Table of Contents Author Guidelines Submit a Manuscript
Science and Technology of Nuclear Installations
Volume 2018, Article ID 6964946, 14 pages
Research Article

RELAP5/MOD3.3 Analysis of the Loss of External Power Event with Safety Injection Actuation

Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia

Correspondence should be addressed to Andrej Prošek; is.sji@kesorp.jerdna

Received 30 December 2017; Accepted 13 February 2018; Published 23 April 2018

Academic Editor: Arkady Serikov

Copyright © 2018 Andrej Prošek and Marko Matkovič. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The code assessment typically comprises basic tests cases, separate effects test, and integral effects tests. On the other hand, the thermal hydraulic system codes like RELAP5/MOD3.3 are primarily intended for simulation of transients and accidents in light water reactors. The plant measured data come mostly from startup tests and operational events. Also, for operational events the measured plant data may not be sufficient to explain all details of the event. The purpose of this study was therefore besides code assessment to demonstrate that simulations can be very beneficial for deep understanding of the plant response and further corrective measures. The abnormal event with reactor trip and safety injection signal actuation was simulated with the latest RELAP5/MOD3.3 Patch 05 best-estimate thermal hydraulic computer code. The measured and simulated data agree well considering the major plant system responses and operator actions. This suggests that the RELAP5 code simulation is good representative of the plant response and can complement not available information from plant measured data. In such a way, an event can be better understood.