Abstract
This paper is to develop an applicable and precise RETRAN input for Lungmen Plant in order to predict the behavior of transient in Start-up Test Program (STP). The predictions of RETRAN can be referred to acquaint the staff of STP with the system responses in advance before the actual test, which is the basis to evaluate the appropriate decision during the processes. And it also provides the Regulatory and TPC a parallel tool to benchmark the results of Vendor. In this study the LRM is transferred into an advanced version of RETRAN-3D, and the major control systems are remodeled in RFCS, FWCS and SBPCS. Several verification and validation calculations are conducted for individual control system according to how the manipulation of the control system is close to the related transient. The benchmark results show that the responses of control modules are accepted in acceptance criteria and the Gain setting are already tuned to the optimal value.In this dissertation eight moderate transients in Lungmen FSAR are used to benchmark the ability to evaluate the system responses of Lungmen, including: (1) Loss of Feedwater Heating, (2) Feedwater Controller Failure with Maximum Demand, (3) Single Control Valve Closure in Fast Mode, (4) Generator Load Rejection with No Bypass, (5) Turbine Trip with No Bypass, (6) Reactor Full Isolation, (7) Loss of Feedwater, and (8) All RIPs Trip. From the FSAR benchmark, the RETRAN results are highly in agreement with the FSAR and come to the conclusion of the identical limiting transient (Single Control Valve Closure in Fast Mode). In LFWH, the capability of RETRAN to analyze the slow transient has been verified and can predict the dynamic behavior in transient. In single control valve closure transient, the part arc mode of TCV in LRM is different from the full arc mode in FSAR analysis. The different operation mode leads to the more conservative thermal limit in RETRAN than that of FSAR. On the whole, it is concluded that the LRM is certainly able to catch the trend of the system parameters of core in transient.In the predictions of STP, there are nine tests selected to be analyzed, including those transient type of: (1) decrease in reactor coolant temperature, (2) decrease in reactor feedwater flow, (3) increase in reactor pressure, and (4) RIP trip. The prediction analyses of STP show that the results of RETRAN can exactly catch the system responses to the transient, and the sensitiveity studies can be employed to a reference to the staff of STP. In one feedwater pump trip test the low level scram will be actuated in the case of no auxilliary MDRFP function. In the prediction results of three RIPs trip show that the coastdown speed of tripped RIPs with the minimu hardware inertia of motor/generator is just against the requirement for the coastdown speed, while the case with the minimum analytical inertia comes out to the acceptable coastdown rate between the bounding curves.This dissertation develop the best estimate and safety analysis RETRAN input for Lungmen Plant, and implant the major control system modules into the model. The functions of the control modules have been identified to fulfill the design requirement through the individual step change benchmark and related transient evaluations. But there are still several points like water level prediction, the characteristic of RIP, SCRRI feature etc., which needed to upgrade or verify against the STP database or plant operational data. In general, the LRM show the good agreement with the FSAR cases in transient responses. Based on this conclusion the LRM can be employed to support the operational transient analysis and even the evaluation for equipment or design change cases if the model benchmark further against the appropriate plant data after Lungmen plant has been commercialized.