Monday, 1 October 2012



Some oldies are becoming topical again:
Note: a further comment has been provided by Rudo de Ruijter, Independent researcher, 
          Link added in Comments below.

“Photons and Atoms
by Mike Hohmann on Monday, March 28, 2011 at 2:53pm

OK – one swallow doesn’t make a summer, but at 12:30h on 22 March 2011, German photovoltaic power installations fed 12.1 Gigawatt electricity into the national grid, exceeding the combined contribution of the nine remaining nuclear power stations together providing 12.0 Gigawatt [ 23.03.11]. Considering that current levels of PV installations are far below possibilities, as are wind, biofuel and other CleanEnergy resources, there just isn’t any ongoing need for nuclear energy.

Nuclear power has never been safe, and never will be, it appears – their risks just cannot be insured. The Times [09.09.09.] reports a notional Public Liability premium cover requirement of £620 million per power station, any excess falling on the taxpayer in addition to risks from waste storage and health and life losses. The world’s largest re-insurance company – Munich Re – is reported [ /, 23.03.11] to have declared that it is impossible to say how high an insurance premium should be in the absence of state guarantees, because there is no known modelling method on which to base a risk assessment.

Compare this to the £5million Public Liability Insurance being asked from residents who want to hold a Street Party on the occasion of the forthcoming Royal Wedding.......”

Or as Douglas Adams put it:

“The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair.”

But even if the actual nuclear powered steam engines work as they should, unresolved problems remain for which our grandchildren – and theirs in turn – are unlikely to forgive us.  I enclose copy of a translation of a memorandum received over a year ago:

Translation of a memorandum received from Franz Eder dated 21 April 2011              

Notes on occasion of the nuclear disaster in Japan, and considering general problems with nuclear power
by Franz Eder 21.4.2011

“Die ich rief, die Geister,
   From the spirits that I called,
werd'ich nun nicht los.
   Master, now deliver me!”

                                     GoetheThe Sorcerer’s Apprentice   


The Dangers of Nuclear Accidents

To start with, I would like to make clear that I write these notes from a layman’s point of view for use by other non-specialists like me; a nuclear physicist might well look askance at them.  I am convinced, however, from talking to many other laymen like me that very little about these matters is generally known – which is why I hope these notes may be helpful.

These days we hear and talk much about the “Sustainability” of actions and processes, for example

  • Renewable resources must NOT be used faster than they grow or can be regenerated
  • NON-renewable resources (e.g. oil, gas) may be used only to the extent that renewable resources can NOT be made available.

These requirements for sustainability, while enshrined in law, so far exist only on paper.

The only real example in practice of enduring “Sustainability” is illustrated by the current nuclear disaster in Japan, with its aftermath ‘sustainably’ affecting men, women, children, animals, plants, air and ocean – for generations to come.

[remember Chernobyl in 1986; full list of nuclear disasters and their aftermaths at,1518,756369,00.html#ref=nlint ].

A few technical details:

  1. To ‘switch off’ an atomic power station, or to take it off-line in more technical parlance, requires the careful gradual insertion of control rods among the fuel rods in order to slow down the chain reaction of the nuclear fission process.
  2. During this process, the first 20 to 30 hours are extremely critical because the heat produced is no longer withdrawn by steam for power generation and the fuel rods get hotter.  An increased cooling effort is required, not only with water but also with special coolants to keep the fission process within manageable limits.
  3. After this initial period continual cooling of the reactor is a more normal routine.                [the working temperature of a nuclear reactor is around 800ºC.  It is claimed that the switch-off process can be routinely mastered].
  4. This requires some remarks about the Chernobyl accident.  The operators of the plant wanted to simulate an emergency, disconnected several safety systems in order to test what might happen and how one would need to react.
  5. During this emergency exercise, which also involved temporary reduction in cooling systems, the reactor over-heated to an extent that the control rods were no longer able to slow down the reaction and the rated heat output was exceeded by a factor 100.
  6. This emergency exercise was carried out over several days so that changing teams of operators were put to test in a shift system.

The result was an enormous increase of temperature inside the reactor, finally resulting in an explosion of the whole plant which blew off the 1000t heavy lid of the reactor allowing an unhindered release of radioactivity affecting wide parts of Europe, contaminating grass, mushrooms, milk etc.

In short, nuclear power generation is a very risky business.

-  2   -

The Dangers from Spent Fuel Rods

  • The fuel rods in nuclear reactors generally last for five years producing power in accordance with their design specification through nuclear fission, i.e. they boil water which powers steam turbines which in turn drive generators which finally produce the actual electricity.
  • At the end of their useful life the spent fuel rods are retrieved by robots from the reaction vessel and must be stored in cooling basins within the reactor building because of their high temperature of about 800ºC.  The on-site cooling period varies between one and five years.  Once cooled, these spent fuel rods were then (until 2005) transported to La Hague in France or to Sellafield in the UK to be reprocessed, i.e. 1-5% of the residual uranium are chemically extracted for use in new fuel rods.

Since 2005/6 it is illegal in Germany to send spent fuel rods for reprocessing, so that spent fuel rods have to be directly transported into interim storage facilities, e.g. Gorleben, where they need to be stored for an interim period 40 years before they can be transferred into final storage depots – which, however, do not yet exist.

  • To stay briefly with reprocessing:  the remaining nuclear waste (95-99% of spent fuel rods) remains highly radioactive and is fused with borate glass at a temperature of 1100ºC and poured into stainless steel tubes and sealed by welding; these cocoons have a diameter of 40cm and are 1.40m long.
  • The waste products in a fuel rod represent about 90-99%, the remaining 1-10% yield during reprocessing uranium and plutonium for re-use as fuel rods.

The CASTOR Transport Container

The containers for transporting spent fuel rods or cocoons are known as Castor Containers and are used to convey reprocessed fuel rods and the highly radioactive waste from reprocessing plants in La Hague or Sellafield to intermediate storage at Gorleben.

The technical details of Castor Containers:

Length:                         ~ 6.00m
Width:                           ~ 2.50m
Weight:                         ~ 120t
Load capacity:              ~ 10t ( that is 50-70 spent fuel rods, or 28 glass cocoons).
Cost                             € 1.5million
The Federal Republic of Germany is bound by contracts to take back all nuclear waste that arose from reprocessing spent fuel rods before 2005;  that means that transports from France are necessary until the end of 2011 and those from the UK are programmed to continue for between 2014 to 2017. 

The contents of Castors – whether fuel rods or glass  cocoonsproduce considerable heat, in the order of 400ºC, so that Castors have cooling ribs all over to help dissipate that heat.  In addition, the radiation must be constantly monitored because the 40cm thick envelope does not fully prevent the escape of radioactivity. 

Post-shutdown Residual Heat

When a nuclear reactor is shut down the radioactive decay of fission products continues to emit heat.  The power of this residual heat is about 10% of the thermal power of the reactor when under full load.  Should any cooling systems necessary to dissipate this residual heat stop functioning for any reason then rising temperatures may lead to hydrogen explosions and lastly to reactor melt-down – as happened in Japan.

This process will happen with spent fuel rods which are similarly subject to this residual heat at 10% of design power and must, therefore, be cooled in on-site cooling basins from 800ºC down to 400ºC.  This takes about 1-5 years;  only then is it possible to transport them.

Should anything disrupt the cooling arrangements during this period of residual heat dissipation, then even these spent fuel rods can produce enough heat from continuing nuclear chain reactions to lead to explosions and meltdown similar as might happen to the reactor itself.

The residual heat problem was my real reason for writing these notes because I think I am not the only one unaware of the big risks still latent in burnt-out fuel rods even after the have become useless for energy generation.

Perhaps we may better understand now why these long storage times for up to five years’ cooling within power stations followed by 40 further years in interim storage are necessary.  Only then is it possible to send these nuclear waste products to yet non-existent final depositories where they continue to dissipate heat and radiation. These final depositories are unacceptable to the public anywhere and remain the unresolved problem of the nuclear power industry.

I hope my brief notes may help to understand immediate and long-term dangers from nuclear power generation so that we know that no effort should be spared to rid ourselves from this menace.  Nothing I wrote is “directly copied from any nuclear scientist” but is based on my understanding of articles in Wikipedia and  Writing as a layman, may I be forgiven for any errors..

Issues with Radioactive Waste:

  • A nuclear power station with an output of 1,300MWp (the size of recent German power stations) produces about 50mper year of low heat producing radioactive waste,
  • During reprocessing, a further 10m3  of low heat producing radioactive waste arise
  • In addition app. 3mhighly radioactive fission products need to be dealt with
  • German nuclear power stations produce 450t/year of highly radioactive spent fuel rods
  • Worldwide, 12,000t/year of highly radioactive waste are produced;  by the end of 2010 a total of 800,000t has accrued, of which 70,000t in the US alone.
  • In Germany, the costs for dealing with nuclear waste are exempt from the general principle of the originator being liable for safe removal or storage. The result is that the taxpayer instead has to bear these costs, e.g. € 3million for nuclear waste transports alone, not to mention any other measures for dealing with the sheer never-ending problems with nuclear waste.

Some issues regarding nuclear waste from French and UK Reprocessing Plants:

Abbreviations used:
NPS                 = nuclear power station
RPP                 = reprocessing plant
FR                    = fuel rod
HAW                 = highly active waste
CC                    = Castor container
SD                   = storage depot
Cocoon            = stainless steel container for highly radioactive waste fused within borate glass
Nuclides           = unstable elements subject to radioactive decay

Radioactive Waste from RPPs in France and the UK

The borate glass, or more correctly, the HAW cocoons are stored for two years within the confines of RPPs before they are returned to Germany.  HAW cocoons generate heat so that before any final storage can be arranged they must be allowed to cool sufficiently in interim depots so that the rock caverns for eventual final storage are not overstressed.

The interim storage time for French cocoons is 30-40 years, cocoons from the Uk need to be stored for 40-50 years.

Each spent FR results in 0.6 to 0.9 cocoons, so that radioactive waste from reprocessing results in 2,850 cocoons from France and 700 cocoons from the UK which must be transported back to Germany. 

One Castor container can hold a maximum of 28 cocoons, so that around 130 CCs are needed to transport these ‘hot potatoes’  back to Germany.

Some more interesting numbers:  the average temperature of HAW cocoons is about 400ºC when leaving La Hague.  The maximum allowed safe temperature is 510ºC, but from temperatures above 500ºC the vitreous structure of cocooned waste can already deteriorate and crack, resulting in increased atomic radiation – a risk about which no further details are made public.  Above 600ºC the safe containment of radioactive material within the glass matrix can no longer be maintained.

If you followed me so far, I had in mind to elaborate further on ‘cocoons’, but that led me deeper into the whole nuclear mire than I had imagined. One amongst laymen, I had assumed that radioactive waste once fused within glass would be forever safely ‘locked behind bars’ – but no such luck.

Radiation Intensity of Cocoons

From here on I shall be dealing with some numbers whose significance, I must confess, I don’t fully grasp, but whose consequences are so momentous that I wish, at least,  to put them into perspective.

The nuclear wastes fused with glass inside cocoons are classified as highly radioactive, containing an unimaginably high number of unstable ‘nuclides’ which decay with varying lengths of half-lives. During decay they release particles (alpha and beta decay) as well as electromagnetic radiation (gamma rays).  It is the release of particles that is responsible for creating heat through friction with other atoms.

This is particularly important for the eventual final storage;  highly active waste (HAW) is also classified as ‘thermo-active waste’, usually known as HAW Cocoon.

HAW still contains 98-99% of the nuclear power present in the original fuel rods, for us laymen that’s still the same potential power.  This residual energy arises from the fission products in the reactor (mainly gamma and beta radiation) and trans-uranium  elements created by alpha particles.
At this point in my learning curve it was essential to understand the reasons for the high resultant heat;  to remind ourselves, the cocoons still have a temperature of 400ºC after two years of storage in the RPPs and must be transported at this temperature.

Radiation Dangers from Cocoons

The radiation potential of HAW cocoons is, for laymen like us, unimaginably high.  The half-life of the remaining nuclides can be as high as two million years.   Particles with short or medium long half-lives, e.g. caesium 137 gamma rays, are responsible for the high radiation doses during transport and interim storage, while the longer-lived nuclides, like alpha radiation from Neptunium 237, are the cause for the long-term safety problems at final containment depots.

Comparison of Risks

According specification, HAW cocoons from France can have extremely high radiation values from
- caesium 137,
            - strontium 90, and
                        - plutonium.
Staying with caesium, this means that with 28 cocoons in one Castor container it has the same radiation potential as a CASTOR V  NPS containing 10t of fuel rods.

At this point in the discussion, comparisons may be more useful than numbers, for example:
  • For a German NPS with an output of 1,300MW the total radioactive ‘inventory’ has only a marginally higher radioactive content than a SINGLE Castor container.
  • The content of a single HAW CC is the approximate equivalent of 20% of the nuclear inventory released during the Chernobyl accident.
  • The Gorleben storage depot for cocoons is licenced to contain the radioactive inventory of 2,000 HAW  CCs (that’s 56,000 cocoons).

To end these comparisons, a last example of the immense risks from this radiation load:

  • A single unshielded HAW cocoon has a surface radiation power which is lethal for humans within 60 seconds at a distance of 1.00m.

These examples alone should convince anyone that living with this “witches’ brew” should be avoided.

The data for RPPs and cocoons are taken from an essay by Wolfgang Neumann, physicist at The Ecology Group, Hanover.

I hope these notes have thrown some light – if not  shadows – on the cycle of nuclear power generation, and I should be pleased to receive any comments or corrections.

Franz Eder

“Sellafield-2 will produce 7.5 tons of plutonium every year.  1.5 kilogram of plutonium will make a nuclear bomb.
Sellafield-2 will release the same amount of radioactivity into the environment as Chernobyl every 4.5 years. One of these radioactive substances, krypton-85, will cause death and skin cancer”

The Real Costs of Nuclear Electricity
“It is hardly acceptable on moral grounds to assess the costs of possible consequences of a nuclear radiation catastrophe for life and limb of millions of people as well as the establishment of nuclear contaminated no-go areas in densely populated areas, in financial terms in order to arrive at a cost benefit calculation.”[1]  The same source quotes an estimated public liability premium of Euro 287billion to cover the likely costs of Euro 5trillion from a nuclear meltdown;  nuclear electricity plainly is beyond imaginable costs..   

The movie 4th Revolution [2] quotes the external costs of nuclear electricity at Euro 2.70/kWh. 
Compare this with the current costs of solar PV of Euro 0.14 and onshore wind of Euro 0.07 per kWh (unsubsidised).[3]

1 comment:

  1. Rudo de Ruijter, Independent researcher, has provided a link to his article
    "Raid on Nuclear Fuel Market", to be found at