Mayor Talk - Why not Nuclear Energy

Published in The Beacon 14-Apr-25

The Flamanville nuclear plant in Normandy, France occupying and area of 1 km2.

Recogniszing long ago the importance that solar energy could make towards a clean energy transition I made my own solar cell in my lab at the Australian National University in 1992. Hard to believe that was more than three decades ago.

I first put a proposal on the Ccouncil table to build a solar farm at Whakatāne airport, which has been losing money for years, in about March of 2020. My arguments for such a facility centered on the need to build resilience and energy security and in the recognition that a modern society and economy can only be sustained with cheap energy. The solar farm cwould contribute to reducing council energy costs and in that way there would be a benefit for all rate-payers. Almost six years later I am happy to report that on Thursday, 20 March 2025  of last week (20-Mar-25) Ccouncil finally approved the installation of solar panels on the roof of the Commerce Street Whakatāne Ccouncil building and on our Refuse Recycling Centre and on our Animal Pound in Te Tahi Street and a couple of other council buildings. I guess I can call that a small first step and victory. I can also report that Ccouncil recently contracted BECA to undertake a feasibility study for a small airport solar farm. This will indicate whether such a facility is technically and economically viable.

It will come as a surprise to no one that we are currently experiencing something of an energy crisis in New Zealand and so the energy security I have long talked about is finally being acknowledged.

It is human nature that it often takes a crisis to focus the mind. Winston Churchill put it ‘never let a good crisis go to waste’.

Whilst I remain a solar energy advocate, one drawback of solar energy is that the sun doesn’t always shine; solar is an intermittent form of renewable energy generation. This is not the case for nuclear energy which can be available 24/7 and is also relatively clean. I spent much of my research career working in governmental nuclear research institutions and so I am also a fan of this type of generation. Nuclear energy used to be a dirty word in NZ but not so much these days.

A Quick Primer

Heavy elements in the bottom rows of the periodic table are generally not very stable. The uranium atom for example decays spontaneously with the emission of neutrons. If enough uranium atoms are crammed together in a certain geometry a self-sustaining nuclear chain reaction occurs. The uranium atoms are split into fragments, more neutrons are generated and heat energy is released. The process is called nuclear fission. If a certain critical mass of uranium is exceeded, and if the reaction gets out of control, you effectively have a bomb.

The heat that is produced during nuclear fission can be used to generate steam which can drive a turbine in exactly the same manner as in thermal power plants that uses fossil fuels as the heat source (e.g. Huntly Power Station). The major advantages of nuclear energy are the high energy density and the absence of carbon emissions during reactor operation. Carbon emissions do however occur in other parts of the nuclear fuel cycle such as during the mining of uranium. However, during operation a nuclear fission reactor produces no Green House Gas (GHG) emissions. You get clean electricity, you get it constantly and you get it from a very small footprint of land with very high efficiency.

Post warWorld War 2, over 400 nuclear fission reactors were built around the globe in the space of just a few decades. Driven by the need to achieve energy security, France built about 50 reactors in 20 years which eventually generated 80% of France’s electricity and made the country the biggest electricity exporter in Europe. Then, in 1985 the Chernobyl incident happened and the nuclear industry came to a grinding halt.

The Chernobyl reactor was located in the Ukraine and was of the Soviet era RBMK design (water-cooled with individual fuel channels). The design was such that particular care had to be taken during its operation to control nuclear reactivity. Such plants have not been built since Chernobyl. The irony is that the Chernobyl reactor melted down and then exploded during a series of safety tests in which the reactor was being pushed beyond its limits. The industry eventually recovered from the stigma of Chernobyl and in by 2004 something of a renaissance was taking place.

Scientists working at universities and at industrial and governmental research agencies were starting to get excited and we were letting our imaginations run wild again. All sorts of plans for expansion of the industry were put in motion. The idea of closing the fuel cycle was up for grabs and being worked on and I was part of it. Closing the fuel cycle is another word for circular economy where used fuel is recycled.

The Fukushima Tsunami in March of 2011 once again put the kybosh on all of those plans and it was back to square one again for the nuclear industry. Japan’s nuclear authorities started shutting down many of Japan’s 33 operable reactors. It is important to emphasisze that all 20,000 or so deaths resulting from the Fukushima disaster were from the 15 metre Tsunami, not the explosion of the nuclear reactors at the Fukushima Daiichi plant comprising four reactors (2,719 MW).

Society nowadays has become extremely safety conscious. For instance, these days it seems to take 1 km of road cones to fix a pot hole and everyone has to walk around in high visibility gear. It strikes me as rather odd that infrequent nuclear accidents have precipitated an exaggerated reaction, yet we can mount no effective response to climate change[KB1] . Despite the fact that the nuclear industry has one of the best safety records of any energy industry, it takes more than a decade to license a new nuclear reactor design nowadays and building costs have gone through the roof and the time to build reactors prolonged. It never used to be like this. I could say the same for building a home.

An overbearing regulatory regime and draconian safety standards have made building large reactors prohibitively time consuming and expensive. For instance, the Finish Gen III+ EPR reactor took 12 years to build at a cost of $15B rather than the $5B it was initially expected to cost.

Unfortunately the unfounded hysteria that has hamstrung the nuclear industry has not been matched by fear of global green-house gas emissions. Fossil fuel use continues to increase globally and subsidies have topped seven trillion dollars.

Burgeoning costs aside, people have two main concerns about nuclear energy. The first is the safety of reactors and the second has to do with radioactive waste disposal.

When I was working in nuclear research one of my research focus areas was the development of chemical technology relating to the nuclear fuel cycle and for dealing with radioactive waste. Radioactive waste generated at nuclear power plants comprises the used nuclear fuel (high level waste), materials used to clean cooling water (intermediate level waste) and other materials. The medical industry also generates radioactive waste in the production of radiopharmaceuticals. I wontwon’t go into the details here but let me say that as far as I know no one has ever been killed by radioactive waste.

During the operation of a reactor some of the nuclear fuel (usually uranium dioxideUO2) load has to be replaced and fresh fuel added. The ‘spent’ fuel that is removed is stored in cooling pools under 10 m of water where it takes years to cool. Typically, when a reactor is built spent fuel pools are also built of sufficient size to take all of the spent fuel generated by the reactor over its entire operational life (60+ years). After about five years the fuel is usually removed and loaded into dry-storage casks where it is safe for 100 - 300 years. Although we call it spent fuel, the fuel that is removed still retains 95% of the initial energy content but it is no longer just UO2. During operation the uranium becomes transmuted into many elements including plutonium.

I mentioned the high energy density of nuclear energy. Whereas renewable energy such as solar requires large areas of land and is intermittent, nuclear plants are extremely compact and the electricity generation is constant.

For example, the Flamanville nuclear power plant in Normandy, France, accommodates three reactors on a mere 1 km2 or so of land. The plant produces about 6 GW of electrical energy which is not far off NZ’s entire electricity generation capacity. To generate this amount of energy using solar would require more than 12,000 Ha (120 km2) of land and that energy would only be delivered during certain hours of the day. Although that land area is only a small fraction of New Zealand’s land area (270,000 km2) it is always hard to site solar farms.

Our largest generating station is the Huntly thermal power plant that burns coal and gas and is located on the lower Waikato River. When the plant was built from 1973 to 1983 it had a capacity of 953 MW (ca. 1 GW). Huntly was upgraded in 2004 with the addition of a 500 MW gas turbine plant, and in 2007 the combined cycle gas turbine (CCGT) plant was commissioned to give a total installed capacity of 1,453 MW. The cost of the second upgrade was $520M.

In contrast, other major advantages of solar are speed of deployment and low cost. Compared to nuclear, geothermal and others, solar is the hands down winner in these two departments.

The energy density of nuclear fission is difficult beat. Source: Bhutada, G. Smashing Atoms: The History of Uranium and Nuclear Power. Visual Capitalist 21-Oct-21.

 A serious problem for renewables such as wind and solar is their intermittency. That is, the sun shines in the middle of the day when consumption is lowest whereas little is produced in the early morning and late evening when consumption is highest. At night no electricity is generated. So each source has a certain capacity factor. For nuclear energy the capacity factor is more than 92%. That is, power is generated 92% of the time. The only reason the capacity factor isn’t 100% is that most light water reactors require maintenance and refueling. The capacity factors for wind and solar are about 37 and 27% respectively.

To fully harness these two renewable sources one needs storage. We are lucky compared to most countries because 60 - 780% of our electricity is generated from hydro. Hydroelectricity provides base-load power but can to some extent also can act as a sort of battery. That said, manyost of our hydro-electric generating stations are what is called ‘run of river’ and these have limited scope for holding back water.

By 2040 it is expected that NZ’s electricity consumption will double or triple and this extra electricity is unlikely to be generated by hydro for all sorts of reasons.

That leaves limited options including wind, solar and geothermal. I believe that we have still quite a decent amount of untapped geothermal capacity which might fill about 30% of the extra electricity needed by 2040. NothwithstandingNotwithstanding the much slower rate of deployment compared to solar, conventional geothermal energy is not emissions-free, although this problem seems surmountable by the re-injection of CO2 which appears viable.

Prior to the Fukushima Tsunami Germany had 17 operating reactors. The 2011 Fukushima disaster of 2011 also caused the green-leaning German Government to close down eight reactors. Today only five5 out of the 17 plants remain in operation and they will be shut down soon. To compensate for this abrupt loss of generation, Germany has taken to building out renewables and is continuing to burn significant amounts ofing more coal and gas than ever. They were using a lot of Russian gas but since the Americans blew up the Nord Stream pipeline supplying that gas they have had to import LNG from other parts, including the United States and at three to four times3-4x the cost, and burn more coal.

I feel it would have been better to leave the nuclear plants operating because the worst kind of waste that humans are currently generating is the CO2 which we are sending into the atmosphere. That has to be urgently reduced to zero.

If a country values energy security and has few cheaper and cleaner non-nuclear options available then nuclear energy may make some sense. However, there is a lot to be said for the clean and safe base-load power that nuclear plants can supply.