Sensitivity study of a new model for assessing time-dependent risk in ageing NPP
نویسندگان
چکیده
The nuclear power plants risk reduction by application of the probabilistic safety assessment is one of the main focuses of the nuclear safety today. The goal is the reduction of the unavailability of the nuclear power plants safety systems. On the other hand, the world NPP fleet is ageing fast. Equipment ageing has gradually become a major concern in the nuclear industry since the number of safety systems components, that are approaching their wear-out stage, is rising fast. A previously developed model for assessing time-dependent unavailability of ageing safety equipment is briefly presented and discussed herein. One of the essential features of the model is that it simultaneously considers the effects of performing surveillance testing as well as preventive maintenance, corrective maintenance and overhaul. Also, the ageing-implicated adverse effects on component availability are being explicitly considered as an integral part of this time-dependent unavailability model. Subsequently, the model can be coupled to commercial software for systemand plant-level modelling. This paper is aimed towards performing sensitivity analysis of the developed model. A component level resolution is selected as the basis for performing the analysis. Investigation of the influence of different component-relevant input parameters on the calculated equipment unavailability is the goal of the analysis. The dependency of the calculated component unavailability on the corresponding surveillance test interval is of a particular interest. The results are presented and discussed.
منابع مشابه
A New Time-Dependent Unavailability Model Considering Equipment Ageing: A Multi-Objective Optimization Case Study Example
Managing a nuclear power plant (NPP) calls for evaluation and trading off the conflicting objectives of safe operation and economic burden. The reduction of NPP risk is strongly correlated to the reduction of NPP safety systems unavailability. The application of the probabilistic safety assessment in order to reduce safety systems unavailability is one of the prime goals in the nuclear safety a...
متن کاملA new study of an EOQ model for deteriorating items with shortages under inflation and time discounting
We discuss the effects of inflation and time discounting on an EOQ model for deteriorating items under stock-dependent demand and time-dependent partial backlogging. The inventory model is studied under the replenishment policy starting with no shortages. We then use MATLAB to find the optimal replenishment policies. The objective of this model is to maximize the total profit (TP) which inclu...
متن کاملIntegrated model for pricing, delivery time setting, and scheduling in make-to-order environments
Usually, in make-to-order environments which work only in response to the customer’s orders, manufacturers for maximizing the profits should offer the best price and delivery time for an order considering the existing capacity and the customer’s sensitivity to both the factors. In this paper, an integrated approach for pricing, delivery time setting and scheduling of new arrival orders are prop...
متن کاملA single-vendor and a single-buyer integrated inventory model with ordering cost reduction dependent on lead time
Lead time is one of the major limits that affect planning at every stage of the supply chain system. In this paper, we study a continuous review inventory model. This paper investigates the ordering cost reductions are dependent on lead time. This study addressed two-echelon supply chain problem consisting of a single vendor and a single buyer. The main contribution of this study is that the in...
متن کاملIdentifying patterns of the dynamic credit risk of banks customers and financial institutions: case study- an Iranian bank
Credit risk assessment has always been one of the most important concerns of banks. Widely used models such as financial models have been used to assess credit risk so far. But increasing non-performing loans indicates that today these models cannot assess the credit risk of customers. Inconstant and uncertain environmental, social and political factors affect customer behavior and change custo...
متن کامل