Abstract
A theoretical and experimental investigation has been carried out to study natural circulation characteristics of an Indian PHWR under reduced inventory conditions. The theoretical model incorporates a quasi-steady state analysis of natural circulation at different system inventories. It predicts the system flow rate under single-phase and two-phase conditions and the inventory at which reflux condensation occurs. The model predictions were compared with test data obtained from FISBE (Facility for Integral System Behaviour Experiments), which simulates the thermal hydraulic behaviour of the Indian 220 MWe PHWR. The experimental results were found to be in close agreement with the predictions. It was also found that the natural circulation could be oscillatory under reduced inventory conditions.
Kurzfassung
Theoretische und experimentelle Untersuchungen wurden durchgeführt, um die Eigenschaften des Indischen Schwerwasserreaktors bei reduziertem Inventar zu bestimmen. Das theoretische Modell beinhaltet eine quasi-stationäre Analyse des Naturumlaufs bei verschiedenem Systeminventar. Es sagt die Strömungsdichte des Systems unter Ein-Phasen- und Zwei-Phasenbedingungen voraus, sowie das Inventar, bei dem Rückflusskondensation auftritt. Die Modellvoraussagen wurden verglichen mit Testdaten aus sog. FISBE Experimenten, in denen das thermohydraulische Verhalten des Indischen 220 MWe Schwerwasserreaktors simuliert wurde. Die experimentellen Ergebnisse stimmen gut mit den Vorhersagen überein. Ein weiteres Ergebnis war, dass der Naturumlauf bei reduziertem Inventar oszillieren kann.
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