摘要:

The monolithic solid‐oxide fuel cell (MSOFC) is a promising electrochemical power generation device that is currently under development at Argonne National Laboratory. The extremely high power density of the MSOFC leads to MSOFC systems that have sufficiently high energy densities that they are excellent candidates for a number of space missions. The fuel cell can also be operated in reverse, if it can be coupled to an external power source, to regenerate the fuel and oxidant from the water product. This feature further enhances the potential mission applications of the MSOFC. In this paper, the current status of the fuel cell development is presented—the focus being on fabrication and currently achievable performance. In addition, a specific example of a space power system, featuring a liquid metal cooled fast spectrum nuclear reactor and a monolithic solid oxide fuel cell, is presented to demonstrate the features of an integrated system.

ISSN:0094-243X    

DOI:10.1063/1.40145

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

Fusion offers the potential for a very high specific power, providing a large specific impulse that can be traded‐off with thrust for mission optimization. Thus fusion is a leading candidate for missions beyond the moon. Here we discuss a new approach for space fusion power, namely Inertial‐Electrostatic Confinement (IEC). This method offers a high power density in a relatively small, simple device. It appears capable of burning aneutronic fuels which are most desirable for space applications and is well suited for direct energy conversion.In view of its potential, IEC is currently undergoing experimental and theoretical study as a fusion power source at the University of Illinois. The goal of the research is to create a confined plasma inside multiple nested spherical potential wells. These wells are formed by injecting ions into a highly transparent, high voltage (5–50 kV) sphericl cathode. Multiple passes of ions through the center create a high density non‐Maxwellian core. Preliminary experimental results are presented here.

ISSN:0094-243X    

DOI:10.1063/1.40146

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

As the human race moves outward into the solar system with both robotic and piloted spacecraft there will be an ever evolving need for nuclear power and eventually for nuclear propulsion. Studies have already been completed which show the scientific merits of such exciting missions as Jovian grand tours, Uranus and Neptune orbiters and probes and a Pluto flyby—missions which can only be accomplished with nuclear power. The Space Exploration Initiative with its goal of going to the Moon, Mars and beyond will benefit from nuclear reactors to power surface operations and radioisotope power sources for use in planetary surface rovers. In summary, NASA will continue to need nuclear power as it helps advance the human race into the solar system and beyond.

ISSN:0094-243X    

DOI:10.1063/1.40147

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

A joint DOE/DOD/NASA Nuclear Propulsion Project is being planned and implemented under the leadership of the NASA Lewis Research Center. The plan includes both Nuclear Electric Propulsion and Nuclear Thermal Propulsion. Two major national workshops were held in the summer of 1990 to provide a data base for and identify technology needs for a wide range of NTP and NEP concepts. A Joint DOE/DOD/NASA steering committee has reviewed the results and recommendations from the workshops and identified the high priority issues for near‐term implementation. Efforts will be initiated on these issues in FY91 by an interdepartmental/agency team based on available resources.

ISSN:0094-243X    

DOI:10.1063/1.40148

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

Nuclear technologies can directly support advanced space initiatives. For near‐Earth missions, nuclear technology can be used to power air traffic control, communications and manufacturing platforms, provide emergency power for manned platforms, provide power for maneuvering units, move asteroids for mining, measure the natural radiation environment, provide radiation protection instruments, and design radiation hardened robotic systems. For the Lunar and Mars surfaces, nuclear technology can be used for base stationary, mobile, and emergency power, energy storage, process heat, nuclear thermal and electric rocket propulsion, excavation and underground engineering, water and sewage treatment and sterilization, food processing and preservation, mineral exploration, self‐luminous systems, radiation protection instrumentation, radiation environmental warning systems, and habitat shielding design. Outer planet missions can make use of nuclear technology for power and propulsion. Programs need to be initiated to ensure the full beneficial use of nuclear technologies in advanced space missions.

ISSN:0094-243X    

DOI:10.1063/1.40149

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

The NERVA‐class Nuclear Thermal Rocket (NTR), with performance nearly double that of advanced chemical engines, has long been considered an enabling technology for human missions to Mars. NTR engines address the demanding trip time and payload delivery needs of both cargo‐only and piloted flights. But NTR can also reduce the Earth launch requirements for manned lunar missions. First use of NTR for the Moon would be less demanding and would provide a test‐bed for early operations experience with this powerful technology. Study of application and design options indicates that NTR propulsion can be integrated with the Space Exploration Initiative scenarios to deliver performance gains while managing controlled, long‐term disposal of spent reactors to highly stable orbits.

ISSN:0094-243X    

DOI:10.1063/1.40033

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

This paper presents the safety program conducted to determine the response of the General Purpose Heat Source (GPHS) Radioisotope Thermoelectric Generator (RTG) to potential launch accidents of the Space Shuttle for the Galileo and Ulysses missions. The National Aeronautics and Space Administration (NASA) provided definition of the Shuttle potential accidents and characterized the environments. The Launch Accident Scenario Evaluation Program (LASEP) was developed by GE to analyze the RTG response to these accidents. RTG detailed response to Solid Rocket Booster (SRB) fragment impacts, as well as to other types of impact, was obtained from an extensive series of hydrocode analyses. A comprehensive test program was conducted also to determine RTG response to the accident environments. The hydrocode response analyses coupled with the test data base provided the broad range response capability which was implemented in LASEP.

ISSN:0094-243X    

DOI:10.1063/1.40034

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

The use of a radioisotope thermoelectric generator fueled with plutonium‐238 dioxide on the Space Shuttle‐launched Ulysses mission implies some level of risk due to potential accidents. This paper describes the method used to quantify risks in the Ulysses mission Final Safety Analysis Report prepared for the U.S. Department of Energy. The starting point for the analysis described herein is following input of source term probability distributions from the General Electric Company. A Monte Carlo technique is used to develop probability distributions of radiological consequences for a range of accident scenarios thoughout the mission. Factors affecting radiological consequences are identified, the probability distribution of the effect of each factor determined, and the functional relationship among all the factors established. The probability distributions of all the factor effects are then combined using a Monte Carlo technique. The results of the analysis are presented in terms of complementary cumulative distribution functions (CCDF) by mission sub‐phase, phase, and the overall mission. The CCDFs show the total probability that consequences (calculated health effects) would be equal to or greater than a given value.

ISSN:0094-243X    

DOI:10.1063/1.40168

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

Concerns raised during the Ulysses Final Safety Analysis Review (FSAR) process called the solid rocket motor (SRM) fragment velocity prediction model into question. The specific area of concern was that there was a section of the SRM casing which was exposed to SRM chamber pressure as the grain (fuel) was consumed. These questions centered on the velocity of fragments which originated from the field joint region given that failure occurred between 37 and 72 seconds mission elapsed time (MET). Two dimensional coupled Eulerian‐Lagrangian calculations were performed to assess the hot gas flow field which resulted from SRM casing fragmentation. The fragment to gas interface‐pressure time‐history obtained from these analyses was reduced to a boundary condition algorithm which was applied to an explicit‐time‐integration, finite element, three dimensional shell model of the SRM casing and unburned fuel. The results of these calculations showed that the velocity of fragments originating in the field joint was adequately described by the range of velocities given in the Shuttle Data Book (1988). Based on these results, no further analyses were required, and approval was obtained from the Launch Abort Subpanel of the Interagency Nuclear Safety Review Panel to use the SRM fragment velocity environments presented in the Ulysses FSAR (1990).

ISSN:0094-243X    

DOI:10.1063/1.40035

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

The recent 6 October 1990 launch and deployment of the nuclear‐powered Ulysses spacecraft from the Space ShuttleDiscoveryculminated an extensive safety review and evaluation effort by the Interagency Nuclear Safety Review Panel (INSRP). After more than a year of detailed independent review, study, and analysis, the INSRP prepared a Safety Evaluation Report (SER) on the Ulysses mission, in accordance with Presidential Directive‐National Security Council memorandum 25. The SER, which included a review of the Ulysses Final Safety Analysis Report (FSAR) and an independent characterization of the mission risks, was used by the National Aeronautics and Space Administration (NASA) in its decision to request launch approval as well as by the Executive Office of the President in arriving at a launch decision based on risk‐benefit considerations. This paper provides an overview of the Ulysses mission and the conduct as well as the results of the INSRP evaluation. While the mission risk determined by the INSRP in the SER was higher than that characterized by the Ulysses project in the FSAR, both reports indicated that the radiological risks were relatively small. In the final analysis, the SER proved to be supportive of a positive launch decision. The INSRP evaluation process has demonstrated its effectiveness numerous times since the 1960s. In every case, it has provided the essential ingredients and perspective to permit an informed launch decision at the highest level of our Government.

ISSN:0094-243X    

DOI:10.1063/1.40036

出版商:AIP    

年代:1991

数据来源: AIP