Computer Models Used to Support Cleanup Decision-Making at Hazardous and Radioactive Waste Sites

Massive efforts are underway to clean up hazardous and radioactive waste sites located throughout the United States. To help determine cleanup priorities, computer models are being used to characterize the source, transport, fate, and effects of hazardous chemicals and radioactive materials found at these sites. Although the U.S. Environmental Protection Agency (EPA), the U.S. Department of Energy (DOE), and the U.S. Nuclear Regulatory Commission (NRC)have provided preliminary guidance to promote the use of computer models for remediation purposes, no agency has produced directed guidance on models that must be used in these efforts. As a result, model selection is currently done on an ad hoc basis. This is administratively ineffective and costly, and can also result in technically inconsistent decision-making. To identify what models are actually being used to support decision-making at hazardous and radioactive waste sites, a project jointly funded by EPA, DOE, and NRC was initiated. The purpose of this project was to: (1)identify models being used for hazardous and radioactive waste site assessment purposes; and (2)describe and classify these models. This report presents the results of this study. A mail survey was conducted to identify models in use. The survey was sent to 550 persons engaged in the cleanup of hazardous and radioactive waste sites; 87 individuals responded. They represented organizations including federal agencies, national laboratories, and contractor organizations. The respondents identified 127 computer models that were being used to help support cleanup decision-making. There were a few models that appeared to be used across a large number of sites (e.g., RESRAD). In contrast, the survey results also suggested that most sites were using models which were not reported in use elsewhere. Information is presented on the types of models being used and the characteristics of the models in use. Also shown is a list of models available, but not identified in the survey itself.     

Ramifications of Risk Measures in Implementing Quantitative Performance Assessment for the Proposed Radioactive Waste Repository at Yucca Mountain, Nevada, USA

As part of its preparation to review a potential license application from the U.S. Department of Energy (DOE), the U.S. Nuclear Regulatory Commission (NRC) is examining the performance of the proposed Yucca Mountain nuclear waste repository. In this regard, we evaluated postclosure repository performance using Monte Carlo analyses with an NRC-developed system model that has 950 input parameters, of which 330 are sampled to represent system uncertainties. The quantitative compliance criterion for dose was established by NRC to protect inhabitants who might be exposed to any releases from the repository. The NRC criterion limits the peak-of-the-mean dose, which in our analysis is estimated by averaging the potential exposure at any instant in time for all Monte Carlo realizations, and then determining the maximum value of the mean curve within 10000 years, the compliance period. This procedure contrasts in important ways with a more common measure of risk based on the mean of the ensemble of peaks from each Monte Carlo realization. The NRC chose the former (peak-of-the-mean) because it more correctly represents the risk to an exposed individual. Procedures for calculating risk in the expected case of slow repository degradation differ from those for low-probability cases of disruption by external forces such as volcanism. We also explored the possibility of risk dilution (i.e., lower calculated risk) that could result from arbitrarily defining wide probability distributions for certain parameters. Finally, our sensitivity analyses to identify influential parameters used two approaches: (1). the ensemble of doses from each Monte Carlo realization at the time of the peak risk (i.e., peak-of-the-mean) and (2). the ensemble of peak doses calculated from each realization within 10000 years. The latter measure appears to have more discriminatory power than the former for many parameters (based on the greater magnitude of the sensitivity coefficient), but can yield different rankings, especially for parameters that influence the timing of releases.     

Methods and Rationale for Derivation of a Reference Dose for Methylmercury by the U.S. EPA

In 2001, the U.S. Environmental Protection Agency derived a reference dose (RfD) for methylmercury, which is a daily intake that is likely to be without appreciable risk of deleterious effects during a lifetime. This derivation used a series of benchmark dose (BMD) analyses provided by a National Research Council (NRC) panel convened to assess the health effects of methylmercury. Analyses were performed for a number of endpoints from three large longitudinal cohort studies of the neuropsychological consequences of in utero exposure to methylmercury: the Faroe Islands, Seychelles Islands, and New Zealand studies. Adverse effects were identified in the Faroe Islands and New Zealand studies, but not in the Seychelles Islands. The NRC also performed an integrative analysis of all three studies. The EPA applied a total uncertainty factor (UF) of 10 for intrahuman toxicokinetic and toxicodynamic variability and uncertainty. Dose conversion from cord blood mercury concentrations to maternal methylmercury intake was performed using a one-compartment model. Derivation of potential RfDs from a number of endpoints from the Faroe Islands study converged on 0.1 microg/kg/day, as did the integrative analysis of all three studies. EPA identified several areas for which further information or analyses is needed. Perhaps the most immediately relevant is the ratio of cord:maternal blood mercury concentration, as well as the variability around this ratio. EPA assumed in its dose conversion that the ratio was 1.0; however, available data suggest it is perhaps 1.5-2.0. Verification of a deviation from unity presumably would be translated directly into comparable reduction in the RfD. Other areas that EPA identified as significant areas requiring further attention are cardiovascular consequences of methylmercury exposure and delayed neurotoxicity during aging as a result of previous developmental or adult exposure.     

The U.S. Nuclear Regulatory Commission Safety Goal Policy: A Critical Review

The most recent U.S. Nuclear Regulatory Commission (NRC) statement of safety goal policy is a significant advance over previous versions. However, some areas of the policy are still in need of refinement, and the resolution of several key questions was deferred pending further review. To clarify some of these issues, this paper presents a critical review of the NRC safety goal policy to date.     

A Decision Theory Perspective on the Disposal of High-Level Radioactive Waste

In this paper the problem of high-level nuclear waste disposal is viewed as a five-stage, cascaded decision problem. The first four of these decisions having essentially been made, the work of recent years has been focused on the fifth stage, which concerns specifics of the repository design. The probabilistic performance assessment (PPA) work is viewed as the outcome prediction for this stage, and the site characterization work as the information gathering option. This brief examination of the proposed Yucca Mountain repository through a decision analysis framework resulted in three conclusions: (1) A decision theory approach to the process of selecting and characterizing Yucca Mountain would enhance public understanding of the issues and solutions to high-level waste management; (2) engineered systems are an attractive alternative to offset uncertainties in the containment capability of the natural setting and should receive greater emphasis in the design of the repository; and (3) a strategy of waste management should be adopted, as opposed to waste disposal, as it allows for incremental confirmation and confidence building of a permanent solution to the high-level waste problem.     

Science and Decisions: Advancing Risk Assessment

At the request of the U.S. Environmental Protection Agency (EPA), the National Research Council (NRC) recently completed a major report, Science and Decisions: Advancing Risk Assessment, that is intended to strengthen the scientific basis, credibility, and effectiveness of risk assessment practices and subsequent risk management decisions. The report describes the challenges faced by risk assessment and the need to consider improvements in both the technical analyses of risk assessments (i.e., the development and use of scientific information to improve risk characterization) and the utility of risk assessments (i.e., making assessments more relevant and useful for risk management decisions). The report tackles a number of topics relating to improvements in the process, including the design and framing of risk assessments, uncertainty and variability characterization, selection and use of defaults, unification of cancer and noncancer dose‐response assessment, cumulative risk assessment, and the need to increase EPA's capacity to address these improvements. This article describes and summarizes the NRC report, with an eye toward its implications for risk assessment practices at EPA.     

Analysis of the Treatment, by the U.S. Department of Energy, of the FEP Hydrothermal Activity in the Yucca Mountain Performance Assessment

The U.S. Code of Federal Regulations, 10 CFR Part 63, stipulates that the expected performance of the geological high-level nuclear waste repository must be demonstrated through a total system performance assessment (TSPA). The TSPA represents an analysis that identifies all features, events, and processes (FEPs) that might affect the disposal system and examines the effects of the identified FEPs upon the performance of the system. Secondary minerals from the thick unsaturated zone of Yucca Mountain were deposited from waters with temperatures up to 70-90 degrees C. U-Pb dating constrained the ages of the elevated temperatures to the period between 10 and 5-6 million years ago. Relatively youthful circulation of thermal waters (hydrothermal activity) would be of concern for the safety of the disposal facility. A phenomenological model was advanced by the U.S. Department of Energy (DOE), which proposed that the minerals were deposited by infiltrating meteoric waters that were heated upon contact with the bedrock; it was hypothesized that the latter was conductively heated by a shallow silicic magma body. The model rendered processes responsible for elevated water temperatures inconsequential for the safety of the proposed nuclear waste facility. However, attempts by DOE at validating the model by means of numeric thermal simulations and analogue system observations were unsuccessful. Regulations specify two criteria for exclusion of a FEP from consideration in the TSPA: low probability and low consequence. The lack of a plausible phenomenological model makes it impossible to apply either of these two criteria to the FEP Hydrothermal Activity. Despite the lack of a valid criterion for exclusion, it was excluded from the TSPA. Both the development of DOE's thermal model and the formal FEP analysis were associated with deviations from DOE's quality assurance regulations.     

Issues in Ecological Risk Assessment: The CRAM Perspective

In 1989, a Committee on Risk Assessment Methodology (CRAM) was convened by the National Research Council (NRC) to identify and investigate important scientific issues in risk assessment. One of the first issues considered by the committee was the development of a conceptual framework for ecological risk assessment, defined as "the characterization of the adverse ecological effects of environmental exposures to hazards imposed by human activities." Adverse ecological effects include all biological and nonbiological environmental changes that society perceives as undesirable. The committee's opinion was that a general framework is needed to define the relationship of ecological risk assessment to environmental management and to facilitate the development of uniform technical guidelines. The framework for human health risk assessment proposed by the NRC in 1983 was adopted as a starting point for discussion. CRAM concluded that, although ecological risk assessment and human health risk assessment differ substantially in terms of scientific disciplines and technical problems, the underlying decision process is the same for both. Therefore, CRAM recommended that the 1983 risk assessment framework be modified to accommodate both human health and ecological risk assessment. CRAM defined an integrated health/ ecological risk assessment framework consisting of the four components: Hazard Identification, Exposure Assessment, Exposure-Response Assessment, and Risk Characterization. CRAM further provided recommendations on the scope of issues to be addressed in ecological risk assessment, critical research needs, and mechanisms for providing more detailed guidance on the scientific content of ecological risk assessments.     

核心能力:组织文化和组织学习作用

本文研究组织文化、组织学习、核心能力和组织绩效之间的相互影响关系,并以华南地区的139家企业为对象进行实证研究。本文的理论贡献在于证实了:(1)组织文化通过影响组织学习进而影响核心能力;(2)组织学习影响核心能力进而影响组织绩效;(3)核心能力对组织绩效有直接的正向影响;(4)组织文化对组织绩效没有显著的直接影响,但通过组织学习和核心能力的构建间接影响组织绩效;(5)组织学习对组织绩效没有显著的直接影响,但通过核心能力的构建间接影响组织绩效。本文的研究结果对于深刻理解核心能力的形成及正确认识组织文化和学习在组织管理中的作用有重要的借鉴价值。     

An empirical examination of the science–technology relationship in the biotechnology industry

Understanding how a firm's scientific capability influences its technology development has important implications on the firm's research and development (R&D) strategies. However, the current literature reveals a puzzling outcome in its empirical investigations on the science–technology relationship. While many studies show the positive influence of a firm's scientific capability on its technological performance, a few others indicate that if a firm focuses its attention more on cutting edge science, its overall technological performance will suffer. We suggest that these findings can be reconciled by conceptualizing and measuring the scientific capability of the firm differently. This paper attempts to demonstrate how different notions of scientific capability are associated with different performance outcomes. Furthermore, a firm's scientific capability facilitates the integration of new knowledge to produce valuable technologies when a firm broadens its search for new knowledge. The paper highlights the nuances of conceptualizing and measuring the firm's scientific capability in two different ways: number of scientific publications and non-patent references. The findings also shed light on the mechanism through which science accelerates technological progress inside a firm.     

Assessing the effects of ‘big brother’ in a workplace: The case of WAST

The extensive and growing use of electronic performance monitoring in organisations has resulted in considerable debate over the years. This paper focuses on workplace monitoring at the Welsh Ambulance Services Trust (WAST), a provider of emergency services for the people of Wales, in the UK. The key objectives include examining the nature of performance monitoring at its call centres and determining whether employees are micromanaged through the use of workplace surveillance. The findings cover staff (both management and non-management) perceptions, gathered through a questionnaire and interviews as well as observations made in the study areas. The findings revealed that workplace electronic monitoring is not intrinsically all good or all bad. It is value neutral and offers a win–win situation.     

Functional Assessment and Intervention for Organizational Behavior Change: Improving the Timeliness of Staff Meetings at a Human Services Organization

We implemented functional behavioral assessment (FBA) at a human services organization to reduce the tardiness of scheduled staff meetings. Following baseline, FBA focused on antecedent and consequence conditions that affected staff arriving on time to scheduled meetings. These data were subsequently presented at a staff meeting in which staff planned an intervention to improve the timeliness of meetings. The intervention, composed of premeeting reminders, positive reinforcement for arriving on time, and meeting termination criteria (to facilitate meeting-to-meeting transitions), was implemented in a multiple baseline design across 3 types of meetings. As a result of the intervention, the number of minutes late that meetings started decreased. We discuss FBA within organizational behavior management that targets performance improvement objectives.     

A Comparison of Lecture Versus Role-Playing in the Training of the Use of Positive Reinforcement

Managers of organizations, often in coordination with personnel departments, create training programs for their staff. The emphasis in human service organizations is to train staff to use behavior modification techniques, especially to reinforce appropriate client behavior. Unfortunately, published research evaluating the quality of this training has been almost nonexistent (Kazdin & Moyer, 1976). Two different instructional formats of training were compared in this study: two groups received a lecture on reinforcing appropriate behavior and two groups role-played the act of reinforcing appropriate behavior. Follow-up observations of the staff showed that the performance of the lecture-trained staff was stable or declined after an initial improvement. The performance of staff who role-played, however, continued to improve. Feedback and physical action may be the reasons for the superiority of role-playing over a lecture format.     

Deliberation: Integrating Analytical Results into Environmental Decisions Involving Multiple Stakeholders

The National Research Council has recommended the use of an analytic/deliberative decision making process in environmental restoration decisions that involve multiple stakeholders. This work investigates the use of the results of risk assessment and multiattribute utility analysis (the "analysis") in guiding the deliberation. These results include the ranking of proposed remedial action alternatives according to each stakeholder's preferences, as well as the identification of the major reasons for these rankings. The stakeholder preferences are over a number of performance measures that include the traditional risk assessment metrics, e.g., individual worker risk, as well as programmatic, cultural, and cost-related impacts. Based on these results, a number of proposals are prepared for consideration by the stakeholders during the deliberation. These proposals are the starting point for the formulation of actual recommendations by the group. In our case study, these recommendations included new remedial action alternatives that were created by the stakeholders after an extensive discussion of the detailed analytical results.     

Implementation of a Posted Schedule to Increase Class-Wide Interobserver Agreement Assessment

The present study investigated the impact of an antecedent intervention in the form of a daily posted schedule on the interobserver agreement (IOA) assessment of educational goals implemented within a classroom at a private school serving individuals with disabilities. During baseline, the percentage of academic goals with interobserver agreement was low and stable (M?=?5%). Teacher performance improved during the intervention (M?=?92%). A reversal replicated this effect and performance maintained during 6-week, 6-month, and 1-year follow-up probes. Results suggest a daily posted schedule can effectively increase interobserver agreement assessment by direct-care teaching staff.     

Modeling the problem of locating collection areas for urban waste management. An application to the metropolitan area of Barcelona

Reverse logistics problems arising in municipal waste management are both wide-ranging and varied. The usual collection system in UE countries is composed of two phases. First, citizens leave their refuse at special collection areas where different types of waste (glass, paper, plastic, organic material) are stored in special refuse bins. Subsequently, each type of waste is collected separately and moved to its final destination (a recycling plant or refuse dump). The present study focuses on the problem of locating these collection areas. We establish the relationship between the problem, the set covering problem and the MAX-SAT problem and then go on to develop a genetic algorithm and a GRASP heuristic to, respectively, solve each formulation. Finally, the quality of the algorithms is tested in a computational experience with real instances from the metropolitan area of Barcelona, as well as a reduced set of set covering instances from the literature.     

Involving Families and Staff in Service Improvement

This study was designed to improve an important service for severely mentally retarded adolescents and adults. The overall objective was to investigate the effect on client and staff behavior of implementing procedures designed to achieve change in three priority service areas selected by the families and staff. The experimental design was a three phase time series design. In the final phase, three procedures designed to achieve change in the selected areas were introduced sequentially. The service areas selected were staff organization, staff-family communication and clients' recreational activities. The setting supervisors monitored staff use of the procedures by means of a structured checklist and gave staff direct feedback on their performance. Checklists used by the researchers revealed consistent use of the procedures by staff. Observational measures showed marked changes in the behavior of both staff and their clients. Comparisons of interviews with staff and families conducted prior to and following the interventions revealed general satisfaction with changes achieved and increased staff emphasis on client teaching. This study demonstrated the feasibility and desirability of involving staff and families in making plans for service improvement.     

高绩效人力资源管理系统与企业绩效研究——以中国创业板上市公司为例

本文采用案例研究方法,对中国创业板上市公司的人力资源管理系统建设与企业绩效的相关性进行研究,研究发现,现阶段的中国创业板上市公司高绩效人力资源管理系统由员工选拔与配置、员工培训、员工参与、薪酬水平、激励薪酬、内部晋升、绩效管理等七个方面构成。高绩效人力资源管理系统的建立有利于企业自主创新能力的形成,但不能提升企业绩效。研究认为:通过高绩效人力资源管理系统形成的自主创新能力需要与企业外部环境动态性相匹配才能提升企业绩效。本研究为资源基础理论在我国的运用找到了使用条件,为创业板上市公司提升绩效提供了思路。     

A multicriteria decision analysis model for faculty evaluation

In the context of increasing demands for social and financial accountability of universities, the required implementation of transparent faculty evaluation systems constitutes a challenge and an opportunity for universities strategically aligning the activity of academic staff with the university goals. However, despite growing interest in the performance appraisal of faculty, only a few reported studies propose models that cover the full range of academic activities and the models in use are typically based on ad hoc scoring systems that lack theoretical soundness. This article approaches faculty evaluation from an innovative comprehensive perspective. Based on the concepts and methods of multiple criteria value measurement, it proposes a new faculty evaluation model that addresses the whole range of academic activities and can be applied within and across distinct scientific areas, while respecting their specificities. Constructed through a socio-technical process, the model was designed for and adopted by the Instituto Superior Técnico, the engineering school of the Technical University of Lisbon. The model has a two-level hierarchical additive structure, with top-level evaluation areas specified by second-level evaluation criteria. A bottom non-additive third level accounts for the quantitative and qualitative dimensions of academic activity related to each evaluation criterion. The model allows (a) the comparison of the performance of academic staff with performance targets reflecting the strategic policy concerns of university management; (b) the definition of the multicriteria value profile of each faculty member at the top level of the evaluation areas; (c) the computation of an overall value score for each faculty member, through an optimisation procedure that makes use of a flexible system of weights and (d) the assignment of faculty members to rating categories.