May 1, 2021 · Estimation of the final debris distribution at the Fukushima Daiichi Nuclear Power Station (1F) is inevitable for a safe and effective decommissioning. It is necessary to clarify possible failure modes of the reactor pressure vessel (RPV), which is influenced by the thermal status of slumped debris that highly depends on the in-vessel accident ...

Main differences between accidents at 1F and TMI-2 (Points for practical use of previous knowledge and consideration of research subjects) • In-reactor structure and fuel bundle BWR has more complicated lower plenum structure • Inventory of core materials Ratio of Zircaloy to UO 2 is higher in BWR Control rod consists of B 4

Aug 1, 2022 · A PWR system that refers to the TMI-2 accident is typical for SA codes and testing, on the other hand, a BWR system like 1F is uncommon, understanding the 1F internal state is challenging. The present study conducted the ELSA-1 test, a test that focused on damage from eutectic melting of the liquid metal pool and control rod drive (CRD), to ...

Dec 15, 2023 · The paper presents the results of a CLADS-MADE-03 BWR mock-up assembly degradation in high-temperature steam under a transient heating rate of 1 K/s, which are the assumed accident conditions for the beginning of the accident at the Unit 1 of the Fukushima Dai-Ichi Nuclear Power Station.

Apr 2, 2021 · To approach real 1F fuel configuration as much as possible, typical Japanese BWRs’ materials were used. A test assembly contained the part of the control blade between the two groups of the fuel rods (Zircaloy-2) encased into the Zircaloy-4 channel boxes ( Figure 1 ).

However, core degradation in a boiling water reactor (BWR) like the 1F has not been comprehensively studied. Since the TMI-2 accident, many researchers have focused on the initial core melting process and aspects related to the rupture of the pressure vessel in a pressurized water reactor (PWR).

• 1F fuel debris removal provides one of the most significant opportunities for international criticality safety technical collaboration today – New capabilities/technologies to help with fuel debris removal also align with needs of US applications

degradation in a boiling water reactor (BWR) like the 1F has not been comprehensively studied. Since the TMI-2 accident, many researchers have focused on the initial core melting process and aspects related to the rupture of the pressure vessel in a pressurized water reactor (PWR). The diff ering structure between

To support 1F decommissioning by understanding the final redistribution of B and C, a mock-up assembly in the Large-scale Equipment for Investigation of Severe Accidents in Nuclear reactors (LEISAN) facility was designed to recreate the accident conditions of Unit 2 at 1F.

Nov 18, 2019 · The new R&D programme of JAEA/CLADS tests complements the previous investigations related to BWR severe accidents. A series of tests aim at closing the gaps in understanding of the Fukushima Dai-Ichi degradation sequence at each unit.