The Fukushima Event: The Outline and the Technological Background

Table 3

Amount (approximate) of radioactivity stored in Fukushima Units 1 to 4 at the time of start of the event.

Item	RC-NPP Unit No.			SFP-NPP Unit No.
	1	2	3	1	2	3	4
FA no.	400	548	548	292	587	514	1331
Irradiated FA no.	—			192	559	462	1127
Noble gases (Xe, Kr)	2.49*	3.42*	3.42*	0.06°	0.17°	0.14°	0.34°
Halogens (I, Br)	2.94*	4.04*	4.04*	3.0e10	8.8e10	7.4e10	18.1e10
Alkali metals (Cs, Rb)	0.35*	0.49*	0.49*	1.08°	3.18°	2.64°	6.46°
Tellurium (Te, Sb, Se)	2.45*	3.36*	3.36*	0.05°	0.15°	0.13°	0.31°
Barium-strontium (Ba, Sr)	3.58*	4.91*	4.91*	1.39°	4.07°	3.38°	8.28°
Noble metals (Ru, Rh, Pd, Mo, Tc, Co)	9.63*	13.2*	13.2*	0.83°	2.46°	2.05°	4.99°
Lanthanides (La, Zr, Nd, Eu, Nb, Pm, Pr, Sm, Y, Cm, Am)	10.5*	14.4*	14.4*	1.21°	3.55°	2.94°	7.21°
Cerium (Ce, Pu, Np)	29.2*	40.0*	40.0*	1.45°	4.27°	3.54°	8.67°
Total/RC & SFP Units	61.1*	83.8*	83.8*	6.07°	17.85°	14.82°	36.26°
Total /RC & SFP	2.29e20			0.075e20
Total	2.37e20 Bq [= 2.37e8 TBq = 6.41e9 Ci]

*e18; °e17.