HTGR Knowledge Base

Conference Article: Analysis of Reactivity Induced Accidents for HTR-10

Serhat Kose, Ihsan Kilic, Technology Dept. Turkish Atomic Energy Authority, Ankara, TURKEY

Abstract

Initiating events for accidents has been classified into five groups for HTR-10, by Chinese Authorities. The fourth group (Class IV) events are considered as Design Basis Accident (DBA) cases regarding their consequences. There are three types of initiating events in Class-IV, resulting in reactivity accidents: "Water ingress into primary circuit system", "Uncontrolled withdrawal of one control rod at power combined with the condition of safe earthquake" and "Uncontrolled withdrawal of a bunch (more than one) of control rods at cold start-up condition". A computer program, named ATA (Accident and Transient Analysis Code for HTR), has been developed, based on AIREK-code, which is currently in use in the point kinetic module of RELAP5 code. The AIREK code calculates the power history concerning reactivity excursions with delayed precursors up to 49 groups. ATA code has been combined with a reactivity feedback module, including feedback effects due to fuel, gas and reflector temperature variations. Also, some modules of MORECA code, which calculates the temperature and energy deposition for high temperature gas cooled reactors with prismatic fuel elements, has been modified for HTR-10. The modified modules which compute maximum fuel, gas and reflector temperatures have been coupled with the ATA code. In this study, reactivity accidents initiated by Class-IV events have been analyzed with the ATA computer code. In the analysis, six delayed precursor groups have been used. The analyses show that maximum fuel centerline temperatures for all studied accidents remain below the safety limit 1600oC.

view the full text of this article (10 pages, format: PDF, size= 178kB)

key words: Gas Cooled Reactor, Nuclear Technology
Reference:
Proceedings of the Conference on High Temperature Reactors, Beijing, China, September, 22-24, 2004
International Atomic Energy Agency, Vienna (Austria)
HTR-2004, pp:1-10