Analysis Of Steam Generator Tube Rupture (SGTR) Accident And Its Isolation On PWR

Abstract:

An Analysis of SGTR accident and its isolation on PWR using RELAP/SCDAP has been done. This analysis uses a standard PWR refererring on Tsuruga Unit 2 NPP as a model.

The analysis is performed at results of SGTR simulation bassed on RELAP input file developed by NUPEC. Where responses of reactor control system entirely depend on automatic setting. Manual control is only done to achieve the leakage isolation. The simulation results show that the reactor control system has responded as expected such as reactor trip, actuation of feedwater control system, turbine bypass control system, main steam relatief control system, and safety injection. By assuming that leakage isolation is failed at the early stage, the feedwater inside the secondary side has overflowed the steam dome of the affected and the intact steam generator, which triggers the opening of main steam relief valves (MSRV) as also the uncontrolled release of fision products to the environment. Nevertheless the leakage isolation by actuating the pressuriser relief valves (PORV) followed by termination of safety injection, both manually, has been sucessfully achieved. The resulted accident scenario shows the necessity to modify several reactor control system mentioned before into manual actuation, so that the accident sequences will be more identical with the references.

Keywords: SGTR, RELAP/SCDAP, Leakage Isolation.

Oleh: Andi Sofrany Ekariansyah

Pusat Teknologi Reaktor dan Keselamatan Nuklir-Batan