Do we Need Nuclear Power?

The new coronavirus that causes COVID-19 is a respiratory infection. But that doesn't mean the effects of the virus are confined solely to the nose, throat and lungs. Indeed a study from researchers in Germany this week, looking at men who caught COVID in Iran, has found that the infection can have long term effects on fertility. The study found that sperm counts drop and there are signs of persistent inflammatory changes in the male genital tract. Chris Smith spoke about this with Bill Colledge, who is a male reproductive physiologist at Cambridge University commenting on the paper just out in the journal Reproduction, from Justus-Liebig University...

Bill - This is a really fascinating study. Scientists have looked at the fertility of individuals in Iran to see what effect the COVID-19 virus might have on their reproductive parameters. They actually studied a group of 84 males that were recovering from a COVID infection and they compared that group to 105 healthy age matched individuals that didn't have a COVID infection and they looked at a variety of different factors. Including substances normally found in semen and they also measured indicators of fertility, such as the number of sperm and the motility of the sperm.

Chris - How often did they look at these people?

Bill - They looked every 10 days or so after they'd got over the viral infection and they looked out to about 60 days.

Chris - And were all of the people equivalently unwell with these all hospitalised patients, or were they people with mild illness?

Bill - They all had the virus. Some of them were sort of milder symptoms than others. Some of them were more severe. Some of them had to be hospitalised, but the point is that when they were looking at these individuals, they had got over the viral infection. So they're looking at what the impact might be after the viral infection, rather than during the virus.

Chris - So what did they actually find then when they followed them up both at short time points compared with, you know, as time went on, what did they see?

Bill - They looked for substances in the semen and they found an increased level of these specific factors, which are called interleukins, that modulate activity of the immune system. They also looked at the number of sperm and the motility of the sperm, and they found that these were compromised in the individuals that had had the virus.

Chris - And did they stay compromised because that's a critical thing, isn't it? You could argue, well, you've just been very unwell. It's possible that that's the cause of having a lower level of some of these markers of fertility in the short term but what happens if you, if you look at longer time points, did it bounce back?

Bill - Well, I mean, the real surprise with this study is that these individuals had compromised fertility out to about 60 days after they had the infection. So up to two months later. There was a suggestion that they were starting to recover, but even at two months they still had problems with sperm counts and the production of these interleukins. I suspect that in a longer timeframe they'll probably get better, but it does illustrate that you get the viral infection you recover, but you can still have some health issues that can go out up to two months.

Chris - And presumably, although they've got sort of markers that we know go along with a person having a lower level of fertility, they haven't followed this through and said, and now we've tested to show these people really are suffering from lower fertility.

Bill - No, they certainly haven't. So they've got lower sperm counts, but they haven't shown whether that affects fertility. So they don't know whether it would affect the ability of that individual to have a child. They also haven't done any direct look at the testes in terms of its structure. They've just looked at the parameters in the semen. So they don't really know what's going on within the testes.

Chris - Is there any risk that it could do damage to the DNA in the sperm, in such a way that, that people could have babies with genetic problems in the aftermath of the father having what might amount to infection with Coronavirus in the testes?

Bill - There is a suggestion in this paper that they have found there could be damage to the DNA within the sperm. Hopefully, that will only be a short term effect and the beauty of the testes is that it has a population of cells which can divide and replenish to produce more sperm as long as there's no damage to that population of stem cells. Then the individual should be okay and should be able to make normal sperm later.

Chris - So should people then do you think as a cautionary note, avoid trying for a baby, if they're in the immediate aftermath of COVID infection?

Bill - Well, there's a risk. If you have a COVID infection and it's affecting the quality of your sperm, you may want to perhaps not try and have a baby. It might be sensible to wait a few months.

Chris - And do women have anything to worry about?

Bill - There's no indication that women have anything to worry about. The process of sperm formation and egg formation is significantly different. Hopefully it wouldn't cause a similar effect, but again, that study hasn't been done.

We are all now well aware of the effect that diseases caused by microorganisms can have on humans but it’s not just viruses that can cause disease, parasites are big business too. And in particular African sleeping sickness, also called trypanosomiasis, which is spread by tsetse flies, kills thousands. But this week, in work published in PLOS Biology, scientists have shown how a drug called nitisinone, which is already used in humans to treat a genetic disease, turns out to be “kryptonite” for a tsetse fly, and other blood-sucking insects too.  Martin Khechara heard how, from the Liverpool School of Tropical Medicine’s Álvaro Acosta-Serrano...

Álvaro - Tsetse flies, who are responsible for transmitting a deadly disease in Africa, known as African trypanosomiasis, need to digest blood quickly, coming from the blood meal that they take from humans or animals, and they need to metabolise quickly, some of these blood components. One of those is known as tyrosine. Tyrosine is an amino acid. We knew that when we blocked that, the flies died. So by using a specific drug nitisinone, which is the drug that is currently used to treat a rare human disease. And when Tsetse flies are exposed to that drug, they quickly die.

Martin - How did you find out the drugs that you've used in your study actually kills the Tsetse flies?

Álvaro - My collaborator in this work, Dr. Marcos Sterkel, discovered that degradation of tyrosine for other blood feeding insects is also lethal, is fatal for the insects if we block it. So he proposed to study this in Tsetse because Tsetse has a very fast rate of blood digestion, and the faster it is, the more likely it is this drug will act better. And in fact, within a few hours that the flies are exposed, in the presence of blood, for example, definitely they get killed by the action of this drug

Martin - Does killing these flies actually stop people getting the disease?

Álvaro - Absolutely, the best we can do is to reduce the populations of flies that would be close to some urban and more rural areas. So in terms of controlling the diseases, in this case, Tsetse fly transmit. This kind of strategy that we are suggesting would be one way to control transmission, in parallel with a continued supply of drug treatments and using other ways to control Tsetse fly population.

Martin - So could this drug work in other blood sucking things?

Álvaro - This drug works, literally, for any blood feeder insects, that transmit disease in wild places. One of those diseases that we are actually working on is on mosquitoes, and mosquitoes that transmit malaria in Africa. And we got very exciting, preliminary data suggesting that we could potentially use this drug in different ways to control mosquito populations.

Martin - So how would you see this drug working actually in the real world?

Álvaro -Well, there's a long way to go now, and we need to really do the field test. Depending how we use these for animals, or for humans perhaps in outbreak situations, we can say this could help in partnership with other strategies to control what is called vector-borne diseases.

Martin - Is the drug expensive. If it's going to be used in countries where money could be tight?

Álvaro - The drug is a little bit pricey at the moment, because it's only useful to treat these rare genetic diseases, but also there are thousands of compounds working in a similar way. So the idea is to screen for novel compounds, that would be cheaper. So I think there is great potential to exploit these compounds depending on the biology, and depending on the kind of insect that we try to control.

If you want to discuss the neccesity of nuclear power, you should start by setting the scene. So here’s Eva Higginbotham to explain: What is Nuclear Power, and how does it work?

Eva - Nuclear energy comes from the cores, the nucleus, of certain atoms. You can make this energy by smashing nuclei together, which is nuclear fusion. This is why the Sun gives out light, but we haven’t quite figured out how to do that sustainably on Earth.

The other way is by breaking nuclei apart, which is nuclear fission. Nuclear power plants here on Earth work through fission.

Most (though not all) atoms you come across day to day, like most of the ones in you, or in your table, are stable. They don’t really change, and they don’t really feel like changing.

But some are unstable. We call these radioactive. This is because they have too much stuff in their nucleus. Carbon usually has 6 protons, and 6 neutrons in its nucleus. And it’s stable.

But Carbon-14 has 6 protons, and 8 neutrons. It’s unstable, and radioactive. Over time, it will decay, giving out energy until it turns into something else that is stable. We can harness that energy for nuclear power. Although not for carbon, it’s not nearly unstable enough.

Uranium is though. Uranium is so unstable that if you hit it with a neutron, it will break into two new nuclei, and will give out a few more neutrons. A tiny little bit of the mass of the uranium will be converted into energy, because E=mc squared. Energy = mass...times the speed of light squared. And a little bit of mass turns into a lot of energy. And the neutrons that were made can go off to break up more uranium atoms, and the cycle goes on and one

That’s the energy we use in nuclear reactors. The energy given off, is used to heat water, which turns into steam, and powers a turbine.

If there are too many neutrons, breaking up too much uranium, making too much heat it can be dangerous. But we have ways to control them.

Control rods are rods which control things. They’re made of elements that are good at catching neutrons, leaving fewer around to split uranium, slowing the reaction.

There have been some very high profile nuclear disasters, like Chernobyl in 1986 and Fukushima in 2011. But in general, when managed correctly, nuclear power is safe.

And renewable energy is not without its risk to life. Hydroelectric dams have burst, and people can fall from wind turbines. (although all renewable energies are much safer to human life than fossil fuels.)

So the debate in the industry is less concerned (although not unconcerned) with the question of “is nuclear power safe”, and more concerned with “is nuclear power necessary?”

The big question is, do we need nuclear at all? Is it cost effective, or a money pit? And are the alternative, non-nuclear options up to the job in terms of dependability and resilience? And can they meet the changing pattern of energy consumption, especially as we wean ourselves off fossil fuels and plug in more electric cars? Is nuclear an expensive luxury or an essential ingredient in our race to cut carbon emissions to combat climate change? Chris Smith spoke with two academics about this. Michael Rushton is at Bangor University where he looks at nuclear materials and how they behave. And David Toke is from the University of Aberdeen where he works on energy policy and renewables...

Michael - The energy generated in 2019 was about 325 terawatt hours. That's significant, but that only represents 20% of our overall energy use, we also have heating and transport; so as we decarbonise, it's expected a lot of that will be moved to electricity production. That's why we're talking about, "how do we expand electricity generation capacity?" Nuclear at the moment generates 17% of that, and in terms of the low carbon component of that energy generation, that's about 32%. It's diminishing at the moment - we've got quite an old nuclear fleet - so the discussion now is, "how do we replace our existing nuclear power stations?" Or indeed, some people argue we shouldn't.

Chris - Yes indeed, because I think we've got six nuclear installations that are scheduled to shut by 2030; this is less than 10 years away. What are we going to replace them with? I mean, is there a plan to replace them at all?

Michael - Well currently, in the South West, they're building the Hinkley Point C reactor. It's a French design, it's an EPR reactor which will generate 3.2 gigawatts of power - that's its maximum output, that's between two reactors - and that's under construction now. The typical build time for one of these very large reactors is about eight years. It's currently underway now, and once complete, it will be expected to generate 7% of the UK's electricity. There are plans underway to build another one of those, another duel EPR set up: Sizewell C. Sizewell B, of course, is the last nuclear reactor we built in the UK, which represented a change from what we'd been doing before: it was a pressurised water reactor. During the early days of nuclear and through to the early eighties, the UK had gone its own way and made gas reactors, so we've got these quite novel reactors running at the moment. And only through the eighties, when we built the PWR, did we start building the same sorts of reactors that the rest of the world built. And that's how we're continuing now with these light water reactors.

Chris - David Toke: it's a big number, isn't it? Nearly a third of the electricity now flowing through our grid is coming from renewables. Now if you'd said that to somebody 10 years ago, they probably would have massively underestimated where we would be by today. It really has come on in my view.

David - Yes. And I think there's a massive potential to do more. I think the government's climate advisors suggest that we're going to need a very big increase in electricity production; but based on their figures, you would actually need to take up, in terms of space, only 7% of the UK's offshore waters to supply all the energy requirements of the UK in 2015. By all I mean ALL; not just currently supplied by electricity, but transport, heating, industry, et cetera.

Chris - That's not much is it? I mean, it points to another important thing we should probably discuss, which is of course: when you build a nuclear power station - at least the current design of nuclear power stations we have right now - you're putting an enormous spend and an enormous facility in one place. And of course, we don't all live in one place, so that immediately means you've got a distribution problem. So is there another advantage to distributing things like wind farms? I mean, I know you've got to bring the energy ashore in the first place, but that can be done. Is there an advantage to spreading things out a bit more rather than focusing the energy in one place, like in a big nuclear installation?

David - Well, yes, it is easier on the electricity system if things suddenly go down; but also we're moving into a much more digitalised, computer-controlled age, where we have an integration of energy supply and energy demand. We're going to have cars that talk to the electricity system and transfer energy both ways through batteries, and we'll even have washing machines that talk to the grid in future. Decentralised forms of energy - that is, energy that produces without a centralised command from the grid - are really much more in tune with modernity than, dare I say, clunky old nuclear power.

Chris - I suppose you'd say though, Michael - not withstanding what Dave is pointing out - that actually the sun doesn't shine at night and the wind doesn't always blow.

Michael - No, it certainly doesn't. On the figures from last year, the wind turbines only generated 30% of their total output. Then there are whole days, we all know the cold, clear days where you have extended periods of high pressure over the entire country, and those are the days you want to turn your heating on. So if we're talking about electrifying heating and the wind's not blowing, what do you do then? You need something to fill in that lack of power. Also, to come back to that idea of the area, I've got some numbers written down in front of me: Hinkley Point C is a 430 acre site. There's a wind farm just down the road from me where I live that generates 567 megawatts - and that's six times less power than the Hinkley Point C installation - and that takes up 50 times the area. So nuclear power is incredibly compact, and frankly, not everyone wants to look at wind turbine spoiling nasty views.

Chris - Well I don't think many people want to look at Hinkley Power Station necessarily either!

Michael - But it's a small installation, and you don't have to look at it. Turn your back. But wind turbines take up a considerable part of the coastline.

Chris - Well can we look at the cost for a second? Because David: how much does the 30% or so of our energy coming from renewables...how much does that cost to install in the first place? Because I've just looked at the price tag for Hinkley, which Michael's just mentioned -` this new nuclear power station, which is still...prices are still rising - the price tag on that is 23 billion pounds. So how much does our infrastructure from renewables cost to install?

David - A small fraction of that price. But can I come back to the points that were made? Sure, I accept that you can go days on end without sufficient wind or sun, but you can easily store the renewable energy by converting it into a range of different liquid fuels, or even water capacity, and use extremely cheap engines or turbines to produce the electricity when you need it. And if you have a system involving substantial amounts of nuclear power, because it has to be made - for financial reasons - to run practically all the time, it's inflexible; and you'll end up knocking off a lot of wind farms off the grid and wasting their energy. This is already happening in Scotland, where there's a lot of grid constraints. We've done quite a bit of research on that. And with that wind power or solar power that's wasted, you can in effect store it and use it when you want it; and we've got plenty of batteries to even out flows within the day; and you've got longer term means of storage, as I say! And this business about the space things are taking up: well, as I say, we're developing wind farm technology that's increasingly cheap in price that's miles and miles away from the shore. Floating wind turbines, even, so you don't need to worry about seeing them. I don't think there's a problem here. I mean, admittedly, there's more space for wind turbines on shore in Scotland than there are around Cambridge, but really that doesn't matter with the amount of offshore resources we've got for offshore wind in this country.

Chris - One thing that's not that far away though, is 2050. At the rate at which time is increasingly on wheels, and that's the date that we have said, we're going to try and be zero carbon. But looking at the figures, we've got a long way to go. We're still obtaining in the ballpark of half our energy from fossil fuels. And if, as Michael's pointing out, you end up with the wind not blowing, and the sun not shining at certain points of the day, we do need something to smooth things out, and we don't have, I know what you said, but we don't have the infrastructure yet to have mass storage of this energy. And it's very expensive to do so. People have put forward ideas of; let's shunt some of the spare energy into people's car batteries. But a few percent of people have electric cars at the moment. And an even smaller proportion will be willing to have their batteries potentially damaged, by the relentless shunting of energy backwards and forwards from their car onto the grid. So there's quite a way to go. Wouldn't you say, David? Yeah?.

David - Well, yes, but you try building nuclear power stations. I mean, we've had attempts to get new nuclear online, first announced by Tony Blair in 2006. And if we're lucky, very lucky, we might get one online 20 years later, in 2026. I mean, you can take carbon dioxide out of the air and change it into some synthetic fuel like petrol. There are probably better means of even doing it than that, and you can store these things, hydrogen, through water storage. God knows, lots of things, but no money is being spent on this. This could be quite easily put together, a market set up to get the best mix of technologies to provide long-term storage. But we've got an energy system, and energy companies that have their business in either or both fossil fuels and nuclear power. And of course they're not producing any policy reports, or any pressure to do stuff about a hundred percent renewable energy system. They've got it all tied up. Well, we need to get people to push for the government, to get some thinking on providing a much higher level of energy from renewable energy, leading up to eventually what will be a hundred percent renewable supply.

Chris - Michael, there was an interesting idea floated by Rolls Royce recently, and this was their concept of what they dub an SMR, small modular reactors. We've talked about big installations like Sizewell and Hinkley, which are massive. In comparison, Rolls Royce envisage a fleet of small reactors, which they're saying you could build more locally. You could make them more aesthetic. Why do they think that that's the way to go?

Michael - Well, there's multiple reasons, really. The main problem with nuclear, it's nothing technical. We can build reactors, like as was mentioned before. The French built 56 reactors over 15 years to produce 50 gigawatts, and basically decarbonised their electricity system. One of the few in the world. So the trouble is getting the finance to build the reactors. That's the thing that's causing a problem at the moment. The main running cost of a nuclear reactor is meeting the debt. It's paying the mortgage on the reactor. So if we could bring that down to rates where you could borrow in the commercial markets and not have to go for handouts to the government, that would be beneficial. So one thought to do that is to make the reactor smaller. If you can bring the cost down to around 300 million pounds, and bring capacity to the grid incrementally, you can have a reactor that's quick to build, three or four years, it's earning for you, and you can borrow more easily to build the next one. And you can incrementally bring capacity to the grid. Because at the moment with these big reactors, we're dumping a lot of capacity on the grid in one go, right? So you have to wait eight years and then you get a huge amount of power, and you get that for about 60 to 80 years, right? So these things are going to be around for two to three times longer than wind turbines and that sort of thing. So that needs to be born in mind. There's other things we could do with small modular reactors. Because they're small, the components can be built in factories. So you get those economies of scale. The idea is if you build lots of them, you bring the unit costs down dramatically. Rolls Royce are also talking about, could we start doing things like cogeneration. Reactors generate lots of heat. And one of the issues we're going to have in the future is not everything can be electrified. Not all our industries can be converted to electricity.

Chris - Things like making concrete, making iron and steel. That kind of thing.

Michael - Certainly. Particularly the iron and steel case, like a blast furnace uses coal as a chemical there, it's not used just for the heat. So you could use a bit of hydrogen, that's already been mentioned, you know, nuclear can also generate hydrogen. Nuclear can also pump in a bit of heat. For iron and steel, you'd actually be looking at a second generation of reactors looking more the mid 2030s. So this way you'd go back to what Britain is good at actually, gas reactors, which can run a lot hotter. If you could get those up to 800 or 900 degrees, you could make steel using nuclear power. If there was a bit of a push that we do have the technology to decarbonise these difficult to decarbonise processes, that aren't suitable for electrification.

Chris - It's a fascinating application, actually, the idea of coupling up a reactor to really use it as a heat source rather than just an electricity source. Now, just in closing, I'd actually like to come back to a point that both of you have made along the way, and that's this question of aesthetics, and also the perception we were hearing from Matt Rooney earlier about what people's perceptions are about these different things. And there's a difference between older people and young people. People who have, and haven't had experience in the industry, are more or less educated about the science involved. So what do you think, David first, needs to really happen from your perspective for more people to be supportive of where you're coming from in this regard?

David - I think people are supportive of where I'm coming from. I think curiously enough, the outlandish ideas, I'm not trying to be insulting or anything, are with things like small modular reactors, which have been tried many times before, and they actually exist in the form of nuclear submarines. And they're extremely expensive. I mean, there are a million issues with that. I think this really is a question of engineering, interest taking account of what is wishful thinking. Renewable energy, solar power, wind power, electric cars, batteries are the thing that are cheapest, obviously practical, we ought to firm that up, improve the systems for that. And we can produce hydrogen for niche sources, like making concrete and so on from that, I don't see a problem with that. That's ready. We can go ahead with that, now. We don't have to entertain these, what I think are unlikely ideas.

Chris - Michael, you've got a bit of an uphill struggle to come up with a compelling argument, really, when you're faced with the fact that you could just build a whole heap of wind turbines, and they're not going to be a blot on the landscape, if you don't want them to be, you take them away.

Michael - A lot of the previous discussion is predicated on technologies that don't exist at the scale that they needed for. So if you want to go to these large amounts of wind 70, 80, 90%, that means you've displaced things like dispatchable sources, like gas. Now, as we've gone through, the wind doesn't blow all the time. So how are you going to fill that gap? Well, we've already had the discussion that we're going to use batteries, apparently. Now the largest battery storage methods at the moment cost a lot of money. There's also competition for those cells for making electric cars, which we also need to decarbonise transport. So, the current battery storage lasts for only a few hours at very low power outputs. It's not credible, what's being argued here. So all these ideas that washing machines that can talk to the generator, that doesn't exist now, right? We're in the middle of a climate emergency. Why are we reaching for tools that don't exist? We should rely on the technologies that have been proven over 60 years.