Wed. Mar 6, 2024 10:55 AM - 12:35 PM 315 (Conference Center 3F)

Chair:Yasuki Ohtori(Tokyo City University)
Co-Chair: Naoto Kasahara (The University of Tokyo)

Organizer: Naoto Kasahara (Tokyo City University)
Co-organizer: Thambiayah Nitheanandan (CNSC)
Co-organizer: Shunichi Suzuki (The University of Tokyo)
Aim and Scope for Special Session:
Conventional purpose of structural mechanics is to prevent structural failure under DBE (Design basis events). Design is preparation for assumed events. Typical design approach is confirmation to meet conservative criteria under given conditions.
However above approach becomes irrational for BDBE (beyond design basis events) and the Fukushima daiichi nuclear plant.
There are large uncertainties in loading assumption of BDBE and remaining strength of the Fukushima daiichi nuclear plant. The conservative design approach for failure prevention leads to expensive and unrealistic solutions.
From the viewpoint of risk reduction, the preventive approach is effective for high probability and low consequent damage events (DBE). For low probability and high consequent damage events (BDBE), mitigation approach becomes appropriate.
The aim of this special session is to discuss about new structural mechanics approaches for BDBE and Fukushima Daiichi Nuclear plant.
As leading practices, new idea with pioneering research will be presented.
The first presentation is safety enhancement of pipes against beyond design temperature and pressure. Both mechanical and thermal properties are improved.
Next is counter measure of Fukushima daiihci nuclear plants, where strength of damaged components are unclear. Paying attention to low temperature and pressure conditions, mitigation of failure consequence with early failure detection is planed.
Third one is mitigation of failure consequence of operating plants under BDBE. Idea is adoption of passive safety structures without catastrophic failures. Prior small failure reduce loads and avoid catastrophic failure with large impact on safety performance.