Abstract
The concept of “SOUTEI” or “Assumption” is commonly used to set target levels (or boundary conditions) in the fields of engineering in order to design apparatus, devices, or industrial systems. However, after the Great East-Japan Earthquake and its dreadful consequences of the Fukushima Atomic Power Plant, the term “beyond the scope of assumption” has often been misconstrued by the people and the authorities concerned. The study aims to clarify the points at issue, discussing the following problem areas from the risk assessment.
(1) Causes of misinterpretation
(2) Types of misinterpretation
(3) How to set the target levels for assumption
(4) Risk management of the assumption plan, and accommodating behavior in case the assumption plan fails
(5) People who are opposed to the method of assumption
(6) Meaningless assumption
(7) The philosophy of an assumption and it’s cultural background
