Wednesday, 24 September 2008

OPAL's minor flaw

OPAL Reactor

A recent article quoted Greens Senator Scott Ludlum as calling for the 20 MW OPAL research reactor to be shutdown until the reflector leakage can be repaired.

Ludlum has called ANSTO's comments on the technical nature of the leak, "spin" and links today's technical concerns to potential safety concerns in the future.

The facts are that the OPAL core sits in the centre of the reflector vessel - but not within it. The fuel is not cooled by the reflector's heavy water, but instead by the significantly more massive quantity of regular [light] water sitting in the reactor pool. In the photo above the reflector is the circular tank in the centre [in a way resembling a large wheel of Swiss cheese]. The box in the centre of the reflector is the array of 16 fuel assemblies. The axial penetrations in the reflector [large and small holes that pass through the entire height in the vertical direction] support the generation of products such as neutron doped silicon or medical and industrial isotopes as well as the completion of irradiation experiments. Neutron beams [or rather their massive shutters] can be seen exiting the pool at the periphery of the reflector.

Power reactors are economic/business machines that receive compensation directly proportional to the electrons their turbines pump out onto the grid. Unlike a power reactor, a research reactor's lifeblood is neutron production. Heat in most cases is typically an unused byproduct [occasionally it is used for district heating]. The purpose of the reflector is to improve neutron economy.

As neutrons burst onto the scene from a 'split' U-235 atom [average is about 2.5 neutrons per thermal fission], they typically have too much energy to be useful. They must be 'slowed' or moderated. Think of a billiard ball flying down the table. Unless you're very brave, you would not try to catch it unless it was travelling relatively slow. It's similar with neutrons. They must be slowed so target material [U-235 atoms, silicon, neutron beam lines, etc.] can better use them. Also, if the neutrons are slowed within a minimum distance from the core there are increased odds that this neutron will travel back into the core to be used for the fission of fuel [i.e. they are reflected].

Heavy material [such as lead, steel or concrete] is used to shield radiation . But other materials such as graphite and water are much better neutron moderators. Heavy water is a better moderator than light water. With one more neutron in its neucleus the heavy water deuterium atom absorbes slightly more energy than a normal hydrogen atom per collission. [From above analogy, imagine slowing down our billiard ball with impacts from ping-pong balls or slightly heavier golf balls]. So to maximise the neutron economy in OPAL [provide the most usable neutrons per fission], heavy water is used to moderate the neutrons in the reflector. However, heavy water is very expensive.

The reflector is kept at a lower pressure than the reactor pool. Any leakage path will allow light water into the reflector. When this happens to a significant extent, some fraction of available neutrons will not be slowed enough to be used in the target material. Neutron efficiency will have decreased. As a research or isotope production machine - OPAL will become slightly less effective.

Therefore leakage into the reflector vessel has no safety consequence. There appears to be no grounds for Ludlum's "spin" accusation.

I believe OPAL staff are planning to construct a heavy water purification system to process a slip stream of the reflector circulation loop. This slip stream will then be purified to remove light water [this is possible, for example, because heavy water has a boiling point slightly above light water: 101.4 C].

The ANSTO response to Ludlum's claim may be found here.

Sunday, 21 September 2008

Business group calls for nuclear

The Australian Chamber of Commerce and Industry, in a recent submission to the government's green paper on climate change.

The report in the Australian notes Australia's high per-capita emissions, our elevated reliance on coal and the role nuclear power can play to address both in the context anticipated emission reduction goals.

Many of the 350,000 businesses represented by the ACCI are small to medium sized enterprises. They will not be able to relocate off-shore, are not able to invest in low carbon technologies, can not pass on higher prices to consumers, but face the simple threat of going bust.

In the report, the opposition's position is that they would like nuclear power to be considered, but add any consideration must be bipartisan.

Wednesday, 17 September 2008

Call for a national energy policy

An Op-Ed in the Business Spectator makes a pitch for an Australian energy policy.

During the drive to develop, promote and implement an emissions trading scheme, government has said very little about the specific technologies to be deployed to achieve relevant goals while maintaining a viable economy. These details, as well as strategies to ensure long term energy security, would normally be found in a national energy policy; the last of which for Australia was issued in 2004.

Some of us harbour a suspicion that the Rudd government thinks its emissions trading plans – plus the enlarged renewable energy target – make up a national energy policy. If this is true, it is a serious error of judgement and one capable of causing immense trouble if the government tries to make policy on the run to deal with the inevitable ‘unintended consequences'.

It is madness to rely on the "lucky country" approach to energy policy today. Australian governments have to ensure they have an overall plan for managing energy issues in an exceptionally difficult global environment.
In addition to defining a strategic course for Australia's interim and long term energy future, a national energy policy also has tactical implications. A defined policy will free up billions of dollars in capital investment currently stranded on the sidelines due to undefinable and unpredictable economic risk. Ongoing lack of investment contributes to the more tangible follow-on risk of poor energy quality and reliability due to the failure of energy infrastructure/capacity growth to match increasing demand as well as the inadequate mitigation of supply risk through diversity of supply, diversity of supplier and diversity of supply route.

Sunday, 14 September 2008

Uranium mining now likely in WA

Brendon Grylls, leader of the WA Nationals, has announced the formation of a coalition government with the Liberals, paving the way for West Australia to join the Northern Territory and South Australia in Uranium mining and export operations.

The result follows an aggressive anti-Uranium mining election campaign by outgoing WA PM Allen Carpenter.

Uranium mining in West Australia could – in the coming years – exploit up to eight major deposits according to Reuters.

Queensland is now Australia’s sole anti-Uranium mining state with significant, identified Uranium reserves according to the Australian Uranium Association.

Friday, 5 September 2008

Garnaut - Targets and Trajectories

The report may be found here.

There are two references to nuclear power, copied below.

What the rest of the world notices most about Australian emissions is that ours are the highest per capita in the OECD; that over the past several decades they have been growing faster than those in other OECD countries; and that while in 1971 the emissions intensity of Australian primary energy supply was similar to the OECD as a whole, in recent years it has been more than one-third higher (Draft Report, Chapter 8, Figure 8.6). There are good reasons why Australia became relatively more dependent on a high-emissions source of energy, coal, while the remainder of the OECD was reducing the proportionate role of coal and increasing the contributions of low-emissions energy, including nuclear. But whatever the reasons, they are not easily reconciled with the idea that Australia is leading the world in emissions reduction.

It is often said in Australia that developing countries are strongly resistant to reductions in emissions, and that it is unrealistic to expect them to participate in global constraints on emissions. This is too simple. China’s selective withdrawal of export rebates within its value added tax, the export taxes on a range of energy-intensive products, its discouragement of expansion of energy-intensive industries and its specific regulatory constraints on investment in steel, aluminium and cement production add up to more substantial constraints on the most emissions-intensive industries than would occur in Australia in the early years of an emissions trading system. China’s active encouragement of low-emission sources of power (hydroelectric, wind, nuclear, biomass, biofuels) goes beyond current Australian efforts. These measures stand alongside a domestic policy commitment to reduce the energy intensity of economic activity by four percentage points per annum until 2020. Data released in August 2008 show the energy intensity of Chinese GDP falling by 3.7 per cent in 2007—the first sign of good intentions on energy intensity being reflected in policy outcomes.

In the two country examples above Australia's rejection of nuclear power compared to the OECD is linked to our current emissions reduction challenges. China, on the other hand, through its deployment of nuclear power - in concert with the parallel deployment of other technologies and strategies - has already achieved tangible evidence of their 'good intentions'.

There is a special section devoted to the future use of coal [heavily dependent on near zero leakage CCS technology]. The report remains technology-neutral beyond these statements, referring only to 'low-emissions technologies'.

Section 6 of the report addresses the fact that despite Australia's contribution of only 1.5% of total global emissions - 'Australia matters'. Garnaut concludes:

Australia matters. What we do matters. When we do it matters. It would be really silly to take action with costs to ourselves meant to assist the emergence of a good international agreement, but to do it too late to have a chance of avoiding high risks of dangerous climate change. What we do now, in time to influence the global mitigation regime from the end of the Kyoto period, is of high importance. What we do later runs the risk of being inconsequential in avoiding dangerous climate change.

There are already reports in the media calling the proposed trajectories inadequate. Calls for greater reductions within the context of a sustainable Australian economy will continue to increase the attractiveness of nuclear power.

Tuesday, 2 September 2008

Insuring a nuclear renaissance

By nature insurers take a dispassionate, objective perspective when assessing the convergence of risk and consequence. Insurance related developments can therefore serve as a broad industry touchstone – in this case the future of worldwide commercial nuclear power deployment.

Lloyd’s has included a feature in their current issue of Market Magazine. In this article they begin by acknowledging that “The global nuclear industry’s star is rising”. An example of interest being:

“China, which connected its first commercial reactor to its national grid in 1991, now has 11 working reactors and six under construction. It plans a six-fold increase in nuclear capacity by 2020 and then a further three- to four-fold increase by 2030.”
Michael Dawson, Active Underwriter of Chaucer’s Nuclear Syndicate projects most nuclear new-build will simply replace current facilities nearing the end of their design life and that nuclear’s share of energy in developed countries will remain at about 20% until around 2025. Dawson predicts total ‘nuclear business’ to subsequently increase after 2025.

Interestingly for Australia, fuel security is highlighted as a risk whose management is critical to the global expansion of nuclear power. This is consistent with international efforts and attention being given to fuel supply such as the GNEP and a special topic of the IAEA’s 50th General Conference approximately two years ago.

The article discusses specific areas of risk such as construction, flooding and a hypothetical release of radioactive material as well as more recent additions such as those related to environmental impacts and decommissioning.

Mark Tetley, Managing Director of the British nuclear pool, Nuclear Risks Insurers concludes, “I’m very positive about the UK’s nuclear new build framework, as I believe it will be the most sophisticated globally. The insurance market is already playing a central role in helping the Government develop this model.”

The magazine includes numerous inserts and factoids. A few of interest are included below.

Lloyd’s has been involved in nuclear insurance since the British nuclear pool, Nuclear Risks Insurers (NRI), was founded in 1956.

NRI’s capacity comes from eight insurance companies and 16 Lloyd’s syndicates. NRI represents the largest single block of risk transfer insurance capacity in the world, at more than £400m. It also reinsures other nuclear pools worldwide. It covers risks including property, nuclear fuel and waste plants, construction work on nuclear sites and transport liabilities.

In the UK, the industry is governed by various national laws and international conventions. These set limits of damage beyond which the state is effectively the insurer of last resort.

For details of international nuclear liability conventions from the World Nuclear Association.

Monday, 1 September 2008

Russia on receiving end of energy diplomacy

Throughout recent years, Russia has been accused of using its energy resources as an instrument of diplomacy, isolating the taps on oil pipelines going into Europe last winter and as recently as last month. The linked article also explains a certain perceived, energy dependence related EU handicap with respect to the EU's ability to conduct firm negotiations with Russian with respect to the conflict in Georgia.

But Australia has some leverage on the issue thanks to Russia's increasing interest in uranium - specifically the deal struck about 1 year ago regarding Australia's supply of uranium to Russia. Foreign Minister Stephen Smith said, "When considering ratification, the government will take into account not just the merits of the agreement but recent and ongoing events in Georgia and the state of Australia's bilateral relationship with the Russian Federation."

Smith made Australia's views clear to Russia when he summoned the Russian envoy last week to call on Moscow to pull its troops in Georgia back to the positions they held before the conflict began on August 8. He added that Russia's recognition of independence for the former Georgian regions of South Ossetia and Abkhazia was unhelpful.