Supposedly the daughters can provide 5 to 7% of the thermal energy of a fissioning facility, but since the Unit 1 was evidently about to get changed out, this could be more like 15%. For a 480 MW unit, this would mean that 36 to 72 MW of heat had to be removed, assuming that all fission reactions were stopped by the control rod insertion.

DaiIchi 1: 460MW
DaiIchi 2 and 3: 784 MW

All the reactors at Dai-Ni, three of the four are undergoing LoCA events, are rated 1.1GW each.

One of the Onagawa Plant reactors (operated by Tohaku, a different utility) is also reportedly in LoC. The ratings are 524MW and 2x825 MW.

So, in what may be my last act of "advising", I'll advise you to cut the jargon. -- My old PhD advisor, to me, 26/2/11