| Autor: |
Hironobu Iwanami, Tomoharu Hashimoto, Tanaka Motoi, Satoshi Mizuno, Takashi Uemura, Ryuichi Tayama |
| Rok vydání: |
2020 |
| Předmět: |
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| Zdroj: |
Volume 2: Nuclear Policy; Nuclear Safety, Security, and Cyber Security; Operating Plant Experience; Probabilistic Risk Assessments; SMR and Advanced Reactors. |
| DOI: |
10.1115/icone2020-16721 |
| Popis: |
A dose assessment methodology was developed for IS-LOCA (Interface System – Loss of Coolant Accident) event, which is one of the design basis accidents in BWR plants, and a dose assessment at site boundary was implemented for the accident scenario by applying the evaluation method. The main objective of the assessment is to review a conventional conservative dose assessment model in the accident scenario. The conventional conservative model is a method due to considering all fission products (FP) in liquid migrate to airborne (i.e. 100%) when reactor water is discharged from piping break area, while the developed new methodology is a method to evaluate transition behavior of fission products precisely by using flash fraction (FF) from liquid to airborne and consider it. As the result of dose assessment, it was confirmed that the calculated dose during IS-LOCA event was about one-fifteith reduced by adopting the new model from the conventional model. The content of this paper includes: • Background and purpose that led to the dose assessment methodology development during IS-LOCA. • An evaluation method by using discharged amount of reactor water at piping break area and flash fraction (FF) from liquid to airborne based on Regulatory guide 1.183 published by U.S. NRC. • Another evaluation method that takes into account the fluctuation due to depressurization of reactor pressure per time step from the start of accident until completion of isolation at piping break area in addition to the above method. • Comparison between dose results at site boundary based on these methods and conventional conservative model. This results will give a precise information for public and it will be useful for making emergency evacuation plan. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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