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The National Aeronautics and Space Administration (NASA) plans to create a program for the human exploration of Mars that will rely heavily on nuclear technologies. NASA has an established nuclear technology program that recently became the focus of public protest over the risk from the technologies. Focusing on the Cassini mission to Saturn, the citizens protesting the mission claimed that the risk was environmental, global and moral. This protest is the first coherent international protest ever faced by the U.S. space program. The language and ideas espoused by the anti-nuclear groups protesting the use of plutonium-238 to power the Cassini spacecraft shows a clear linkage between anti-nuclear power and environmental protests and nuclear war protests. The analysis focuses on the use messages and meanings that underlie the protestor's use of three acronyms: Not in My Backyard (NIMBY), Not on Planet Earth (NOPE), and Not [in] Outer Space Either (NOSE). The anti-space nuclear power protest is predicted to have significant consequences for NASA's planned human missions to Mars because of NASA's reliance on nuclear technologies such as radioisotope thermoelectric generators and nuclear reactors. / Master of Science

The analysis of the environmental impact of routine radioactive gaseous releases from operating nuclear power stations is discussed using a radiation dose assessment. This analysis includes a discussion of the origin of radionuclide effluents, a discussion of federal policies, and a calculation of radiation doses to man. A model of estimating the radioactive dose from gaseous effluents from light-water-cooled reactors is described using guidelines described in the Code of Federal Regulations and the Nuclear Regulatory Commission's Regulatory Guides. The environmental impact of these sources is then analyzed using dose rates calculated along critical exposure pathways for various radioactive nuclides. Examples are given using factors that have been heretofore documented in the literature. The major radionuclides in the airborne effluents from a PWR, used as an example are noble gases, H-3, radioiodines, and radioactive particles. The results from the methodologies described in this paper are compared to federal radiation limits.

The vulnerability of electrical cables exposed to a fire environment is of particular concern to the nuclear power plant community. The community is interested in data that could be used for predicting cable failures during a fire situation. For this reason, a cable test program was conducted using two different types of cable insulation. Several different exposure heat fluxes were tested, as well as different test arrangements such as cable trays and conduits. The program revealed that a single failure temperature for all cable types is not recommended, but if it is necessary a reasonable temperature could be chosen for the thermosets tested in this project.

Thesis (Master of Engineering in Electrical Engineering)--Cape Peninsula University of Technology, 2018. / Worldwide a movement is underway to replace the burning of limited fossil fuel reserves for power generation with a cleaner, more efficient, yet still reliable and cost-effective method. Even though renewable technologies are often among the most common proposed, they are still limited by factors such as cost when considering large scale generation. Further requirements for replacing fossil fuel generation methods include the need to provide a continuous and reliable output for base load requirements, which is difficult to guarantee when making use of renewables alone. The proposed alternative is nuclear energy, as it is a reliable and cleaner method of power generation as compared to fossil fuels, capable of providing cost effective energy in the long run. The downside to nuclear energy, however, is the negative perception and general dislike of this method of generation, especially among the public who have been around this technology since its early days of implementation. The aim of this study is, therefore, to inform and prove that nuclear technology has evolved and come a long way since its early days, by making use of advanced technological solutions to address the fears associated with this technology from many years ago. The study further aims to prove that technologies such as advanced safety systems, new generations of reactors, advanced containment structures for both reactors and waste containment, as well as new waste disposal methods, have evolved nuclear energy into a safer and cleaner alternative method of power generation. This is achieved by first considering the origin of the negative perceptions surrounding the technology, and the nuclear accidents of the past, which have greatly influenced opinions about nuclear technology even up until today. After identifying the concerns and fears surrounding nuclear energy, research was conducted concerning how the latest technologies and innovations in safety systems are used to address these concerns, and ultimately eliminate the threats where possible. With the biggest concern identified, namely a core meltdown event leading to the release of radioactive material into the environment, two simulations were conducted to illustrate the unlikelihood of such an event occurring. The purpose of these simulations was, moreover, to illustrate the complexity and reliability of the various safety systems incorporated into the design of a nuclear power plant, preventing such a feared release of radioactivity from occurring. The research also importantly revealed that the dangers and possible threats posed by nuclear technology are often grossly overestimated, as under normal operating conditions a coal power plant, in fact, releases more radiation into the environment than a nuclear power plant. Further research reveals that the feared nuclear waste, produced by the nuclear industry yet regulated and disposed of properly, is only a small fraction of the highly hazardous waste produced on an annual basis worldwide. It is also revealed that in terms of fatalities, fossil fuel generation, on average, is responsible for more deaths annually than the biggest nuclear disasters that have ever occurred. Addressing the fears and concerns surrounding nuclear technology is therefore important, as this valuable resource may otherwise remain under-appreciated and under-utilised because of the misperceptions which currently exist amongst the public. This furthermore results in the unnecessary exhaustion of fossil fuel reserves, and concomitant pollution of the environment – all due to antiquated fears surrounding nuclear power plants.

An approach for developing a computer-based aid to assist in monitoring and assessing nuclear power plant status during situations requiring emergency response has been developed. It is based on the representation of regulatory requirements and plant-specific systems and instrumentation in the form of hierarchical rules. Making use of inferencing techniques from the field of artificial intelligence, the rules are combined with dynamic state data to determine appropriate emergency response actions. In a joint project with Portland General Electric Company, a prototype system, called EM-CLASS, was been created to demonstrate the knowledge-based approach for use at the Trojan Nuclear Power Plant. The knowledge domain selected for implementation addresses the emergency classification process chat is used to communicate the severity of the emergency and the extent of response actions required. EM-CLASS was developed using Personal Consultant Plus (PCPlus), a knowledge-based system development shell from Texas Instruments which runs on IBM-PC compatible computers. The knowledge base in EM-CLASS contains over 200 rules. The regulatory basis, as defined in 10 CFR 50, calls for categorization of emergencies into four emergency action level classes: (1) notification of unusual event, (2) alert, (3) site area emergency, and (4) general emergency. Each class is broadly defined by expected frequency and the potential for release of radioactive materials to the environment. In a functional sense, however, each class must be ultimately defined by a complex combination of in- plant conditions, plant instrumentation and sensors, and radiation monitoring information from stations located both on- and off-site. The complexity of this classification process and the importance of accurate and timely classification in emergency response make this particular application amenable to an automated, knowledge-based approach. EM-CLASS has been tested with a simulation of a 1988 Trojan Nuclear Power Plant emergency exercise and was found to produce accurate classification of the emergency using manual entry of the data into the program. / Graduation date: 1997

A prototype real-time process monitoring emergency classification expert system, RT/EM-CLASS, has been developed for use at the Trojan Nuclear Power Plant. This knowledge-based system features the integration of electronically sensed plant data with the menu selection data representation of its predecessor, EM-CLASS. This prototype demonstrates the techniques required to acquire plant process data from another computer and use that data in an expert system to determine the proper Emergency Action Level. Several benefits are realized by the RT/EM-CLASS application. These include: The resources required to make a classification are reduced thereby freeing the responsible person to devote time to other important tasks. The classification may be completed more often and with better data than the current system allows. The human user is less likely to make an erroneous Emergency Action Level classification. Prototype implementation required resolution of an efficiency problem of relating plant process data to the expert system data forms. This was achieved through the development of multi-conditional rules that significantly reduce the size of the rule set. The development of RT/EM-CLASS presents a methodology for building knowledge based applications that perform nonintrusive real-time monitoring of dynamic systems. This methodology features Use of existing analytical and Al tools where possible Monitoring of a dynamic system Non-intrusive acquisition of data from the system This technology might be applied to portions of the nuclear engineering design process (control rod programming in Boiling Water Reactors, for example) to emulate the guidance and activities of an expert. A substantial portion of the effort by the expert engineer involves preparation of the code input, running the computer code, analyzing the results, and based on the results, deciding what case to submit next. A suitably designed expert system could act in the place of the engineer in this dynamic design process. This methodology has been tested against the 1988 emergency exercise at the Trojan Nuclear Power Plant. / Graduation date: 1992

The main objective of this research is: (1) to develop a model and perform numerical simulations to evaluate the radiation field and the resulting dose to personnel and activation of materials and structures throughout the IRIS nuclear power plant, and (2) to confirm that the doses are below the regulatory limit, and assess the possibility to reduce the activation of the concrete walls around the reactor vessel to below the free release limit. IRIS is a new integral pressurized water reactor (PWR) developed by an international team led by Westinghouse with an electrical generation capacity of 335 MWe and passive safety systems. Its design differs from larger loop PWRs in that a single building houses the containment as well as all the associated equipment including the control room that must be staffed continuously. The resulting small footprint has positive safety and economic implications, and the integral layout provides additional shielding and thus the opportunity to significantly reduce the activation, but it also leads to significantly more challenging simulations. The difficulty in modeling the entire building is the fact that the source is attenuated over 10 orders of magnitude before ever reaching the accessible areas. For an analog Monte Carlo simulation with no acceleration (variance reduction), it would take many processor-years of computation to generate results that are statistically meaningful. Instead, to generate results for this thesis, the Standardized Computer Analyses for Licensing Evaluation (SCALE) with the package Monaco with Automated Variance Reduction using Importance Calculations (MAVRIC) will be used. This package is a hybrid methodology code where the forward and adjoint deterministic calculations provide variance reduction parameters for the Monte Carlo portion to significantly reduce the computational time. Thus, the first task will be to develop an efficient SCALE/MAVRIC model of the IRIS building. The second task will be to evaluate the dose rate and activation of materials, specifically focusing on activation of concrete walls around the reactor vessel. Finally, results and recommendations will be presented.

Thesis (M. Soc. Sc.)--University of Hong Kong, 1988.