Charles W. Morrow

Development Path for Z-Pinch IFE

Abstract The long-range goal of the Z-Pinch IFE program is to produce an economically-attractive power plant using high-yield z-pinch-driven targets (~3GJ) with low rep-rate per chamber (~0.1 Hz). The present mainline choice for a Z-Pinch IFE power plant uses an LTD (Linear Transformer Driver) repetitive pulsed power driver, a Recyclable Transmission Line (RTL), a dynamic hohlraum z-pinch-driven target, and a thick-liquid wall chamber. The RTL connects the pulsed power driver directly to the z-pinch-driven target, and is made from frozen coolant or a material that is easily separable from the coolant (such as carbon steel). The RTL is destroyed by the fusion explosion, but the RTL materials are recycled, and a new RTL is inserted on each shot. A development path for Z-Pinch IFE has been created that complements and leverages the NNSA DP ICF program. Funding by a U.S. Congressional initiative of

Guideline for bolted joint design and analysis : version 1.0.

4M for FY04 through NNSA DP is supporting assessment and initial research on (1) RTLs, (2) repetitive pulsed power drivers, (3) shock mitigation [because of the high yield targets], (4) planning for a proof-of-principle full RTL cycle demonstration [with a 1 MA, 1 MV, 100 ns, 0.1 Hz driver], (5) IFE target studies for multi-GJ yield targets, and (6) z-pinch IFE power plant engineering and technology development. Initial results from all areas of this research are discussed.

A Concept for Containing Inertial Fusion Energy Pulses in a Z-Pinch-Driven Power Plant

This document provides general guidance for the design and analysis of bolted joint connections. An overview of the current methods used to analyze bolted joint connections is given. Several methods for the design and analysis of bolted joint connections are presented. Guidance is provided for general bolted joint design, computation of preload uncertainty and preload loss, and the calculation of the bolted joint factor of safety. Axial loads, shear loads, thermal loads, and thread tear out are used in factor of safety calculations. Additionally, limited guidance is provided for fatigue considerations. An overview of an associated Mathcad{copyright} Worksheet containing all bolted joint design formulae presented is also provided.

Comparison of Average Transport and Dispersion Among a Gaussian Model, a Two-Dimensional Model and a Three-Dimensional Model

The Z-Pinch Power Plant (ZP-3) is the first concept to use the results at Sandia National Laboratories’ Z accelerator in a power plant application. Assuming high-yield fusion pulses (of 1 to 20 GJ per shot at a rate of 0.1 Hz), we consider a unique shock and energy absorbing system to contain the energy. One concept answers the need for system standoff from the fusion reaction with a replaceable mechanical cartridge manufactured on-site. System studies suggest integrated blanket designs for absorbing the fusion energy, cartridge manufacture of recycled materials, and cartridge installation/replacement to maintain a reasonable duty cycle. An effective system design for ZP-3 requires an integrated blanket to shield the permanent structures from the high-energy neutron flux and strong shock wave, breed tritium, and simultaneously absorb the released fusion energy. We investigate the feasibility of this integrated blanket concept and explore the principles of a containment chamber—a crucible—and the containment mechanisms. An operational cycle is proposed to physically load hardware in 10-s intervals while maintaining operational conditions. Preliminary pressure and shock calculations demonstrate that high-yield inertial fusion energy pulses can be contained if the appropriate energy-absorbing materials are used.

An Overview of the Direct Energy Conversion Proof of Principle Power Production Program

The Nuclear Regulatory Commission’s (NRC’s) code for predicting off-site consequences, MACCS2[1] (MELCOR Accident Consequence Code System, Version 2), is used for Level 3 Probabilistic Risk Analysis Consequence analyses, planning for emergencies, and cost-benefit analyses. It uses a simplified model for atmospheric transport and dispersion (ATD), that is, a straight-line Gaussian model. This model has been criticized as being overly simplistic, even for its purpose. The justification for its use has been that only average or expected values of metrics of interest are needed for planning and that a simplified model, by averaging metrics of interest obtained using numerous weather sequences one-by-one, compensates for the loss of structure in the meteorology that occurs away from the point of release. The simple model has been retained because of the desire to have short running times on personal computers covering the entire path through the environment, including the food and water pathway, and covering essentially a lifetime of exposure to a contaminated environment.

On Synergy Between a High Temperature Gas-Cooled Reactor and a LNG Vaporization Plant

The United States Department of Energy, Nuclear Energy Research Initiative (NERI) Direct Energy Conversion Proof of Principle (DECPOP) project has as its goal the development of a direct energy conversion process suitable for commercial development. We define direct energy conversion as any fission process that returns usable energy without an intermediate thermal process. A prior Direct Energy Conversion (DEC) project [1] has been completed and indicates that a viable direct energy device is possible if several technological issues can be overcome. The DECPOP program is focusing on two of the issues: charged particle steering and high voltage hold-off. This paper reports on the progress of the DECPOP project. Two prototype concepts are under development: a Fission Electric Cell using magnetic insulation and a Fission Fragment Magnetic Collimator using magnetic fields to direct fission fragments to collectors. Included in this paper are a short project description, an abbreviated summary of the work completed to date, a description of ongoing and future project activities, and a discussion of the potential for future research and development.Copyright

An Overview of the Direct Energy Conversion Power Production Program

The Liquefied Natural Gas (LNG) chain of processes consumes the equivalent of 10% of initial natural gas flow for liquefaction, transportation and regasification of the natural gas. It is possible with the right process to recover some of this lost investment during the regasification process. The High Temperature Gas Cooled Reactor (HTGR) nuclear power plant appears to possess the characteristics needed to accomplish this recovery. This synergy of processes and fluid properties between an LNG regasification plant and an HTGR provides an opportunity to enhance an already efficient nuclear power generation scheme. Boiling LNG (112 K) provides an ideal cold side heat sink for the helium based Brayton cycle of the HTGR. Helium remains in the gas phase at these low temperatures. The resulting large temperature difference (1000 K) between the high temperature and low temperature sides of a thermal cycle means Carnot efficiencies approach 90%. Achievable efficiencies approach 77%, an increase from 48% for current ambient temperature cooled HTGR designs. Thus a LNG/HTGR plant can deliver half again more power for similar capital investments and operating costs. In addition, boiling LNG with helium saves fuel gas costs for the regasification plant. This paper will show that this combination is feasible and economic. Since both processes are designed to run at maximum capacity, duty cycles and plant availability criteria match. For coastal locations, both processes possess similar site selection criteria. Finally, combining the processes will impose no unmanageable safety constraints on either system and in fact could make safe operation easier to attain. This paper will provide general overviews of an HTGR power plant and of the LNG-to-market sequence, concentrating on regasification plants. The paper will then describe a process that combines an HTGR power plant with an LNG regasification facility to the advantage of both. At full load, the economic benefit for a dual installation supporting what would be a 1.1 GWe power plant before improvement would be approximately

Nuclear risk assessment for the Mars 2020 mission environmental impact statement.

423 million per year.Copyright

Analysis of dose consequences arising from the release of spent nuclear fuel from dry storage casks.

The United States Department of Energy, Nuclear Energy Research Initiative (NERI) Direct Energy Conversion (DEC) project has as its goal the development of a direct energy conversion process suitable for commercial development. We define direct energy conversion as any fission process that returns usable energy without an intermediate thermal process. Enough of the project has been completed, roughly two thirds, to indicate that a viable direct energy device is possible. This paper reports on the progress of the DEC project. Three concepts are under development: Fission Electric Cell using magnetic insulation, Magnetic Collimator using magnetic fields to direct fission fragments to collectors, and Gas Vapor Core Reactor using magnetohydrodynamics to generate electrical current. Included in this paper area a short project description, an abbreviated summary of the work completed to date, a description of ongoing and future project activities, and a discussion of the potential for future research and development.Copyright

SHRAPNEL GENERATION FROM RECYCLABLE TRANSMISSION LINES

In the summer of 2020, the National Aeronautics and Space Administration (NASA) plans to launch a spacecraft as part of the Mars 2020 mission. One option for the rover on the proposed spacecraft uses a Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) to provide continuous electrical and thermal power for the mission. An alternative option being considered is a set of solar panels for electrical power with up to 80 Light-Weight Radioisotope Heater Units (LWRHUs) for local component heating. Both the MMRTG and the LWRHUs use radioactive plutonium dioxide. NASA is preparing an Environmental Impact Statement (EIS) in accordance with the National Environmental Policy Act. The EIS will include information on the risks of mission accidents to the general public and on-site workers at the launch complex. This Nuclear Risk Assessment (NRA) addresses the responses of the MMRTG or LWRHU options to potential accident and abort conditions during the launch opportunity for the Mars 2020 mission and the associated consequences. This information provides the technical basis for the radiological risks of both options for the EIS. SAND2013-10589, January 2014 NRA for Mars 2020