Abstract
The French natural uranium-graphite power-reactor programme has been developing - from EDF 1 to EDF 4 - in the direction of an increase of the unit power of the installations, of the specific and volume powers, and of an improvement in the operational security conditions. The high power of EDF 4 (500 MWe) and the integration of the primary circuit into the reactor vessel, which is itself made of pre-stressed concrete, make it possible to make the most of the annular fuel elements already in use in EDF 1, and to arrive thus at a very satisfactory solution. The use of an internally cooled fuel element (an annular element) has led to a further step forward: it now becomes possible to increase the pressure of the cooling gas without danger of causing creep in the uranium tube. The use of a pre-stressed concrete vessel makes this pressure increase possible, and the integration of the primary circuit avoids the risk of a rapid depressurization which would be in this case a major danger. This report deals with the main problems presented by this new type of nuclear power station, and gives the main lines of research and studies now being carried
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Bourgeois, J;
[1]
Saitcevsky, B
[2]
- Commissariat a l'Energie Atomique, Saclay (France). Centre d'Etudes Nucleaires
- Electricite de France (EDF), 75 - Paris (France)
Citation Formats
Bourgeois, J, and Saitcevsky, B.
Developments in natural uranium - graphite reactors; Developpement des reacteurs a graphite et uranium naturel.
France: N. p.,
1964.
Web.
Bourgeois, J, & Saitcevsky, B.
Developments in natural uranium - graphite reactors; Developpement des reacteurs a graphite et uranium naturel.
France.
Bourgeois, J, and Saitcevsky, B.
1964.
"Developments in natural uranium - graphite reactors; Developpement des reacteurs a graphite et uranium naturel."
France.
@misc{etde_20668387,
title = {Developments in natural uranium - graphite reactors; Developpement des reacteurs a graphite et uranium naturel}
author = {Bourgeois, J, and Saitcevsky, B}
abstractNote = {The French natural uranium-graphite power-reactor programme has been developing - from EDF 1 to EDF 4 - in the direction of an increase of the unit power of the installations, of the specific and volume powers, and of an improvement in the operational security conditions. The high power of EDF 4 (500 MWe) and the integration of the primary circuit into the reactor vessel, which is itself made of pre-stressed concrete, make it possible to make the most of the annular fuel elements already in use in EDF 1, and to arrive thus at a very satisfactory solution. The use of an internally cooled fuel element (an annular element) has led to a further step forward: it now becomes possible to increase the pressure of the cooling gas without danger of causing creep in the uranium tube. The use of a pre-stressed concrete vessel makes this pressure increase possible, and the integration of the primary circuit avoids the risk of a rapid depressurization which would be in this case a major danger. This report deals with the main problems presented by this new type of nuclear power station, and gives the main lines of research and studies now being carried out in France. - Neutronic and thermal research has made it possible to consider using large size fuel elements (internal diameter = 77 mm, external diameter 95 mm) while still using natural uranium. - The problems connected with the production of these elements and with their in pile behaviour are the subject of a large programme, both out of pile and in power reactors (EDF 2) and test reactors (Pegase). - The increase in the size of the element leads to a large lattice pitch (35 to 40 cm). This makes it possible to consider having one charging aperture per channel or for a small number of channels, whether the charge machine be inside or outside the pressure vessel. In conclusion are given the main characteristics of a project for a 500 MWe power station using such a fuel element. In particular this project is compared to EDF 4 in order to show the advantages resulting from such developments in gas-graphite natural metallic uranium reactor systems; these are: a doubling of the specific and volume powers, and a three-fold reduction in the number of channels. The research now under way will make it possible to calculate the reduction in capital costs which will result from these important technical advances. (authors) [French] Le programme francais de centrales a graphite et uranium naturel s'est developpe, d'EDF 1 a EDF 4 - dans la voie d'un accroissement de la puissance unitaire des installations, de la puissance specifique et de la puissance volumique, et d'une amelioration des conditions de securite de fonctionnement. La puissance elevee d'EDF 4 (500 MWe) et l'integration du circuit primaire dans le caisson, lui-meme en beton precontraint, permettent ainsi de tirer le meilleur parti des elements combustibles tubulaires utilises des EDF 1, et d'arriver ainsi a une solution tres satisfaisante. L'emploi d'un element combustible refroidi interieurement (element annulaire) permet de faire un nouveau pas en avant: il devient alors possible d'augmenter la pression du gaz de refroidissement sans craindre le fluage du tube d'uranium. L'emploi d'un caisson en beton precontraint permet une telle augmentation de pression, et l'integration du circuit primaire elimine les risques d'une depressurisation rapide qui aurait presente dans ce cas un risque majeur. On aborde dans ce rapport les principaux problemes poses par ce nouveau type de centrale et on indique les grandes lignes des recherches et etudes effectuees en France: - Les etudes de neutronique et thermique ont permis d'envisager l'emploi d'elements combustibles de grandes dimensions (diametre interne = 77 mm, diametre externe = 95 mm), tout en conservant l'uranium naturel. - Les problemes de fabrication de ces elements, et de leur comportement en pile, font l'objet d'un programme important, tant hors pile que dans les piles de puissance (EDF 2) et les piles d'essais (Pegase). - L'augmentation des dimensions du combustible conduit a un pas du reseau tres important (35 a 40 cm), on peut alors envisager de disposer d'un trou de chargement par canal ou pour un petit nombre de canaux, que les machines de chargement soient placees a l'interieur ou a l'exterieur du caisson. En conclusion on donne les principales caracteristiques d'un projet de centrale de 500 MWe utilisant un tel element combustible. On compare en particulier un tel projet a la centrale EDF 4, afin de mettre en evidence les gains que peuvent apporter de tels developpements a la filiere gaz-graphite et uranium metallique naturel, dont les plus importants sont: le doublement de la puissance specifique et de la puissance volumique, et la reduction d'un facteur 3 du nombre de canaux. Les etudes en cours permettront de preciser l'importance de la reduction sur le montant des investissements qui sera apportee par ces progres techniques importants. (auteurs)}
place = {France}
year = {1964}
month = {Jul}
}
title = {Developments in natural uranium - graphite reactors; Developpement des reacteurs a graphite et uranium naturel}
author = {Bourgeois, J, and Saitcevsky, B}
abstractNote = {The French natural uranium-graphite power-reactor programme has been developing - from EDF 1 to EDF 4 - in the direction of an increase of the unit power of the installations, of the specific and volume powers, and of an improvement in the operational security conditions. The high power of EDF 4 (500 MWe) and the integration of the primary circuit into the reactor vessel, which is itself made of pre-stressed concrete, make it possible to make the most of the annular fuel elements already in use in EDF 1, and to arrive thus at a very satisfactory solution. The use of an internally cooled fuel element (an annular element) has led to a further step forward: it now becomes possible to increase the pressure of the cooling gas without danger of causing creep in the uranium tube. The use of a pre-stressed concrete vessel makes this pressure increase possible, and the integration of the primary circuit avoids the risk of a rapid depressurization which would be in this case a major danger. This report deals with the main problems presented by this new type of nuclear power station, and gives the main lines of research and studies now being carried out in France. - Neutronic and thermal research has made it possible to consider using large size fuel elements (internal diameter = 77 mm, external diameter 95 mm) while still using natural uranium. - The problems connected with the production of these elements and with their in pile behaviour are the subject of a large programme, both out of pile and in power reactors (EDF 2) and test reactors (Pegase). - The increase in the size of the element leads to a large lattice pitch (35 to 40 cm). This makes it possible to consider having one charging aperture per channel or for a small number of channels, whether the charge machine be inside or outside the pressure vessel. In conclusion are given the main characteristics of a project for a 500 MWe power station using such a fuel element. In particular this project is compared to EDF 4 in order to show the advantages resulting from such developments in gas-graphite natural metallic uranium reactor systems; these are: a doubling of the specific and volume powers, and a three-fold reduction in the number of channels. The research now under way will make it possible to calculate the reduction in capital costs which will result from these important technical advances. (authors) [French] Le programme francais de centrales a graphite et uranium naturel s'est developpe, d'EDF 1 a EDF 4 - dans la voie d'un accroissement de la puissance unitaire des installations, de la puissance specifique et de la puissance volumique, et d'une amelioration des conditions de securite de fonctionnement. La puissance elevee d'EDF 4 (500 MWe) et l'integration du circuit primaire dans le caisson, lui-meme en beton precontraint, permettent ainsi de tirer le meilleur parti des elements combustibles tubulaires utilises des EDF 1, et d'arriver ainsi a une solution tres satisfaisante. L'emploi d'un element combustible refroidi interieurement (element annulaire) permet de faire un nouveau pas en avant: il devient alors possible d'augmenter la pression du gaz de refroidissement sans craindre le fluage du tube d'uranium. L'emploi d'un caisson en beton precontraint permet une telle augmentation de pression, et l'integration du circuit primaire elimine les risques d'une depressurisation rapide qui aurait presente dans ce cas un risque majeur. On aborde dans ce rapport les principaux problemes poses par ce nouveau type de centrale et on indique les grandes lignes des recherches et etudes effectuees en France: - Les etudes de neutronique et thermique ont permis d'envisager l'emploi d'elements combustibles de grandes dimensions (diametre interne = 77 mm, diametre externe = 95 mm), tout en conservant l'uranium naturel. - Les problemes de fabrication de ces elements, et de leur comportement en pile, font l'objet d'un programme important, tant hors pile que dans les piles de puissance (EDF 2) et les piles d'essais (Pegase). - L'augmentation des dimensions du combustible conduit a un pas du reseau tres important (35 a 40 cm), on peut alors envisager de disposer d'un trou de chargement par canal ou pour un petit nombre de canaux, que les machines de chargement soient placees a l'interieur ou a l'exterieur du caisson. En conclusion on donne les principales caracteristiques d'un projet de centrale de 500 MWe utilisant un tel element combustible. On compare en particulier un tel projet a la centrale EDF 4, afin de mettre en evidence les gains que peuvent apporter de tels developpements a la filiere gaz-graphite et uranium metallique naturel, dont les plus importants sont: le doublement de la puissance specifique et de la puissance volumique, et la reduction d'un facteur 3 du nombre de canaux. Les etudes en cours permettront de preciser l'importance de la reduction sur le montant des investissements qui sera apportee par ces progres techniques importants. (auteurs)}
place = {France}
year = {1964}
month = {Jul}
}