Todd H. West

Nuclear reactor safeguards and monitoring with antineutrino detectors

Cubic-meter-sized antineutrino detectors can be used to non intrusively, robustly, and automatically monitor and safeguard a wide variety of nuclear reactor types, including power reactors, research reactors, and plutonium production reactors. Since the antineutrino spectra and relative yields of fissioning isotopes depend on the isotopic composition of the core, changes in composition can be observed without ever directly accessing the core itself. Information from a modest-sized antineutrino detector, coupled with the well-understood principles that govern the core’s evolution in time, can be used to determine whether the reactor is being operated in an illegitimate way. A group at Sandia is currently constructing a 1 m3 antineutrino detector at the San Onofre reactor site in California to demonstrate these principles.

Implications of Modeling Range and Infrastructure Barriers to Adoption of Battery Electric Vehicles

Compared with traditional vehicles, light-duty battery electric vehicles (BEVs) currently have price premiums and noncost limitations, such as reduced range, sparse public recharging infrastructure, and long recharge times. These additional limitations can be captured in different ways in a consumer choice model. Three approaches are implemented to noncost barrier modeling, and results are compared. A penalty approach quantifies limitations as additional costs to the consumer, and two threshold approaches determine BEV suitability by the frequency that daily driving distance exceeds the vehicle range. GPS-based trip data are used to form ensemble distributions of low-, medium-, and high-intensity driving distances to support the analysis. All approaches show limited (5%) adoption of BEVs by 2050, and the BEV mileage fraction trails the stock fraction because of the use of substitute vehicles for high-mileage trips and adoption biased toward lower driving intensity segments. In fact, a majority of the electrified miles driven stem from plug-in hybrid electric vehicles, not BEVs. Of the BEVs, the powertrains offering 150- to 250-mi ranges are responsible for more than 50% of sales. Results also hint that longer-range BEVs act as primary household vehicles, but lower-range BEVs serve as secondary household vehicles. A parametric exploration shows that mechanisms to mitigate the hardship of the noncost barriers can significantly increase adoption rates but that reducing battery price alone does not. However, these mechanisms can be different for different modeling approaches.

An assessment of antineutrino detection as a tool for monitoring nuclear explosions

The antineutrino is the only real-time nuclear signature from a fission explosion that propagates great distances through air, water, and ground. The size and sensitivity of antineutrino detectors has increased dramatically in the last decade, and will continue to do so in the next, thanks in part to the renewed interest in neutrino physics brought on by the recent discovery that neutrinos may have mass. The evolution of antineutrino detectors, and the evident interest of the signature as a means for monitoring nuclear tests motivates this review of the capabilities of existing and possible future detectors as test ban verification tools. The authors find that existing liquid scintillator ionization detectors, operating a few tens of meters below the Earths surface and containing a few thousand tons of active material, could be used to monitor an area of a few square kilometers for nuclear explosions at the 1 kt level. Purified water Cerenkov detectors of sizes comparable to existing detectors (50,000 m{sup 3}) could be used to detect 1 kt explosions at distances of a few tens of kilometers. If neutron-absorbing dopants such as sodium chloride or gadolinium could be added to purified water, the resulting background reduction would allow extension of the range for sensitivity to a pulse of 10 antineutrino events from a 1 kt explosion out to approximately 1000 km. Beyond 1000 km, backgrounds from the worlds nuclear reactors would become prohibitively large. The engineering hurdles for such detectors would be formidable. The size of a doped detector operating at the 100 km range, suitable for cooperative monitoring of existing nuclear test sites, is about 60 times that of the largest existing water detector, and would require a factor of several dozen more photomultiplier tubes than what is now used in large scale physics experiments. At a price per phototube of

Heavy Duty Vehicle Futures Analysis.

1000, capital costs would amount to several billions of dollars, even for a detector at this modest range. This cost is perhaps the key obstacle to construction, along with excavation requirements and the requirement of high radiopurity for large volumes of water and dopant. Detectors sensitive to a 1 kt explosion at a few kilometer distance would still cost tens of millions of dollars, and are unlikely to be useful except in the context of confidence-building measures.

Guiding optimal biofuels

This report describes work performed for an Early Career Research and Development project. This project developed a heavy-duty vehicle (HDV) sector model to assess the factors influencing alternative fuel and efficiency technology adoption. This model builds on a Sandia light duty vehicle sector model and provides a platform for assessing potential impacts of technological advancements developed at the Combustion Research Facility. Alternative fuel and technology adoption modeling is typically developed around a small set of scenarios. This HDV sector model segments the HDV sector and parameterizes input values, such as fuel prices, efficiencies, and vehicle costs. This parameterization enables sensitivity and trade space analyses to identify the inputs that are most associated with outputs of interest, such as diesel consumption and greenhouse gas emissions. Thus this analysis tool enables identification of the most significant HDV sector drivers that can be used to support energy security and climate change goals.

Summary and results of the joint WMD-DAC/Alameda County bioterrorism response plan exercise.

In the current study, processes to produce either ethanol or a representative fatty acid ethyl ester (FAEE) via the fermentation of sugars liberated from lignocellulosic materials pretreated in acid or alkaline environments are analyzed in terms of economic and environmental metrics. Simplified process models are introduced and employed to estimate process performance, and Monte Carlo analyses were carried out to identify key sources of uncertainty and variability. We find that the near-term performance of processes to produce FAEE is significantly worse than that of ethanol production processes for all metrics considered, primarily due to poor fermentation yields and higher electricity demands for aerobic fermentation. In the longer term, the reduced cost and energy requirements of FAEE separation processes will be at least partially offset by inherent limitations in the relevant metabolic pathways that constrain the maximum yield potential of FAEE from biomass-derived sugars.

Feasibility, economics, and environmental impact of producing 90 billion gallons of ethanol per year by 2030

On June 12,2003, the Alameda County Public Health Department and Sandia National Laboratories/CA jointly conducted an exercise that used a Weapons of Mass Destruction-Decision Analysis Center (WMD-DAC) bioterrorism attack simulation to test the effectiveness of the countys emergency response plan. The exercise was driven by an assumed release (in the vicinity of the Berkeley Marina), and subsequent spread, of a small quantity of aerosolized, weapons-grade anthrax spores. The simulation used several key WMD-DAC capabilities, namely: (1) integration with an atmospheric dispersion model to calculate expected dose levels in the affected areas, (2) a individual-tracking capability for both infected and non-infected persons as they made decisions, sought treatment, and received prophylaxis drugs, and (3) a user interface that allows exercise participants to affect the scenario evolution and outcome. The analysis of the countys response plan included documenting and reviewing the decisions made by participants during the exercise. Twenty-six local and regional officials representing the health care system, emergency medical services and law enforcement were involved in responding to the simulated attack. The results of this joint effort include lessons learned both by the Alameda County officials regarding implementation of their bioterrorism response plan and by the Sandia representatives about conducting exercises of this type. These observations are reviewed in this report, and they form a basis for providing a better understanding of group/individual decision processes and for identifying effective communication options among decision makers.