RETRACTED: Fault-Event Trees Based Probabilistic Safety Analysis of a Boiling Water Nuclear Reactor’s Core Meltdown and Minor Damage Frequencies

Abstract

A systematic probabilistic safety assessment for a boiling water nuclear reactor core is performed using fault trees and event trees analysis models. Based on a survey of the BWR’s safety systems against potential hazards, eight independent failure modes (initiating events) triggered scenarios are modelled and evaluated in the assembled fault-event trees, obtaining the two key outcome probabilities of interest, i.e., complete core meltdown (CCMD) frequency and minor core damage (MCD) frequency. The analysis results indicate that the complete loss of heat sink accounts for the initiating accident most vulnerable to CCMD (with a frequency of 1.8 × 10 − 5 per year), while the large break in the reactor pressure vessel is the least susceptible one (with a frequency of 2.9 × 10 − 12 per year). The quantitative risk assessment and independent review conducted in this case study contributed a reference reliability model for defense-in-depth core optimizations with reduced costs, informing risk-based policy decision making, licensing, and public understanding in nuclear safety systems.

60 GHz Optimised Nickel-free Gold-plated Enclosed Coplanar Waveguide Liquid Crystal Phase Shifter

“…This work numerically investigates and experimentally optimises a novel nickel-free gold-plated ECPW LC-based phase shifter at 60 GHz for broadband last-mile applications [5] [11]. By comparative analysis of adaptive meshing inside metals versus surface impedance model without meshing inside, we derive the threshold that conventional surface impedance model is invalid.…”

Monte Carlo Simulation of the UK’s First EPR Nuclear Reactor Startup Core Using Serpent

“…Sensitivity calculations and validation against the experimental data (after the core starts commissioning in the future) could be performed with ease based on the whole-core model developed in this work for multi-objective optimisations. The knowledge obtained from the EPR Monte Carlo modelling is also transferrable for simulating an AP1000 startup core, so that a comparison with the EPR's core performance and neutron economy could be performed, targeting a more reliable, low-carbon and cost-competitive nuclear power solution to approach the future energy challenges [24][25][26] in the UK.…”

Multi-ring Subgroup Method in Characterising Highly Self-shielded Gadolinia Burnable Poison Pins for the UK EPR Nuclear Fuel Assembly

“…The agreement in results verifies the proposed subgroup method for the whole fuel assembly modelling. The demonstrated subgroup approach with multi-zone capability could benefit a wider range of recently advanced nuclear reactor cores with self-shielded burnable poisons, hence informing the core design and optimisation [10]- [27] targeting the fuel economy and nuclear energy safety [28] [29].…”