We have 2 ice injection systems for the reactors. First - manual, injects a stack of ice into the reactor each 0,5 seconds. We use that during startups of the reactors and in emergency situations. Second, automatic, injects a stack of ice into the reactors each 8 seconds, if the temperature is higher than 100 (most of the time, it just prevents it from injecting ice when the reactor is shut down). In both systems, if the reactor is filled or if not a whole stack could fit into the reactor, the extra ice goes to an incinerator.
An energy condenser with single energy collector MK3 provides basically infinite source of ice.