Patent Number: 
Section: claims

1. A molten salt reactor, comprising:a tubular reactor core comprising graphite and defining an internal space; anda graphite fuel wedge that defines multiple fuel channels, wherein the fuel wedge is received within the internal space, wherein an outer surface of the fuel wedge comprises a first contoured shape, wherein an internal surface of the internal space comprises a second contoured shape, wherein the first contoured shape of the fuel wedge substantially corresponds in shape to and contacts the second contoured shape of the internal surface of the tubular reactor core as the reactor core operates, and wherein the fuel channels are configured to allow a fissionable fuel to flow from a first end of the fuel wedge to a second end of the fuel wedge. 2. The reactor of claim 1, wherein the fuel wedge comprises:a first section comprising a first portion of the fuel channels; anda second section comprising a second portion of the fuel channels,wherein the first section and the second section are disposed end to end within the internal space such that the first and second portions of the fuel channels are aligned such that the fissionable fuel flows from the first portion to the second portion of the fuel channels during reactor operation. 3. The reactor of claim 2, further comprising an alignment pin that extends between the first section and the second section of the fuel wedge to keep the first and second portions of the fuel channels aligned. 4. The reactor of claim 2, further comprising a seal comprising graphite, which is disposed between the first section and the second section of the fuel wedge. 5. The reactor of claim 2, further comprising a raised graphite seal portion that extends from a first end of the first section of the fuel wedge, and wherein a second end of the second section of the fuel wedge comprises a graphite recess that is configured to receive the raised graphite seal portion to form a seal between the first section and the second section. 6. The reactor of claim 1, further comprising a variable pump that is configured to force the fissionable fuel through the fuel channels at a variable rate. 7. The reactor of claim 1, wherein the reactor core further comprises a first reactor end cap that caps a first portion of the reactor core, and wherein the reactor further comprises a diffuser plate defining a plurality of holes, the diffuser plate being disposed between a portion of the first end cap and the fuel wedge. 8. The reactor of claim 1, wherein the fuel wedge further comprises a standoff spacer that is disposed at an end of the fuel wedge and that is configured to channel the fissionable fuel into the fuel channels. 9. The reactor of claim 5, wherein a second end of the first section of the fuel wedge comprises a standoff spacer that is configured to channel the fissionable fuel into the fuel channels. 10. A molten salt reactor, comprising:a tubular molten salt reactor core comprising graphite and defining a tubular internal space;a first fuel wedge comprising graphite and defining a first set of fuel channels; anda second fuel wedge comprising graphite and defining a second set of fuel channels,wherein the first and second fuel wedges each comprise an outer surface that is configured to contact and to substantially follow an internal circumference of the tubular internal space as the reactor operates,wherein the first and second fuel wedges are received within the internal space,wherein the first and second sets of fuel channels comprise a fissionable fuel comprising a molten salt, and wherein the first and second sets of fuel channels allow the fissionable fuel to flow from a first end of the internal space to a second end of the internal space through the first and second sets of fuel channels. 11. The reactor of claim 10, further comprising a fuel pin rod that is smaller than the first fuel wedge, that has a different shape than the first fuel wedge, that defines a first fuel channel, and that is disposed between the first fuel wedge and the second fuel wedge. 12. The reactor of claim 10, wherein the molten salt reactor core is longer than about 4 meters. 13. The reactor of claim 10, wherein the first fuel wedge comprises:a first section comprising a first length of the first set of fuel channels; anda second section comprising a second length of the first set of fuel channels,wherein the first section and the second section are disposed end to end within the internal space such that the first and second lengths of the first set of fuel channels are aligned and allow the fissionable fuel to flow directly from the first length to the second length of the first set of fuel channels as the reactor operates. 14. The reactor of claim 13, further comprising an alignment pin that extends between the first section and the second section of the first fuel wedge to keep the first and second lengths of the first set of fuel channels aligned with each other. 15. The reactor of claim 13, further comprising a raised seal portion that comprises graphite and extends from a first end of the first section of the first fuel wedge, and wherein a second end of the second section of the first fuel wedge comprises a recess that is configured to receive the raised seal portion to form a seal between the first section and the second section. 16. The reactor of claim 15, further comprising an alignment pin that extends between the first section and the second section of the first fuel wedge to keep the first and second lengths of the first set of fuel channels aligned with each other. 17. The reactor of claim 10, wherein a length of a longitudinal axis of the molten salt reactor core runs at angle between 5° and about 45° with respect to a horizontal plane. 18. A molten salt reactor, comprising:a tubular reactor core comprising graphite and defining an internal space; anda first graphite fuel wedge that defines multiple fuel channels,wherein the first fuel wedge is received within the internal space,wherein the fuel channels are configured to allow a fissionable fuel to flow from a first end to a second end of the first fuel wedge,wherein the first fuel wedge has a substantially sector-shaped prism configuration having an outer surface comprising a first contour that is configured to substantially match and contact a shape of a contour of an internal surface of the internal space, andwherein the first fuel wedge comprises a first fuel wedge section and a second fuel wedge section that are coupled together end to end with a seal comprising graphite, which is disposed between the first and second sections such that the fissionable fuel is able to flow between the first and second sections. 19. The reactor of claim 18, further comprising an alignment pin that extends between the first fuel wedge section and the second fuel wedge section such that the fissionable fuel flows between the first and second fuel wedges as the reactor operates. 20. The reactor of claim 18, wherein the reactor core is disposed in and in contact with a reflector comprising graphite.