Time to reconsider

Nuclear power generation in New Zealand was a serious option in the 1970's, but after the Maui gas field was discovered things were put on hold until  the new millennium. The time has come to consider it again, says Bryan Leyland.

For many years New Zealand has had a nuclear free policy. In the beginning, this policy was aimed entirely at nuclear weapons. The government decided that we would have nothing to do with ships that might - or might not - have been carrying nuclear weapons.  Regrettably, this understandable aversion to nuclear weapons was soon transferred to nuclear powered ships.

As David Lange once told me, this was because, "I was unable to persuade cabinet that there was a difference between a nuclear reactor and an atomic bomb." (This is also mentioned in his autobiography.) Although New Zealand's anti-nuclear legislation does not exclude nuclear power stations, the Government and many other people in New Zealand choose to believe that it does.

The Government believes that generating 90 percent of our electricity from renewables will not increase the cost of power because, it claims, wind power costs about  7c/kWh. However, recent investigations by the Electricity Commission that show that wind power will cost at least 11 c/kWh to generate appear to have been ignored.

The Energy Strategy underestimates load growth, ignores the need to replace existing thermal power stations and fails to discuss the fact that the true cost of wind power will be even higher than 11c/kWh because allowance must be made for the cost of backup generation and the cost of the additional transmission lines.

Analyses carried out by the Electricity Commission show that wind power can compete with gas or coal fired generation only if the carbon price is around $45 per tonne. This will increase the cost of electricity by about $1.8 billion per annum, or $500 per annum per household. Wholesale electricity prices will increase from about seven cents to something like 12 cents. Domestic prices will increase by 20 percent or more. This is a very high price to pay for a policy that, for sure, will make no difference to the climate and is aimed at a problem that probably does not exist.

Many overseas governments have adopted a low carbon policy endorsing nuclear power and the reason is quite obvious: It is the only large scale technology available that can make a substantial difference to carbon emissions without increasing the cost of power. Nuclear power already generates 17 percent of the world's electricity - about the same as hydropower. Modern nuclear power stations are simpler, cheaper and much safer than existing stations. A recent study for Australia showed that with a moderate carbon tax, nuclear power was even cheaper than Australia's very low cost coal fired generation and a lot cheaper than wind power.

Nuclear power generation for New Zealand was being actively considered in the 1970's and two sites were identified on the Kaipara harbour. Civil engineering investigations were carried out and engineers were sent overseas for training in nuclear power technology. When we discovered the Maui gas field, the project was put on hold until "after 2000". The time has come to consider it again.

There is no doubt that sites North of Auckland are ideal. They could supply 1000-2000MW of electricity to the city from the North, eliminating the need to spend $500 million on transmission across the harbour, the need for the $1 billion 400kV transmission line from the South, and the need to spend $500 million on the DC link to carry 500MW of power from the proposed wind farms in the South Island. If this transmission saving is credited to the nuclear stations, then nuclear power will almost certainly be the lowest cost option.

We are often told that the 1000MW plus size of modern nuclear reactors is too big for the New Zealand power system. Not so. Modern reactors are available with unit sizes below 1000MW. The CANDU reactor from Canada is available right now in sizes between 350 and 650MW. Many CANDU reactors are operating successfully in Canada and in other countries. Additional advantages are that they produce relatively low level waste, and can burn thorium that is not only abundant and found in New Zealand, but is unsuitable for nuclear weapons.

The very promising, inherently safe (i.e. cannot melt down) "Pebble Bed Modular Reactor" now being built in South Africa comes in sealed modules rated at about 200MW. A power station of 6-8 modules would be ideal for New Zealand. These reactors are able to change load quite rapidly and can operate efficiently down to 40 percent of maximum output. For a small system like ours, this would be a very significant advantage.

Much is made of the problems of disposing of nuclear wastes. No doubt, this is a problem but one for which there are technological solutions. Much of the nuclear waste that needs to be disposed of is from past weapons manufacture and several waste repositories are being built in the world right now. Waste disposal would not be a problem for New Zealand because any contract for a nuclear reactor would also include the supply of the fuel and its later reprocessing and disposal. 

The accident at Chernobyl is often used as an argument against nuclear power. But using Chernobyl as an argument against modern reactors is no different from saying that we should not travel in modern cruise liners because the Titanic did not have enough lifeboats or that we should not drive in cars because the Model T Ford did not have seat belts and air bags. Like ships and cars, modern power stations must be judged on their own merits. 

To me, a hydropower engineer, the dangers of nuclear power generation do not even come close to the risk of failure of large dams. The failure of a large dam could easily kill hundreds of thousands of people and destroy vast areas of agricultural land. To give one example, a recent report says that the Mosul Dam in Iraq has serious problems with its foundations and could fail catastrophically. If it does, 500 million people could be drowned. This dam will require constant monitoring and remedial action into the foreseeable future.

I believe that nuclear power should be actively considered as an option for power generation in New Zealand. Those that choose to believe that carbon dioxide causes dangerous man-made global warming should also strongly support nuclear power.

I do not think that we should tolerate a situation where the inability of a past Labour cabinet to understand the difference between a nuclear reactor and an atom bomb and the prime minister's conviction that "nuclear power is not for New Zealand" means that a much more expensive and unreliable power supply is imposed on us. It is a viable option and it should be considered.