Example Work Domain Analysis for a Reference Sodium Fast Reactor

Abstract

T he nuclear industry is currently designing and buildin g a new generation of reactors that will include different structural, funct ional, and environmental aspects, all of which are likely to have a significant impact on the way these plants are operated. In order to meet economic and safety objectives, these new reactors will all utilize advanced technologies to some extent , including new materials and advanced digital instrumentation and control systems. New technologies will affect not only operational strategies, but will also require a new approach to how functions are allocated to humans or machines to ensure optimal performance. Uncertainty about the effect of large-scale changes in plant design will remain until sound technical bases are developed for new operational concepts and strategies. Up-to-date models and guidance are needed for the development of operational concepts for complex socio-technical systems. T his report describes how the classical Work Domain Analysis method has been adapted to develop operational concept frameworks for new plants. T his adaptation of the method is better able to deal with the uncertainty and incomplete information typical of first-of-a-kind designs. Practical examples are provided of the systematic application of the method in the operational analysis of sodium-cooled reactors. Insights from this application and its utility are reviewed and arguments for the formal adoption of Work Domain Analysis as a value-added part of the Systems Engineering process are presented. NOT E: It is assumed that readers are familiar with previous milestone reports; hence, some important background information that would have added substantially to the bulk of this report has been omitted. References to previous reports are included where relevant. StrAn Strategies Analysis

Work Domain Analysis Methodology for Development of Operational Concepts for Advanced Reactors

“…As described in Section 2.2.3 of the January 2015 milestone report section 2.2.3 (Hugo & Oxstrand, 2015) one of the most important applications of the results from the WDA is the development of operational strategies, which can be defined as a sequence of short-term and long-term operations that transform goals, plans, decisions, policy, rules, and procedures into the technical processes necessary for humans and systems to produce the defined production outcomes of the enterprise. The success and quality of the output will be influenced by the constraints that are imposed upon the sociotechnical system as a whole.…”

“…The January 2015 milestone report (Hugo & Oxstrand, 2015) describes the relationships between the five levels of the FAF. These relationships are called means-ends links, which eventually also provide a means to identify constraints.…”

“…The Example WDA report (Hugo & Oxstrand, 2015) described how the operation of a NPP can be characterized in terms of specific conditions, the evolution of those conditions over time, specific performance parameters involved, start and end states of various systems, and many more. The accurate definition of operational conditions is important in planning the response to normal, abnormal, and emergency conditions where decisions that are made are dependent on availability and comprehensibility of large amounts of data and information.…”

“…As described in Hugo & Oxstrand (2015), the success and quality of the WDA output will be influenced by the identification of the constraints that are imposed upon the sociotechnical system as a whole. In this phase of the analysis it is necessary to identify and describe the technical or physical, environmental, psychological, organizational, political and regulatory constraints that may affect the development and implementation of the new plant's operational concepts.…”

“…The example below illustrates a part of the FAF that was developed for a generic SFR described in the January 2015 report (Hugo & Oxstrand, 2015). It shows the top three levels of the FAF partly expanded, and the bottom two levels collapsed.…”