Terrestrial applications of the heatpipe power system

A terrestrial reactor that uses the same design approach as the Heatpipe Power System (HPS) may have applications both on earth and on other planetary surfaces. The baseline HPS is a potential, near-term, low-cost space fission power system. The system will be composed of independent modules, and all components operate within the existing database. The HPS has relatively few system integration issues; thus, the successful development of a module is a significant step toward verifying system feasibility and performance estimates. A prototypic, refractory-metal HPS module is being fabricated, and testing is scheduled to begin in November 1996. A successful test will provide high confidence that the HPS can achieve its predicted performance. An HPS incorporating superalloys will be better suited for some terrestrial or planetary applications. Fabrication and testing of a superalloy HPS module should be less challenging than that of the refractory metal module. A superalloy HPS core capable of delivering > 100 kWt to a power conversion subsystem could be fabricated for about $500k (unfueled). Tests of the core with electric heat (used to simulate heat from fission) could demonstrate normal and off-normal operation of the core, including the effects of heatpipe failure. A power conversion system also could be coupled to the core to demonstrate full system operation

HPS: A space fission power system suitable for near-term, low-cost lunar and planetary bases

Near-term, low-cost space fission power systems can enhance the feasibility and utility of lunar and planetary bases. One such system, the Heatpipe Power System (HPS), is described in this paper. The HPS draws on 40 yr of United States and international experience to enable a system that can be developed in <5 yr at a cost of <$100M. Total HPS mass is <600 kg at 5 kWe and <2000 kg at 50 kWe, assuming that thermoelectric power conversion is used. More advanced power conversion systems could reduce system mass significantly. System mass for planetary surface systems also may be reduced (1) if indigenous material is used for radiation shielding and (2) because of the positive effect of the gravitational field on heatpipe operation. The HPS is virtually non-radioactive at launch and is passively subcritical during all credible launch accidents. Full-system electrically heated testing is possible, and a ground nuclear power test is not needed for flight qualification. Fuel burnup limits are not reached for several decades, thus giving the system long-life potential

Study on Alternative Cargo Launch Options from the Lunar Surface

In the future, there will be a need for constant cargo launches from Earth to Mars in order to build, and then sustain, a Martian base. Currently, chemical rockets are used for space launches. These are expensive and heavy due to the amount of necessary propellant. Nuclear thermal rockets (NTRs) are the next step in rocket design. Another alternative is to create a launcher on the lunar surface that uses magnetic levitation to launch cargo to Mars in order to minimize the amount of necessary propellant per mission. This paper investigates using nuclear power for six different cargo launching alternatives, as well as the orbital mechanics involved in launching cargo to a Martian base from the moon. Each alternative is compared to the other alternative launchers, as well as compared to using an NTR instead. This comparison is done on the basis of mass that must be shipped from Earth, the amount of necessary propellant, and the number of equivalent NTR launches. Of the options, a lunar coil launcher had a ship mass that is 12.7% less than the next best option and 17 NTR equivalent launches, making it the best of the presented six options

Thermal-hydraulic performance of a water-cooled tungsten-rod target for a spallation neutron source

A thermal-hydraulic (T-H) analysis is conducted to determine the feasibility and limitations of a water-cooled tungsten-rod target at powers of 1 MW and above. The target evaluated has a 10-cm x 10-cm cross section perpendicular to the beam axis, which is typical of an experimental spallation neutron source - both for a short-pulse spallation source and long-pulse spallation source. This report describes the T-H model and assumptions that are used to evaluate the target. A 1-MW baseline target is examined, and the results indicate that this target should easily handle the T-H requirements. The possibility of operating at powers >1 MW is also examined. The T-H design is limited by the condition that the coolant does not boil (actual limits are on surface subcooling and wall heat flux); material temperature limits are not approached. Three possible methods of enhancing the target power capability are presented: reducing peak power density, altering pin dimensions, and improving coolant conditions (pressure and temperature). Based on simple calculations, it appears that this target concept should have little trouble reaching the 2-MW range (from a purely T-H standpoint), and possibly much higher powers. However, one must keep in mind that these conclusions are based solely on thermal-hydraulics. It is possible, and perhaps likely, that target performance could be limited by structural issues at higher powers, particularly for a short-pulse spallation source because of thermal shock issues

User`s information for the Monte Carlo burnup code monteburns

monteburns, a burnup computer code that uses the Monte Carlo technique, was developed at Los Alamos National Laboratory to be applied to a variety of nuclear design calculations (see accompanying paper on the development of monteburns). It is a fully automated burnup code that incorporates multiple irradiation steps and many other options. However, two of the most important aspects of developing a code are describing how to use it and benchmarking it. Thus, the operational aspects and benchmarking results from monteburns are discussed in this summary

Nuclear and thermal analysis of the heatpipe power and bimodal systems

This paper discusses the nuclear and thermal analysis of two fission-powered concepts: (1)the Heatpipe Power System(HBS), which provides which provides power only, and (2) the Heatpipe Bimodal System (HBS), which provides both power and thermal propulsion. The HPS and HBS systems can provide substantial levels of power and propulsion at low mass with a high degree of safety and reliability. The systems have been designed to utilize existing technology and facilities, which will make the development cost relatively low

Heatpipe space power and propulsion systems

Safe, reliable, low-mass space power and propulsion systems could have numerous civilian and military applications. This paper discusses two fission-powered concepts: The Heatpipe Power System (HPS), which provides power only; and the Heatpipe Bimodal System (HBS), which provides both power and thermal propulsion. Both concepts have 10 important features. First, only existing technology and recently tested fuel forms are used. Second, fuel can be removed whenever desired, which greatly facilitates system fabrication and handling. Third, full electrically heated system testing of all modes is possible, with minimal operations required to replace the heaters with fuel and to ready the system for launch. Fourth, the systems are passively subcritical during launch accidents. Fifth, a modular approach is used, and most technical issues can be resolved with inexpensive module tests. Sixth, bonds between dissimilar metals are minimized. Seventh, there are no single-point failures during power mode operation. Eighth, the fuel burnup rate is quite low to help ensure >10-yr system life. Ninth, there are no pumped coolant loops, and the systems can be shut down and restarted without coolant freeze/thaw concerns. Finally, full ground nuclear test is not needed, and development costs will be low. One design for a low-power HPS uses SNAP-10A-style thermoelectric power converters to produce 5 kWe at a system mass of {approximately}500 kg. The unicouple thermoelectric converters have a hot-shoe temperature of 1275 K and reject waste heat at 775 K. This type of thermoelectric converter has been used extensively by the space program and has demonstrated an operational lifetime of decades. A core with a larger number of smaller modules (same overall size) can be used to provide up to 500 kWt to a power conversion subsystem, and a slightly larger core using a higher heatpipe to fuel ratio can provide >1 MWt