OECD - Nuclear Energy in Perspective

The OECD has released an informative nuclear energy summary, Nuclear Energy and Addressing Climate Change. The document is only 8 pages (with figures and tables), but it efficiently addresses the following questions:

• Does nuclear power produce CO2 emissions?


• To what extent is nuclear energy used now?


• Can nuclear power capacity be expanded quickly?


• Are supplies of nuclear fuel adequate?


• What about safety, waste and proliferation concerns?

USA: celebration and pause for reflection

Oyster Creek - Lacey Township, New Jersay- USA

Of the 104 operating nuclear power plants in America, only three were connected to the Grid in 1969: R. E. Ginna, Nine Mile Point - 1, and Oyster Creek. All plants connected before that year [most of them much smaller demonstration facilities] have since permanently shutdown. Of those three, only two received their full commercial operating license within that year: the two GE BWR's [boiling water reactors] - twin plants in fact - Nine Mile and Oyster Creek. Both licenses are listed in the PRIS website as having been issued on December 1, 1969. However, Oyster Creek was connected to the grid in September and Nine Mile in November. This makes Oyster Creek the oldest operating nuclear plant in the USA. Worldwide, only two operating gas cooled reactors in the UK are older.

1969 is a significant year in the USA for many reasons [something about an Eagle landing, etc.*]. With respect to nuclear power, '69 has relevance because operating licenses issued to US nuclear power plants extend for 40 years. Many facilities have applied and received license extensions for an additional 20 years. Nine Mile and Ginna already received their extensions, but Oyster Creek's application was aggressively fought by local environmental groups and some notable celebrities [literally, a cause célèbre]. But the technical review of all issues has concluded the plant remains safe and last week the Oyster Creek application was approved by the NRC, paving the way for another 20 years of operation. Congratulations are in order to the staff who operate and maintain the facility as well as the original engineering design and construction teams.

According to the NRC webpage [and assuming my math is correct], the number of approved license extensions is 51. Updating that page for Oyster Creek, will bump the total to 52 units - exactly half of the current US operating fleet.

But that's not all. Oyster Creek is now part of Exelon. However, way back when, Oyster Creek was the responsibility of Jersey Central Power and Light [JCP&L] - a part of General Public Utilities [GPU]. Another company within GPU was Metropolitan Edison or Met.Ed. Met. Ed. also worked to deploy nuclear power plants, but instead of electing for the GE BWR, went to B&W for a PWR [pressurised water reactor]. They located their two units on a decent size island in the middle of the Susquahanna River in south-central Pennsylvania; a three mile long island to be precise.

The Three Mile Island Unit II accident occurred 30 years ago last week [March 28, 1979]. No deaths or injuries directly resulted from the accident, but the resulting hysteria - fanned by an uninformed and sometimes blood thirsty media - did harm some people. The financial impact to Met. Ed. and GPU was much more significant. GPU's stock plunged to pennies per share. A spin off company, GPU Nuclear, was created to manage the nuclear assets including the Unit II cleanup, Unit I restart and of course ongoing operation of Oyster Creek [itself challenged as resources were diverted to TMI]. An in progress project to construct a sister plant to Oyster Creek on the same site in the state of New Jersey was cancelled in the wake of GPU's financial meltdown. The accident had effects on other nuclear projects and existing plants throughout America and beyond.

Diagram to explain the TMI-II accident (www.nrc.gov)

Those who claim nuclear plant employees, their managers, or owners purposefully and irresponsibly accept safety related risks for the sake of profit are ignoring the significant lessons learned from the TMI-II accident.

While a financial disaster, technically the plant's safety systems performed to perfection. Had it not been for erroneous plant operator intervention, even the financial consequences would have been nil. The facility would have very probably been easily restarted. During the event, control room operators purposefully isolated emergency cooling water - that the protection systems had automatically started - due to the operator's misinterpretation of a single indicator on the control room panel. But even DESPITE this action - the luxury of hindsight reveals that this was in fact about the WORST possible action to take given the true scenario - [I'll say it again] DESPITE this action, the multiple redundant, multi-barrier protection systems performed their function to protect the surrounding environment and population by controlling and containing the resulting mess. Credit must also go to the engineers and operators within the organisation. Once the above indicator was cross-checked against other indications [at the rear of the operating panel], the subsequent actions were well managed; courageously managed is probably more accurate. We should all ask ourselves if we would have the guts to do it. But I doubt their confidence was derived from some 'battler's bravado'. They knew the plant's technical capabilities and in particular those of the safety systems. They were informed by frequent contamination surveys and omnipresent radiation monitoring.

As Patric Moore has said, from the prospective of nuclear safety, the Three Mile Island Unit-II accident was and remains a phenomenal success, a testament to Western nuclear engineering design, construction and enduring quality.

I doubt there are many, but to all those who have worked for GPU, GPU Nuclear, then AmerGen and now Exelon over this entire time period - congratulations, well done and enjoy your well deserved retirement.

* Just as there were two fully commercial nuclear power plants licensed in 1969, there were also two moonshots. Both Apollo 11 and 12 took place in 1969.

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.

World Energy Outlook - 2007

I've started to digest this 670-plus page behemoth. Per the publication copyright terms and conditions, I am permitted to copy / share up to 15% (about 100 pages) without prior written approval of the IEA. Be sure, I'm not going to do that, but here are some relevant data that I found of potential interest.

(all emphasis is mine)

From the executive summary

Urgent action is needed if greenhouse-gas concentrations are to be stabilised at a level that would prevent dangerous interference with the climate system. The Alternative Policy Scenario shows that measures currently being considered by governments around the world could lead to a stabilisation of global emissions in the mid-2020s and cut their level in 2030 by 19% relative to the Reference Scenario. OECD emissions peak and begin to decline after 2015. Yet global emissions would still be 27% higher than in 2005. Assuming continued emissions reductions after 2030, the Alternative Policy Scenario projections are consistent with stabilisation of long-term CO2-equivalent concentration in the atmosphere at about 550 parts per million. According to the best estimates of the Intergovernmental Panel on Climate Change, this concentration would correspond to an increase in average temperature of around 3°C above pre-industrial levels. In order to limit the average increase in global temperatures to a maximum of 2.4°C, the smallest increase in any of the IPCC scenarios, the concentration of greenhouse gases in the atmosphere would need to be stabilised at around 450 ppm. To achieve this, CO2 emissions would need to peak by 2015 at the latest and to fall between 50% and 85% below 2000 levels by 2050. We estimate that this would require energy-related CO2 emissions to be cut to around 23 Gt in 2030 – 19 Gt less than in the Reference Scenario and 11 Gt less than in the Alternative Policy Scenario. In a “450 Stabilisation Case”, which describes a notional pathway to achieving this outcome, global emissions peak in 2012 at around 30 Gt. Emissions savings come from improved efficiency in fossil-fuel use in industry, buildings and transport, switching to nuclear power and renewables, and the widespread deployment of CO2 capture and storage (CCS) in power generation and industry. Exceptionally quick and vigorous policy action by all countries, and unprecedented technological advances, entailing substantial costs, would be needed to make this case a reality.

Clearly, exceptionally vigorous policy action – entailing substantial costs – would be needed to make the 450 Stabilisation Case a reality. Such action would need to start immediately: each year of delay would reduce substantially the likelihood of achieving the target.

The below trend reflects the required energy supply changes required to satisfy the 450 stabilisation case. These changes are to be made IN ADDITION to aggressive changes (which already include significant increases in nuclear power) required to satisfy the 'Alternative Policy Scenario'.

And for those of you worried about the future of coal - fear not. You'll notice that the overall demand for coal doesn't change too much (add the brown and the red) - even within the most aggressive scenario as shown below. Anyone claiming any differently, is just promoting a culture of fear to get votes.

And there is much, MUCH more. Their message is clear - urgent, global action is required 'immediately', and that action will include - among many other changes - the significant deployment of additional nuclear power generation technologies around the world.

Green nuclear power coming to Norway

As reported by Cosmos Magazine:

Image courtesy of Cosmos Magazine & Justin Randall

Norway remains quite active in the areas (among others) of nuclear non-proliferation, energy security, and global environmental stewardship. Norwegians - specifically - are looking to Thorium based nuclear power technology to solve the overlapping problems of all three after Norway's state-owned energy company, Statkraft, this week announced plans to investigate building a thorium-fuelled nuclear reactor.

Some relevant highlights of the technology:

• The reaction is 'driven' by a nuclear accelerator (called an Accelerator Driven Sub-critical (ADS) system, and therefore can not maintain a self-sustained nuclear reaction [improved safety].
• ADS technology can be used to 'burn' waste products from existing nuclear reactors. Relevant studies were completed for example as part of the US Advanced Fuel Cycle Initiative [waste management and proliferation avoidance].
• The technology produces significantly less high level waste.(see 'New age nuclear', Cosmos, issue 8) [waste minimisation and management].
• Byproducts of the Thorium reaction do not include materials that pose increased weapons proliferation risks (Plutonium and Uranium) [non-proliferation].
• Thorium is significantly more abundant than Uranium and does not require high-tech enrichment technologies [sustainability, energy security and non-proliferation]. [Enrichment being the central issue responsible for the dramas in Iran at the moment, for example.]

The article also discusses an amazing flop in Norwegian public opinion in less than a year, with 80% now favouring Thorium nuclear technology development. [All emphasis is mine]

"It would be a sin of omission not to consider it," said Bård Mikkelsen, CEO of Statkraft, in an interview with the Norwegian newspaper Dagbladet.

"Norway has taken the lead on this. We are an energy nation; we have large supplies of thorium – not as much as Australia of course – but we have a very advanced energy industry, and we have a responsibility to the world," said Lillestøl [a nuclear physicist at the University of Bergen, Norway]. "Without nuclear energy we will destroy the world, we will spend all the coal, oil and gas, and we will be left with an energy desert."

As with other things nuclear, there are industrial opportunities and interest within Australia. But one quoted Sydney nuclear scientist expressed his doubts about Australian political will and research resource commitment, claiming Australia is 'lagging behind' while European Union, India, the US, Japan and Russia all work to develop thorium energy technologies.

For further information, including identified reserves per country, see Also:

Thorium Power Limited

World Nuclear Association - Thorium

UIC - Thorium

US Geological Survey (USGS) - Thorium

Data on nuclear risk

The UK Centre for Ecology and Hydrology has studied nuclear risks and impact on human health within the context of other relevant risk factors.

General conclusions

The full report.

Spent Nuclear Fuel Cask Crash Testing

Spent nuclear fuel cask tests were performed by Sandia National Laboratories in 1977. Although older casks were used, they meet the same regulatory standards as modern casks.

(In) the first test, a truck carrying a 22-ton spent fuel cask impacted a 690-ton concrete block at 60 miles per hour. It was cleaned up and impacted a second time, but at 84 miles per hour.

The cask also survived this more violent crash with only minor damage.

In the third test, a diesel locomotive crashed into a truck at 81 miles per hour. The stalled truck carried a 25-ton shipping cask. Cask deformation was minimal and the ability of the cask to contain and shield its radioactive contents was not compromised.

The final impact test had a 74-ton shipping cask, carried by a cask rail car, crash into the concrete block at 81 miles per hour. The same cask and rail car were then positioned over a pool of jet fuel and subjected to an engulfing fire, much more severe than the fire that might occur in a train wreck. After 90 minutes – three times the duration of current qualification test criteria – surface temperatures exceeded 1,400 degrees Fahrenheit. But inside the cask, where the spent fuel rods would be contained, temperatures were below 300 degrees – not enough to melt the spent fuel rods.