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Title: Computer Models for IRIS Control System Transient Analysis

Technical Report ·
DOI:https://doi.org/10.2172/933157· OSTI ID:933157

This report presents results of the Westinghouse work performed under Task 3 of this Financial Assistance Award and it satisfies a Level 2 Milestone for the project. Task 3 of the collaborative effort between ORNL, Brazil and Westinghouse for the International Nuclear Energy Research Initiative entitled “Development of Advanced Instrumentation and Control for an Integrated Primary System Reactor” focuses on developing computer models for transient analysis. This report summarizes the work performed under Task 3 on developing control system models. The present state of the IRIS plant design – such as the lack of a detailed secondary system or I&C system designs – makes finalizing models impossible at this time. However, this did not prevent making considerable progress. Westinghouse has several working models in use to further the IRIS design. We expect to continue modifying the models to incorporate the latest design information until the final IRIS unit becomes operational. Section 1.2 outlines the scope of this report. Section 2 describes the approaches we are using for non-safety transient models. It describes the need for non-safety transient analysis and the model characteristics needed to support those analyses. Section 3 presents the RELAP5 model. This is the highest-fidelity model used for benchmark evaluations. However, it is prohibitively slow for routine evaluations and additional lower-fidelity models have been developed. Section 4 discusses the current Matlab/Simulink model. This is a low-fidelity, high-speed model used to quickly evaluate and compare competing control and protection concepts. Section 5 describes the Modelica models developed by POLIMI and Westinghouse. The object-oriented Modelica language provides convenient mechanisms for developing models at several levels of detail. We have used this to develop a high-fidelity model for detailed analyses and a faster-running simplified model to help speed the I&C development process. Section 6 describes an ACSL model that Westinghouse started but suspended developing for the moment. ACSL is an old simulation language that Westinghouse used on many projects. It may (or may not) offer some advantages during the later stages of detailed plant design and analysis, but supporting the ACSL model does not appear to be necessary at this time. Section 7 summarizes our expectations for future development.

Research Organization:
Westinghouse Electric Company LLC, Cranberry Township, PA (United States)
Sponsoring Organization:
USDOE - Office of Nuclear Energy, Science and Technology (NE)
DOE Contract Number:
FG07-05ID14690
OSTI ID:
933157
Report Number(s):
STD-AR-06-04 (rev. 2); TRN: US0804272
Country of Publication:
United States
Language:
English