Abstract
After spent fuel assemblies have been discharged from the reactor, reactivity will fluctuate as the cooling period progresses because of changes in the number density of fissile nuclides and neutron absorber nuclides. The purpose of this project was (1) to quantify the contribution of each individual nuclide to the reactivity of the fissile system, (2) to identify nuclides that are responsible for the fluctuation in reactivity, and (3) to determine the effect of the number of nuclides on reactivity. This paper will present the results of the study of the behaviour of the keff with respect to variation in the duration of the cooling period during storage.
Kurzfassung
Nach dem Entladen abgebrannter Brennelemente aus einem Reaktor schwankt die Reaktivität mit fortschreitender Kühlung wegen Änderung der Teilchenzahldichte der Spaltnuklide und der Neutronenabsorbernuklide. Zweck der Untersuchungen im vorliegenden Beitrag war es, (1) den Beitrag eines jeden individuellen Radionuklids zur Reaktivität des Spaltsystems zu identifizieren, (2) Nuklide, verantwortlich für die Reaktivitätsschwankungen zu identifizieren, und (3) den Effekt der Anzahl der Nuklide auf die Reaktivität zu bestimmen. Dieser Beitrag stellt die Ergebnisse der Untersuchungen des Verhaltens von keff in Bezug auf Schwankungen bei der Abkühldauer während der Lagerung vor.
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