China’s faces technical challenges to develop thorium based nuclear power

By 2017 the Chinese are expecting to be running an experimental molten salt reactor, whilst other countries and commercial organisations, are being left behind. China’s first step towards liquid fuelled thorium reactors is, in essence, to reproduce the work done by Oak Ridge National Nuclear Laboratory (ORNL) in the sixties, when ORNL built and ran the Molten Salt Reactor Experiment MSRE. But what are the problems and challenges facing the Chinese as front runners in the drive to start up a liquid fuelled thorium reactor (LFTR)? 

Alvin Weinberg

Under Director Alvin Weinberg, back in the sixties and seventies a number of them were identified by the MSRE at Oak Ridge National Nuclear Laboratory.  In the test environment some of these challenges seemed to have answers, whilst others are still to be solved.  They are all written up in reports and published papers, now freely available on the internet, or at the ORNL archives.  You can be sure that they have been well studied by the many Chinese visitors to Oak Ridge.

Materials Hastelloy - N

The MSRE ran at around 670 deg C and the combination of high temperature and radiation made the selection of materials critically important.

The Molten Salt Reactor Experiment

Based on laboratory tests Hastelloy –N (originally known as INOR-8), a nickel alloy with molybdenum and chromium developed by ORNL, was chosen for the reactor containment vessel and for piping and heat exchangers. 

 Chemical Composition of Hastelloy N™

•     Carbon 0.04-0.08

•     Chromium 6.00-8.00

•     Molybdenum 15.00-18.00

•     Iron 5.00 max

•     Manganese 0.8 max

•     Aluminum + Ti 0.5 max

•     Boron 0.01 max

•     Sulfur 0.03 max

•     Nickel remainder

During construction questions arose concerning the stress-rupture life and fracture strain, which were found to be drastically reduced by thermal neutron irradiation. 

An out-of-pile corrosion test program was carried out for Hastelloy-N^[9] which indicated extremely low corrosion rates at MSRE conditions.  Capsules exposed in the Materials Testing Reactor showed that salt fission power densities of more than 200 W/cm³ had no adverse effects on compatibility of fuel salt, Hastelloy-N, and graphite.  With their chosen salt mixture (see below) and at the operating temperature, they found that Hastelloy N was adequately resistant against corrosion and embrittlement for its design life in the MSRE.  Since this was an experimental reactor, however, this is not the same as saying that it will last the 30 years necessary for a commercial reactor.

Later experience showed that the mechanical properties of Hastelloy – N do deteriorate as a result of exposure to thermal neutrons but that the addition of small amounts of titanium and hafnium significantly improve its performance. to select the most resistant alloy much more long term operational experience is needed.

MSRE core

Graphite Moderator
As in Light Water Reactors, the graphite moderator blocks were found to swell and crack in the high radiation environment.  As a minimum this creates a maintenance issue since the blocks have to be replaced.  More seriously, depending on the reactor design, it can block fluid pathways and lead to hot spots.

Research into graphite production methods and coatings was carried out by ORNL but it remained an unsolved problem in the early seventies.

There are many ways to design a nuclear reactor and other possibilities of moderating the neutron flux may need to be tried.  

Alternatively one could opt for an un-moderated molten salt reactor design working in the fast spectrum.  Such a reactor would be able to burn actinides and eliminate almost entirely the production of highly radioactive waste having a long half life.  This is the subject of research at Grenoble, France but it has never been attempted on the scale of an experimental reactor so far.

Tritium removal

Tritium is generated in small quantities within the molten salt as a breakdown product of lithium 6. Tritium, or hydrogen-3, is made by bombarding lithium-6 (⁶Li) with a neutron (n). This neutron bombardment will cause the lithium-6 nucleus to fission, producing helium-4 (⁴He) plus tritium (³T) and energy.

Tritium is highly radioactive and must be sequestered in a secure storage facility.  If, however, the lithium salt used is purified to 99.995% Lithium -7, then the quantities of tritium produced amount to only a few hundred grams per year from a 1GWe reactor. 

At the temperatures concerned, however, tritium can pass through the heat exchanger material and get into the secondary cooling loop from where it could escape into the environment.  ORNL developed a secondary loop coolant system that would chemically adsorb the few hundred grams of residual tritium to a less mobile form, so that it could be trapped and removed from the secondary coolant, rather than diffusing into the turbine power cycle.  ORNL calculated that this technique would, by itself, reduce tritium emissions to the environment to acceptable levels 

The tritium was then extracted and successfully oxidized over copper oxides and captured in a pair of water bubblers.  No tritium was found in the exhaust gases.  

The process of capturing the already low concentration of tritium from the molten salt was found to be not very straightforward and more work is need to develop this or other process options.

The Lithium Problem

ORNL chemists did extensive pioneering work to find the best mixture of salts to give the desired physical and chemical characteristics.  Many were tested but they opted for Flibe, a mixture of lithium and beryllium fluorides.

Present day research programmes may need to revisit the choice of lithium because it’s necessary to use only lithium 7 and to remove the 7.5 % of the naturally present lithium 6 isotope.  Otherwise, depending on the concentration, lithium 6 would either transmute in the reactor into tritium, as mentioned above, or prevent the reactor from starting up due to its high neutron absorption characteristics.

But this is only part of the lithium problem.   At present only two countries are carrying out lithium isotope separation, China and Russia.

Since lithium 6 can be used to make tritium its production is strictly monitored. 

Interestingly in the US Castle Bravo hydrogen bomb, tested at Bikini Atoll on 1^st March 1954, it was assumed that only the 30% of lithium-6 present in the lithium charge would react in a hydrogen bomb, but the contribution from an overlooked reaction due to the presence of the remaining 70% of lithium-7  caused an unexpected increase in yield of 250%,  making the 15 Megaton explosion the largest thermonuclear device tested at that date.

The US stopped separation of these isotopes, using the mercury amalgam method, a number of years ago due to concerns about its toxicity and the fact that large quantities of mercury had been lost from the Oak Ridge National Nuclear Laboratory inventory in an unknown manner.

So the lithium problem presents a difficulty to any private sector group not working in co-operation with a government having a form of lithium isotope separation technology. 

Other salt mixtures not using lithium are possible and many were tested at ORNL in the laboratory but so far they are completely untested in reactors and may affect the choice of reactor materials.

Storage of Solidified Salts

At the end of the MSRE programme the molten salts were stored as a solidified material.  It was found that fluorine and uranium hexafluoride were continuously released by radiolysis.   As a temporary measure the solidified contents were periodically reheated to induce recombination, but eventually the uranium was removed from the salts in an expensive and challenging cleanup programme.  A solution to this problem would be to remove the uranium prior to storage of the solidified salt by sparging the molten salt with fluorine gas, to create uranium hexafluoride which can be re-introduced into the reactor. 

Plutonium must also be removed to prevent radiolysis, which can be done by the addition of sodium carbonate to create plutonium dioxide. 

Conclusion

This is by no means a full list of the issues which arose during the operation of the MSRE. (Section 7 of the Weinberg Foundation's recent Report on Thorium-Fuelled Molten Salt Reactors gives several more). So there are plenty of technical challenges to address as the Chinese firstly repeat the MSRE experiment, and then extend it into larger reactor designs.  Personally I’m extremely pleased that the Chinese have the vision, the money and the forward thinking to restart and extend the pioneering work that was done at ORNL in the sixties and seventies   The use of thorium reactors running at atmospheric pressure will be much safer and will produce much less radioactive wastes than the current 50 year old designs of the existing Light Water Reactor fleet.  For me safe and abundant nuclear power is the only way of avoiding the prospect of runaway global warming, because conservation of energy, and the intermittent nature of the main renewable sources, cannot provide more than a part of the answer to the rapidly increasing global demand for energy.

Under Weinberg's leadership ORNL had a world leading  combination of nuclear scientists, engineers, chemists and metallurgists all working under one organisational umbrella.  They were capable of taking any brief concerning nuclear power generation and turning it into reality quickly and efficiently.  The USA allowed much of this expertise to dissipate when the Nixon administration fired Alvin Weinberg because he disagreed with the administration’s chosen programme of liquid metal cooled fast breeder reactors.  By the time that programme was closed down the USA  had forgotten about the highly promising liquid fluoride technology that is once again coming to the fore. 

It’s a pity that the US, like other western countries, has not yet found the courage or political will to overcome the inertia inherent in the nuclear establishment, which is committed to the Pressurised Light Water Reactor and the uranium–plutonium fuel cycle.   Coming from the UK, I’ve seen many examples over the years where pioneering research is done by underfunded organisations, only to be developed by other better placed countries.  It’s a symptom of the West’s debt-burdened economic decadence in the face of the challenge of the Far East, but in fifty years time, if all goes well, we’ll thank the Chinese for picking up and developing ORNL’s 50 year old Liquid Fluoride Reactor research, even if we have to pay the licence fees to China for our neighbourhood power station.

Although there are some signs of increasing openness, and their thorium programme is a good example, it’s also worrying that the Chinese, as communists, do not have a fully representative form of government.  I sincerely hope that the Chinese thorium programme doesn't get caught up in some sort of revolutionary “Chinese Spring” that could set their programme back decades.



Here are some other posts that might interest you if you have read this far.

An outline of the Chinese thorium program given by Kun Chen,Professor and Deputy Director, Department of Nuclear Safety and Engineering, Shanghai Institute of Applied Physics.
http://johnpreedy.blogspot.fr/2012/08/the-chinese-thorium-programme.html

A detailed review of Robert Hargraves' book "Thorium- energy cheaper than coal".
http://johnpreedy.blogspot.fr/2012/11/thorium-energy-cheaper-than-coal.html

China has a virtual monopoly on the production of rare earth elements of which process thorium is a byproduct.
http://johnpreedy.blogspot.fr/2012/09/the-thorium-problem.html

Horace Preedy - A Tribute



Horace Preedy on his 107th birthday

Dad was born on 17th January 1906, in East Ham, the third of four children. At the age of three he caught diphtheria and was taken to hospital in a hansom cab. He survived but contracted a heart murmur for which he was grateful later.

He left school at fourteen and worked for a while as an apprentice painter and decorator.  He progressed to working in the City, starting as a messenger then as a clerk for a firm of stockbrokers. Here he met Mum and she recalled the event in the reminiscences that she wrote at the age of 91. She says:-

“There was one customer who fancied the country girl who served him in the teashop at Stratford Broadway where she worked and asked if he could see her after work. The other girls asked his name. She said she didn’t know and they laughed and teased her saying, “It’s not Horace is it?” At their next meeting she asked him his name, “It’s not Horace is it?”, she said. He burst out laughing and said that it was. She said “I can’t call you that! Don’t you have any other names?”

He told her that his other names were Horace Robert Arthur, and so Bob was chosen, and he remained Bob in the office for years.”

They were married in Chingford in June 1935, and in the late thirties they lived in a bungalow in Billericay, owned by Horace’s parents, on a third of an acre, with a garden lovingly tended by Horace. They had two dogs and they used to play badminton and tennis at the local club. They’d achieved the dream life style of a young couple in the 1930’s and the only thing missing was a child or two.

A year and a half later the slump of the thirties had caught up with the City and Horace, always cautious, was concerned that he might be next to be sacked: so he took a part-time job with the GPO in the Brentwood Telephone Exchange. Some days he would come home from the City and then cycle six miles to the Exchange for an evening’s work. In August 1939, after a year’s probation, his status as a civil servant became permanent. He left his job in the Stock Brokers and went to work as a telephonist.

On 3rd September 1939 war was declared. He continued to work as a telephonist, frequently riding his bike to work at night whilst air raids were in progress. In 1942 he was drafted into the Signals Regiment and was well behind the front lines as the invasion advanced across France in 1944.

He liked to tell the story that in 1944 his unit was due to be sent to Burma. Dad was 38 at the time. The doctor who examined him at the medical looked at his papers, in which he was classified as A1, and said,

“You don’t want to go do you?” He certainly didn’t want to be sent to fight the Japanese in the jungles of Burma so he said “ No sir!” .
The doctor said “You have a heart murmur, but it’s well compensated and nothing to worry about,” and classified him C3. This meant that he was unfit for tropical service! It was a lucky escape because there were few survivors from his unit after their tour of duty!

The bungalow in Billericay was sold during the war and Mum, by now pregnant with Brenda, was sleeping on her brother’s sofa. Brenda was born in October 1944. Accommodation was very scarce by the end of the war and in the winter of 1944 Mum and Dad found a few rooms to rent in Westcliff on Sea, where they lived for the next 38 years.

At first the gloomy house, with navy blue wallpaper, was shared with two old ladies. In the scullery there was a stone sink, a copper to heat water over a gas ring, and a bath, which was not plumbed in and had to be bailed out. Needless to say, in my childhood, baths were only a weekly event.

After discharge from the Army he went back to the GPO, but soon he took the Civil Service Officers exam, passed and was allocated to the War Damage Commission. This meant getting up at 5 o’clock, walking to the station to catch the steam train to Liverpool street and then taking the tube to Acton. They still worked Saturday mornings so on Saturdays he had to travel for a total of six hours to work for four!

He applied for promotion, passed and was transferred to the National Assistance Board, which later became the Department of Social Security. His job was to visit claimant’s on Canvey Island to assess their cases. He had an auto-cycle, a sort of primitive moped, which meant dressing up in waterproofs and driving to work in all weathers. When he found old people struggling to get by he applied his own discretion and was able to give them some extra money for household items, but he was not at all sympathetic to men who wouldn’t work.

He bought a car in the early sixties. I remember that one day we took it to Canvey Island to fetch a little Yorkshire terrier from an old man who could no longer look after it. It was filthy and smelly, with matted hair and an aggressive nature. It was my job to restrain it on the back seat! When we got home Dad dressed up in a plastic mac and sou’wester, dumped the little dog in the bath, cut off most of his fur and gave him a good wash. In the next few months a beautiful silver-haired Yorkie, called Nobby, became one of the family, but he was definitely Dad‘s dog. Several years later, when Nobby was dying of heart trouble, my father would sleep in a deck-chair downstairs in order to stay with him at night, and reassure him when he was in pain.

Dad was a pioneer of DIY in the fifties and bought a table saw, which was dangerously plugged into an unearthed lighting fitting. He was very practical, he knew about carpentry and even how to "wipe" a lead pipe joint, but where he learnt it from I’ve no idea! As a child I used to watch him working and whenever I asked a question he patiently explained what he was doing.

While he worked steadily at modernising and improving the house, which by now he had bought, he sang songs from the 1930’s especially the Fred Astaire numbers that he used to dance to in his twenties. He always had a tune going on somewhere in his head. He‘d wanted to learn the violin when he was young but couldn’t persuade his parents to buy him one. He never did learn to play a musical instrument, but he was, none-the-less, very musical. When she was helping him with the decorating, Brenda remembers him singing “When Father Papered the Parlour” a hit from 1910. Less characteristically, she also remembers him dancing with her down the hill to the station to the tune of “ We’re off to see the Wizard…“ when we were going to a cousin’s wedding.

Normally though, he liked peace and quiet. In the evenings after work he was always outside in the small garden patiently chopping up things with his secateurs to feed the worms. Brenda and I both owe our love of gardening to him.

In 1982 Mum and Dad moved from Southend to Wantage to be nearer Brenda, and her husband Les. Here, as well as having a larger garden to keep him busy, he could still be seen painting the bungalow at the age of 92.

It was typical of him that he almost never complained and accepted what life sent his way. He was very patient, stoical and only rarely showed any anger. He didn’t need a lot of people around him but he had a strong sense of duty to his parents, his family and to a few close friends. He was polite right through to the end of his life, a real gentleman, and always said thank you when you took him a cup of tea or a meal.

In his later years, unlike my mother, he was still mobile, but he suffered progressively from memory loss, so he acted as my mother’s arms and legs while she told him what she wanted, and where to go to find it!

When Mum died from a massive stroke at the age of 97 we asked Dad, on the way back from the funeral, if he knew where we’d been and he said no. Sometimes Nature can be kind as well as cruel.

He never smoked and only drank alcohol at Christmas. He owes a good part of his very long life to these things, but Brenda has been his carer for the last ten years, whilst he slowly declined, and she has looked after him attentively. I’m quite sure that without her care he would have died some years ago.

She has also made it possible for him to die peacefully at home, in his own bed, at 107, the seventh oldest man in Britain. He died in his sleep on 2nd June 2013.

Thanks Dad for providing a stable and loving family home for us to grow up in. We’ll both miss you.

John Preedy

Le Printemps des Poètes - 2013

Every year the Lieu Commun at St Céré holds an event for the French National Poetry Fortnight which is called “Le Printemps des Poètes”.  The theme this year was Les Voix du Poème, (the voices of the poem). With such a vague theme there is plenty of scope for different interpretations; including using different voices to read one poem; or reading poems in various languages; or perhaps one person reading a poem in several different voices as each character speaks. Le Lieu Commun opted for the first two of these possibilities.

Fourteen people were asked, or volunteered themselves, to take part on 16^th March and several rehearsals were held in the month before.  Participants chose their own poems, which were subjected to a limited amount of scrutiny by the group for length and suitability. Most of the poems were in French but some were in English, Spanish and Arabic. There was a Spanish song about poetry sung by Jean-Louis and Patrice.

Reading poems outdoors in the Place Mercadial needs to be lively and requires some direction, otherwise the public would quickly lose interest, so Raymonde, who has worked in the theatre, became involved.  She encouraged the performers to engage with the audience, to project their voices and to be expressive.  Her contribution was very effective and allowed the group to achieve such a high standard.

Several texts were split up amongst the performers with each speaking a verse or asking a question. The whole event took about forty minutes.  

Poems were read by, Marie-Ange, Brigitte, Jean-Louis, Joss, Dominique, Quince, Patrice, Pôline, Linda, Ouria, and Albert.  Christine and Agnes organised and paraded the titles before each poem and Quince played short interludes on the piccolo. 

I didn't notice that Albert was missing from the group photo when I took it, so here he is reciting his poem La Pluie (the rain).

Renaud was a very impressive bicycling gendarme who had the role of dispersing these disruptive poets at the end of their performance. 

He continued in character and was effectively moving on the crowd around the refreshments table in the Maison des Consuls afterwards. 

Thanks to Alain and Gilberte for the copious supply of home made cakes.

The Poems

Au bout du monde - Robert Desnos

Ode Maritime -Fernando Pessoa

La voix - Robert Desnos

L'évadé- Boris Vian

Quartier Libre- Jaques Prévert

La Poesia es un arma cargada de futuro - Gabriel Celaya

Haïku - Vent d'avril

Cahier d'un retour au pays natal - Aimé Cesairé

Las de tout ceux - Thomas Tranströmer

Création - Serge Behar

Piedras Antarcticas - Pablo Neruda

Le chat carême - Maurice Carême

La chute de la lune - Mahmoud Darwich

La Poesie ça sert à quoi?

Conversation de l'arbre et du vent - Marie José Christien

Ila Oumi ( Ma mère) - Mahmoud Darwich

La Voix - Charles Baudelaire

La goutte d'eau - Raymond Queneau

Bergeries - Eugène Guillevic

Daïnouri Choque – A Unique Singing Teacher

Yesterday, with the rest of the quartet, I went on a singing course, which was absolutely fascinating. The teacher, Daïnouri Choque, concentrated on the production and blending of the sound but not in a classical fashion. He didn't look for power, or placement of the voice, but worked by getting us to listen to the natural vocal harmonics and how they change with vowel sounds. 

In order to demonstrate, in a very dramatic way, what he meant about harmonics he sang one note and by changing something inside his mouth he produced a series of harmonics which formed part of "the Ode to Joy" from Beethoven's 9th. The harmonics were quite high pitched but, once you tuned yourself in to them, they were very clear. Then he got us producing them ourselves but obviously in a much less controlled manner. Each vowel has its characteristic natural harmonics and when you slowly change from one vowel to another you can hear the harmonics re-aligning themselves in the space between the fully formed vowel sounds.  His preferred sequence of French vowels was i, é, eu, o and the inverse.

So what was the objective here? When I was contemplating the course I have to admit that I had no idea what it was going to be like, or what we were expecting to achieve. Our bass had been before, but all that I could understand from his description was that Daïnouri taught singers how to listen and sing together better. It’s a truism that all musicians or singers working in any type of ensemble have to learn how to play in tune and in time with the others. Sometimes for amateurs this isn’t easy, but that’s usually a question of more practice. What Daïnouri teaches is much more.  He wants the sound to blend at a harmonic level so that individual voices truly enter into the combined sound of the group.  When it’s done correctly the sound has a clarity and unity that is heard in some professional groups like cathedral choirs and other ensembles singing sacred music. 

After a morning of individual exercises, in the afternoon we sang some pieces from our own repertoire and I complained that one of them was pitched too high for my voice. He offered to help me and he sang next to me.  He tuned his harmonics to mine resulting in an enormous change in the quality of the sound and a tremendously intimate connection at a musical level.  The sound was so coherent that it took on a character of its own.  It was like someone else singing inside you but using your own voice to produce the sound. That was a most remarkable and exceptional moment.  I have never experienced anything like it before.

When we sang with all four voices, since he has also been a choirmaster, he knew exactly how to balance the quartet, and how to get us to form the same vowel sounds, so that the result was better than we have ever sung before. We were already singing the chord that starts each piece to get the pitch right but he also taught us to form the same vowel sound so that the harmonics were aligned. The effect of this is similar to that which I describe in the paragraph above. The collective sound is reinforced by each voice and a greater degree of clarity and resonance is created even in a dry acoustic.  In some of the more vertical pieces we were able to sustain this throughout. 

All of this was done without the ego tripping displayed by some teachers and without being fixed on any one technique or method. His explanations were always clear and sensible and when it’s necessary he has the experience to adapt his teaching to the requirements of the individual.  His method is to work with the ear, the body and the voice.  He spent quite a long time with our Alto, getting her to reduce the muscular tension that she naturally has. This gets worse when she's nervous and prevents her from controlling her voice, especially when singing sustained long notes. She found his calmness in explaining diaphragm breathing and how to stand in a relaxed manner very effective. It allowed her for the first time to really understand what was happening with her body, not just whilst singing, and she was very impressed with the insights that she gained. 

His courses usually last a week but we were able to make a special arrangement with him to tack a day onto another course that he was leading near Villeneuve sur Lot and what an extraordinary day it was!

Daïnouri leads workshops all over France, Belgium and Switzerland.  He works with groups of individuals, choirs and choir masters.

Parsifal - New York Metropolitan Opera

Live Relay - 2 March 2013

Wonderful singing from the Principals but the production is flawed.

It has been said that Parsifal is un-stageable.  It’s true that there are quite long moments while the singers are waiting for the music to allow them to move on to the next action.  In the case of Parsifal there isn’t much action anyway and the real movement is often in the music.

It’s also true that familiar concepts for the presentation of operas need to be challenged and in this way operas are renewed down the generations.  Sometimes this is successful, sometimes not.  François Girard has responded to Parsifal by setting it, supposedly, in the not too distant future.   

Act One had the Knights of the Grail in white shirts and black trousers.  The stage was a sloping desert of cracked dried mud, with a small rivulet running through it that turned red when Amfortas took his bath.  The Knights were on the right of the rivulet as a seated circular group, moving together from side to side or using their arms to reinforce the action.  Women in dark clothes were on the left.  They were mostly static. The Grail was a simple golden chalice and no lighting was used to suggest its power.  At the end of the Act the rivulet opens up into a chasm into which Parsifal stares mystified and wondrous.

Act Two, is set in Klingsor’s magic garden, which is generally portrayed as a beautiful colourful place; the text says it is in a wooded valley.  The flower maidens are usually seductive and alluring. Girard put the flower maidens, wearing white nightgowns and having long black hair, in a dark red cave dripping with blood.  If you think of early horror movie female vampires you’ll get the general impression.  
Throughout the act all the performers were standing in a lake of stage blood and, as they knelt or moved, it stained their clothes.  Klingsor had to pick it up in cupped hands and throw it about or pretend to!   A river of blood flowed down the back of the stage between the rocks at the entrance to the cave.  It’s difficult to imagine anything less likely to create a mood of seduction or more likely to distract one from the music. At the end Parsifal just takes the spear from an unresisting Klingsor and that’s it!  In fact so dramatic was this moment that my companion slept through it, although to be fair this interpretation is supported directly by the text!

Act Three returned to the desert of cracked mud, which had now been transformed into a post-apocalyptic scene reminiscent of science fiction from the sixties and seventies.  Klingsors’ realm has been destroyed and, amid graves lightly dusted with snow, men and women stood about looking shocked and filthy, like refugees from the holocaust.  There were a few overturned plastic chairs.  Nonetheless it remained difficult to escape the medieval origins of the work, which is Wagner's interpretation of Parzival, the 13^th Century poem written by Wolfram von Eschenbach.  Instead of a 21^st century coffin Titurel was swaddled in white wrappings like a mummy as he was laid in his grave and Amfortas’ spear, now carried by Parsifal, was prominent.

Clearly there is blood in Wagner’s text.  Amfortas’ wound bleeds continually and blood from the body of Christ is at the source of the power of the Grail.   Blood is also suggested by Klingsors’ self-emasculation in his mistaken attempt to gain purity, but it is not the primary focus of the story of the opera, which is to achieve redemption.  In this production there was too much blood, which had a visual impact far too powerful for its role in the text.  The director also employed too much coordinated group arm waving, which distracted from the performance as a whole.

But what a performance!  All of the principals gave powerful and impressive readings of their parts.  They acted strongly, especially Peter Mattei as Amfortas, the physical nature of his suffering being matched by his range of vocal colours.  René Pape was a powerful and indefatigable Gurnemanz, who was also very human and engaging.  Evgeny Nikitin as Klingsor couldn’t have been more angry and evil.  Katarina Dalayman, sings her role very well but she was not successful when playing the seductress Kundry in the second Act.  One was left thinking that she could have been Parsifal’s long lost mother, and her heart didn’t really seem to be in it, but later her memorable duet with Jonas Kaufmann’s Parsifal was overflowing with intensity.  

Both of them gave absolutely everything here and I’m sure that their voices more than filled the Met.  Daniele Gatti conducted the whole evening impeccably from memory with assurance and artistry. This was an exceptional cast for an exceptional piece but I’m sorry that I can’t say the same for the production.

A minor gripe about the sound before I finish.  It was noticeable that the balance for the quiet passages and offstage voices was not correct.  There was a lot of low frequency background noise, as if the microphones were too far away from the performers.  I didn’t notice this problem when they did Götterdämmerung a year ago on MET HD Live so they need to do something to address it.

Why Young Apple Trees Die in Midi-Pyrenees

About three years ago we planted five apple trees. Three have died, another is sick, leaving only one which is reasonably healthy.

They have never grown strongly and we assumed that this was due to the extreme dryness which we suffer from in the summer, but this is not the case.  When these trees start to die the trunks have a diameter of about five centimetres (two inches).   

The bark near the base of the trunk goes soft and then this spreads around the trunk.  By this stage there is no cure and the trees end up on the bonfire.  So far this problem has not affected other types of trees in the garden.

These trees were bought from several local nurseries, but the three which have died have come from the largest, so we went to ask them what was going wrong.  After checking that it was not the result of mower damage, the helpful and knowledgeable assistant at Jarriges asked if the damage started on the Western side of the tree.   I had already registered that it seemed to start on the South Western side.  He then said that sometimes their suppliers grow the trees too close together and so when they are small they don’t get enough direct sun to harden the bark.  If they are then planted out in a position where they receive direct sun from the South and West their bark cooks and is damaged.  A fungal disease then enters and the rot starts.

The solution is to protect the trees by wrapping sacking around the trunk until they are well established. 

Since the nursery is aware of the problem it’s a great pity that we were not given this advice when they were bought.

Thorium - Energy Cheaper than Coal - A Review

Robert Hargraves in his book “Thorium - Energy Cheaper than Coal” has decided to take the layman reader with him on a journey through the highly technical subject of energy and power generation.  His objective is to persuade the reader that it's possible, by making the right choices, to generate energy cheaper than that currently produced from coal in the US. 

So he starts with what you might call “Energy 101”, which would not be out of place in a high school curriculum.  Why is energy important to civilisation?  What is it and in what forms does it present itself? How is it stored and released? By page 60, however, he moves on to the serious issues behind the whole book: the rapidly increasing worldwide demand for energy, how that demand could be satisfied: the consequences of the various options and the link between the consumption of energy and prosperity. 

His book is stuffed with facts, charts and graphics.  He’s clearly done a lot of research but, in the absence of numbered references in the text, the diligent reader should know that they are listed as URL links, page by page, from p401.  I reached the middle of the book before I discovered this!

Energy Sources

Energy Sources  (Chapter 4 pp101-175) is very well developed and comprehensively reviews the advantages, disadvantages, limitations, efficiencies, utilisation factors and costs of energy generated from Coal, Gas, Wind, Solar, Solid Biofuels, Liquid Biofuels, Hydroelectric, Oil and Nuclear sources.  He also deals with energy Conservation and Storage.  It’s quite a tour de force in so few pages.  He’s enthusiastic about the efficiency of the Combined Cycle Gas Turbine, but he effectively demolishes Wind Power because it needs public subsidies and backup power plants running on gas, which can be rapidly started up when the wind drops.  Unfortunately these can actually contribute more carbon dioxide than Gas Turbines running on their own (p136).  He doesn’t make judgements about these subjects, he just lets the numbers speak for themselves!

Gas from Shales and Schists - Fracking

Writing from the North American perspective leads Hargraves to favour gas from shales and schists.  Because he’s convinced that replacing coal burning with much more efficient combined cycle gas turbine generators would lead to less overall release of CO2, he advocates harvesting natural gas from the “fracking” of shales (p121).  This conclusion contrasts dramatically with widespread European opposition to fracking from all fronts, not just the environmentalists.  Hargraves’ confident assurances that the gas bearing shales, (and schists) are well below the water table, and therefore fracking will not cause contamination of aquifers, doesn’t stand up.  Nature, geology and engineering are not so neat and tidy!  In France this pressure has forced the President, Francois Hollande, to announce that “fracking” will not be allowed to proceed.  Mind you in France no decision is ever irrevocable!

LFTR’s v The Rest

The Liquid Fluoride Thorium Reactor (LFTR) is presented in chapter 5, along with a plethora of other reactor designs, some of which offer significant advantages over the conventional uranium based Pressurised Water Reactor.  Many of these alternative designs were developed at Oak Ridge National Nuclear Laboratory, which ran a demonstration molten salt reactor from 1965 until the programme was closed down by the Nixon administration in 1969. 

Research on the Pebble Bed Advanced High Temperature Reactor (PB-AHTR) is being pursued in the US, with modest government funding of $7 million over three years, by UC Berkeley, MIT and U Wisconsin, whilst in China, with a $400 million budget and 432 people, they expect to have a demonstration PB-AHTR cooled by molten salt running by 2015 and an LFTR by 2017.   

Following the model of earlier chapters Hargraves begins with the physical fundamentals, in this case that means starting with the nuclear physics of fission and radioactive decay, then he continues by describing the technologies and finally gives a summary of the advantages of the LFTR.  The result is that the lay reader is presented with quite a lot of difficult to digest detail before the real advantages of the LFTR are described.  I’ve grappled with the problems of presenting of this material myself and, whilst Hargraves’ approach is logical and consistent, there is a definite risk of losing the reader in the technicalities.

By the end of chapter 5, I was much more aware of the multiplicity of different nuclear reactor types which have been built in the past, or are now proposed or are actively under development.  He describes numerous designs, along with their advantages and disadvantages; fast or thermal spectrum; solid or liquid fuel; water, gas, liquid metal or molten salt cooled; and of course those using the uranium/plutonium or thorium fuel cycles.  It’s a very useful one stop source for anyone wishing to be more informed about the background of innovation in the nuclear industry that’s going on behind utilization of the dominant pressurized water reactor.  It’s easy to assume that the conservative nature of the major stakeholders is stifling new developments but that’s certainly not always the case. 

Safety

Hargraves, in chapter 6, concentrates on the safety record of the nuclear power industry compared to other industries and by restricting his argument to fatalities he makes a strong case for nuclear power.  He goes on to comment on the perception of the risks of radiation compared to the reality of radiation arising from nuclear power installations.  Again he’s right and presents much evidence to support his case but, by concentrating on fatalities, he downplays the consequences of a major radiation discharge in terms of the disruption and fear that it engenders.  Even if the population concerned have a minor risk of suffering health problems the establishment of exclusion zones means that they will most likely have lost their livelihood or their property or even both.  They will also be terrified of the long term effects on their families.  The WHO report on Chernobyl states that this is the major adverse effect of that disaster.  To appreciate how this weighs on the public mind just consider the reaction to the Tsunami, in which about 23,000 people died, and then to the release of radioactive materials at Fukushima, which has so far yet to cause any direct health effects but where potential predicted cancer deaths range from none to 100.

He presents some surprising statistics, such as 1 in 77 Americans will die as a result of traffic accidents.  But of course we all accept that we have to use the roads!

“Don’t confuse me with the facts, I know what I think!” 

The fundamental problem when trying to convince people that nuclear power can be safe is that it’s a complex subject which concerns diverse technical issues and evaluation of risks.  These are very difficult to discuss successfully with non-technically minded people.  I find that you frequently arrive at the stage of “Don’t confuse me with the facts, I know what I think!”  So for many committed environmentalists there's little hope of persuading them that new nuclear power designs can be very safe indeed because, not being equipped to evaluate the evidence, they prefer not to trust the messenger and revert to views based on emotion.  There are, however, a few environmentalists who have listened to the LFTR message and they agree that it, and other inherently safe fourth generation nuclear plant designs, represent the only practical way of rapidly reducing carbon dioxide emissions and therefore avoiding the planet-wide, but less immediate, environmental disaster that awaits future generations. 

In this chapter Hargraves also addresses nuclear waste and weapons proliferation.

Energy generated from LFTR's for a Sustainable World is a great introduction to alternative technologies for replacing fossil fuels for use in transport: and also to using cheap energy from nuclear power to substitute for fossil fuels in chemical process industries and desalination plants.  This vision is not unlike that of Weinberg’s in the 1960’s when he proposed "making the deserts bloom" using nuclear powered desalination.  It may happen one day if the economics are right.  Energy, which is cheaper than that generated from coal, is a necessary, but not sufficient, condition because there’s much more in play here than just the cost of energy.  There would also need to be an acceptance that nuclear power plants and chemical plants, or even cement plants could cohabit on the same sites. 

I’ve visited a few cement plants and they are notable for their lack of security and their proximity to the quarries.  Their technology is really very simple.  I can’t imagine how you would graft a nuclear power plant onto one without a major investment in staff and security that would greatly increase the cement companies operating costs.  I really doubt that cement manufacturing companies would be interested in upgrading their technical capabilities to the required level or taking on the regulatory and technical risks.  Perhaps some sort of "Industrial Park", full of process industries with high energy demands, centred on a nuclear plant built and operated by an experienced nuclear company could be possible, but the whole thing would most likely have to be started from scratch and be very large.  In the European context, with financial uncertainty, a strong environmental lobby, high population densities and restrictive planning laws, it would be an unusually major investment the like of which is now rarely seen. 

The final chapter entitled Energy Policy is a fact packed discussion of the fragmented nature of energy policy and the highly subsidized nature of the energy sector in both the US and European contexts.  He calls for better political leadership in this area, something which the West seems unable to deliver but which the Chinese, in the energy sector at least, appear to be very well placed.

Conclusion

Robert Hargraves starts out by writing for the lay reader and ends up writing for the technically educated thorium enthusiast.  On the way he covers all aspects of energy and not just nuclear power.  In a trajectory that takes its reader from an introduction to energy which is suitable for a high school pupil, to the sort of detail that might interest a post-graduate student of nuclear engineering or environmental studies, he has written a comprehensive book so packed with facts concerning energy costs, efficiencies, utilisation factors and design details that it will serve as a useful reference book for some years to come.