Prototype Design, Analysis, and Results for a Liquid Radiological Waste Control Room
Human factors researchers at Idaho National Laboratory are collaborating with a utility partner to address human factors in the modernization of their radiological waste control room. The collaborating utility, Palo Verde, plans to remove all control boards associated with the liquid radiological waste system, which include controls, indicators, and alarm systems, and replace them with modernized digital instrumentation and controls and displays. To be sure the new system either supports current operational performance or enhances it, researchers have carried out three planning and analysis activities: expert operator review, function allocation analysis, and human factor principles and design applications. Researchers utilized access to expert operators to gain information about the system. Operators were asked to detail a procedure exemplifying typical interactions with the liquid radiological waste system and provide it to Idaho National Laboratory with a list of functionalities to incorporate (Section 4.1). Later, operators were asked to provide additional feedback to inform a prototype with adequate realism to support sound analysis of the system design (Section 4.2). Other operators not associated with the utility partner were also involved in experiment design and prototype evaluation (Section 4.2). Due to the extent of the upgrade, care was given to measure the change in the operator’s role (Section 7). As part of the modernization, some plant systems are expected to be equipped with automation or sensors that send information directly to the control where previously operators were required to enter controlled areas to find the information. Such updates made slight changes to operator role requirements, but the impact was negligible. The way the system is operated will remain largely the same, but operator convenience and safety is expected to increase. Additionally, to map operator tasks during the selected procedure, an Operational Sequence Diagram was created (Section 7.1). The diagram helped to account for every interaction and piece of equipment needed to create the prototype design. Alternatively, the diagram can be created following the final design to identify any function reallocations due to redesign. Human factors principles were also applied to the design. An ergonomic assessment was performed on the workspace resulting in various recommendations for placing and designing the new workstation (Section 6). A 3 D mockup of the control room was created to depict the options available with in-depth descriptions of each. Furthermore the prototype design incorporates well known human factors principles. However, to be sure the principles are sound in the control room context, the researches have designed an experiment to measure the impact design decision has on operator performance. The experiment is described in detail in Section 5. Lastly, a tool emerged as this effort began called the NUREG 0711 Crosswalk (Section 8). The tool has multiple uses, but it was primarily intended to communicate how the researcher’s action directly mapped to specific results suggested in the Nuclear Regulatory Commission review guideline. The tool also maps how current results impact future decisions in the modernization process.