Experimental study on the swelling performance of GMZ24 bentonite buffer material under Fe(II) reducing environment

IF 2.1 3区工程技术 Q1 NUCLEAR SCIENCE & TECHNOLOGY

Nuclear Engineering and Design Pub Date : 2025-07-03 DOI:10.1016/j.nucengdes.2025.114280

Zhang Ming , Tian Lehan , Xie Jingli , Hu Dongke , Zhou Fangliang , Zhang Yanfei , Gu Zhanfei

{"title":"Experimental study on the swelling performance of GMZ24 bentonite buffer material under Fe(II) reducing environment","authors":"Zhang Ming , Tian Lehan , Xie Jingli , Hu Dongke , Zhou Fangliang , Zhang Yanfei , Gu Zhanfei","doi":"10.1016/j.nucengdes.2025.114280","DOIUrl":null,"url":null,"abstract":"<div><div>The release of Fe(II) from iron-based waste disposal tanks during the operation of high-level waste (HLW) repository can seriously affect the swelling behaviour of the buffer barrier, with implications for the safety and stability of the repository. Conventional dilatometer are susceptible to Fe(II) corrosion and Fe(II) oxidation by air. In this study, a self-made dilatometer is develop to measure the swelling characteristics of GMZ24 bentonite at different Fe(II) concentrations. The experimental results showed that the stabilisation time of GMZ24 bentonite swelling ratio was shortened from 331.2 h to 32.1 h, and the swelling pressure was shortened from 130.8 h to 22.1 h as the concentration of Fe(II) was increased from 0 to 2.69 mol/L. The final swelling pressure and swelling ratio showed an exponential decrease, with the swelling ratio decreasing from 84.4 % to 30.1 %, and the swelling pressure decreasing from 1050 kPa to 700 kPa. The results of hydrochemical tests and mineralogical analyses showed that the attenuation of the swelling performance of bentonite was mainly attributed to the following two aspects: First the cation exchange between Na<sup>+</sup> and Fe(II) in bentonite; Second the mineral phase transformation of montmorillonite to berthierine. Based on the ion double layer theory, this study derives relationships describing the variation of GMZ24 bentonite swelling pressure and swelling ratio as a function of Fe(II) concentration. This study provides a scientific basis for predicting the swelling behaviour of GMZ24 bentonite buffer barrier material for HLW repository.</div></div>","PeriodicalId":19170,"journal":{"name":"Nuclear Engineering and Design","volume":"442 ","pages":"Article 114280"},"PeriodicalIF":2.1000,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Nuclear Engineering and Design","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0029549325004571","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"NUCLEAR SCIENCE & TECHNOLOGY","Score":null,"Total":0}

引用次数: 0

Abstract

The release of Fe(II) from iron-based waste disposal tanks during the operation of high-level waste (HLW) repository can seriously affect the swelling behaviour of the buffer barrier, with implications for the safety and stability of the repository. Conventional dilatometer are susceptible to Fe(II) corrosion and Fe(II) oxidation by air. In this study, a self-made dilatometer is develop to measure the swelling characteristics of GMZ24 bentonite at different Fe(II) concentrations. The experimental results showed that the stabilisation time of GMZ24 bentonite swelling ratio was shortened from 331.2 h to 32.1 h, and the swelling pressure was shortened from 130.8 h to 22.1 h as the concentration of Fe(II) was increased from 0 to 2.69 mol/L. The final swelling pressure and swelling ratio showed an exponential decrease, with the swelling ratio decreasing from 84.4 % to 30.1 %, and the swelling pressure decreasing from 1050 kPa to 700 kPa. The results of hydrochemical tests and mineralogical analyses showed that the attenuation of the swelling performance of bentonite was mainly attributed to the following two aspects: First the cation exchange between Na⁺ and Fe(II) in bentonite; Second the mineral phase transformation of montmorillonite to berthierine. Based on the ion double layer theory, this study derives relationships describing the variation of GMZ24 bentonite swelling pressure and swelling ratio as a function of Fe(II) concentration. This study provides a scientific basis for predicting the swelling behaviour of GMZ24 bentonite buffer barrier material for HLW repository.

查看原文本刊更多论文

Fe（II）还原环境下GMZ24膨润土缓冲材料溶胀性能的实验研究

高放废物储存库运行过程中，铁基废物处理池中铁（II）的释放会严重影响缓冲屏障的膨胀行为，影响储存库的安全和稳定。传统膨胀计易受Fe（II）腐蚀和Fe（II）被空气氧化。研制了自制膨胀仪，测量了GMZ24膨润土在不同Fe（II）浓度下的膨胀特性。实验结果表明，随着Fe（II）浓度从0增加到2.69 mol/L， GMZ24膨润土溶胀比稳定时间从331.2 h缩短到32.1 h，溶胀压力从130.8 h缩短到22.1 h。最终溶胀压力和溶胀比均呈指数级下降，溶胀比由84.4%降至30.1%，溶胀压力由1050 kPa降至700 kPa。水化学试验和矿物学分析结果表明，膨润土溶胀性能的衰减主要归因于以下两个方面：一是膨润土中Na+与Fe（II）之间的阳离子交换；二是蒙脱石矿物相转变为菱镁石。基于离子双层理论，推导了GMZ24膨润土溶胀压力和溶胀比随Fe（II）浓度变化的关系。该研究为预测GMZ24膨润土缓冲屏障材料的溶胀行为提供了科学依据。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Nuclear Engineering and Design 工程技术-核科学技术

CiteScore

3.40

自引率

11.80%

发文量

377

审稿时长

5 months

期刊介绍： Nuclear Engineering and Design covers the wide range of disciplines involved in the engineering, design, safety and construction of nuclear fission reactors. The Editors welcome papers both on applied and innovative aspects and developments in nuclear science and technology. Fundamentals of Reactor Design include: • Thermal-Hydraulics and Core Physics • Safety Analysis, Risk Assessment (PSA) • Structural and Mechanical Engineering • Materials Science • Fuel Behavior and Design • Structural Plant Design • Engineering of Reactor Components • Experiments Aspects beyond fundamentals of Reactor Design covered: • Accident Mitigation Measures • Reactor Control Systems • Licensing Issues • Safeguard Engineering • Economy of Plants • Reprocessing / Waste Disposal • Applications of Nuclear Energy • Maintenance • Decommissioning Papers on new reactor ideas and developments (Generation IV reactors) such as inherently safe modular HTRs, High Performance LWRs/HWRs and LMFBs/GFR will be considered; Actinide Burners, Accelerator Driven Systems, Energy Amplifiers and other special designs of power and research reactors and their applications are also encouraged.