The Fukushima Event: The Outline and the Technological Background

Table 9

Summary of background for the Fukushima Daiichi accident.

No.	Topic*	EHP	Notes
1	External PIE features	YES	Feedback from monitoring of natural events.
2	DSA: SBO and LOOP analyses	—	Notes at rows 6 and 7 apply.
3	LOOP mitigation effort	YES	Promptly bringing additional DG to the site**.
4	SFP loss of cooling	YES	Light pumping device sufficient**.
5	PSA: PIE and DG reliability	YES	Failure in estimating DG reliability under tsunami (and aging).
6	PSA: core and containment failure	—	Core melt “expected”.
7	PSA: SFP failure	—	SFP fuel failure “expected”.
8	The licensing	YES	Aging and integrated individual NPP to be better considered.

*Topics (1) to (8) are listed in a synthetic way. **Operators or managers from the Fukushima Utility.