The presence of the external driving-source reduces the effects of reactivity level variations on neutron kinetics of Accelerator Driven Systems (ADS). It is well known, for instance, that ADS respond more benignly than critical systems to reactivity insertions. This Accelerator Driven Systems characteristic has been further analysed in the present work. In particular, possible low feedback reactivity-effects, that mitigate critical system transients induced by coolant flow reductions, have been investigated in the worst hypothetical scenario: i.e. during an unprotected Loss of Flow accident (LOFWS) in solid-fuel systems. Since the ADS dynamics is mainly decided by the external source, a parametric study has been performed to investigate feedback effects in ADS, by considering not only different values of the system sub-criticality level, but also different hypothesis on the external-source control-strategy. Owing to the approximations adopted in present work calculations, the LOFWS transient results can not be considered as definitive. Nevertheless, some general considerations on different strategies to control ADS look quite evident.
Some Considerations in Reactivity Effects and Source Intensity Control of Accelerator Driven Systems
Bianchini, G.;Carta, M.;D'Angelo, A.
1999-08-29
Abstract
The presence of the external driving-source reduces the effects of reactivity level variations on neutron kinetics of Accelerator Driven Systems (ADS). It is well known, for instance, that ADS respond more benignly than critical systems to reactivity insertions. This Accelerator Driven Systems characteristic has been further analysed in the present work. In particular, possible low feedback reactivity-effects, that mitigate critical system transients induced by coolant flow reductions, have been investigated in the worst hypothetical scenario: i.e. during an unprotected Loss of Flow accident (LOFWS) in solid-fuel systems. Since the ADS dynamics is mainly decided by the external source, a parametric study has been performed to investigate feedback effects in ADS, by considering not only different values of the system sub-criticality level, but also different hypothesis on the external-source control-strategy. Owing to the approximations adopted in present work calculations, the LOFWS transient results can not be considered as definitive. Nevertheless, some general considerations on different strategies to control ADS look quite evident.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
