NRE reactors of different Nuclear Engine Power Installations (NEPI) based on tested technologies have actually no alternatives in deep space investigations with the help of unmanned space probes and piloted interplanetary devices [1]. The developments of NREs were stopped only temporarily because humankind could not afford to spend a huge amount of money for large-scale cosmic studies. It is most likely that the NRE program should become an international collaboration program in the future, like programs for the development of the international thermonuclear experimental reactor (ITER), high-power accelerators, etc. The program would have a global character, in view of its legal. Ecological and other aspects, because the program involves the use of fission materials of the highest armament quality, it should be under international control. NRE reactors for different purposes would be based on different HRE geometries with fuel compositions providing the required efficiency. To fulfill the tasks in cosmic flights, the NRE reactor should have high reliability, with the no-failure probability no less than 0.99.

The different versions of a device operating in many regimes and capable of producing, along with the reactive thrust, the electric energy for ensuring the activity of a spacecraft were extensively developed beginning from the early 1980s [2].

They should work not only in the basic, engine regime but also in two energy regimes at low power for a few years and high power during approximately half of the specified time resource of the engine regime. The high-power regime presents no difficulties in tests because, according to all its parameters, the reactor is loaded much more weakly than in the basic regime of the IVG-1. In the low-power regime, the heat carrier flows around the HRA only outside its housing, while the heat from HREs is transferred to the housing by radiation through heat insulation. This regime is quite different from the basic regime, when the fuel is considerably burned out (down to no less than 3-5 % of the initial amount) and the chemical composition can change due to the incongruent evaporation of materials. Therefore, the efficiency of the HRA and HRE components under these conditions requires additional investigations.

It is clear that the outlook for the development and building of active cores for nuclear space energy devices will be first and foremost related to the improvement

A. Lanin, Nuclear Rocket Engine Reactor, Springer Series in Materials Science 170, 103

DOI: 10.1007/978-3-642-32430-7_8, © Springer-Verlag Berlin Heidelberg 2013

in the construction and technology of heating sections containing fuel compositions with the heat-releasing density 40MW l-1 at elevated temperatures (above 3,200K) in the engine regime and to ensuring that fission products are kept in HREs for a few years at the temperature 2,000 K in a deep vacuum or in hydrogen-containing working substances at pressures from 0.1 to 0.2atm.

The available design and technological groundwork for working of NRE reactor testify to basic possibility of creation HRA, efficient both on regimes of the reac­tive thrust, and on regimes of long work in Brighton cycle at a power production for orbiting spacecraft equipment [3]. Over the previous years, a row of thermal energy transformation concepts in electric by bimodal [4] by a fast-neutron reactor with a lithium cooling contour or with thermal emission (accordingly NEED-2 and NEED-3) have been developed (Table8.1).

Quite probably, for that the raise of working capacity of constructive elements of the NEED engineering production of nanosize materials will be developed [5, 6]. New heat insulating materials, resistant in the hydrogen environment on the basis of fibrous, porous, and multilayered carbides and nitrides of refractory metals will be created.

The Commission of the President of Russia on the Modernization and Technolog­ical Development of Russian Economics in 2009 recommended reconsidering the question of developing a spacecraft with a nuclear rocket engine. In 2010, the Gov­ernment of Russia provided the initial financial support for the development of an outline for a project of a megawatt nuclear energy device, with the possible beginning of the module construction in 2018.