A nuclear powered world

“Nations sign on to the Global Nuclear Energy Partnership” ran the Sunday press release from politicos in Vienna. But, sign on to what, exactly? Oh yes, broad uptake of nuclear power without weapons proliferation etc, etc, but again, what exactly - at the nuts and bolts level?

To tease out an answer it was best to be, not hobnobbing with suave diplomats in Vienna's splendour on a balmy Sunday afternoon, but in deep discussion with front-line nuclear “grunts” at the Centre on the Grove, in Boise, Idaho for an intensive week.

For Idaho, home to a major US national nuclear laboratory and birthplace of commercial nuclear electricity, played host to more than 500 researchers from around the world attending “Global 2007”, this year's convention of the nuclear industry's premier conference series on advanced nuclear systems.

“Global”, which usually deals with far-off innovation, much of it only ready for implementation well after the presenters are dead, is traditionally hosted by rotation, and this year was not the US' turn. But US nuclear policymakers made a persuasive case that they needed a high profile venue to deliver their GNEP program to nuclear “insiders”. And so attendees were treated to a technical nuclear smorgasbord - from imminent, next-step reactors to on-the-horizon technologies - served up in a socio-economic/political milieu of third world development, energy/greenhouse concerns and constraints, and nuclear non-proliferation.

The mid-term advanced nuclear reactors at the heart of “Global” are these days tagged by the label "Generation IV". Intended to put the nuclear industry on a truly sustainable footing through the end of the 21st century and beyond, these reactors are unlike present-day commercial nuclear power reactors, which primarily "burn" the uranium 235 isotope. Rather, the Generation IV class - within which there is a number of design types - by completely “burning” all uranium, and also thorium, fuelstocks, together with long-lived in-reactor created byproducts - will enable the full utilisation of uranium and thorium resources, while at the same time massively reducing both the volume and the radioactivity of waste left over from the fission process.

It was clear from the conference presentations that, in many aspects, overseas researchers, whose robust funding has continued through the US nuclear power "doldrums" of recent decades, are well ahead of their US colleagues. This has significant impact on US ability to assert political leadership on the nuclear front.

The most evident example of international excellence is perhaps India's work on the thorium fuel cycle. India's presenter at Global said his country's energy needs, which track an ongoing GDP growth of 8-9 per cent per annum, were extremely large, and so energy security was of primary national concern. But India's population density precluded some alternative measures, such as using arable land to grow biofuel crops - food production would always take precedence. Hence India had a three-stage plan for indigenous development of nuclear power, culminating, in about 2040, in a principally thorium-fueled reactor suite, with uranium/plutonium fueled fast reactors used as fuel breeders.

India is poor in uranium resources but rich in thorium deposits, so the country's self-interest in pursuing thorium research is obvious. However, since thorium is roughly three times as abundant as uranium in the earth's crust, the promise of a viable thorium-fueled nuclear power system is of universal appeal.

Generation IV is an ambitious plan, matched only by the more immediate problem of how to achieve the transition. For though a simple leap to Generation IV would be preferable, the technology - fast neutron spectrum reactors which will breed U233 from thorium and Pu239 from uranium, then burn the products - will not be commercially ready until 2030 at the earliest, and probably not before 2040. Given an intervening period of projected rapidly escalating world energy demand in the face of exacerbating greenhouse conditions sans nuclear, the world simply can't wait for Generation IV.

Within the nuclear industry, present-day power reactors are referred to as "Generation II". To bridge the gap between this extant Generation II and sustainable Generation IV, much effort is being directed towards a nearer-term (circa 2010-12) roll-out of "Generation III/III+" systems. These will be "conventional" reactors, in the sense of principally burning uranium 235, plus plutonium obtained from spent fuel reprocessing. But for capital cost economy and enhanced operational reliability they will be standardised plants, and some of the designs will be tuned, not just towards electricity generation, but also towards water desalination, district heating, or the large-scale production of hydrogen for use as a transport fuel.

US Government policy with respect to both Generation III/III+ and Generation IV is twofold: advancement of US domestic energy security, and the promotion of nuclear power as an international energy solution without increasing the risk of nuclear weapons proliferation. It is the latter part of this policy which has given rise to the Global Nuclear Energy Partnership (GNEP): an initiative to provide developing countries with nuclear energy on a turnkey basis: that is, via total provision of reactors and fuel, with full takeback, by GNEP supplier members, of spent reactor fuel for reprocessing and storage.

The rationale is that the spread of material, technology and know-how considered to represent nuclear weapons proliferation risks can best be controlled by dividing the nuclear world into two tiers: those countries which already possess such means, the so-called nuclear suppliers, and those countries, the nuclear recipients, which would voluntarily eschew developing “trigger” steps in the nuclear fuel cycle.