Calibrating a gas chromatograph to measure tritium using calorimetry

The availability of calibrated gas mixtures in a tritium plant is an important precondition for correct analysis of unknown gas samples because a quantitative analysis with a gas chromatograph (GC) requires frequent calibration checks. To calibrate a GC for tritium, certified gas mixtures with different tritium concentrations are necessary. These mixtures can be produced directly in a laboratory. In this case an independent method is needed to determine the tritium concentration in the mixture with high accuracy. Calorimetry is the method of choice because its accuracy is better than 1% and it is non-destructive method.Using the closed tritium loop of the Tritium Laboratory Karlsruhe (TLK), different mixtures containing tritium in the range 1–100% have been produced and measured with one of the in-house calorimeters. After that the GC of the CAPER facility at TLK has been calibrated several times with an uncertainty of a few percents.     

Review of tritium confinement and atmosphere detritiation system in hot cells complex

The tritium confinement strategy adopted during the past years in the ITER hot cell building is compared to the safety requirements given by the standard ISO-17873 “Nuclear facilities - criteria for the design and operation of ventilation systems for nuclear installations other than nuclear reactors”. In fact, this is the reference safety guideline recommended by French licensing authorities.Several features of the considered design of the hot cell building are not in agreement with these guidelines. Main discrepancies concern the zoning of the hot cell complex, the flow rates of ventilation, and the possibility to recycle the room atmosphere and to detritiate the effluent air. These aspects are discussed together with some proposed modifications of the design.     

SiC薄膜的阻氚性能研究

在不锈钢基体表面用离子束混合技术沉积SiC薄膜,然后用能量为5 keV的H+对其辐照直至剂量达到1×1018/cm2,再用二次离子质谱分析(SIMS)分析H+在SiC薄膜中深度分布和正离子谱,研究薄膜的阻氢性能和阻氢机理;最后采用渗透实验对涂覆在不锈钢基体表面的SiC材料的氚渗透系数进行测试,对其阻氚性能进行验证.结果表明,在不锈钢基材表面涂覆的SiC薄膜具有良好的阻氢性能,可将氚的渗透率降低4个数量级以上,SiC薄膜的阻氢是由于氢与薄膜中的硅、碳悬挂键反应形成诸如C-H、C-H2、C-H3、Si-H、Si-H2和Si-H3引起的.     

大米样品总氚与其组织自由水氚的相关性

大米样品的总氚(TT)与其组织自由水氚(TFWT)具有非常显著的相关性,其线性回归方程为TT=1.0671+1.3605TFWT。该方程的应用为大米样品总氚测定提供了一个简便的方法。     

Estimates of routine tritium discharges from ETHEL

The European Tritium Handling Experimental Laboratory (ETHEL) at JRC-Ispra is constructed within the ESSOR reactor complex and is therefore required to be consistent with the existing site license agreement. This paper summarizes the status of ETHEL under the Italian licensing legislation and focuses, in particular, on the problem of tritium discharges under routine conditions. First, the available margins for additional tritium releases from the ESSOR complex are established by taking into account the existing operational requirements. The discharge requirements of ETHEL are then estimated by analyzing the various in-plant routes by which tritium may be released to the environment under normal operation conditions. An analysis is also undertaken for assessing the radiological impact on the population due to exposure and ingestion pathways. It is shown that the expected gaseous releases and tritiated aqueous discharges comply comfortably with the existing site limits and the fraction available for ETHEL.     

青海湖地区氚的分布特征

本文报道了青海湖地区天然水中氚的分布及其变化。本区氚的平均含量为342±33T.U.;河水与井水中的平均值为316±30T.U.;湖水为363±34T.U.。河水中氚的含量随季节而发生变化;表层湖水中氚的分布较均匀,而其垂直分布与湖水温度有关。     

The control of tritium in ETHEL

The operation of the European Tritium Handling Experimental Laboratory (ETHEL) will require the implementation of means and procedures for allowing tritium control within the facility. For that purpose, account must be taken of the particular characteristics of tritium, such as its high mobility, capacity to dissolve in materials, often limited precision when performing inventory measurements. This paper estimates the influence of these effects on the overall tritium balance in ETHEL. By employing available models for predicting tritium hold-up, it is estimated that three to four grams of tritium may potentially remain irreversibly fixed in various plant items of the standard laboratory infrastructure (exclusive of experimental circuits). On the other hand, the highest overall precision that may be attained with the present plant regarding inventory measurements is estimated to be of the order of few percent. On the basis of the above estimates, the allowable limits for the Material Unaccounted For (MUF) are discussed.     

高比活度[甲基一~3H]胸腺嘧啶核苷的制备

以５—甲酰基尿嘧啶为起始原料，采用“二步法”：第一步合成了氚标记的５—羟甲基尿嘧啶，第二步合成了氚标记的胸腺嘧啶。放射性比活度分别达到１．６ＰＢｑ／ｍｏｌ和２．２ＰＢｑ／ｍｏｌ，再经酶促反应，生成氚标记胸腺嘧啶核苷，其比活度达２．２ＰＢｑ／ｍｏｌ，放化纯度大于９５％     

防氚高分子复合材料的制备及其性能

利用氯化聚乙烯、聚偏二氯乙烯(Polyvinylidene chloride,PVDC)、高密度聚乙烯等高分子材料复合防氚材料。采用渗透实验测量氚气渗透率;通过测量断裂强力和剥离力测量力学性能;通过测量浸泡化学试剂前后的溶失率、断裂强力下降率、剥离力下降率等表征材料的耐化学性能。结果表明,氚气在防氚高分子复合材料中的渗透率为3.44×10-10 m3/(m2?s);与PVC相比,氚气渗透率降低约70倍。PVDC薄膜复合后断裂强力提高约20倍,经纬向断裂强力为721 N。防氚高分子复合材料浸泡5种化学试剂后,最大溶失率为0.29%、断裂强力最大下降率为5.1%,其力学性能、耐化学性能均满足《防护服装酸碱类化学品防护服》(GB24540-2009)等相关标准的要求。     

高压氘氚气氛下不锈钢吸附氚的初步研究

本工作对于氚在不锈钢表面的吸附和解吸行为进行了初步研究.样品在n(D)∶n(T)=1∶1,230℃时,15 MPa下恒温8 h后,接着在27 MPa下恒温6 h的情况下进行了氚的吸附,测量了室温下和加热到1173 K时的解吸氚量和总吸附量.其结果如下:不锈钢的总吸附氚量是857.4 MBq·cm-2,不锈钢的解吸氚量是722.2 MBq·cm-2;在本实验的条件下,在室温和加热条件下,不锈钢所释放的氚中,化学成分主要是HTO和HT两部分,大部分以HT形式存在;不锈钢的自由氚占吸附总氚量的7.34%;不锈钢的热解吸谱存在三个解吸峰,其解吸温度分别为439、530和843K.     

产氚回路中氚的在线监测研究

描述一套产氚回路中氚的在线监测装置——流气式正比计数系统。测试该系统的坪曲线、本底、探测效率等性能后,开展了氚在线监测实验研究。结果表明,该系统性能稳定,控制好测量条件,可作产氚回路中氚的在线监测设备。     

Application of High Energy Protons in Inertial Confinement Fusion by Using the Fast Ignitor Concept for DT Fusion

A short-laser-pulse driven ion flux is examined as a fast ignitor candidate for inertial confinement fusion. The main mechanism for ion acceleration is charge separation in a plasma due to high-energy electrons driven by the laser inside the target. Another very new branch of fast ignition research is the investigation of the use of laser generated proton beams. In the present paper aims to provide insights into the feasibility of the fast ignition concept with high energy beams of protons generated in laser–plasma interactions. The optimum parameters of an ion beam and laser pulse that are suitable for an ignition spark in a hot precompressed DT fuel are estimated as a rough guide. Also, in this paper we estimate the radius of Deuterium–Tritium (DT) fuel pellet that is equal to the protons range in DT plasma.     

氘和氚标记ST—1435的制备

在氘或氚化溶剂中,16-次甲基-17α-乙酰氧基-19-羧基-孕甾-4-烯-3、20-二酮(Ⅰ)通过脱羧反应制得[10-~2H]ST-1435或[10-~3H]ST-1435(Ⅱ)。氘标记ST-1435经质谱分析表明有1—3个氘原子掺入到ST-1435分子中去,其中m/e 371(M~+)的氘掺入率为22.6％。氚标记ST-1435的比活度为52.5TBq/mol,放化纯度>95％。     

高探测效率氚测量仪

本文设计的高探测效率氚测量仪是集核探测、电子、信息处理等技术于一体,利用流气式正比计数器,采用先进的微处理器、数据和信息处理技术,具有低功耗、高探测效率的便携式测量仪器.经过应用实验表明,仪器性能指标为:坪长300 V,坪斜0.608%/100 V,探测下限0.221 Bq·cm-2(测量时间600 s),仪器稳定性0.56%/h,仪器变异系数2.88%,探测效率84%(3H源,2π表面发射率1307 min-1).     

用于含氚废气的无机载体疏水催化剂研制

为处理含氚废气筛选无机疏水载体,通过酸萃、高温灼烧对载体改性,经附铂、焙烧、还原后制备无机载体型Pt、Pd催化剂,常温下氢(氚)气的催化氧化实验中,几种催化剂表现相似的催化性能,氚气的单程转化率均大于90%,均可用于含氚废气处理。XRD测试结果显示,载体改性提高了载体的结晶度,有利于增加载体疏水性,降低附在载体上的铂晶粒尺寸,提高铂的分散度,但附铂后灼烧再还原的方法降低了铂的分散度。ZrO2的加入降低了钯晶粒尺寸,提高了钯的分散度。     

A neutron poison tritium breeding controller applied to a water cooled fusion reactor model

The generation of tritium in sufficient quantities is an absolute requirement for a next step fusion device such as DEMO due to the scarcity of tritium sources. Although the production of sufficient quantities of tritium will be one of the main challenges for DEMO, within an energy economy featuring several fusion power plants the active control of tritium production may be required in order to manage surplus tritium inventories at power plant sites. The primary reason for controlling the tritium inventory in such an economy would therefore be to minimise the risk and storage costs associated with large quantities of surplus tritium. In order to ensure that enough tritium will be produced in a reactor which contains a solid tritium breeder, over the reactor's lifetime, the tritium breeding rate at the beginning of its lifetime is relatively high and reduces over time. This causes a large surplus tritium inventory to build up until approximately halfway through the lifetime of the blanket, when the inventory begins to decrease. This surplus tritium inventory could exceed several tens of kilograms of tritium, impacting on possible safety and licensing conditions that may exist.This paper describes a possible solution to the surplus tritium inventory problem that involves neutron poison injection into the coolant, which is managed with a tritium breeding controller. A simple PID controller and is used to manage the injection of the neutron absorbing compounds into the water coolant of a stratified blanket model, depending on the difference between the required tritium excess inventory and the measured tritium excess inventory. The compounds effectively reduce the amount of low energy neutrons available to react with lithium compounds, thus reducing the tritium breeding ratio. This controller reduces the amount of tritium being produced at the start of the reactor's lifetime and increases the rate of tritium production towards the end of its lifetime. Thus, a relatively stable tritium production level may be maintained, allowing the control system to minimize the stored tritium with obvious safety benefits. The FATI code (Fusion Activation and Transport Interface) will be used to perform the tritium breeding and controller calculations.     

L-脯-L-亮-甘氨酰胺(PLG)的离子束氚标记及其在鼠脑内的分布

本文用离子束氚标记技术制得氚标记PLG。经磋胶纸层析法纯化,氚化三肽的比活度为6.81GBq/mmol,放化纯度>95％,具有完全的生物活性。由腹腔注射~3H-PLG,直接测定大鼠脑内部分组织的放射性分布,提示用药4.5h后,垂体、纹状体有较高的放射性,而下丘脑和中脑的放射性较低。     

First results with the upgraded TLK tritium calorimeter IGC-V0.5

At Tritium Laboratory Karlsruhe (TLK) calorimetry has been used for almost 20 years as the main accountancy method for tritium inventory. An extensive work has been carried out in order to improve the existing calorimeters. This paper covers the efforts made for the upgrade of the IGC-V0.5 calorimeter. We replaced the hardware interface – including the obsolete PC – and developed a new control and data acquisition software. The new software applies a smart automatic process control during measurements, significantly reducing measurement time and possible user errors. The three PID control loops have been re-tuned using the standard closed loop Ziegler–Nichols procedure to find the optimal PID parameters. Five calibration runs have been performed between 0.5 μW and 1 W, and their results are being presented and discussed.     

ITER中国液态锂铅实验包层模块氚渗透分析

对ITER中国液态锂铅实验包层模块的氚渗透途径进行了初步分析,并建立了氚渗透模型;在确保环境安全的前提下,通过计算LiPb中的氚分压分析了氚渗透量及氚总量的分配情况;在此基础上通过改变进入氚提取系统中LiPb比例(F)和涂层氚渗透减少因子(TPRF)对氚提取及渗透的影响做了灵敏性分析.