The disclosure relates to a high temperature gas-cooled reactor core including a plurality of elongate fuel elements arranged in the form of a multi-lobed prism. Each prismatic fuel element includes an elongate prismatic body and a plurality of elongate fuel channels located within the prismatic body, wherein the cross-sectional area of each prismatic fuel element in a plane parallel to the bases of the prismatic fuel element is no more than 800 cm.sup.2 and wherein a ratio of the height of the prismatic body to its greatest width is greater than or equal to 3.0.

The disclosure relates to a high temperature gas-cooled reactor core including a plurality of elongate fuel elements arranged in the form of a multi-lobed prism. Each prismatic fuel element includes an elongate prismatic body and a plurality of elongate fuel channels located within the prismatic body, wherein the cross-sectional area of each prismatic fuel element in a plane parallel to the bases of the prismatic fuel element is no more than 800 cm.sup.2 and wherein a ratio of the height of the prismatic body to its greatest width is greater than or equal to 3.0.

The disclosure relates to a high temperature gas-cooled reactor core including a plurality of elongate fuel elements arranged in the form of a multi-lobed prism. Each prismatic fuel element includes an elongate prismatic body and a plurality of elongate fuel channels located within the prismatic body, wherein the cross-sectional area of each prismatic fuel element in a plane parallel to the bases of the prismatic fuel element is no more than 800 cm.sup.2 and wherein a ratio of the height of the prismatic body to its greatest width is greater than or equal to 3.0.

The disclosure relates to a high temperature gas-cooled reactor core including a plurality of elongate fuel elements arranged in the form of a multi-lobed prism. Each prismatic fuel element includes an elongate prismatic body and a plurality of elongate fuel channels located within the prismatic body, wherein the cross-sectional area of each prismatic fuel element in a plane parallel to the bases of the prismatic fuel element is no more than 800 cm.sup.2 and wherein a ratio of the height of the prismatic body to its greatest width is greater than or equal to 3.0.

The known fully ceramic microencapsulated fuel (FCM) entrains fission products within a primary encapsulation that is the consolidated within a secondary ultra-high-temperature-ceramic of Silicon Carbide (SiC). In this way the potential for fission product release to the environment is significantly limited. In order to extend the performance of this fuel to higher temperature and more aggressive coolant environments, such as the hot-hydrogen of proposed nuclear rockets, a zirconium carbide matrix version of the FCM fuel has been invented. In addition to the novel nature to this very high temperature fuel, the ability to form these fragile TRISO microencapsulations within fully dense ZrC represent a significant achievement.

The known fully ceramic microencapsulated fuel (FCM) entrains fission products within a primary encapsulation that is the consolidated within a secondary ultra-high-temperature-ceramic of Silicon Carbide (SiC). In this way the potential for fission product release to the environment is significantly limited. In order to extend the performance of this fuel to higher temperature and more aggressive coolant environments, such as the hot-hydrogen of proposed nuclear rockets, a zirconium carbide matrix version of the FCM fuel has been invented. In addition to the novel nature to this very high temperature fuel, the ability to form these fragile TRISO microencapsulations within fully dense ZrC represent a significant achievement.

A thermal-neutron reactor core includes: a solid moderator expanding to a lengthwise direction; a fuel in the moderator, parallel to the lengthwise direction of the moderator, the fuel containing a fissile material; a cooling tube parallel to the lengthwise direction of the moderator; and a plurality of kinds of burnable poison included in the fuel. The may contain a metal hydride. Furthermore, the plurality of kinds of burnable poison may include one burnable poison containing a concentration of one particular isotope of that one burnable poison.

A thermal-neutron reactor core includes: a solid moderator expanding to a lengthwise direction; a fuel in the moderator, parallel to the lengthwise direction of the moderator, the fuel containing a fissile material; a cooling tube parallel to the lengthwise direction of the moderator; and a plurality of kinds of burnable poison included in the fuel. The may contain a metal hydride. Furthermore, the plurality of kinds of burnable poison may include one burnable poison containing a concentration of one particular isotope of that one burnable poison.

The known fully ceramic microencapsulated fuel (FCM) entrains fission products within a primary encapsulation that is the consolidated within a secondary ultra-high-temperature-ceramic of Silicon Carbide (SiC). In this way the potential for fission product release to the environment is significantly limited. In order to extend the performance of this fuel to higher temperature and more aggressive coolant environments, such as the hot-hydrogen of proposed nuclear rockets, a zirconium carbide matrix version of the FCM fuel has been invented. In addition to the novel nature to this very high temperature fuel, the ability to form these fragile TRISO microencapsulations within fully dense ZrC represent a significant achievement.

The known fully ceramic microencapsulated fuel (FCM) entrains fission products within a primary encapsulation that is the consolidated within a secondary ultra-high-temperature-ceramic of Silicon Carbide (SiC). In this way the potential for fission product release to the environment is significantly limited. In order to extend the performance of this fuel to higher temperature and more aggressive coolant environments, such as the hot-hydrogen of proposed nuclear rockets, a zirconium carbide matrix version of the FCM fuel has been invented. In addition to the novel nature to this very high temperature fuel, the ability to form these fragile TRISO microencapsulations within fully dense ZrC represent a significant achievement.