Madam, - David McGuinness (July 12th) asks when the day of "peak uranium" will arrive. This echoes statements made frequently by Minister Eamonn Ryan and others that "uranium is running out".
The trite answer is "about 4500 AD". An OECD report (June 2006) states that "the total identified amount of conventional uranium stocks is about 4.7 million tonnes, sufficient for 85 years". Not bad, considering there has been little exploration for the past 25 years owing to depressed prices.
Like all geological resources, uranium can be depleted, but if fast-breeder reactors - which can use uranium fuel 30 times more efficiently than conventional reactors - were more widely used, these could provide greenhouse-gas-free power from existing resources for about 2,500 years. And if that were not enough, there are also unconventional sources of uranium in low-grade deposits and even sea-water.
Sweden, with a population of 9 million people and 10 reactors (putting it in third place after France and Belgium in terms of nuclear-generated electricity), is host to an enormous resource of low-grade uranium in the alum shale formation which runs for about one-third of the country's length. Even Ireland has small partially-explored deposits in Donegal and Carlow.
All possible energy resources must be considered. Petroleum-derived products should be conserved exclusively for aviation, shipping and petrochemicals. Road vehicles and trains could use electricity produced from nuclear, hydro, wind, wave and tidal sources.
Burning coal, oil and gas for electricity generation and home-heating is no longer sustainable and we are running the risk of provoking runaway climate change, perhaps boiling off the atmosphere (as happened on Mars and Mercury), in which case there would be nobody around in 4500 AD to worry about depleting uranium stocks. - Yours, etc,
GEORGE REYNOLDS
(Consulting Geophysicist),
Annamoe,
Co Wicklow.