Use of Zirconium-Based Moderators to Enhance Feedback Coefficients in a MOX-Fueled Sodium-Cooled Fast Reactor

• Published in: Nuclear science and engineering Vol. 171; no. 2; pp. 136 - 149
• Main Authors: Merk, Bruno, Kliem, Sören, Fridman, Emil, Weiss, Frank-Peter
• Format: Journal Article
• Language: English
• Published: La Grange Park, IL Taylor & Francis 01.06.2012; American Nuclear Society
• Subjects: Applied sciences; Borides; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fission nuclear power plants; Fuels; Insertion; Installations for energy generation and conversion: thermal and electrical energy; Nuclear engineering; Nuclear fuels; Nuclear power generation; Nuclear reactor components; Nuclear reactors; Preparation and processing of nuclear fuels; Sodium; Voids; Stability; Coolant; Zirconium hydride; Temperature effect; Unsteady state; Nuclear fuel; Neutron leakage; Nuclear reactor; Actinide; Zirconium; Sodium; Fast breeder; Fast reactor; Mixed fuel; Sodium oxide
• ISSN: 0029-5639; 1943-748X
• DOI: 10.13182/NSE10-58

This work shows the effect of the use of moderating layers on the sodium void effect in sodium-cooled, mixed oxide-fueled fast breeder reactors. The moderating layers consist of either zirconium boride ZrB 2 or zirconium hydride ZrH 2 . The two investigated ZrH 2 layers (0.1 and 0.2 mm thick) cause a strong reduction of the sodium void effect. Additionally, these layers significantly improve the fuel temperature effect and the coolant effect of the system. All changes caused by the insertion of the ZrH 2 layers result in a significantly increased stability of the fast reactor system against transients. The moderating layers have only a small influence on the breeding effect and on the production of minor actinides. The effect in the infinite system can be fully combined with the traditional methods of increasing the neutron leakage.