Do we Need Nuclear Power?

Is nuclear power a necessity, or something we could go without?
02 February 2021
Presented by Chris Smith, Adam Murphy
Production by Adam Murphy.


Two nuclear power cooling towers


This week, we’re looking at nuclear power and asking, in today’s world, whether we really need nuclear power? Are the alternatives really practical alternatives, or are we just kidding ourselves? Plus in the news, is the UK right to lengthen the gap between Covid vaccines? Evidence that coronavirus infection dents male fertility, and a very strange rodent, with a very strange accent!


In this episode

A close up of a wall calendar

The science of vaccine spacing
Keith Neal, University of Nottingham

This week the UK passed the grim milestone of 100,000 COVID fatalities. But on a more positive note, two pharmaceutical companies, Novavax and Janssen, both announced solid phase 3 trial results for their new coronavirus vaccines. And in the UK, 8 million people have now received at least one dose of either the Pfizer or AstraZeneca vaccine. But, apart from recent moves on the part of the EU which could affect supplies of vaccines to countries outside the bloc, many are also concerned about the decision to delay the second doses of their vaccine in order to protect more people in the short term. The British Medical Association have been vocal, calling for an urgent review of the UK’s strategy and saying the gap between the first and second doses should be reduced to 6 weeks. The doctors' union say the UK’s approach is "increasingly isolated internationally" and "is proving difficult to justify". On the contrary, other experts have defended the decision and some have even slapped down the BMA as ill-informed, arguing instead that the delay may even lead to better long-term immunity. Chris Smith asked University of Nottingham infectious disease epidemiologist Keith Neal what he makes of all this, and what, does he think, should be our long-term vaccination plans for COVID-19?

Keith - If you've got 10,000 doses of vaccine, you could give 10,000 people 70% protection. Or you could give 5,000 people 90% protection. That means we protect a lot more people. Also, if the vaccine does interrupt transmission, we would actually stop more transmission chains by doing it this way.

Chris - Do we actually have evidence that it works like that though, because one of the criticisms that people have been levelling at those responsible for making this change is that they are departing from the clinical trial evidence. They're departing from what the manufacturers have initially said should happen and therefore, this is risky.

Keith - The manufacturers are constrained by what they're allowed to say by their own pharmaceutical association. We often give vaccines for viruses naught and six months apart, as for hepatitis A, and the human papilloma virus and they work very well. Having a short period between the two vaccines was really a necessity so that we could get the results of the vaccine trials in quickly. If we had a six month gap, we wouldn't still know what the results were.

Chris - Therefore, are we actually trying to learn, right now, what the answer to this question is? In other words, are there various measures in place to learn from what we are doing, having changed this a little bit to find out whether we are on solid ground by doing this?

Keith - Part of the advantage of a national health service system is that we'll be able to identify anybody who gets COVID after they've had a vaccine. So we'll be able to rapidly identify whether it is or is not working to the degree that we hope it does.

Chris - And is there any evidence emerging yet? Because obviously we've got 6 million people or more now who have had vaccines, so there are a very significant number of people who can be followed.

Keith - I actually haven't seen any of the published data, although I did have one care home where as part of a routine screening an outbreak was identified quite widespread in the home. They'd been vaccinated 10 and 11 days earlier, and none of them had got ill. They were all asymptomatic.

Chris - What's your thoughts on how the rollouts are actually going with the vaccine now and are you encouraged by the sorts of numbers that we're seeing? Do you think this is enough?

Keith - Having been involved in planning mass vaccination campaigns before I'm very encouraged about how far it has gone. Yesterday's figures suggested over one in 11 of the entire population had been done and we're up to three quarters of the over eighties where most of the deaths occur. This is an amazing achievement really from having not had even known about disease really this time last year.

Chris - And looking to the future, obviously we don't know because we don't have a crystal ball. What's going to happen in terms of next winter? Do we have any insights yet about how long the protection is going to last from this vaccine and how were we going to plan for the virus, possibly sidestepping these vaccines? If we continue to get variants and things like that coming along?

Keith - I'd like to think that we can model it on the flu program. We know that the flu virus changes much faster than the Coronaviruses do and simply if we actually have to have a flu and COVID vaccine simultaneously in the winter, then we've got one arm for flu vaccine and the other one for the COVID vaccine. We can actually tweak the COVID vaccine in about six weeks, which is much faster than we can change the flu vaccine. Given now we have a large army of people who trained to give vaccinations. We might have to actually be able to scale up our flu vaccine campaign in general and have a flu COVID vaccine.

Chris - Are you optimistic?

Keith - I'm not pessimistic. I mean, I continue to hear stories of the vaccine won't work, it will come back, the virus will change. Each of those, we are able to defeat and we are learning rapidly about how to do things better. I think what will happen. We need to have better ways of trying to identify Coronavirus in the population and the lateral flow devices will help this and they will. The main name of them is to find people who are asymptomatic so we may be in a position of having regular testing for a while.

A sperm and egg meeting

COVID impacts male fertility
Bill Colledge, University of Cambridge

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.

the Statue of Liberty sinking into water

Changes in the U.S pandemic approach
Dennis Carroll, Global Virome Project

Joe Biden is now the new president of the USA, assuming responsibility for both the largest economy, and the country with by far the greatest number of COVID cases, in the world. So what’s going to happen now? Will the two-trillion-dollar COVID relief and stimulus plan he’s proposing work? Or will he, like his predecessor Donald Trump, fail to rein-in a pandemic still spreading like wildfire? Dennis Carroll, former head of the pandemic programme for the USA’s international development department, told Phil Sansom why the situation in his country matters even to those outside it...

Dennis - The United States accounts for, what, 5% of the world's population. Yet we account for 25, 30% of all of the transmission that's going on in the world today. You know, it's important what's going on in the United States, not because it's the United States. What's important is that there are 330 million people in this country. And right now the virus has free rein to go anywhere and infect anyone, almost. That leaves the rest of the world vulnerable, because we've seen new variants of this virus are emerging and these variants are really a reflection of how many people have been infected, and how many opportunities this virus has had to replicate. And in the United States, right now, we're seeing a greater frequency of replication, just by the sheer number of people who are infected. We do not have a system to look for new variants.

Phil - Could you then talk me through Biden's strategy as he's communicated it?

Dennis - Well, first and foremost, he signed a series of what are called executive orders, taking steps to ensure that we would maximise the distribution and availability of the vaccine. He has put very much in play, 100 million Americans being vaccinated within the first 100 days of his presidency. And he is making sure that there's both the logistics, and the necessary training available to ensure that the infrastructure to deliver these vaccines are in play, and that people have access to them. He made Dr. Anthony Fauci, his chief medical advisor, and Tony Fauci immediately took steps to signal to the World Health Organisation, that the US has rejoined the WHO, reaffirmed our commitment and our support for WHO, but in particular, signal the US commitment to be a partner in COVAX. The international effort led by WHO, and Gavi, and UNICEF to make equitable access of vaccines to countries around the world.

Phil - You said a hundred million vaccinated in the first a hundred days. That's almost a third of the US population. Isn't it?

Dennis - 100 million people is essentially one third of the American population, but they'll also need a second dose. So it's basically saying that there'll be 1 million people vaccinated per day. And in fact, when you look at the numbers, there has been a dramatic uptick just in the last five days. And we've been averaging somewhere on the order of about 1.2, 1.3 million vaccinations per day. But let's also be clear, if you're vaccinating 1 million people a day. By the time we get to the end of 2021, we'll only have three quarters of the American population vaccinated, fully vaccinated with two doses, meaning that the ability to have some measure of normalcy, stretches beyond this particular year.

Phil - The USA is obviously a very corporate country and nowhere is that more evident than with healthcare. And so when it comes to giving out the vaccine, are the hundred million people who hopefully get it in the first hundred days, are they going to be the people that can afford it, or the people that need it?

Dennis - Well, first and foremost, the vaccines will be made available at no cost, a number of corporate entities have stepped forward, to say they're prepared to bring the full force of their corporate capabilities to support the distribution of this vaccine. Major corporations like Walgreens and CVS, that have primary access to pharmaceutical goods across the United States. We've similarly seen Amazon say that they're prepared to use their logistics distribution capabilities. So it's a very positive step forward, particularly in terms of addressing some of these issues about equitable access

A close-up of the head of a blowfly.

18:23 - A new way to fight sleeping sickness

Using an old drug in a new way to combat sleeping sickness

A new way to fight sleeping sickness
Álvaro Acosta-Serrano, Liverpool School of Tropical Medicine

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.

A picture of someone talking, drawn on a blackboard

22:42 - Naked mole rats have accents

When they squeak to each other, they squeak with an accent...

Naked mole rats have accents
Gary Lewin, Max Delbrück Center for Molecular Medicine

Naked mole rates are bizarre creatures that can live for up to 32 years and are totally insensitive to pain caused by acid or the spicy ingredient in chilli peppers! They’re also highly cancer-resistant, and can survive for hours in extremely low oxygen air. They are unfortunately also extremely ugly. But now, pulbished in the journal Science, scientists can add a new item to the naked mole rat CV; it turns out that they speak to each other, and they do it in different dialects. Eva Higginbotham heard how from Gary Lewin, from the Max Delbrück Center for Molecular Medicine in Berlin...

Gary - Naked mole rats are moles that live underground and they come from East Africa, and they live in desert regions where there's not a lot of vegetation. They are very unusual because they live underground in very large colonies and the colony can be up to 300 animals, but on average, it's about 40 animals. These animals are really strange because they also have a queen just like ants and bees. And when you keep mole rats, you realise that they're always, constantly, seem to be talking to each other in the colony. And so we were interested to see what these sounds are for, and that's when we started to look. The most common vocalisation really sounds like a bird - it's called a soft chirp. We decided to analyse these soft chirps, and so we looked at thousands of these soft chirps, and we figured out with a very special mathematical program that actually every single animal has its individual soft chirp. So each animal had its own voice.

Eva - How did you actually make these recordings of the mole rats? Were you sort of taking a mole rat and holding it up to a microphone and hoping it would make some noise?

Gary - More or less yeah, so we take each individual animal out and put it in front of a microphone and push it gently and then they will start to vocalise. And we did this hundreds and hundreds of times to get thousands and thousands of vocalisations. Now the soft chirp is only one of 24 vocalisations that the mole rat makes, but it makes up over 90% of all of their vocalisations. We don't know what it means, but we kind of guess that it's like a greeting call. So it's like a hello, hello, kind of call.

Eva - I see, so mostly they're just going around saying hi! Hi Hi! Hi! Hi - all the time!

Gary - Exactly. Yeah. We then also went on to use the same algorithm to ask whether different colonies have different voices. And it turns out that each colony seems to have its own distinctive dialect that was figured out by the machine learning algorithm. But we wanted to see if that's really used by the animals, so we did an experiment actually, where we played back soft chirps to an animal and asked whether the animal would answer the chirp if it was from its own colony or if it was from a foreign colony. And it turns out that the mole rats would chirp back to a loudspeaker if the chirp was from its own colony, but not from a foreign colony. And you have to be aware that these naked mole rats are rather like humans in the sense that they're very xenophobic - so if a member of another colony comes into their colony, they will actually almost immediately recognise this animal as a foreigner and kill the animal. And so we figured out that maybe the dialect of the animals is actually a way that the animals can use to identify foreigners that might come into their colony.

Eva - Where do you think the animal acquires its accent or its dialect from, do you think it's somehow genetic?

Gary - We don't think it's genetic because we specifically asked whether dialects can be learned by young animals. So we were able to foster baby mole rats from one colony into another colony. And indeed what they do is they really adopt the new dialect. So as they're growing up in the first six months of their life, as long as they're exposed to the dialect, they will learn that dialect. So it seems to be very important that the animal adopts the dialect so that he's at home and recognised as a member of that colony.

Eva - What do you think we can learn about how other animals communicate by understanding how mole rats communicate?

Gary - I think one thing that is very important here is that the mole rat has been around a lot longer than we have. We know that the mole rat has been around for at least 20 million years. And so they already display features of a vocal culture, that means a culture that is learned from their peers, and we often think that's something that is unique to humans. But what's interesting about the mole rat is that we can actually study in the laboratory what is the difference between a mole rat brain and let's say the brain of a mouse, which is not at all social, to see how evolution came up with this sociality, this ability to live in a society together. So we think we can learn a lot about being social by studying the biology of the naked mole rat.

Cartoon schematic of an atom

28:18 - How does nuclear power work?

How do we turn nuclear energy into usable power?

How does nuclear power work?
Eva Higginbotham

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?”


31:07 - The state of the UK's power grid

A snapshot of how much power is used in the UK, and where it comes from.

The state of the UK's power grid
Matt Rooney, Institution of Mechanical Engineers

To really get a grip on where the conflict around nuclear power lies, it’s important to understand the state of nuclear power today, and how people feel about it. Matt Rooney is Head of Policy at the Institute of Mechanical Engineers, and he joined Adam Murphy to give a snapshot of the UK's energy...

Matt - So this is obviously changing quite rapidly due to de-carbonisation, but broadly about 40% of the last couple of years has come from renewable sources. So that's wind solar, hydro, and biomass primarily. About 40% comes from fossil fuels, primarily gas, but also coal and oil. And then just less than 20% has been from nuclear fission.

Adam - So that's a snapshot of things right now, but what are the trends - what's growing, what's falling?

Matt - So the two big trends over the last few years that will continue - the first is a massive decline in coal. And this has obviously been good news for decarbonisation because it's the most carbon intensive fuel we use. And the second is an expansion of all renewables, really, but particularly offshore wind. And the reason for the coal decline has been government policy - so the government has committed to phasing out coal by 2025, but also these plants are older, and also they have to pay a carbon tax, and as it's the most carbon intensive fuel it pays the highest carbon tax. Offshore wind is more a triumph of engineering because the industry has managed to bring down costs over the last few years. Astoundingly, the cost of offshore wind has come down by more than half. So it's become one of the go-to low carbon technologies.

Adam - What about how people feel about nuclear power? What are the perceptions right now?

Matt - So last year, the Institution of Mechanical Engineers commissioned ICM to conduct a poll into nuclear power in the UK and how the public feels about it. The headline figures were 40% support nuclear power for electricity production in the UK, and 27% oppose. Delving a little bit deeper into the results, the biggest factor was age. So if you're a young person, you're more likely to be skeptical of nuclear power. And the older you get, the more likely you are to be pro-nuclear. One of the other questions we asked people was, do you think nuclear power is low carbon? And the results for this were interesting because they tracked broadly with the age groups of whether they're pro or anti. So only 26% of young people think that nuclear power is low carbon, so that's 18 to 24 year olds. Whereas for 65 to 74 year olds, 61% of people think that nuclear power is low carbon.

Adam - And what kind of things have got us to the point where these beliefs are the way they are?

Matt - It's difficult to say, but young people have obviously been very enthusiastic about tackling climate change. So organisations like Greenpeace and Extinction Rebellion are very anti-nuclear power. So that may have influenced the views of young people.

Adam - Sometimes I wonder if things like Homer Simpson, you know, the nuclear safety technician played a role. Do you think that that had an impact?

Matt - I'm only being slightly facetious when I think the Simpsons have a large role to play in negative views about nuclear power, and also TV shows like HBO's Chernobyl. Big accidents get into the public's mind - that can influence things, and we did see that after the Fukushima accident where in Japan, in particular, understandably, attitudes towards nuclear power declined massively, but also in countries like Germany as well.

Adam - And what about other places that have different views - France is the one that springs to mind, they're much more pro-nuclear. What's going on differently there?

Matt - Yeah, so when you ask people who are pro-nuclear what they associate nuclear power with it's things like a national endeavor or energy independence and energy security. France built up most of their nuclear power industry in the seventies and eighties, it was an astounding feat really. They completely decarbonised their electricity system in 20 years using almost completely nuclear power. And it was a national program and it was not built on decarbonisation, it was done for energy security reasons off the back of the oil shocks of the 1970s.

An electric pylon sitting in the middle of a field

35:40 - Is nuclear power necessary?

Do we need nuclear power? We look at both sides of the argument...

Is nuclear power necessary?
David Toke, University of Aberdeen, Michael Rushton, Bangor University,

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 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.


QotW: Why do some people shiver when they pee?

Listener Eleanora asked: "I want to know why my dad shivers when he pees." Phil Sansom managed to find the answer from neurologist Kieren Allinson and Jalesh Panicker, a neuro-urologist...

Eleanora - Hi! I want to know why my dad shivers when he pees.

Phil - Eleanora told us she also experiences this herself, so her dad is not unique - and neurologist Kieren Allinson agrees.

Kieren - “Pee-shivers” - or having an involuntary shiver when you go for a pee - is a real thing that some people do experience.

Phil - Jalesh Panicker, neuro-urologist (a fantastic job title) says it’s more often experienced by boys and men...

Jalesh - ...particularly when peeing large volumes standing up. We don’t fully understand why it happens, however there are a couple of possibilities.

Phil - Jalesh and Kieren can take it from here.

Jalesh - The first idea is more from common sense, and based on the fact that we shiver when feeling cold.  When peeing, warm private areas and pee are exposed to cold air...

Kieren - ...and you might just shiver automatically to warm up. But I find this harder to believe as it would cause shivering when you removed clothing generally, not just when you go to the toilet.

Jalesh - It’s more likely that pee shivers is down to nerves.

Kieren - It has to do with the autonomic nervous system, which is part of the nervous system which controls involuntary things like body temperature, sweating, shivering etc.

Jalesh - The decision to pee or not to pee may be voluntary; however, the act of peeing is controlled by the autonomic nervous system. The parasympathetic component  (which handles resting state functions such as digestion) springs into action  and instructs the bladder muscle to push urine out of the bladder. When urine leaves the body, oddly the blood pressure drops slightly and the sympathetic component (which handles the fight or flight response) then kicks in, releasing a shower of neurotransmitters in an effort to raise the blood pressure. This results in mixed signals between these two components of the autonomic nervous system, which is thought to trigger an involuntary shiver.

Kieren - It affects men more than women, probably because they stand up to pee, and therefore are more prone to the drop in blood pressure, because the blood has to get to their head past more gravity. Unfortunately we don’t know why it affects some people and not others.

Phil - So let me summarise. Your autonomic nervous system is the nerves you can’t control. It’s got multiple parts, one of which, called the parasympathetic component, helps you pee. This can lower your blood pressure, accidentally triggering the sympathetic component, which may be giving mixed signals which cause the shiver. Thanks to our forum users for coming to the same conclusion - plus, user Evan pointed out that sometimes a shake gets out the last few drips. Next time - a question that is music to my ears! It’s from listener Dennis.

Dennis - Assuming there are a finite number of musical notes - chords, notes, octaves - at what point, how many years, would we use all combinations of musical themes such that no more music could be created?


The main problem with nuclear that wasn’t addressed is what do we do with the waste?

Thanks for raising this. The reason that this was not addressed in the programme is because we have looked at this question specifically in the last year. Here's the reference:

The issue still should have been raised to present a balanced discussion/debate. Thank you for linking the old episode though.

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