机械泵油氚污染的测定及其处理

本文在定量研究已被污染的机械泵油的猝灭作用的基础上,提出了一种图解外推法较准确地测出已污染机械泵油中的氚含量。并试验了一系列对被污染的机械泵油处理的方法。     

Nuclear analysis of a laser fusion reactor,SENRI-I

A neutronic analysis of the laser-driven inertial-confinement fusion reactor SENRI-I is presented. Three-dimensional Monte Carlo calculations were performed to examine the effects of laser beam ports on the flux distribution, tritium breeding ratio, thermal energy deposition in the blanket, and radiation streaming. A Monte Carlo code was also used for the time-dependent radiation-damage analysis accounting for the time of the flight spread of neutrons and the results are compared to the analysis for the HIBALL design. Induced radioactivity was estimated, based on the one-dimensional transport calculation and depletion analysis. The calculated results reveal the advantages of the SENRI-I design with a thick Li layer compared to other reactor systems employing a dry-wall scheme.     

Anomalous vapour pressure over liquid D-T

The presence of a few tenths mol % helium in hydrogen causes anomalous vapour pressures as high as 10 kPa. This effect is caused by the combination of a small cold cell, a single, long fill tube, and the insolubility of helium in liquid hydrogen. This effect is important in the handling of deuterium-tritium, as radioactive decay produces He³.     

三代压水堆内陆厂址放射性流出物排放问题及改进建议

由于内陆厂址受纳水体容量有限,使得核电内陆厂址面临的一个关键问题就是液态流出物排放。本文通过对比分析三代压水堆内陆厂址液态流出物排放与现有排放国家标准要求,发现三代压水堆两项指标不能满足内陆厂址要求,即除氚、¹⁴C外其他放射性核素和氚排放均不能满足内陆厂址要求。针对除氚、¹⁴C外其他放射性核素排放,建议增加化学絮凝、离子交换床和反渗透装置以满足100 Bq/L的排放要求。针对氚排放,通过调整排放方式能满足2台机组氚排放要求,使得下游1 km处氚浓度不超过71 Bq/L;多机组内陆电厂的氚排放建议利用联合电解催化交换(CECE)和水精馏(WD)技术,以达到分离氚的目的。     

Radiochemical analysis of rubble and trees collected from Fukushima Daiichi Nuclear Power Station

To characterize the rubble and trees contaminated by radionuclides released by the recent accident at the Fukushima Daiichi Nuclear Power Station, the radiochemical analysis protocols were modified using those developed by the Japan Atomic Energy Agency for the waste generated by research, industrial, and medical facilities. The radioactivity concentrations of gamma-ray-emitting nuclides ⁶⁰Co, ⁹⁴Nb, ¹⁵²Eu, and ¹⁵⁴Eu, and beta-particle-emitting nuclides ¹⁴C, ¹²⁹I, ³⁶Cl, ⁷⁹Se, and ⁹⁹Tc were successfully applied by the modified analytical method. In contrast, the radioactivity concentrations of ³H, ⁹⁰Sr, ¹³⁷Cs, and alpha-particle-emitting nuclides were applied by the conventional method. Unfortunately, ³⁶Cl, ⁹⁴Nb, ¹²⁹I, ¹⁵²Eu, ¹⁵⁴Eu, and alpha-particle-emitting nuclides were below the detection limit of the conventional method. The measured radioactivity concentrations, except for that of ³H, were not uniform in the area but depended on the reactor unit. Although the radioactivity concentrations were varied widely, this analysis successfully clarified the characteristics of the radioactivity concentrations of the rubble and trees.     

高纯氢中微量杂质的微气相色谱分析

建立了一种微型气相色谱仪测定聚变堆燃料模拟气H2中He、Ne、N2、CH4、CO等杂质气体含量的方法。实验研究了微气相色谱的柱温、柱头压、进样时间等因素对H2中杂质气体分析的影响,并探究了微气相色谱对微量杂质气体的检测效果。研究结果表明,该方法能实现对H2中杂质组分的快速完全分离,可对H2中数十ppm含量的CH4气体实现定量检测,能满足氚工厂对杂质气体快速定量分析的要求,是一种快速、准确、实用的分析方法。     

整体式除氚催化剂的制备及催化氧化性能

针对大型核设施产生的大流量废气的处理,发展低气阻的整体式催化剂尤为必要。本工作在整体式堇青石载体上生长分子筛涂层,以离子交换法负载活性组分Pt,获得的整体式催化剂具有高的金属分散度,达到了60%。使用该催化剂,在15 ℃、体积空速为10 000～40 000 h^-1、1.0%（体积分数）H₂的条件下实现大于99.9%的H₂转化率;在25 ℃、体积空速为50 000 h^-1 、1.0% H₂的条件下实现H2的完全转化。在更低的H₂浓度下（0.1% H₂和0.5% H₂）,该催化剂在湿条件下的H₂转化率低于干条件下的H₂转化率,表明水蒸气会抑制室温催化活性。由于分子筛涂层较Al₂O₃涂层具有更低的吸水性,整体式Pt/sil-cord催化剂在湿条件下具有比Pt/Al₂O₃高得多的室温催化活性（0.1% H₂下,转化率为80%,而在Pt/Al₂O₃ 上的转化率为13%）,表现出较好的抗湿性。     

基于BIXS方法的气体中高浓度氚在线测量技术

工艺气体中高浓度氚的在线测量要求探测器具有体积小、密封性好、稳定性高等特点。针对该需求,本工作基于氚β射线诱发X射线谱测量方法（BIXS）建立了高浓度氚在线测量实验系统,采用PENELOPE程序建立了理论计算模型,对系统中5个关键参数进行了设计优化,搭建了1.77 mL小体积BIXS实验系统,使用含氚的氢氩混合气体对实验系统进行了响应能谱测量,并对获得的BIXS能谱谱形进行了初步分析。实验结果表明,对于含氚的氢氩混合气体,BIXS系统重复测量结果显示全谱计数率偏差＜0.8%,Ar的K_α峰计数率偏差＜1.3%,Au的M_α峰偏差＜3.8%,整体稳定性较好;不同压强下BIXS实验系统测量结果显示,BIXS能谱总计数率、Ar的K_α峰强度以及轫致辐射谱强度随压强增加呈线性上升趋势,但Au的M_α峰强度在该气氛下几乎不随氚的分压改变。     

Fe-Al/Al2O3阻氚涂层热处理条件对HR-2不锈钢力学性能影响

采用室温力学拉伸试验、显微硬度测试、X射线衍射及组织观察等方法研究了“室温熔盐电镀铝+热处理+选择性氧化”工艺路线制备Fe-Al/Al₂O₃阻氚涂层热处理过程对HR-2奥氏体不锈钢力学性能及显微组织的影响。结果表明：经热处理后的HR-2不锈钢仍然保持奥氏体组织;980 ℃热处理180 min时抗拉强度为580.48 MPa,硬度值为177.92 HV,伸长率为79.43%,具有优异的塑韧性;700 ℃热处理150 h时抗拉强度为616.47 MPa,硬度值为213.34 HV,伸长率为63.32%;经热处理后的HR-2不锈钢基体力学性能变化不大。现行的涂层制备工艺对基体材料影响较小,满足微观结构与力学性能指标。     

Enzymatic Responses to Low-Intensity Radiation of Tritium

The present study considers a possible role of enzymatic reactions in the adaptive response of cells to the beta-emitting radionuclide tritium under conditions of low-dose exposures. Effects of tritiated water (HTO) on the reactions of bacterial luciferase and NAD(P)H:FMN-oxidoreductase, as well as a coupled system of these two reactions, were studied at radioactivity concentrations ≤ 200 MBq/L. Additionally, one of the simplest enzymatic reactions, photobiochemical proton transfer in Coelenteramide-containing Fluorescent Protein (CLM-FP), was also investigated. We found that HTO increased the activity of NAD(P)H:FMN-oxidoreductase at the initial stage of its reaction (by up to 230%); however, a rise of luciferase activity was moderate (<20%). The CLM-FP samples did not show any increase in the rate of the photobiochemical proton transfer under the exposure to HTO. The responses of the enzyme systems were compared to the ‘hormetic’ response of luminous marine bacterial cells studied earlier. We conclude that (1) the oxidoreductase reaction contributes significantly to the activation of the coupled enzyme system and bacterial cells by tritium, and (2) an increase in the organization level of biological systems promotes the hormesis phenomenon.