cost and build time for larger reactors, resulting in increased safety. Latest generation are financed, as the cost of borrowing
NPPs, particularly small modular reactors (SMRs), have increased safety features and money can be prohibitively high, and
failsafe system that are designed to prevent melt-down and allow safe shutdown of NPPs. differs from state debt in the range of
2 to 3%, high risk equity finance where
Build time real interest rates on could vary from 10
The construction cost and time of nuclear power plants is determined by many factors to 15%. This is why some projects, such
including design revisions during construction, large plant size and complex large- as state-supported projects in China,
scale technology, lack of standardisation, serialisation and modularisation, plant safety could be very competitive while others,
and environmental concerns, prevention of accidents and risks, change in regulatory such as private equity funded Hinkley
standards during construction, and actions of environmentalists and nuclear opponents. 2 Point C in the UK, could be expensive.
Several units under construction worldwide that have experienced lengthy build times An interesting question here is whether
are often quoted as the norm for the industry. The fact is that single first-off customised nuclear would now qualify for low
units can be expected to take long to build while multiple units of a standardised design interest “green” loans in the same way
built on a fleet basis will take considerably less. Countries that have built standardised that renewables do.
power plants are able to achieve shorter construction times (France, Japan, Korea and Costing models and economics aside,
Russia). The serial construction of several plants, modularisation and other methods of there is a vast difference between the
2
construction adopted by these countries have substantially reduced construction times. cost of a single first-of-a-kind reactor and
Japan’s Kashiwazaki-Kariwa Nuclear Power Plant Unit 6 is the world’s fastest-built nuclear the cost of a fleet of 20 or 40 reactors of
power plant, taking only 39 months for completion. the same standard design in a continuous
build programme.
Cost
Nuclear power plants require large upfront investments, compared to other sources of New technologies
energy, and the affordability of new nuclear power plants is a major concern cited by Thorium Reactors
critics of any new nuclear build programme. The unit cost of electricity however, being Thorium is being considered as a fuel for
the ultimate figure that affects the consumer, is relatively low. It takes into consideration several new reactor designs. One of the
the long operating lifetime of NPPs, even though the capital cost comprises a large advantages of the thorium reactor is that
portion (60 to 80%) of the total lifetime cost. The typical lifespan of a new nuclear plant is spent fuel from conventional reactors can
60 years with a possible extension to 80 or 100 years. be used as a fuel component.
The issue that has most effect is the amortisation period of the capital cost. At the one Thorium (Th-232) is not itself fissile
extreme one could amortise the costs over the design lifetime of 60 years, which would and so is not directly usable in a thermal
give a fixed levelised cost of electricity (LCOE) for the lifetime, or at the other extreme neutron reactor. However, it is ‘fertile’
one could amortise over the standard period for renewable plant (20 years), which would and upon absorbing a neutron will
give two sets of costs: the unit cost for the first 20 years, and then the unit cost for the transmute to uranium-233 (U-233) ,
a
remaining 40 or 80 years, which would comprise operating costs only and would be very which is an excellent fissile fuel material.
low. The average costs over the lifetime of the plant are likely to be very different. All thorium fuel concepts therefore
From an investment point of view, no-one other than governments, or perhaps require that Th-232 is first irradiated in a
pension funds, would invest in a project that requires 60 years to give a return of capital reactor to provide the necessary neutron
invested, so the second model is the most likely to be adopted. This would give an dosing to produce protactinium-233.
apparent high unit cost for nuclear initially, with much lower costs over the balance of the The Pa-233 that is produced can either
plant’s lifetime often being ignored. 3 be chemically separated from the parent
Today’s market is based on quick returns, and an investment of this sort that might thorium fuel and the decay product
satisfy the needs of transgenerational equity, but hardly those of investors who expect a U-233 then recycled into new fuel, or the
benefit in their lifetime, is not likely to be attractive. U-233 may be usable ‘in-situ’ in the same

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