Super-Phenix

Super-Phenix is the name of the Nuclear reactor of the ex- nuclear plant of Creys-Malville on the commune of Creys-Mépieu, in the Isere. Super-Phenix is a prototype French of fast reactor and coolant sodium making following the experimental Nuclear reactors Phoenix and Rapsodie.

History

Two postulates led to the construction of Super-Phenix: the anticipation of a sustained high growth of the energy needs and the existence of a stock limited of natural uranium. In such a scenario, only the breeder reactors (of which the die with fast neutrons) appear durable.

In April 1976, French the Prime Minister Jacques Chirac authorizes the company NERSA to place order of Super-Phenix.

The project of the power station of Super-Phenix is the fruit of an international collaboration between EDF (51%), the Italian company Enel (33%) and the German company SBK (16%). In the beginning, an engine was to be built in each country partner but, following political pressures, only Super-Phenix was born.

The July 31st 1977, a demonstration against the project was held in Creys-Malville, it was one of most important of the history of the movement Antinucléaire French. The CRS used offensive grenades to push back the demonstrators, making a death, Vital Michalon and a hundred casualties, of which two (Michel Grandjean and Manfred Schultz) had to be amputees of a hand or a foot. At the time of this demonstration, several demonstrators tried to force the barriers intended to protect the building site. A gendarme is also amputee of a hand.

The January 18th 1982, an attack with the rocket launcher aimed at the building site of the Nuclear plant of Super-Phenix, without making victims. The authors of the attack were not identified, but, in 2003, Chaïm Nissim, former deputy ecologist of Geneva, affirmed to be the author and to be gotten about it the weapon near the group of the terrorist Carlos.

The Nuclear plant of Creys-Malville is brought into service in 1985. It encounters technical difficulties and administrative (it is a prototype) which cause multiple stops including one three years and half: January 19th, 1994, the daily newspaper Le Monde title “After three years and half of stopping of the breeder, the authorities of safety propose a restarting of Super-Phenix under conditions. ”

On arrival of the Plural left, the Greens claimed the stop and the dismantling of Super-Phenix. The Commission of the production and the exchanges of the National Assembly noted in April 1997 that “the dead halt of the engine is, in any event, more expensive than the continuation of the activity even burdened with a low level of availability of the infrastructure”. Moreover, the report/ratio of the Sénat concludes, on assessment of the Court of Auditors, that “on the whole, taking into account the assumptions of EDF, to delay the stop of the operation of the power station until the end of convention between the partners in NERSA, that is to say fine 2000, would have probably been overall neutral on the financial plan. ”

Extracts of the report/ratio of the Senate established in 1998:

“the cost of construction and operation of Super-Phenix exceeded the initial estimates. In his report/ratio of January 1997, the Court of Auditors evaluated it to 60 billion francs distributed between the partners of European consortium NERSA43 (*) to the amount of 51% for EDF, 33% for the Italian electrician Enel and 16% for the consortium SBK, which gathers the German electricians RWE, Dutch SEP and Belgian Electrabel. Actually, taking into account the value of the electricity provided to the network by the engine, the expenditure would rise, according to it, to 40,5 billion francs. ”

In 1997, Lionel Jospin, Prime Minister for the France, announce: “Super-Phenix will be abandoned”. Lionel Jospin having taken its decision, a Ministerial decree of the December 30th 1998 led to its final adoption. The called upon reasons, influenced by the pressure of the public opinion, was that the weak price of the Uranium did not justify any more the investments in this technology.

The expenses of compensation for the foreign shareholders of NERSA, déboutée by the decision of the French government, were compensated by supplies of current of EDF to these foreign partners between 1996 and 2000.

Operation

The fast reactor Super-Phenix was an engine which developed a power comparable with that of a section of a traditional nuclear plant or of two Thermo plants of strong power: 3000 MWth and 1240 MWe, is a gross return of 41,3%. The preferential fuel of the engine is plutonium 239 but could also use MOX (plutonium on support depleted uranium) resulting from the reprocessing. The development of this fuel used also in the traditional power stations was also one of the called upon causes of the dismantling of Super-Phenix.

The principle of operation of Super-Phenix is that of an engine with Nuclear fission using fast neutrons (without moderating) and using Sodium liquid as coolant in its primary coolant circuit. Each Fission of heavy core releases about 200 MeV. Consequently, 1 MWh corresponds 1 G from fuel. For an operation with full power 300 days per annum, the consumption of Super-Phenix would thus have been of 3000 X 300 = 900 kg of Plutonium, that is to say about a ton. This figure is to be compared with the 15 106 tons of oil annual of a Thermo plant, or even to the 27 tons of uranium enriched by a Pressurized water reactor.

The fission of fuel, induced by a neutron flux, releases from energy at the same time as a certain number of Neutron S, of which a part will induce again Fission S, thus maintaining the chain reaction. In addition, some Neutron S take part in the Transmutation of the Uranium -238 into Plutonium -239, which is also Fissile.

The heat produced in the Super-Phenix engine was evacuated with Sodium liquid (550°C). Indeed, it was necessary at the same time that the material is a effective Caloporteur (like water) and that it does not slow down the Neutron S (contrary to water). This first circuit (primary) of Sodium échangait heat with a secondary circuit of Sodium, then with a circuit with water, which actuated the turbines of the alternator after Vaporisation.

The coolant circuit of Super-Phenix was of type swimming pool ( pool reactor ): the Sodium of the primary education circuit, potentially radioactive, was confined inside the tank and an intermediate exchanger allowed the heat transfer with the secondary coolant system of Sodium. This constituted a major technological innovation compared to the system in particular used on Rapsodie and the American breeders: cooling by loops ( loop reactor ) where several loops (2 in the case of Rapsodie and up to 6 for certain engines) of Sodium allowed the exchange between primary education circuit and secondary circuit, radioactive primary education sodium then not being confined inside the tank.

Neutron balance of a REFERENCE MARK

It is supposed that the only fissile material is Uranium 235. The numbers indicated are orders from grandeur.100 fissions of Uranium 235 on average 250 neutrons release, which give place to the following reactions:

100 neutrons cause 100 new fissions, thus maintaining the chain reaction, and consuming 100 cores of fissile material,
70 neutrons undergo fertile captures by 70 cores of fertile material uranium 238, transforming them into as many fissile plutonium 239 cores,
75 neutrons undergo non-fission captures, either by fissile cores (30 neutrons), or by cores of the cooling agent, structures of the heart, elements of control or fission products,
5 neutrons flee out it heart (to be captured by neutron shieldings).

Neutron balance of Super-Phenix

It is supposed that the only fissile material is plutonium 239. 100 fissions of ²³⁹Pu release on average nearly 300 neutrons. These neutrons will undergo the following reactions:

100 neutrons cause 100 new fissions, maintaining the chain reaction and consuming 100 fissile cores of ²³⁹Pu,
100 neutrons undergo, in the heart even engine, a fertile capture by 100 cores of ²³⁸U, transforming them into as many fissile cores of ²³⁹Pu,
40 neutrons undergo a sterile capture, either by fissile cores (20 neutrons), or by cores of the cooling agent, structures, elements of control or fission products,
60 neutrons flee out of the heart itself, where they essentially undergo (50 neutrons) a fertile capture by 50 cores of ²³⁸U, transforming them into as many cores of ²³⁹Pu; the other neutrons (10) undergo a sterile capture, either in the covers, or in the neutron shieldings.

Comparison of the assessments

Let us calculate in both cases the regeneration rate TR, that is to say by definition the report/ratio of the number of fissile cores produced by fertile capture with the number of fissile cores destroyed by fission and captures sterile.

$TR_ {REFERENCE MARKS} = \ frac {70} {100 + 30} = 0.6< 1$ (one should not forget the neutrons destroyed by sterile capture (i.e lost for the reaction)) ,
$TR_ {InterneSuperph} = \ frac {100} {100+20} = 0.8 < 1$ , where one takes into account only regeneration in the heart,
$TR_ {TotalSuperph} = \ frac {100 + 50} {100 + 20} =1.25 > 1$ , where one takes into account regeneration in the heart and the covers.

It is thus seen that an engine such as Super-Phenix is breeder thanks to the presence of covers. Contrary, to surround a REFERENCE MARK of covers would not be used for nothing, being given the low number of neutrons which flee out of the heart.

Super-Phenix was designed to produce more Plutonium that it does not consume any, it is what is called the Surgénération. This extraordinary property is due to the neutron balance explained above (the regeneration rate is higher than 1). Research was carried out on Super-Phenix to try out such a breeder reactor. This research went mainly on the Neutronique, and in particular on a detailed examination of the assessment of Neutron S in the engine. This research was partially stopped by the closing of Super-Phenix.

Discusses on Super-Phenix

Super-Phenix was in the center of a sharp controversy, its defenders arguing on his interest, the militants Antinucléaire S exposing of many arguments against him: After the fight of the ecologists the Greens against Super-Phenix since its planning and construction, a domestic network called Sortir the nuclear power was formed with its closing, gathering hundreds of organizations: ecological local committees, associations, movements of citizen and parties.

Accident risks and safety

The risk of the major accident is always possible, although very weak (a racing of the heart of the type of that of the Catastrophe of Tchernobyl is indeed improbable because of the negative reactivity of fuel) .

The power station contains five tons of Plutonium and 5.000 tons of Sodium liquid, which ignites spontaneously in contact with the Air, and explodes in contact with the Eau by producing Hydrogène, itself extremely reactive. In addition, one cannot still extinguish a fire of more than few hundreds of kilograms of sodium.

Since 1976, an engineer of EDF - J.P. Pharabod - declares in Sciences and Life (n°703, April 1976) which “it is not unreasonable to think that a serious occurring accident with Super-Phenix could kill more than one million people. ” what started a sharp polemic in France on the safety of Super-Phenix.

The December 8th 1990, part of the roof of the room of the Turbine S collapsed because of snow, requiring to rebuild the superstructure of half of the building. The engine was stopped this day. engine should have resisted the fall of a private plane. -->

One of the problems for safety is the increase in the Viscosité fluid coolant (liquid sodium) in the event of badly controlled pollution.

Interest of breeding

According to the industrialists of the nuclear power, breeding always represents a solution with the problem of the uranium shortage. Indeed, even if the forecasts of the Années 1970 appeared too pessimistic because of the policies of control of the energy expenditure the shortly of the oil crises and an undervaluation of the quantity and content of the uranium layers economically exploitable, the uranium reserve (at the current level of consumption) is estimated between 50 and 90 years following projections.

The energy of the fast neutrons, contrary to the pressurized water reactors, makes it possible to transform not only all the initial heavy atoms, but also those, with long life, generated by the reaction: Neptunium, Plutonium, Americium, Curium, etc Moreover, one engine of this type can be used in breeding to optimize the output matter (natural uranium is transformed little by little into Plutonium which is burned in its turn) or in sousgeneration, in which case it burns fissile material excesses and in particular makes it possible to eliminate military plutonium. Lastly, a fast reactor could accelerate the transmutation of fission products to long life into products with shorter life and thus contribute to reduce toxicity in the long term these waste. Such studies were led to Super-Phenix and are continued on the engine Phoenix, in agreement with the Loi Battles.

Developed technical training

Super-Phenix allowed ECA and EDF to develop pointed techniques. Technological data were collected, in particular as for the Caloporteur: liquid sodium. This knowledge could be re-used for the future fast reactors with coolant sodium, one of the solutions recommended by the International forum Generation IV, which gathers the great powers of the civilian nuclear: Germany, the United States of America, France, the United Kingdom, Italy, Japan, etc

Decisions of construction/closing

According to the opponents, the dismantling of Super-Phenix was decided without public consultation, just like its construction. Its promoters underline on the contrary that the abandonment of Super-Phenix was decided by a Ministerial decree , while its construction had been decided by a Loi.

Assessment

Cost

The cost of the Super-Phenix operation was very high on the plan Financier. The building costs (ten billion francs for a forecast of four billion) and maintenance with Super-Phenix during its operation were evaluated to 40,5 billion French francs and the price of sound Démantèlement was estimated at 16,5 billion French francs: with final the industrial experiment was often considered to be expensive, the possibility of an industrial exploitation “normal” being disputed

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