Verification by analytical means of the efficiency of some accident management measures for SBO at a CANDU-6 NPP

Elena Dinca, Daniel Dupleac, Ilie Prisecaru


This paper presents the analysis of the consequences of a Station Black-Out (SBO) accident at a CANDU-6 NPP, considering both the reference case, without any heat sink credited for nuclear fuel cooling and the situation when an accident management measure is implemented for the prevention of a severe accident. This measure, consisting in the steam generators’ depressurization followed by addition of water into the steam generators from the dousing tank, has been considered in the analysis to be implemented according to the actual emergency operating procedure specific for SBO initiating event, at Cernavoda NPP, considering different flowrates for the water added into SGs after their depressurization. The aim of these calculations is the verification by analytical means of the efficiency of these management measures in ensuring the seat sink after a SBO at a CANDU-6 NPP. Selected accident sequences have been analysed using the RELAP/SCDAPSIM.MOD3.6(a) computer code.


CANDU, SBO, severe accident, SG depressurization, RELAP/SCDAPSIM, nuclear safety, accident analysis


International Atomic Energy Agency, IAEA TECDOC 1727, “Benchmarking Severe Accident Computer Codes for Heavy Water Reactorâ€, Vienna, 2013

FAUSKE&ASSOCIATE Inc. and OPG Inc., “MAAP-CANDU — Modular Accident Analysis Program for CANDU Power Plantâ€, Vols. 1–3 (1998)

Korea Atomic Energy Research Institute, “Development of Computer Code for Level 2 PSA of CANDU Plantâ€, KAERI/RR-1573/95 (1995)

SCDAP/RELAP5 Development Team, “SCDAP/RELAP5/MOD3.2 Code Manualâ€, Vol. 1-5, NUREG/CR-6150, INEL-96/0422, 1998

L. J. Siefken, C. M. Allison, J. K. Hohorst, “RELAP/SCDAPSIM/MOD3.5 - Improvements Resulting from QUENCH and PARAMETER Bundle Heating and Quenching Experimentsâ€, 2010, ISS, Idaho Falls, USA

Ghe. Negut, Al. Catana, I. Prisecaru, D. Dupleac, “Thermal Hydraulics of the CANDU Degraded Coresâ€, 2007

M. Mladin, D. Dupleac, I. Prisecaru, “SCDAP/RELAP5 application to CANDU6 fuel channel analysis under postulated LLOCA/LOECC conditionsâ€, 2008

M. Mladin, D. Dupleac, I. Prisecaru, “Evaluation of the RELAP5/SCDAP Accident Analysis Code Applicability to CANDU Nuclear Reactorsâ€, U.P.B. Sci. Bull., Series C, Vol. 71, Iss. 4, ISSN 1454-234x, Bucharest, 2009

M. Mladin, D. Dupleac, I. Prisecaru, “Verification of Modified SCDAP/RELAP5 Against CANDU Fuel Deformation Experimental Resultsâ€, INCONE17, Brussels, 2009

D. Dupleac, M. Mladin, I. Prisecaru, “SCDAP/RELAP5 Analysis of Progression of Severe Accident in CANDU 6 Plantâ€, INCONE17, Brussels, 2009

D. Dupleac, M. Mladin, I. Prisecaru, “Effect of CANDU Fuel Bundle Modelling on Severe Accident Analysisâ€, Paris, 2009

Budu, D. Dupleac, “Pressure Tube Oxidation Heat Addition in an Accident in a CANDU Type Nuclear Power Plantâ€, U.P.B. Sci. Bull., Series C, Vol. 73, Iss. 2, Bucharest, 2011

CNCAN, „National Report on the Implementation of the Stress Testsâ€, Decembrie 2011

Youngho Jin, Soo-Yong Park, Yong-Mann Song, “Application of Severe Accident Management Guidance in The Management of an SGTR Accident at The Wolsong Plantsâ€, Kaeri, Daejon, 2008

T. Nitheanandan et al., “Backup and Ultimate Heat Sinks in CANDU Reactors for Prolonged SBO Accidentsâ€, Nuclear Engineering and Technology, Vol.45 No.5, 2013

S.M. Petoukhov, “MAAP4-CANDU simulation results for CANDU 6 accident management measure: steam generator secondary side water make-up from dousing tank for the station blackout scenarioâ€, The 19th Pacific Basin Nuclear Conference (PBNC 2014), Vancouver, British Columbia, Canada, 2014

A.Bonelli, O.Mazzantini, D.Dupleac, E.Dinca, L. J. Siefken, C. M. Allison, J. K. Hohorst „RELAP/SCDAPSIM/MOD3.6 – Development of Severe Accident Models for Heavy Water Reactors Including CANDU and Atucha-2â€. I. Proc. ICAPP 2015, May 03-06, Nice, France, (Paper 15080), 2015

Full Text: PDF


  • There are currently no refbacks.

Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 License.

"No endorsement" policy: Unless explicitly stated otherwise, the opinions, analyses, discussions, views and recommendations outlined in the articles published in the International Nuclear Safety Journal (INSJ) are solely those of their respective authors and not of the editors, owners or publishers of the INSJ.