Reactivity monitoring with imposed beam trips and pulsed mode detectors in the subcritical experiment YALINA-Booster

• Reactivity monitoring is one of the urgent problems that require a solution in order to achieve a license for a future full-scale ADS. As a part of the EUROTRANS experiments at the YALINA-Booster facility, presented in this conference, a set of measurements with imposed beam-trips has been performed. Traditionally, the source jerk method has been used in subcritical systems to obtain the reactivity by comparing the total neutron flux before the neutron source removal to the semi-stable delayed neutron flux after the source removal. The deuterium-tritium neutron source of the YALINA-Booster facility can, in addition to pulsed mode operation, operate with continuous beam with short imposed millisecond-scale interruptions, thus providing the possibility to monitor the reactivity at each beam trip in the source jerk manner. In order to test the validity of the beam-trip reactivity values determined by using detectors operating in current-mode (also presented in this conference), the reactivity values of the YALINA-Booster assembly obtained through the beam-trip technique using pulsed-mode detectors is presented in this work. In these experiments, a beam-trip frequency of 1 Hz and an interruption time of ∼20 ms have been chosen and two different core loadings with effective multiplication factor around 0.95 have been investigated. These two different loadings with close to equal reactivity but different source multiplication characteristics make it possible to explore the effect of the different source multiplications. In addition, the response of the imposed beam-trip reactivity monitoring technique to reactivity insertions and removals has been studied through control rod movements. Experimental data from fission chambers have been acquired from all three zones of the core: the fast booster zone, the thermal zone and the reflector.

Subject headings

NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

Keyword

Beam trip

Continuous beams

Current mode

Delayed neutrons

Deuterium-tritium

Effective multiplication factor

Experimental data

Fission chambers

Pulsed mode

Pulsed-mode operation

Reactivity insertion

Reactivity monitoring

Source multiplication

Subcritical experiments

Subcritical systems

Thermal zones

Three zones

Urgent problems

Detectors

Deuterium

Monitoring

Neutron beams

Neutron flux

Neutron sources

Nuclear engineering

Removal

Tritium

Experiments

Publication and Content Type

ref (subject category)

kon (subject category)