Emerging I&amp;C Technologies Under the Shifting Regulatory Environment in South Korea

Gyunyoung Heo,Poong Hyun Seong,Hyun Gook Kang

doi:10.3389/fenrg.2015.00019

Abstract

The role of Probabilistic Safety Assessment (PSA) has been supplementary and Risk-Informed Applications (RIAs) based on the insight from PSA has also been utilized limitedly in the licensing process for Nuclear Power Plants (NPPs) in South Korea. However, as the technical significance of PSA is getting increased, PSA has become a mandatory part of Safety Analysis Reports and Periodic Safety Review. It is worthwhile to highlight the role of emerging Instrumentation and Control (I&C) technologies including human-machine interface (HMI) in developing more credible and realistic PSA models. Particularly, it is expected that the information technology (i.e. software) embedded in digital I&C can adjust over- and under conservatism in analyzing risk. In this study, authors proposed the cases which would be able to significantly reduce risk if advanced I&C supported by information technologies is applied. In regard, the several enabling techniques and their effects are proposed. In order to improve the commercial competitiveness of NPPs, the need of collaboration and synergetic outcome of I&C, HMI and PSA should be emphasized.

Highlights

Though there are little differences in the regulatory infrastructures of all nuclear facilities in countries, probabilistic safety assessment (PSA) has performed important roles in optimizing regulatory resources while keeping nuclear safety higher
Evaluation on Human Error Impact during Test/Maintenance While automation is the aid for operators, proactive simulation technique can be the aid for test/maintenance crews in nuclear power plants (NPPs)
The entire framework that we established is composed of four components: (1) the human-error analyzer to connect possible failure modes resulting from human errors with other estimators, (2) the frequency estimator to quantify the occurrence of maintenance-related failure modes, (3) the risk estimator to determine minimal cutsets and to compute the variation of the core damage frequency (CDF) using the fault tree analysis and turbine cycle simulation, and (4) the derate estimator to determine the electrical power loss under abnormal plant configurations caused by human error

Summary

Introduction

Though there are little differences in the regulatory infrastructures of all nuclear facilities in countries, probabilistic safety assessment (PSA) has performed important roles in optimizing regulatory resources while keeping nuclear safety higher. PSA has become mandatory section of safety analysis reports (SARs) for construction license and operating permit, and periodic safety review (PSR) performed every 10 years, technical responsibility of PSA is getting more important This should be the results of improved PSA models with less aleatory as well as epistemic uncertainty during the past decades. Even though human error probability is considered in the probabilistic approach, the operator’s behavior in digitalized environment is not fully understood; so, we are not able to make sure whether the current PSA model over- or under-estimates results. In conventional PSAs, which mainly include the models of analog I&C systems, I&C systems were considered as so called support function providers It means that the function of I&C systems was understood and limited as safety signal generation or processing for supporting front-line systems such as safety valves and pumps. Once the digitalized I&C systems are introduced, new technical chances opened by virtue of increased computing capability, huge data warehouse, wide networks, and TABLE 1 | Comparison between deterministic and probabilistic approaches

As realistic as possible

Enabling Techniques

Conclusions and Recommendations