Forum:Close game Stardust Assault vs Summon Reactors

Let's say I have 2 summon reactors on the field and my opponent is about to special summon Stardust Assault during the endphase. He has 1500 life points left. If stardust's summon triggers both of the summon reactor's effect, can stardust negate both of them and destroy both? Since both summon reactor's effect activate at the same time?Oreos74