Reactor breach.  When the reactor takes damage Dim, greenish light spreads within a 30-foot-radius sphere around the reactor. The light spreads around corners. When a creature moves into the reactor breach area for the first time on a turn or starts its turn there, that creature must succeed on a DC 15 Constitution saving throw or take 4d10 radiant damage, and it suffers one level of exhaustion and emits a dim, greenish light in a 5-foot radius.

at 75 health the area effected spreads to 60ft, at 50 health 90 ft and at 25 the area spreads to 120 ft. The effect fades in 1d4 minutes

Players wearing 0.5 mm of lead shielding have advantage on the constitution check

Reactor Alarm. When the reactor takes damage lights flash and a alarm starts to blare. This has no effect but is really annoying