The reactor was now producing only 5% of the minimum initial power level prescribed for the test. This low reactivity inhibited the burn-off of xenon-135 within the reactor core and hindered the rise of reactor power. Control-room personnel had to raise power by disconnecting most of the reactor control rods from the automatic control rod regulation system and manually extracted the majority of rods to their upper limits in order to promote reactivity and counteract the effect of the poisoning. Several minutes elapsed between their extraction and the point at which the power output began to increase and subsequently stabilized at 160–200 MW (thermal).