Modeling of fuel performance and metallic fission product release behavior during HTTR normal operating conditions

• Published in: Nuclear engineering and design Vol. 210; no. 1; pp. 225 - 238
• Main Authors: Verfondern, K, Sumita, J, Ueta, S, Sawa, K
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.12.2001; Elsevier
• Subjects: Applied sciences; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fission nuclear power plants; Fission reactions; Gas cooled reactors; High temperature reactors; Installations for energy generation and conversion: thermal and electrical energy; Temperature distribution; High temperature reactor; Fission product; Computation code; Nuclear fuel; Metal; HTTR reactor; Nuclear reactor
• ISSN: 0029-5493; 1872-759X
• DOI: 10.1016/S0029-5493(01)00432-0

The computer codes PANAMA and FRESCO developed at the Research Center Jülich have been used for the prediction of fuel performance and fission product release behavior during the normal operation of the Japanese High-Temperature Engineering Test Reactor, HTTR. Basis for the calculations was the so-called ‘Standard HTTR Operation Plan’ with a nominal operation time of 660 efpd including a 110 efpd period with enhanced fuel temperatures. Fuel performance model calculations with the PANAMA code have shown that for the temperature distribution given, only a small additional failure fraction is expected. The diffusive release of metallic fission products from the fuel occurs mainly from the central core layers with the maximum temperatures whereas there is little contribution from the upper layer. Silver most easily escapes the fuel. The release data for strontium and cesium also reveal a significant fraction to originate from still intact particles. The comparison with the calculations obtained with the JAERI models has shown a good agreement for the release from the coated particles.