Final Thoughts

After 14 weeks of writing a blog I do not claim to be an expert on nuclear power and there are likely many issues I have missed out given the wide-ranging debate associated with our energy future. I came to this blog as an impartial and fairly uneducated observer of the nuclear power debate, what I offer here is my impression of nuclear power after researching and writing this blog.

So to begin with the most obvious question to ask would be do I support nuclear power? Well yes, as I outlined in 'Can we live nuclear free?', I do not feel we can afford to completely cut all ties with atomic energy in the face of climate change. Specifically I feel nuclear power plants could offer added stability in the fight against climate change. It is currently cheaper than most renewable technologies and would allow countries where land is sparse to generate a greater proportion of carbon-free energy. That said, moving later into the century I hope that with greater investment in renewables and a spread in sustainable living, reliance on nuclear power could be reduced; it Is after all a finite resource.

In accepting nuclear power it means that I do not consider the risk and environmental damage associated with the industry large outweighs the risk of taking inadequate action on climate change, which I feel is possible if we solely rely on renewables to reduce emissions globally. So how big a gamble do I perceive nuclear power to be?  Well unfortunately there isn’t a unit of measurement to quantify risk, but the impression I got is that most of the risk comes from extreme events. I do not feel mishaps during day to day running are very likely, reactor designs have moved on since the 1980s and meltdown protocols have been sharpened. Where the real threat lies is during times where normal protocol can’t be followed during earthquakes and flood events, where the technology meets head on with the external environment. In these circumstances the threat is not solely from the extreme event itself, as explored in my fifth post but is exacerbated by an inherent risk in nuclear power due to the huge amount of heat required and the long lived nature of radiation. The risk is also magnified given that the consequences are often severe and exclusive to nuclear accidents (see 'The Health legacy of Chernobyl').

Despite all of the above I still believe it is a risk worth taking because the main effects of nuclear accidents are regional and climate change threatens us globally. The environmental costs associated with nuclear power are still ambiguous (see 'The ecological threat of Nuclear power') and let us not forget that many renewable resources require land quantities of land, which will no doubt affect animal habitats and human settlements. 

So how far should we go? I would advocate nuclear power in having a 20% share of global electricity by 2050, a 7% increase from present day, and roughly a doubling in generating capacity given the projected rise in global electricity demand. I consider this a realistic target in light of China and India’s planned nuclear development, and a significant proportion allowing more time for renewable technologies to develop. The reasons for stopping at 20% is firstly the economic cost whilst in this blog I mainly focused on the environmental aspects of nuclear power there is uncertainty associated with the overnight costs. Secondly I can’t help but acknowledge  the inherent risk of the technology and the consequences of previous accidents. I feel that with a more rapid global expansion safety and legislation may fall by the wayside increasing risk.

Thank you for reading

14 facts and figures about nuclear power

As I near an answer to my question 'Is nuclear power a risk worth taking?', I thought I would just break things up a little and list a few of interesting and surprising facts I have learnt along the way. 

.Nuclear power provides roughly 6% of the world's energy and 13% of the world's electricity with 437 operational nuclear reactors in 31 countries globally (IAEA, 2013).

. 1 out of 5 houses and businesses in the US are powered by nuclear energy 

. Currently there is known to be 27 million tons of terrestrial  uranium resources,  if nuclear power was to become our main energy resource this amount would quickly become exhausted (Mackay, 2009). 

. Almost all uranium is in the seawater, where there is the potential for up to 4.5 billion tons to be tapped into. So far its extraction has only been achieved in small laboratory experiments, for nuclear energy to be sustainable for millennia rather than centuries, uranium from the oceans could be crucial.  

The diagram above shows sustainable rates of nuclear power production over the next 1000 years (i.e. using solely once-through reactors and mined uranium, resources would last for 1000 years if we produced nuclear power at a rate of 0.55 kWd per person) 125 kWh/d per person is current consumption in Britain Source: Mackay, 2009

. Compared to other carbon free and carbon-neutral options nuclear power requires far less land per watt. A 1000 MW nuclear plant takes up between 1-4 sq km, the equivalent solar park would require 20-50 sq km and wind farm 50-150 sq km (our-energy.com, 2007).

. The mass of fossil fuel consumed by the average British person is 16kg per day, in contrast the amount of uranium 

needed to provide the same amount of energy is 2 grams (Mackay, 2009). 

. Nuclear fusion could become a viable energy option in the future.  The energy released by fusion is three to four times greater than the energy released by fission, however extremely high energy is required to create the correct conditions. A breakthrough was made in October of last year when a US lab became the first to release more energy from the fusion reaction than the energy they used in heating the fuel (BBC, 2013). 

. If nuclear waste is recycled, its lifetime is reduced to 300 years.  This is becoming  possible with the introduction of new fast reactors, which have already had 400 reactor years of service (WNA, 2013). 

.Nuclear power in fact has one of the lowest death rates relative to other electricity generating technologies as the graph shows below. However it should be mentioned that the death toll for events like Chernobyl vary greatly from fewer than 50 to 1 million in a study by Yablakov et al (2009).  The effect of chronic low level radiation exposure is subject to much debate.

Estimates of death rates of electricity generation technologies: Source: Mackay, 2009

. There has not been, in the history of worldwide commercial nuclear power, a known case of stolen commercially used nuclear fuel .

. The average nuclear power plant in the US is 33 years old(Forbes, 2012)

. Estimates by the EIA suggest that new wind generation Is set to be cheaper than new nuclear generation with costs rising following Fukushima (EIA, 2013)

Thanks for reading!

The ecological threat of nuclear power

Another risk factor associated with nuclear power is the potential damage it has on surrounding animal habitats and the functioning of ecosystems close by. There are four ways in which dangerous radioactive materials can be emitted into the environment through the power generation process .

1). Waste rock at uranium mines used to fuel the reactor

2). Radioactive isotopes released during operation

3). Spent nuclear fuel (often at the reactor site) and general nuclear waste

4). Release during accidents

Interesting the second term is largely insignificant., In fact according to the NCRP, coal plants in the US release 100 times the radioactivity of nuclear plants, a mere 0.048 Sv/year is the annual dose rate living close to a nuclear plant (a typical chest x-ray gives a dose of about 0.06 mSv) (Gabbard, 1993). The largest threat comes from accidents which cause far higher dose rates over far greater areas than the other terms. The dose rates experienced following accidents are still not high enough to wipeout all wildlife as with a Nuclear weapon, the real effects are bore from chronic exposure to low doses of radiation over multiple generations.

The effect of low-level radiation exposure on surrounding wildlife is a controversial and complex topic.  There are very few testing grounds where the long term effects of elevated dose rates can be measured and those that there are, are as a result unsafe (e.g. Chernobyl). In addition it is difficult to get a general impression of ecosystem response, as species respond differently to a given dose of radiation, and the amount of radiation received by any one creature depends on the distribution of radioactive particles, the mobility of the creature, and of course where it lives (i.e. in trees, underwater etc) (Goldenstein, 2012).

This is partly why much uncertainty surrounds the true ecological impact of the recent Fukushima nuclear accident.  Dose rates 10 to 100 times (depending on which radionuclide your measuring) higher than the rates considered safe for terrestrial ecosystems were found in areas surrounding the plant during the first month after the accident (Garnier-Laplace et al, 2011). However the expected impacts are tentative, some indicate that cytogenetic (structure and function of cells) damages will certainly be measurable; however changes in reproduction in plants and animals will be difficult to discern against natural variation. At the high dose rates near the coast marked reproductive effects are expected to be noticeable, however there is still uncertainty (Garnier-Lapace et al, 2012).

Scale of potential effect in marine widlife groups and forest biota for different dose rates yellow dotes and red triangles indicate the dose rates measured (Source: Garnier-Laplace et al, 2011)

Essentially in its present state the areas surrounding Fukushima are likely characterised by elevated mortality and defect rates with many ecosystems in shock as a result of the huge influx of radionuclides. However what happens as more time is allowed to pass, dose rates fall and ecosystems adapt.  At Chernobyl more time has passed, the initial impacts were cataclysmic a whole 10 km² region was coined "the red forest" due to the overwhelming presence of orange coloured pine tree needles from dead trees, numerous morphological changes were witnessed in bird and invertebrate populations, and ultimately the event claimed the lives of thousands of plants and animals (Goldenstein, 2012). However more recently the Chernobyl ecosystem has rebounded, numbers of many species have increased and the region's biodiversity is in fact higher now than it was before the accident (Hopkin, 2005).  

Some 100 threatened species on the IUCN red list are now found in the 4000 sq. km evacuated zone and increasing numbers of macrofauna such as wolves, foxes and wild boar all indicate strong supporting productivity below (Source:Hopkin, 2005)

The reasons for this surge in biodiversity? Firstly no human beings, There may be radioactive particles, but with no deforestation, farming, hunting, or transport, animals have flocked to the isolated region in the Ukraine. Some have also argued that the high radioactivity in the region may in fact be of benefit, whereby weaker organisms die off more quickly, mutated by the fallout.  This leaves behind the most resilient which have not suffered problems with growth and reproduction.

"It's evolution on steroids. There are a lot of deleterious mutations in species but these seem to be very quickly weeded out," James Morris of University of South Carolina (Source: Hopkin, 2005)

The view of Chernobyl as a sanctuary for wildlife is not without opposition, many claim the increase in biodiversity to be a false dawn and question its sustainability.   Strong correlations have been found between highly contaminated areas and physical/reproductive changes in birds such as malformed tails and deformed sperm; similar results have also been found for some invertebrate species (Higginbotham,2011).  Perhaps most significantly in a 2005 study by Timothy Mosseau and Anders Moller studying the migration patterns of birds in and out of the area, it was claimed that the exclusion zone is a sink with low survival and fertility rates. They argue that populations are being falsely sustained by constant immigration of a species drawn in by human absence (Higginbotham, 2011). 

Photo showing normal barn swallow (left) and partial albino bird found in contaminated region (Source:BBC, 2005)

It is clear that the situations at Chernobyl and Fukushima are clearly complex. More research is required on both the affect of long-term radiation exposure on wildlife, and ecosystem responses in the immediate aftermath of nuclear accidents. I would summarise from what I have read that the  effects (excluding human depopulation) of nuclear power generation on wildlife are indeed negative, however I believe the beneficial role of nuclear energy as a carbon mitigator outweighs this particular risk. Especially when considered against the potential ecological impact of climate change, which threatens to acidify our oceans, decrease genetic diversity, promote directional selection, initiate rapid migration, and in a worst-case scenario cause extinction rates that would qualify as the sixth mass extinction (Bellard et al, 2012). The effects of radionuclides may be felt in more ecosystems if waste streams increase as a result of increased nuclear power generation. However in contrast to climate change they are unlikely to threaten biome integrity on a global scale. 

Thanks for reading!