State Management of the Environment Part One: An Evaluation of the Michigan Experience

Michigan\u27s citizens, as well as its government, seem but dimly aware of the fact that Michigan-the home of America\u27s most growth-centered industry, the automobile-lies at the very eye of the environmental storm. This article seeks to take a broad look at the shortcomings of Michigan\u27s environmental protection in recent years. In so doing, it groups many of Michigan\u27s recent environmental failings into broad categories which will both clarify the status of Michigan\u27s environmental law climate and provide a basis for its reform. Parts One and Two consist of this analysis and evaluation. Part Three will examine possible solutions and offer suggestions for reform

State Management of the Environment Part Two: A Continuing Evaluation of the Michigan Experience

In Part One of this article, the author outlined the scope and character of Michigan\u27s environmental problems and suggested some of the factors underlying the state\u27s weak and bureaucratic decisionmaking process. Part Two concludes the author\u27s analysis of the fundamental obstacles to effective environmental decisionmaking in Michigan, and Part Three will contain recommendations for reform

The Relationship Between Dependency and Sport Participation, Category of Sport, and Gender in College Athletics

This study investigated the relationship between the personality trait of dependency, including the related construct of locus of control, and sport participation of male and female athletes. The student athletes consisted of 68 females and 95 males from both team and individual sports. Data were collected by means of the dependency scores on the Personality Factory Questionnaire (16PF) and Rotter's Locus of Control instrument. The total sample of athletes was not found to be different from non athletes in dependency, but male athletes were less dependent than male non athletes. Female basketball athletes were more dependent than female volleyball athletes. In addition, athletes were significantly more external on locus of control than non athletes. No meaningful relationship was found between dependency and locus of control. The data revealed from this study suggested that the athletic population is essentially no different from the non athlete population on dependency

Understanding the Transition between High School and College Mathematics and Science

Mathematics and science education is gaining increasing recognition as key for the well-being of individuals and society. Accordingly, the transition from high school to college is particularly important to ensure that students are prepared for college mathematics and science. The goal of this study was to understand how high school mathematics and science course-taking related to performance in college. Specifically, the study employed a nonparametric regression method to examine the relationship between high school mathematics and science courses, and academic performance in college mathematics and science courses. The results provide some evidence pertaining to the positive benefits from high school course-taking. Namely, students who completed high school trigonometry and lab-based chemistry tended to earn higher grades in college algebra and general chemistry, respectively. However, there was also evidence that high school coursework in biology and physics did not improve course performance in general biology and college physics beyond standardized test scores. Interestingly, students who completed high school calculus earned better grades in general biology. The implications of the findings are discussed for high school curriculum and alignment in standards between high schools and colleges

An evaluation of tight-pitch PWR cores

Originally presented as the author's thesis, Ph.D. in the M.I.T. Dept. of Nuclear Engineering, 1979.The impact of tight pitch cores on the consumption of natural uranium ore has been evaluated for two systems of coupled PWR's namely one particular type of thorium system-U-235/U02: Pu/Th02: U-233/ThO2--and the conventional recycle-mode uranium system- U-235/U02: Pu/UO . The basic parameter varied was the fuel-to-moderator volume ratio (F/M) o the (uniform) lattice for the last core in each sequence. Although methods and data verification in the range of present interest, 0.5 (current lattices)< F/M < 4.0 are limited by the scarcity of experiments with F/M > l.0,the EPRI-LEOPARD and LASER programs used for the thorium and uranium calculations, respectively, were successfully benchmarked against several of the more pertinent experiments. It was found that by increasing F/M to "3 the uranium ore usage for the uranium system can be decreased by as much as 60% compared to the same system with conventional recycle (at F/M 0.5). Equivalent savings for the thorium system of the type examined here are much smaller (10%) because of the poor performance of the intermediate Pu/ThO2 core--which is not substantially improved by increasing F/M. Although fuel cycle costs (calculated at the indifference value of bred fissile species) are rather insensitive to the characteristics of the tight pitch cores, system energy production costs do not favor the low discharge burnups which might other- wise allow even greater ore savings (80%). Temperature and void coefficients of reactivity for the tight pitch cores were calculated to be negative. Means for implementing tight lattice use were investigated, such as the use of stainless steel clad in place of zircaloy; and alternatives achieving the same objective were briefly examined, such as the use of D20/H20 mixtures as coolant. Major items identified requiring further work are system redesign to accommodate higher core pressure drop, and transient and accident thermal-hydraulics.DOE Contract no. EN-77-S O2-4570

Design and fuel management of PWR cores to optimize the once-through fuel cycle

Originally presented as the first author's thesis, (Sc.D.) in the M.I.T. Dept. of Nuclear Engineering, 1978.The once-through fuel cycle has been analyzed to see if there are substantial prospects for improved uranium ore utilization in current light water reactors, with a specific focus on pressurized water reactors. The types of changes which have been examined are: (1) re-optimization of fuel pin diameter and lattice pitch, (2) Axial power shaping by enrichment gradation in fresh fuel, (3) Use of 6-batch cores with semi-annual refueling, (4) Use of 6-batch cores with annual refueling, hence greater extended (.doubled) burnup, (5) Use of radial reflector assemblies, (6) Use of internally heterogeneous cores (simple seed/blanket configurations), (7) Use of power/temperature coastdown at the end of life to extend burnup, (8) Use of metal or diluted oxide fuel, (9) Use of thorium, and (10) Use of isotopically separated low a cladding material. a State-of-the-art LWR computational methods, LEOPARD/PDQ-7/FLARE-G, were used to investigate these modifications. The most effective way found to improve uranium ore utilization is to increase the discharge burnup. Ore savings on the order of 20% can be realized if greatly extended burnup (- double that of current practice) is combined with an increase in the number of batches in the core from 3 to 6. The major conclusion of this study is that cumulative reductions in ore usage of on the order of 30% are fore- seeable relative to a current PWR operating on the once-through fuel cycle, which is comparable to that expected for the same cores operated in the recycle mode.DOE Contract no. EN-77-S-02-4570

Analysis of strategies for improving uranium utilization in pressurized water reactors

Systematic procedures have been devised and applied to evaluate core design and fuel management strategies for improving uranium utilization in Pressurized Water Reactors operated on a once-through fuel cycle. A principal objective has been the evaluation of suggested improvements on a self-consistent basis, allowing for concurrent changes in dependent variables such as core leakage and batch power histories, which might otherwise obscure the sometimes subtle effects of interest. Two levels of evaluation have been devised: a simple but accurate analytic model based on the observed linear variations in assembly reactivity as a function of burnup; and a numerical approach, embodied in a computer program, which relaxes this assumption and combines it with empirical prescriptions for assembly (or batch) power as a function of reactivity, and core leakage as a function of peripheral assembly power. State-of-the-art physics methods, such as PDQ-7, were used to verify and supplement these techniques.These methods have been applied to evaluate several suggested improvements: (1) axial blankets of low-enriched or depleted uranium, and of beryllium metal, (2) radial natural uranium blankets, (3) lowleakage radial fuel management, (4) high burnup fuels, (5) optimized H/U atom ratio, (6) annular fuel, and (7) mechanical spectral shift (i.e. variable fuel-to-moderator ratio) concepts such as those involving pin pulling and bundle reconstitution.The potential savings in uranium requirements compared to current practice were found to be as follows: (1) O0-3%, (2) negative, (3) 2-3%; possibly 5%, (4) "15%, (5) 0-2.5%, (6) no inherent advantage, (7) 10%. Total savings should not be assumed to be additive; and thermal/hydraulic or mechanical design restrictions may preclude full realization of some of the potential improvements