The existence of about 450 (443 may be the exact figure) nuclear power reactors around the world turns out to be one of the major threats to life on Earth.

This thread started off as a discussion on whether nuclear power was a safe option that could provide “sustainable” power that produced less greenhouse gas emissions. ie. Should more nuclear power stations be built?

What is now being uncovered is that the existing nuclear power stations are one of the biggest threats to life on Earth and we need to start an urgent program to dismantle them all (this would take decades to achieve and require enormous funds and technical expertise).

Why? The first reason we turned up is financial. Nuclear power stations cost a lot of money to maintain but more to the point they cost a lot of money to decommission. As the world is poised for the big grandmother of all financial meltdowns nuclear power plants are also at risk of melting down as the funds to maintain and decommission them are no longer there.

Now there is another major reason (or even two major reasons) reported in Nexus Magazine Feb-Mar 2012. Nuclear power stations depend critically for their function on having continuous power to cool their fuel cores and their spent fuel ponds. This means they are critically dependent for their safe on-going functioning on the safe on-going functioning of the ordinary electric power grid (our big national power grids).

Sure there are back-up generator systems to generate power to run the cooling systems if the grid goes down but around the world’s 450 nuclear plants these only have short-term supplies (about one week’s worth) of fuel (diesel)to run these back-up generators.

The whole security of the world’s nuclear power plants is dependent on blackouts in our power grids being very short term (one week or less). For example the Nuclear Regulatory Commission in the US currently mandates only one week’s supply of back-up generator fuel to be stored at each reactor site.

This is not always the case and there are several scenarios that could take out power grids for much longer.

What sort of time line is needed for back-up power to the nuclear power plants for cooling to be guaranteed? Well it takes over 5-7 days to slow down a reactor core’s nuclear chain reactions to the point where the core may be removed from the reactor. After removal the fuel rods are quite ‘hot’ in terms of both temperature and radioactivity. For the next 3-5 years these fuel rods must be immersed under many feet of continuously cooled water in order to shield the surrounding area from a high level of radioactivity as well as to prevent catastrophyic meltdown from occurring. the ‘boil-down-time’ for spent fuel rod containment poinds runs from 4-22 days after the loss of the cooling system power.

So basically the answer is however long it takes (worst case scenario) to get the power grid back up and running with the worst case scenario being 5 years.

What could cause massive long-term power blackouts?

Well the meltdowns at Fukushima Daiichi nuclear reactor after the 11 March 2011 earthquake and tsunami were caused by the loss of electric power to the cooling system pumps when the facility’s massive back-up diesel generators were wiped out by the ensuing tidal waves.

But that is pretty local. What could cause whole of nation or region or even whole of the global massive long-term power blackouts?

Whole of nation or region power grid failures could be caused by an EMP strike by terrorists or an enemy nation deliberately detonating a nuclear device at high altitude roughly between 39 and 386 kilometres above the surface of the Earth. Suborbital nuclear detonations of this type have the potential to cause serious damage to electronics and electrical power grids along their line of sight covering huge distances in the order of a circular area 2415 in diameter. This would cause widespread power grid collapse. There was a recent ‘tabletop EMP’ exercise at the National Defense University in the US attended by dozens of the US’s leading first responders public safety experts and military personnel and it simulated a massive grid-down scenario typical of an EMP attack. Apparently even these highly trained personnel had a hard time grappling with the public safety implications of a disaster the size of 50 hurrican Katrinas.

What could take out the whole world’s power grids and be followed by nuclear meltdowns at the whole world’s nuclear power plants unless preparations are put in place urgently to be able to fuel the back-up generators for a very long period?

Extreme geomagnetic disturbances (GMDs) from the sun caused by solar superstorms will take down the whole world’s power grids and be followed by nuclear meltdowns at all the world’s nuclear power plants unless preparations are put in place urgently. So far preventative measures are not in place.

Extreme GMDs are natural occurances that occur irregularly about every 70 years. The last was in 14-15 May 1921 long before the advent of modern electronics and nuclear power plants.

GMDs happen quite frequently and it is their intensity that makes the difference. The most intense in recorded history was the 28 August to 4 September 1859 Carrington Event which is estimated to have been 50% stronger than the 1921 event which was 10 times as strong as one in March 1989 that fried a main power transformer in the Hydro-Quebec system in Canada causing a cascading grid failure and caused damaged transformers in New Jersey and the UK.

Metatech Corporation undertook extensive modelling and analysis of the potential effects of extreme geomagnetic storms basing its modelling on an event with the intensity of the 1921 event. This modelling showed that a GMD of this magnitude would induce massive current and voltage spikes into thousands of kilometres of antenna-like power lines that interconnect the power grid. These current spikes combined with induced harmonic anomalies would severely damage or destroy extra-high-voltage (EHV) power transformers critical to the functioning of the grid. Possibly well over 2000 EHV transformers worldwide would be taken out.

EHV power transformers are custom designed cost over $1million each and there is a lead time of 1-3 years to manufacture and purchase one. Total global manufacturing capacity is roughly 100 EHV transformers per year when the world’s manufacturing centres are functioning properly (ie. the power grid is working!).

The loss of thousands of EHV transformers worldwide will cause catastrophic collapse of the power grid worldwide and will take years at best to put back together.

In this scenario all the nuclear power plants around the world will melt down.

Extreme GMDs happen often as far as our lifetimes are concerned.

Nexus Magazine Feb-March 2012 “Geomagnetic storms EMP and nuclear armageddon”