Assessment of Core Status of Fukushima Daiichi Nuclear Power Plant

摘要

There were some events and phenomena that occurred which have been deemed specific to the Fukushima Daiichi NPP. The primary issues were as follows: 1. Direct steam leakage from the reactor pressure vessels (RPVs) to the drywells through the gaskets of the safety relief valves and/or due to creep damage of the main steam line, and damage of the in-core monitor guide tubes due to buckling. 2. Direct corium leakage from the RPVs to the pedestal floors through the melt portions of the in-core monitor housings.