Abstract
The intention of the startup physics tests was to confirm design characteristics of the core loading and their compliance with safety analysis preconditions. The program of startup tests for the leading unit is usually composed in such a way that is is possible to study as much neutron-physical characteristics as possible in the safest condition of zero power. State-of-the-art safety analysis is including computer codes that use three dimensional neutron kinetics and thermohydraulics models. For the substantiation of such models, for its validation and verification there is a need in reactor experiments that implementing spatially distributed transients. We based on such statements when composing hot zero power physical startup program for the new VVER-1200 unit of Novovoronezh NPP. Several tests unconventional for VVER were developed for that program. It includes measuring the worth for each of control rod groups and measuring of single rod worth from the inserted groups – test that models rod ejection event in some sense.
Kurzfassung
Im Rahmen der Inbetriebsetzungsversuche werden die Designcharakteristiken der Kernbeladung und deren Übereinstimmung mit den vorausberechneten Sicherheitscharakteristiken überprüft. In der Regel wird das Programm der Inbetriebsetzungsversuche der ersten Reaktoren einer neuen Serie so definiert, dass möglichst viele neutronen-physikalische Eigenschaften im sicheren Zustand der Null-Leistung gemessen und untersucht werden können. Aktuelle Sicherheitsanalysen werden mit Computercodes durchgeführt, die dreidimensionale Neutronenkinetik- und Thermohydraulikmodelle verwenden. Zur Nachweisführung der dazu verwendeten Modelle, ihrer Verifizierung und Validierung werden Reaktorexperimente benötigt, die räumlich Parameterverteilungen enthalten. Unter Berücksichtigung dieser Vorgaben wurde das Inbetriebsetzungs-Programm des WWER-1200 des KKW Novovoronezh so definiert, dass auch zahlreiche bislang untypische Tests aufgenommen wurden. Dazu gehören die Bestimmung des Reaktivitätswertes jeder Regelstabgruppe sowie einzelner Stäbe der eingefahrenen Gruppen. Letztere bilden in gewissem Sinn einen Stabauswurf nach.
References
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