esr.org.nz

[An ESR Position Paper]
Jack Woodward, May 10, 2008

Introduction
There has been a global upsurge of interest in nuclear energy and there have been occasional recommendations for its use in NZ. Opposition to such a recommendation based on the key issues of cost, plant safety, emissions, resource availability, the treatment and disposal of nuclear wastes, decommissioning, and nuclear proliferation make its adoption unlikely. I have nonetheless reviewed here the various forms of nuclear reactor available for civil energy generation in the short and medium term, the trend in technologies, and their likely relevance to our local situation as some misleading claims have been made. I conclude that there is no reactor that could realistically be deployed here within the given time frame.

The New Zealand Electricity System
The nature, history and size of our electricity system have a bearing on the ease with which it could accommodate nuclear generation, and I will touch on what I see to be some important features.
Transpower has described the NZ system as “a small islanded network”, based on the small size of the total connected generation (9,000MW is small in international terms), the absence of interconnections to other networks, and the “long and skinny” configuration with load and generation centres of gravity in the north and the south respectively. The HVDC link has facilitated this development, and although the link’s capacity is currently constrained by ageing equipment, it seems certain that by 2012 its ability to transmit up to 1200MW in either direction will have been restored. This is but one shortcoming of a grid whose development has not kept pace with the growth of load and generation in terms of both magnitude and regional trends. Load transfers are constrained at a number of key points, notably with the transfer of power from the south into and across the Auckland isthmus, hence the ongoing controversy over a new 400/220 kV line from Whakamaru to Otahuhu. Strengthening of the grid is being approached as a matter of urgency; this will certainly be required for the satisfactory integration of dispersed sources of renewable energy, and proposed amendments to the governance requirement for the Electricity Commission would address this issue.
There is a limitation on the maximum size of individual generating unit that can be connected to the grid system. Currently the largest units on the system are gas turbines at Otahuhu, Huntly and Taranaki Power stations, all single shaft machines with output in the range 380 to 400 MW. Maximum size is affected by the need for spinning reserve to guard against sudden loss of a unit, as well as the economic need to match the incremental growth of generation with that of load. At least as much spinning reserve is needed (on the same side of any grid constraint) as the load on one spinning shaft. Thus a 1,000MW single shaft nuclear unit would need our three largest gas fired generators to be running unloaded on standby. The advent of larger wind generation facilities adds to the grid stability and reliability constraints in the event of an outage of such large units.
The Electricity Commission has just released Draft Generation Scenarios covering the period out to the year 2037. The five Scenarios involve assumptions ranging from the “Sustainable Path” with maximum exploitation of renewable resources and closure of existing major thermal stations and the Tiwai smelter, to the “High Gas Discovery” Scenario. The latter assumes major new indigenous gas discoveries and the construction of efficient gas-fired thermal plants, together with the development of the most cost-effective renewable sources. A feature of all Scenarios is the construction of diesel- or gas-fired peaking plants in parallel with renewable sources to enhance system security. The assumed average demand growth throughout the study period is of the order of 200MW/annum, and the maximum individual plant or generating unit size under any scenario is of the order of 400MW. Virtually all of the large thermal generating plants in the High Gas Discovery Scenario are assumed to be located in the upper North Island, although coal-fired plants with carbon capture, provisionally allowed-for in the latter part of the planning period, could conceivably be located in Southland.
In any likely scenario the role of nuclear generation would be to provide a base load capability to underpin the renewable generation base, supported by gas-fired peaking units.. It is suggested that in view of the above constraints on the New Zealand grid system, the maximum size of any nuclear reactor and associated single shaft generator would be of the order of 500 MW for at least the next couple of decades.

Requirement for a Nuclear Regulator
The electricity supply industry of New Zealand is regulated by the Electricity Commission, a Crown entity set up under the Electricity Act. Its principal objective is to ensure that electricity is produced and delivered to all classes of consumer in an efficient, fair, reliable and environmentally sustainable manner. To discharge this role it has a small, strong core team of high quality generalists, and engages the services of specialist contractors as appropriate. An additional independent regulatory authority would be required if nuclear generation were added to the mix. The importance attached to the role of the Nuclear Regulator can be gauged from the following:
The IAEA held a Conference of Nuclear Regulators from 60 countries in Moscow in March 2006. A statement released from the Conference included the following declaration: “… the complexity of a nuclear power plant makes it dependent on key factors such as location, management practices and human behaviour – all of which influence safety performance. How can members of the public and stakeholders be assured that a nuclear power plant or any enterprise that has to deal with radioactive material is run safely? This is a job for an independent oversight authority – the regulator.”
Similarly, in his introduction to the “Public Report on the Generic Design Assessment of New Nuclear Reactor Designs”, March 2008, the Chief Inspector of Nuclear Installations in the UK described his role thus: “Our job is about protecting people and society from the hazards presented by the nuclear industry. As new nuclear power stations are being considered for the UK, it is right for us as regulators to start our work to examine the safety and security aspects associated with these power stations’ design”.
Key differences between nuclear and conventional thermal power plants are the heat that must be removed following a full plant trip, and the inability to restart a reactor quickly shut down due to neutron capture by short half life Xenon isotopes. Even with the chain reaction completely shut down a nuclear reactor will generate significant heat from fission product decay for long periods. To prevent a “Loss of Coolant Accident (LOCA)” a long-term stable source of electric power is essential. This is a design requirement of concern to the nuclear regulator, and the type of system in which the nuclear plant is embedded is a significant factor.
The first step in the acceptance of a nuclear reactor design for construction in a particular country is its licensing by the nuclear regulator of that country after due study of all relevant aspects. Were that to become an issue in New Zealand it is likely that our regulator would take a lead from the NRC (USA) or the NII (UK). We would be unlikely to adopt a Chinese, Russian, Indian or even a Japanese design unless it had already received certification by one of the above.
Australia does have an independent nuclear regulator, the Australian Radiation Protection and Nuclear Safety Authority ARPANSA, created under legislation passed in 1998, whose responsibilities include those of our own National Radiation Laboratory, a specialist unit within the Ministry of Health. While it has no civil nuclear power plants, Australia does have many features of a nuclear industry with uranium mines, a research reactor and atomic test sites.

The “Nuclear Renaissance”
Recent developments have been described as a “nuclear renaissance”. In the words of one recent (July 2007) newspaper article2 “Asia is leading the world in the quest for atomic power. … there are at least 110 reactors operating …. Another 18 power reactors are under construction and a further 110 are planned. … China has 5 power reactors under construction, another 63 planned or proposed. India has 8 being built and 24 on the drawing boards.” The list is impressive, but the details are hard to check and the numbers are often inflated. A report3 from the UK, published in March 2006 and using 2005 figures from the IAEA gave the following global picture:
“Altogether 24 reactors are officially under current construction around the world. Nine of the 24 reactors were originally ordered before 1990, and are mostly of dated Russian design. China has ambitious plans (up to 30 reactors) for nuclear construction but currently only has 2 plants on order. India appears to have 8 plants being built (including 2 recent Russian-origin units) but there is some doubt about the commitment or capacity of India to complete these in a timely fashion.”
The Economist reported in September 2007 “Over the next few months America’s Nuclear Regulatory Commission (NRC) expects to receive 12 applications to build nuclear power reactors at 7 different sites. It is preparing to see plans for another 15 at 11 more locations next year.”
In January 2008 the British Government declared its support for a new nuclear power programme that could increase its share of generation to 30% or more. No target was set for the number of reactors to be built, this being left to the market to decide.

Dominant Reactor Designs
Reactors under construction or planned in Asia include units developed locally (Japan, India and China) though based on  Western (generally Westinghouse or General Electric) designs. However in terms of recent or planned construction and out for the next decade at least, there are only three forms of reactor technology4 in serious contention in the UK, Europe or the US: two forms of Light Water Reactor (LWR), the Pressurised Water Reactor (PWR) and the Boiling Water Reactor (BWR); and the Heavy Water Reactor (HWR). All three are technologies that have been in existence since the beginning of the civil nuclear industry, but in their modern forms are categorised as Generation III or III+. Generation III designs are advanced reactors developed during the 1990s. Generation III+ are yet more recent developments intended for deployment by 2010. The latest designs share the following common features: improved safety systems; modular design to reduce costs and shorten construction times; increased fuel burn-up to improve efficiency and reduce nuclear waste volumes; larger unit size to improve economic competitiveness. A point worth making is that a terrific amount of effort and resources is involved in a particular reactor design and certification is particular to that design.
PWR technology was pioneered by Westinghouse, which was originally an American company but is now owned by Mitsubishi. The advanced passive series of reactors was developed in the US in the 1990s, resulting in the AP600 with an output of 600MW. However it was discovered that the AP600 would not be cost effective on the US market so attempts were made to increase capacity using the same technology.
The Westinghouse AP1000, with a rating close to 1200MW, was the first Generation III+ reactor to be approved by NRC in 2004 and an order has just (April 2008) been placed for a pair to be built in Georgia, USA.
The French have used PWR technology in their nuclear programme since the 1970s. The Evolutionary Power Reactor (EPR) is a Generation III+ form of PWR reactor designed in a joint venture by French firm Areva and German firm Siemens. During the course of development the reactor’s capacity has been increased to 1750MW to increase economic competitiveness. The first EPR reactor to be built is under construction in Finland, and is due for completion in 2010-11, two years behind schedule and massively over budget. Construction has started on a second EPR in France.
The Advanced Boiling Water Reactor (ABWR) is General Electric’s evolutionary Generation III design of a standard BWR. Three plants are operating in Japan with others under construction in Taiwan. It is reportedly being developed in four different versions: 600MW, 900MW, 1350 MW and 1700MW. A Generation III+ 1390MW European version is the Economic and Simplified BWR (ESBWR). Large German utility Eon, Areva and Siemens are to cooperate in the development of an intermediate range 1,250 MW BWR. The BWR enjoys certain advantages over the PWR, but a consequence of using steam directly from the coolant to drive the turbine is the presence of radioactive water in all areas of the plant. This could limit its adoption in some regulatory regimes.
The Advanced CANDU reactor (ACR) was designed and built by Atomic Energy Canada Ltd (AECL), and is an evolution of HWR technology dating back to 1962. It uses an innovative light water cooled, heavy water moderated system. The CANDU 6 reactor (700MW) is operating in a number of countries, but work is proceeding on a larger Generation III+ unit, the ACR-1000, with an output of approximately 1200MW.

Other Reactor Types
A form of reactor that has on occasion been put forward as most suitable for New Zealand conditions is the Pebble Bed Modular Reactor (PBMR), which is under development in a number of countries, particularly South Africa, China and Russia. It is a variant of the High Temperature Gas Reactor (HTGR), in which graphite is used as the moderator and Helium gas as the coolant. Several earlier versions of the HTGR have been built but none are still in operation. In the PBMR, low enriched uranium particles are compacted at the core of a large pebble covered in three layers of graphite cladding – hundreds of these are poured into the reactor, leaving space for Helium gas to circulate between the units. Unlike all the reactors described previously, which are large and can operate only as base load units, the South African PBMR is a 110MW module that can operate in load following mode. A larger plant could be made up by a collection of such modules. The PBMR has attracted criticism5 of features of its design, and would certainly be subjected to careful scrutiny by regulators in advance of any certification. The PBMR has been enthusiastically promoted by the nuclear industry, but a recent report6 on its suitability for use in the UK had this to say:
“It was originally hoped to complete a demonstration plant by 2003, … . However there have been delays to this timetable … . Such a plant is now unlikely to be complete before 2010 at the earliest. Given a need both to accumulate operating experience on the plant and to gain safety regulatory approval in the UK, PBMR technology is unlikely to be available in the UK until close to 2020.” The report went on to express concern about sevenfold escalation of cost estimates of the demonstration plant.
The IRIS (International Reactor Innovative and Secure) PWR is an international collaborative project engaged in the design of a 335MW reactor incorporating modular construction and enhanced safety features. It is currently in the preliminary design phases. Although publicity has suggested that deployment is expected around 2012-2015, the same reservations expressed in the case of the PBMR above clearly apply to IRIS. The very moderate term “Appraisal Optimism” has been used to describe forecasts for nuclear projects.
The Australian Uranium Association recently released a Briefing Paper “Small Nuclear Power Reactors”7, containing the introductory statement:
“ There is a move to develop smaller units. These may be built independently or as modules in a larger complex, with capacity added incrementally as required.” The paper briefly describes a bewildering 32 designs of all types: LWRs, HTGRs, Liquid Metal Cooled Fast Reactors and Molten Salt Reactors, variously under development in the US(6) Russia(7), France(3), Japan(6), China(3), South Korea(1), South Africa(1), Argentina(1) and Internationally.(4). The PBMR and IRIS Reactors are included. It would require an excessive degree of Appraisal Optimism to anticipate that any of these designs could negotiate the hurdles of operational experience,
economic performance and safety analysis in time to be considered for utilisation in New Zealand before 2020 say.

Concluding Remarks
Whatever transpires, I suggest that New Zealand could only ever be a very minor player in the nuclear energy game. We would be totally dependent on major overseas corporations in a limited choice of reactor technologies, the availability of nuclear fuel, the offshore disposal of nuclear waste and the advanced expertise required for a multiplicity of complex tasks including eventual plant decommissioning. But right upfront we would have to face the issue of cost and the extent to which subsidies and state guarantees of one form or another would be required.
Arising from the decision by the UK Government to support a major new nuclear energy programme the cost issue has come under close observation there. As noted earlier, to make their equipment more economically competitive nuclear designers are looking for economies of scale, and the ratings of the reactors competing for consideration in the UK fall within the range 1200-1800MW. One published assessment8 nonetheless is that: “Attempts to estimate the cost of a new nuclear programme [in the UK] are unlikely to be accurate because there is not enough reliable, independent and up-to-date information available on the nuclear plant designs available for such calculations to be made. In addition, waste and decommissioning costs are at present not fully known.”
While committing the UK to a dramatic and rapid expansion of nuclear power, the Government insists that this will be up to the market and will not depend on taxpayer support. This position is viewed with scepticism in some quarters. Dieter Helm, Professor of Energy Policy at New College, Oxford claims that
“The nuclear energy policy is fundamentally flawed because it relies on the “fiction” that a new generation of reactors can be built without state support.” The research director of the British Economic Research Council has been brutally explicit in discussing the problem of new nuclear build9: “The financing risks of planning delays, construction overruns and of a wilting long term commitment are simply too great for (any but a few of the largest international utilities) to take on their balance sheet. A failure of the government to seduce one of these large players will force the UK to forego a nuclear replacement programme or even fund it entirely from the public purse.”
The government has insisted that the utility companies that are successful in the forthcoming bidding round will bear their ‘full share’ of decommissioning and waste disposal costs. However a recently-published cost analysis of the storage and disposal of waste, based on rates already being charged to overseas utilities, concluded10 that
“unfortunately the fully commercial price would make disposal far too expensive, killing the prospects of any new nuclear build programme in Britain.” Such concern is heightened by the fact that the bill for the cleanup and decommissioning at 19 nuclear sites around the UK, including the last generation of Magnox reactors, is 73 billion pounds and still rising, and that it is uncertain how this will be paid11. The situation in the US is not greatly different. Under the Energy Policy Act of 2005, the nuclear industry qualified for an estimated $12 billion in tax breaks and other support. The Price Anderson Act caps the industry’s liability at a fraction of the true cost of a major accident. A new Energy Bill that has been passed by Congress includes a provision that could make available tens of billions of dollars more in loan guarantees, and the Energy Dept. will provide up to $2 billion risk insurance against losses resulting from project delays for the first six new nuclear plant projects.
Nuclear industry representatives have stated that without these kinds of taxpayer subsidies they wouldn’t be building any new nuclear plants.
What is understood through many years of development and operation is that the overhead costs associated with smaller sized reactor units that would suit the New Zealand environment (including regulatory oversight, safety and back-up supply systems, and radiation monitoring processes) would make such units uncompetitive with other options in New Zealand. This is why overseas developments have seen units typically grouped into larger “nuclear islands” comprising two or more reactors.
For the smaller reactors discussed earlier, the nuclear industry is banking on economies resulting from a programme of mass production, but in view of all the uncertainties this appears to be wishful thinking. It is assumed that the competitive position of nuclear power as a relatively “carbon free” mode of generation would be improved by application of the cost of carbon through the Emission Trading Scheme.
This would however almost certainly be outweighed by the other compliance costs specific to the nuclear industry, and from the cost of bringing the technology into the country.
There is no reactor in view that could usefully be deployed in New Zealand in the foreseeable future.

1 Professor Emeritus, The University of Auckland; past-President, Engineers for Social Responsibility; Dist. FIPENZ
2 “Power Plant Advance Fuelling Nuclear Fears”, Michael Richardson, NZ Herald, 19/7/07
3 “The Role of Nuclear Power in a Low Carbon Economy”, Paper No. 4, “Economics of Nuclear Power”, Sustainable Development Commission, March 2006
4 “The Race is on”, Engineering and Technology, Vol. 3 No. 2, February 2008, pp 54-57
5 http://www.ieer.org (search for PBMR)
6 “The Role of Nuclear Power in a Low Carbon Economy”, Paper No. 4, “Economics of Nuclear Power”, Sustainable Development Commission, March 2006
7 http://www.uic.com.au/nip60.htm
8 “The Role of Nuclear Power in a Low Carbon Economy”, A Position Paper of the Sustainable Development Commission, March 2006
9 “Nuclear Power – is the White Paper enough?”, Engineering Technology, Vol. 3, Issue 2, April/May 2008.
10 “Waste cost threat to UK nuclear plans”, Financial Times, March 26, 2008
11 “Clean-up cost fear in rush to nuclear”, Evening Standard, April 7, 2008