TCASE 11: Safety, cost and regulation in nuclear electricity generation

Guest post by DV82XLHe is a Canadian chemist and materials scientist. For his previous article on the 2010 Nuclear Security Summit, see here, and on why an informed public is key to acceptance of nuclear energy, see here.

Unless you intend to design a nuclear reactor from scratch, you are going to have to accept whatever level of safety is designed into the one you buy. No original equipment manufacturer (OEM) is going to derate their product to cut costs for you. And that will go for things you will have to build yourself, like the containment, and spent fuel facilities. No one is going to risk their brand letting you install their product on a substandard site. But this is not where costs get out of control anyway.

Nor is it in operating safety protocols, which at any rate are tied into general plant integrity routines that must be done anyway. Ultimately cutting back in this area runs the risk of some failure occurring that might stop the plant from producing power, (i.e. stop making money) or causing harm to an employee. In other words most of this falls under housekeeping anyway.

The only place where costs can be controlled which is often (erroneously) referred to as safety issues, is unreasonable procedural nonsense during the initial build. Even this is not the real expense in and of itself, but it is the delays that these can cause that push cost overruns into the stratosphere. It is seeing that these do not get out of hand that is the real way to keep costs down. In any sane world too, most of these procedural issues would be properly referred to as Quality Assurance, or Quality Control (QC), as they would have little to do with real safety issues, but in the politically charged world of nuclear power plant (NPP) builds, the antinuclear forces spin these to security and safety issues their own ends.

Okay, so how to avoid this sort of pitfall? First and foremost there must be only one government agency/department/ministry/whatever, in charge of oversight, and it needs to be at the national level, and it needs to exercise eminent domain. Once the project has broken ground, it cannot be delayed by politics, or by lower levels of government. Some local water commissioner up for re-election cannot be permitted to bring the project to a halt while he grandstands demanding a second opinion on groundwater contamination, two years after the first one was done and approved. Similarly, abuses of the legal system by non-government organisations (NGO’s) have to be made impossible as well. Many of these like Greenpeace, are well aware of the financial dynamics of these builds, and are past masters at using the courts to get injunctions for the sole purpose of running up the costs, in the hope of getting a project cancelled. In fact they have been successful more than once with this tactic.

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Thinking Critically about Sustainable Energy (TCASE) – the seminar series

In the Thinking Critically About Sustainable Energy (TCASE) series — currently up to 10 parts on the BNC blog — I consider the challenges we face in scaling up renewable or nuclear energy technologies to replace fossil fuels. The blog serialisation of TCASE will continue on BNC, but the format is now also moving into a new communication medium — interactive seminars. In collaboration with the Royal Institution of Australia (RiAus), I have been planning — and will act as host and moderator — for the ‘TCASE Live’ series, launching next week on Wed 7th July 2010. The event is sponsored by the Environment Institute’s Centre for Energy Technology (of which I’m a member), and the Institute for Mineral and Energy Resources.

To book your (free) seat at the first event, click here. Do it soon, to avoid disappointment (the venue can only hold about 130 people). Each session will be held at the Science Exchange in Adelaide (Google Map link), and will also be broadcast soon after each event on the internet (tune into my Twitter feed to keep updated with the podcasts, vodcasts and slides).

Here is the context statement and sequence of events for the 6-part series, run monthly through to the end of 2010:

Thinking Critically for Sustainable Energy: the seminar series

The ability to harness natural resources and transform them into sources of useable energy has been essential in the development of modern society. As a result the supply and consumption of energy has now become central to the economies of developed nations and is vital in sustaining agriculture, construction, transportation and communications.

Since industrialisation, fossil fuels have represented a readily available and inexpensive source of energy. But as more countries become industrialised and the competition for these finite resources begins to increase exponentially, we are now facing the real threat that supply of these fuels may not be able to keep up with demand. Additionally the mining and burning of these fuels has been shown to have many adverse environmental effects. In particular the threat of anthropogenic climatic change due to the combustion of these fuels is now a major global concern.

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TCASE 10: Not all capacity factors are made equal

As I noted in a recent post, my new goal with TCASE posts is for them to be shorter, more targeted and more regular, with the aim being to break big problems in sustainable energy down into very focused questions (each of the new TCASE posts will be a maximum of 1,000 words — my new self-imposed editorial limit for this series!). Editorially, I like to note that if any regular BNC readers are up for submitting a short TCASE post following this format, please email me and I’ll be happy to discuss your idea. Here’s the first of the new batch.

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Capacity factor (CF) is the amount of energy a power station generates over time (usually a year) compared to what it could have produced if it had been running at full power for the whole period. (Please read TCASE 2, Energy Primer, for a fuller explanation). The CF for coal-fired and nuclear power stations averages 85-90%, wind farms ~20-35%, solar farms ~15-40% (the higher figure is for CSP with thermal storage). Gas or hydro can be high or low — depending…

Now, it’s very tempting to use these percentages as though they were directly interchangable, and indeed I’ve found that most journalists and bloggers happily do this (or else ignore CF completely and cite ‘peak’ power as though it were the same thing). It turns out, however, that this is a seriously misleading practice, as I’ll detail over the next few TCASE posts.

Consider this.

The Blowagale wind farm on Roaring Forty Peninsula has 50 of the 2.5 MWe (peak) GE 2.5xl turbines (rotor diameter = 100 m, hub height = 75 – 100 m, cut-in windspeed of 3.5 m/s, peak at 12.5 m/s, cut-out at 25 m/s). Its peak power is therefore 50 x 2.5 = 125 MWe. Over a 3-year period, it has delivered 1,115 GWh of energy to the grid. The peak expectation would have been 125 x 8760 x 3 = 3,285 GWh, so the CF is 1115/3285 = 34%.

The Trex coal-fired power station in Smogsville is a 500 MWe unit that’s been chugging away for the last 30 years. Over the last 3 years, it has produced 11,300 GWh (out of a possible 13,140), for a CF of 86%.

Okay, on an energy-for-energy basis, all we have to do is build 11300/1115 = 10 of the Blowagale-sized wind farms to replace Trex, right? Actually, that’s dead wrong — at least in the real world — for many reasons, which I’ll explore in the next few TCASE posts. Yet, that’s the impression that’s often given by ‘advocates’ (to use a euphemism).

First, let’s briefly consider what has determined these two CFs.

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TCASE 9: Ocean power II – CETO

In TCASE (thinking critically about sustainable energy) #5, I analysed a currently deployed technology for harnessing wave energy – the Pelamis device. If you haven’t read TCASE 5 then please do so now, since it explains some of the basic physical properties of wave energy, the extend of the global resource, etc. In writing the following post, I’ll consider this to be assumed knowledge.

CETO, named after a Greek sea goddess, has been developed by Carnegie Wave Energy (an Australian company), and is described in detail on their website. It is based on a submerged, underwater buoy-like device, anchored to the sea floor, which pumps water to shore at high pressure (6,400 kPa). Read more about the technology here.

The list of advantages of CETO on the website are worth citing here, as they provide a useful target for analysis. Main ones are:

  • 60% of the world live within 60km (40 miles) of a coast, removing transmission issues.
  • Waves are predictable days in advance making it easy to match supply and demand. (Wind is predictable hours in advance at best.)
  • CETO units are designed to operate in harmony with the waves rather than attempting to resist them. This means there is no need for massive steel and concrete structures to be built.
  • CETO wave farms will have no impact on popular surfing sites as breaking waves equate to areas of energy loss. CETO wave farms will operate in water deeper than 15 metres in areas where there are no breaking waves.
  • CETO is the only wave energy technology that produces fresh water directly from seawater by magnifying the pressure variations in ocean waves.
  • CETO contains no oils, lubricants, or offshore electrical components. CETO is built from components with a known subsea life of over 30 years.
  • Wave energy can be harnessed for permanent base load power and for fresh water desalination. The ratio of electrical generation to fresh water production can be quickly varied from 100% to 0% allowing for rapid variations in power demand.
  • CETO uses a great multiplicity of identical units each of which can be mass produced and containerised for shipping to anywhere in the world.

For these reasons, wave power is certainly among the most attractive of the range of possible renewable energy technologies. Unfortunately, it is also one of the most nascent in its development cycle (along with engineered geothermal systems, which is probably even further behind — I’ll cover this in a later TCASE post). Wave power is also up against one of the most hostile environments that any man-made structure has to endure — the salty (corrosive) and capricious (exposed to occasional very high energy events) marine environment.

CETO is certainly an innovative technology: it appears to overcome some of the shortcomings of the Pelamis device, such as a reduced bulkiness with more modular construction and deployment possible, lower vulnerability to storm damage due to anchoring at 25 m, and an added bonus of providing a neat method for reverse osmosis desalination using mechanical rather than electrical energy. The latter seems to be its biggest selling point, as I explain below.

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TCASE 8: Estimating EROEI from LCA

The concept of energy return on investment (EROI), often called energy returned on energy invested (EROEI), is a simple and familiar one. Here is the short definition, from the Encyclopedia of Earth. To cite:

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Energy return on investment (EROI) is the ratio of the energy delivered by a process to the energy used directly and indirectly in that process.

For example given a process with an EROI of 5, expending 1 unit of energy yields a net energy gain of 4 units. The break-even point happens with an EROI of 1 or a net energy gain of 0.

A common related concept is the energy payback period. Every energy system has initial investments of energy in the construction of facilities. The facility then produced an energy out for a number of years until it reaches the end of its effective lifetime. Along the way, additional energy costs are incurred in the operation and maintenance of the facility, including any self use of energy. The energy payback period is the time it takes a facility “pay back” or produce an amount of energy equivalent to that invested in its start-up.

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Wiki also has a decent article about it, and it’s a source of much discussion on websites like The Oil Drum. In short, a simple concept, but fraught with debate. It is not my intention here to wade into the arguments on EROEI of individual energy sources — that would require many TCASE posts, and even after that, I’d be unlikely to get consensus. But feel free to hammer away on the ins and outs of EROEI in the comments.

What I want to do here is propose a simple method for estimating EREOI based on a life-cycle assessment of greenhouse gas emissions. This requires some assumptions, but is useful, I think, because LCA studies are readily available and widely cited, whereas explicit EREOIs via net energy analysis are harder to find and compare in a consistent way.

There have been many well-researched peer-reviewed studies looking at the life-cycle emissions of different energy technologies, expressed in terms of kilograms of CO2-e/MWh (commonly). For non-fossil fuel energy technologies, this is a useful benchmark for calculating EROEI, because their inputs mostly come from fossil fuels, yet they produce no CO2 when generating. So, let’s consider ‘clean energy’ EROEIs on this basis.

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