Modelling effects and their impact on the results of ATHLET solutions of Exercise 1 of the VVER-1000 Coolant Transient Benchmark

• Published in: Progress in nuclear energy (New series) Vol. 48; no. 8; pp. 912 - 921
• Main Authors: Langenbuch, S., Hadek, J., Schmidt, K.-D., Velkov, K.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Tarrytown, NY Elsevier Ltd 01.11.2006; Oxford Elsevier
• Subjects: Applied sciences; ATHLET; Coolant Transient Benchmark; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fission nuclear power plants; Installations for energy generation and conversion: thermal and electrical energy; VVER-1000; Bulgaria; Europe; VVER-1000; Coolant Transient Benchmark; ATHLET; Nuclear power plant; Benchmark calculation; Fission reactor safety; Cooling system; Unsteady state; Computation code; Modeling; Transients; Nuclear reactor
• ISSN: 0149-1970
• DOI: 10.1016/j.pnucene.2006.07.001

The VVER-1000 Coolant Transient Benchmark consists of two phases and refers to experimental data from the Kozloduy Unit 6 Nuclear Power Plant in Bulgaria. The paper describes the modelling features and their impact on the results of the Exercise 1, Phase 1 of the Benchmark obtained by two ATHLET user groups, namely GRS and NRI. The simulated transient is a main coolant pump (MCP) switching on in one loop at reduced power while three other MCPs are in operation. Particular attention is paid to the influence of the reactor vessel modelling and especially of the nodalization in the upper plenum. The comparison and discussion of the two simulation results confirm that the two solutions with the ATHLET system code achieve quite good system response of the plant transient.