Accessible Requires Authentication Published by De Gruyter April 5, 2013

Uncertainty analysis for fission products transport in CANDU primary heat transport during a severe accident

Unsicherheitsanalyse für den Transport von Spaltprodukten im Primärkühlmittel des Reaktors CANDU bei einem schweren Störfall
M. Apostol, M. Constantin and A. Leca
From the journal Kerntechnik

Abstract

The work realized under the Severe Accident Research Network of excellence (SARNET) project has shown that the SOPHAEROS module, part of Accident Source Term Evaluation Code (ASTEC) can be fully used to simulate the fission products transport and deposition phenomena in the CANDU Primary Heat Transport (PHT) system. This paper presents an uncertainty analysis for the fission products transport in the CANDU PHT system during a severe accident to obtain the domains of the output parameters, for this study masses of Caesium, Strontium and Iodine deposited in the PHT system and its nodes, taking into account the associated input parameters uncertainties. Five uncertain parameters, the starting time for the releasing process, the duration of the releasing process, the releasing fractions for Cs, Sr and I have been chosen. To generate aleatory values for the uncertain parameters, a method and software have been developed and Monte Carlo simulations to determine uncertainties propagation through the SOPHAEROS module has been carried out.

Kurzfassung

Die im Rahmen des SARNET-Projekts durchgeführten Arbeiten haben gezeigt, dass das SOPHAEROS-Modul als ein Teil des ASTEC-Codes für die Quelltermabschätzung bei schweren Störfällen gut geeignet ist, um den Transport und die Ablagerung von Spaltprodukten im Primärkühlkreis des Reaktors CANDU zu simulieren. Dieser Beitrag stellt eine Unsicherheitsanalyse für den Transport von Spaltprodukten im Primärkühlkreislauf bei einem schweren Störfall dar, die eine Abschätzung der Ausgangsparameter unter Berücksichtigung der Unsicherheiten von Eingangsparametern, wie zum Beispiel, die Mengen an Cs, Sr und I, abgelagert im Primärkreis und seinen Verbindungsstellen, ermöglicht. Fünf Unsicherheitsparameter wurden ausgewählt: Startzeit des Freisetzungsprozesses, Dauer des Freisetzungsprozesses, Freisetzungsanteile für Cs, Sr und I. Zur Erzeugung von Zufallsvariablen für die Unsicherheitsanalyse wurde eine entsprechende Methodik und Software entwickelt und Monte-Carlo-Simulationen zur Abschätzung der Fortpflanzung der Unsicherheiten im SOPHAEROS-Modul durchgeführt.

References

1 Accident Analysis for Nuclear Power Plants. Safety Reports Series No. 23, International Atomic Energy Agency, Vienna, 2002 Search in Google Scholar

2 Analysis of Severe Accidents in Pressurized Heavy Water Reactors. IAEA-TECDOC-1594, International Atomic Energy Agency, Vienna, June 2008 Search in Google Scholar

3 Approaches and Tools for Severe Accident Analysis for Nuclear Power Plants. Safety Report Series No. 56, International Atomic Energy Agency, Vienna, 2008 Search in Google Scholar

4 D'Auria, F.: Approach and Methods to Evaluate the Uncertainty in System Thermohydraulic Calculations. Mecanica Computacional, Bariloche, Argentina, 2004, Vol. XXIII, p. 1411 Search in Google Scholar

5 Petruzzi, A.; D'Auria, F.: Approaches, Relevant Topics, and Internal Method for Uncertainty Evaluation in Predictions of Thermal-Hydraulic System Codes. Science and Technology of Nuclear Installations, Article ID 32 5071, 2008, 17 pages, 10.1155/2008/32 5071 Search in Google Scholar

6 Van Dorsselaere, J. P.et al.: Sustainable Integration of EU Research in Severe Accident Phenomenology and Management. FISA Conference, Prague, June 22–24, 2009 Search in Google Scholar

7 Allelein, H.-J.; Neu, K.; Van Dorsellaere, J. P.: European Validation of the Integral Code ASTEC (EVITA) – First experience in validation and plant sequence calculation, Nuclear Engineering and Design235 (2005) 285 Search in Google Scholar

8 Clement, B.et al.: LWR Severe Accident Simulation: Synthesis of the Results and Interpretation of the First PHEBUS FP Experiment FPT0. Nuclear Engineering and Design 226 (2003) 5 Search in Google Scholar

9 Constantin, M.: CANDU Model Adaptations. FP6-SARNET, 3rd/ASTEC Users' Club Meeting, Aix-en-Provence, April 2008 Search in Google Scholar

10 D'Auria, F.et al.: Sate of the Art in Using Best Estimate Calculation Tools in Nuclear Technology. Nuclear Engineering and Technology 38 (2006) 11 Search in Google Scholar

11 Baccou, J.; Chojnacki, E.; Jobelin, M.: SUNSET: a Statistical Uncertainty and Sensitivity Evaluation Tool, ASTEC v2.0 Training Course, Aix-en-Provence, France, June 29-July 3, 2009 Search in Google Scholar

12 Buy, R.: SUNSET-ASTEC: Quick Guide line based on the case <<CORIUM>>, ASTEC v2.0 Training Course, Aix-en-Provence, France, June 29-July 3, 2009 Search in Google Scholar

13 Hanna, B. N.: CATHENA: A Thermalhydraulic Code for CANDU Analysis. Nuclear Engineering and Design180 (1998) 113 Search in Google Scholar

14 Gauld, I. C.et al.: ORIGEN-S, NUREG/CR-0200, Revision 7, Vol. 2, Section F7, ORNL/NUREG/CSD-2/V2/R7, April2002 Search in Google Scholar

15 × 600 MWe CANDU-PHW Nuclear Generating Station, AECL, Technical Description, Vol. 1, 1976 Search in Google Scholar

16 Constantin, M.; Rizoiu, A.: Fission Products Distributions in CANDU Primary Heat Transport and CANDU Containment Systems during a Severe Accident. 14th National Conference on Physics, Bucharest, Romania, 13–17 September 2005 Search in Google Scholar

17 Vose, D.: Risk Analysis. A Quantitative Guide. Second edition, John Wiley & Sons, Ltd, England, 2000 Search in Google Scholar

18 Chojnacki, E.; Benoit, J.-P.: The Use of Monte Carlo Simulation and Order Statistics for Uncertainty analysis of a LBLOCA Transient (LOFT-L 2–5). Workshop on the Evaluation of Uncertainties in Relation to Severe Accidents and Level II Probabilistic Safety Analysis, Cadarache, France, 7–9 November 2005 Search in Google Scholar

Received: 2009-12-21
Published Online: 2013-04-05
Published in Print: 2010-08-01

© 2010, Carl Hanser Verlag, München