Dialogue: Nuclear power is best option

By ALAN POLETTI*

This winter's electricity supply crisis has highlighted a problem that has at least three inter-related and challenging facets:

* The need to increase electrical generating capacity in New Zealand.

* The need for a more robust electrical supply system.

* The need to meet international commitments to abate greenhouse gas (GHG) emissions.

Let us look at each of these in turn.

More electrical generating capacity: Electricity demand in New Zealand has grown at 2.4 per cent a year for the past 20 years. Growth at this rate for the next 20 years implies that by the year 2021, 60 per cent more electricity will need to be generated than this year. It is believed that most of this increase will be provided by natural gas.

A robust electrical supply system: An average daily wholesale price peaking at over $400 per MWh compared with an average of nearer $30 per MWh for all of last year clearly shows that our electrical supply system is unable to respond to unexpected problems. It lacks robustness. Putting aside questions concerning the distribution infrastructure, this was because there was not enough effective generating capacity.

New Zealand's commitment to GHG emission abatement: Present proposals by electrical generating companies will inevitably increase these emissions. Other much-touted methods of generating electricity without GHG emissions are unable to provide electricity in the quantities required.

To meet the commitments to abatement, emissions will need to be cut by as much as a third. No options discussed at present will come anywhere near this.

The best solution to such complex problems will be found only by considering all options. I can immediately dismiss one - fuel cells. These merely convert chemical energy stored in hydrogen to electrical energy. The hydrogen in its turn must be generated from some other fuel, such as natural gas or methanol - and the technology is still at the developmental stage.

Two further options are of little use, mainly because they cannot be used on the necessary scale. These are the generation of electricity using solar cells and the use of wind generators. Both work intermittently and not well in a cold, dry winter.

Bioenergy is sometimes suggested - by burning specially produced crops in thermal power plants, or by utilising landfill gases. The former would compete directly with other land uses, in particular, its use for food production.

Landfill gases cannot provide significant generating capacity.

Geothermal electricity has served New Zealand well for many years. It is a marvellous baseload generator, but it is not an abundant resource and has significant environmental problems associated with the discharge of the condensed water, which contains dissolved pollutants such as arsenic.

The second tailrace at Manapouri and the proposed Waitaki River development (if it proceeds) will give extra hydro capacity, but it is remote from the area of greatest demand growth. There are other major hydro resources not yet developed, such as the Buller River, but most would not easily get resource management consent.

Most new or planned generating capacity would use natural gas, but this is a direct producer of the very GHGs whose emission we have pledged to abate.

The new combined-cycle plants are more efficient electrical generators than older ones, but that is all. As they are deployed, our GHG emissions will increase inexorably.

Given the above litany, it is astounding there has been no discussion of an option that can contribute directly to meeting the above three challenges. It is time for a reasoned and rational consideration of nuclear power for New Zealand.

For too long, we have been subjected to a campaign of misinformation by environmental groups who are prepared to bend the truth to suit their own needs. Nuclear power is consequently viewed with apprehension, if not dread, by many New Zealanders. As a solution to our problems, it is not mentioned in polite society.

If, however, we look at the facts and eschew the hysteria that surrounds anything connected with the words "nuclear" or "radiation", we find nuclear power is a most-viable option. It can easily be deployed on the necessary scale.

There are several competing modern designs for 600 MW(e) reactors - about the capacity needed.

Their design has evolved from reactors that have operated for more than 30 years in many Western countries, as well as Japan, South Korea and Taiwan. Their safety record is excellent.

A nuclear power plant could be sited near the area of greatest demand, avoiding the transmission losses from the South Island to the Auckland region.

Its production of greenhouse gases would be negligible. It would contribute significantly to the robustness of New Zealand's electrical power system.

Some objections are easily dealt with, especially the safe disposal of nuclear waste, which is a straightforward technical task.

This is because there is a small amount of waste, and because of its physical properties once it is incorporated in molten glass and sealed in a stainless-steel container.

Burial deep underground will then isolate it from the living environment.

New Zealand's "clean green image" would not suffer. France, which produces 75 per cent of its electricity by nuclear means, has no trouble selling dairy products overseas.

South of Lyon in the Rhône valley, there are two nuclear power plants that produce more electricity a day than all of New Zealand's generators put together.

The region's wines are prized around the world and sell readily.

The reactor would be subject to the International Atomic Energy Agency Safeguards programme. It would not be possible to divert material from the reactor to manufacture nuclear weapons.

Like hydro-electric generators, nuclear plants have a high capital cost. Although their capital cost is higher than for gas-fired plants, their cost of fuel is considerably less.

French nuclear electricity competes favourably on the European market. (They export significant quantities, for instance, to Germany, whose Government has just decided to close all its reactors over the next 20 years.)

In the United States, many nuclear plants now compete favourably with fossil-fuelled plants.

In any plans to meet the three needs set out at the beginning of this article, it is imperative that nuclear power be assessed as a competing technology. It could well be the best and most environmentally responsible one.

* Professor Alan Poletti is emeritus professor of physics at Auckland University and was a member of the special committee looking at the safety of nuclear-powered ships. He was also a member of the international advisory committee that studied Mururoa Atoll.