DE1514963C

DE1514963C - Process for spheroidizing nuclear fuels. Elimination from: 1245791

Info

Publication number: DE1514963C
Application number: DE19621514963
Authority: DE
Inventors: Neville Ronald London Williams
Original assignee: UK Atomic Energy Authority
Current assignee: UK Atomic Energy Authority
Priority date: 1961-06-12
Filing date: 1962-06-12
Publication date: 1973-05-03

Description

Die Erfindung betrifft einen schnellen Leistungsbrutreaktor mit einem Core-Volumen von mehr als 800 Litern und mit im Core axial angeordneten, Brennstoffstäbe enthaltenden Brennelementen mit axial verlaufenden Kühlkanälen und nach oben gerichtetem Kühlmittelfluß, wobei ein aus metallischem Kühlmittel gebildeter Neutronenreflektor oberhalb des Core mit den Kühlmittelkanälen in Verbindung steht. Ein derartiger Reaktor ist aus »Directory of Nuclear Reactors«, Vol. IV, 1962, S. 219 bis 222, bekannt.The invention relates to a fast power breeder reactor with a core volume of more than 800 liters and with fuel elements containing fuel rods arranged axially in the core axially extending cooling channels and an upward flow of coolant, one made of metallic Coolant-formed neutron reflector above the core in connection with the coolant channels stands. Such a reactor is from "Directory of Nuclear Reactors", Vol. IV, 1962, pp. 219 to 222, known.

Brutreaktoren, insbesondere Versuchsbrutreaktoren, mit geringer thermischer Leistung sind schon seit längerer Zeit in Erprobung. In jüngster Zeit ist man dazu übergegangen, sehr große schnelle Leistungs-Brutreaktoren zu erzeugen, um eine möglichst günstige Ausnutzung des nuklearen Brennstoffes zu erreichen. Im allgemeinen besitzt das Core eines solchen Reaktors axial verlaufende Kühlmittelkanäle, durch die das Kühlmittel nach oben fließt. So sind im allgemeinen Reaktoren in der Weise konstruiert, daß ein eventuell auftretender Reaktivitätsanstieg nur durch das Einfahren von Kontrollstäben, die aus Absorbermaterial für langsame (thermische) Neutronen bestehen, kompensiert werden kann.Breeder reactors, in particular experimental breeder reactors, with low thermal output are fine in testing for a long time. Recently there has been a move towards very large, high-speed breeder reactors to generate in order to achieve the most favorable possible utilization of the nuclear fuel reach. In general, the core of such a reactor has axially running coolant channels, through which the coolant flows upwards. Thus, in general, reactors are constructed in such a way that that a possibly occurring increase in reactivity only through the introduction of control rods made of absorber material exist for slow (thermal) neutrons, can be compensated.

Verhältnismäßig kleine Reaktoren haben die Eigenschaft, -einen negativen Kühlmittelvoidkoeffizienten oder -blasenkoeffizienten zu haben und verlieren an Reaktivität durch einen Verlust von Kühlmittel. Eine Gefahr, welche die Auslegung eines sehr großen schnellen Reaktors schwierig macht, liegt in dem positiven Kühlmittelblasenkoeffizienten, der vielen solchen Reaktorauslegungen eigen ist; bei solchenRelatively small reactors have the property of having a negative coolant void coefficient or bubble coefficients and lose reactivity due to loss of coolant. One danger that makes the design of a very large, high-speed reactor difficult lies in the positive coolant bubble coefficient inherent in many such reactor designs; in such

Claims

1 514 claims:

1. Fast performance breeder reactor with a core volume of more than 800 liters and with axially arranged in the core, containing fuel rods with axially extending fuel elements Cooling channels and upward flow of coolant, one made of metallic Coolant-formed neutron reflector above the core in connection with the coolant channels stands, characterized in that the fuel elements (42) are arranged in element boxes (58) in a manner known per se which extend beyond the fuel rods (57) of the elements that the core (10) is also formed ring-shaped in a manner known per se and that the above the fuel rods (57) located in the element boxes part of the coolant the reflector (15) of the Forms fuel assemblies.

2. Reactor according to claim 1, characterized by an annular brood zone (14) below the annular core (10) and an annular brood zone (13 or 12) inside and outside around the annular core (10).

3. Reactor according to claims 1 and 2, characterized in that each of the arranged in the core (10) Fuel elements (42) comprising a bundle of fuel rods (57) and an element box (58), which includes the elongated fuel rods (57) and extends above the tip of the fuel rods (57) extended further.

4. Reactor according to claim 3, characterized in that the major part of each fuel rod (57) contains fissile material and forms a fuel portion (55) during the the lower part of each fuel rod (57) contains breeding material and is designed as a breeding zone (56).

5. Reactor according to claims 1 to 4, characterized in that in each fuel element (42) in the element boxes (58) above the fuel rods (57) located part of the coolant flowing upwards the reflector part (54) of the fuel elements (42) forms.

6. Reactor according to claims 1 to 5, characterized in that a coolant is used liquid metal is provided.

7. Reactor according to claims 1 to 6, characterized in that the coolant is sodium is.

8. Reactor according to claims 1 to 7, characterized in that the annular core (10) a height of 1.22 m (4 feet), an outer median diameter of 3.96 m (13 feet) and has an inner median diameter of 2.7 m (9 feet).

9. Reactor according to claims 1 to 8, characterized in that the annular core (10) is surrounded by a 0.46 m (IV2 foot) wide annular breeding zone (12) and that a 0.46 m (IV2 feet) wide annular brood zone (13) enclosed by the annular core while an axial breeding zone (14) 0.15 m (6 inches) below the annular core (10) and an axial reflector (15) 0.45 m (18 inches) above the annular core (10) are.

10. Reactor according to claims 1 to 9, characterized by devices for leading up of the liquid metal through the axial brood zone (14) through the annular core (10) and the axial reflector (15), the reflective properties of the axial reflector (15) are dependent on the uninterrupted flow of coolant and an emptying of the annular cores (10) emptied by itself from the axial reflector (15).

11. Reactor according to claims 1 to 10, characterized in that hexagonal fuel elements (42) are arranged in the ring.

12. Reactor according to claims 1 to 11, characterized in that the fuel elements (42) consist of a hexagonal element box (58) and a hexagonal bundle of fuel rods (57), which from the Includes hexagonal element box (58) extending 0.45 m (18 inches) above the top the fuel rods (57) extends to delimit the reflector portion (54) and that the fuel rods (57) contain a 20.8% enriched plutonium dioxide-uranium dioxide mixture which forms the fuel part (55) of the fuel elements (42), and a 0.3% enriched one Uranium dioxide, which is designed as the breeding zone (56) of the fuel elements (42).