实验室用小型环隙式离心萃取器

在φ22单级环隙式离心萃取器中进行了水力学实验和铀、酸传质实验。结果表明,当重相堰直径2r_α为12.5mm时,可以在下列条件下稳定操作:总流通量Q≤15ml/min、流比(o/a)为0.1—10、转速n为3000一4000 rpm、体系密度比ρ_o/ρ_a为0.64、0.78、0.88。在上述条件下测得体系密度比为0.79时的铀酸传质级效率为95%—100%。因此该设备可用作实验室规模的萃取工艺研究的单元设备。     

实验室用小型环隙式离心萃取器

设计了直径为22mm的单级和8级环隙式离心萃取器,并进行了水力学和传质试验。结果表明,当重相堰直径为12.5mm时,对单级萃取器,操作范围如下:总流量约15ml/min,转速3000～4000r/min,流比O/A为10～0.1,密度比ρ_o/ρ_A。为0.64～0.88;对8级萃取器,除密度比范围为0.64～0.82外,其它操作范围与单级萃取器相同。根据HNO_3和U的传质试验,两种萃取器的级效率均大于95%,由此可见,这类萃取器可用于实验室溶剂萃取工艺研究。     

实验室用小型环隙式离心萃取器

设计了直径为22mm的单级和8级环隙式离心萃取器,并进行了水力学和传质试验。结果表明,当重相堰直径为12.5mm时,对单级萃取器,操作范围如下:总流量约15ml/min,转速3000～4000r/min,流比O/A为10～0.1,密度比ρ_O/ρ_A为0.64～0.88;对8级萃取器,除密度比范围为0.64～0.82外,其它操作范围与单级萃取器相同。根据HNO_3和U的传质试验,两种萃取器的级效率均大于95%,由此可见,这类萃取器可用于实验室溶剂萃取工艺研究。     

铀钚萃取洗涤-共反萃工艺的离心萃取器台架实验研究

由于快堆MOX乏燃料放射性强,需要缩短停留时间以降低溶剂辐解,本工作以离心萃取器为萃取设备,在短停留时间下进行了快堆MOX乏燃料后处理铀钚萃取洗涤-共反萃工艺研究。研究结果显示,该工艺在单级停留时间约20s时具有良好的铀钚收率,萃取洗涤过程中铀和钚收率均大于99.99%,共反萃过程中铀和钚收率分别为99.99%和99.94%;同时能有效防止第三相的形成,避免钚的聚合沉淀。     

小型环隙式离心萃取器的水力学和传质研究

用单级＝１０ｍｍ小型环隙式离心萃取器研究了水－３０％ＴＲＰＯ－煤油体系在不同条件下的水力学特性和硝酸、Ｆｅ３＋和Ｎｄ３＋的传质特性。在转速４０００—４５００ｒ／ｍｉｎ、流量＜６００ｍＬ／ｈ、相比（ｏ／ａ）１／１０—１０／１情况下，硝酸和Ｎｄ３＋的传质级效率比较高，为９０％左右。由于Ｆｅ３＋的萃取动力学速率比较慢，因此其萃取级效率比较低。     

Φ10mm离心萃取器水力学性能研究

为将Φ10mm离心萃取器用于Purex流程钚纯化循环反萃段的实验研究中,当水相和有机相流比为1∶4,离心萃取器的重相堰直径分别为6.4、6.6和6.8mm时,考察了两相出口料液的夹带情况以及环隙和转筒内液体体积随转速的变化等水力学性能。研究表明,当两相总流量小于9.0mL/min、转速大于4000r/min时,离心萃取器处于稳定可操作区间。此时两相出口料液均不夹带,两相混合区内液体量约为0.7mL,转筒内液体量约为2.2mL。结合总流量可进一步计算得出两相接触时间。     

离心萃取装置中硝酸羟胺还原反萃钚的研究

用十六级分离式混合—离心澄清萃取装置,在20-24℃,30-34℃,45-50℃等不同温度下进行了3B槽硝酸羟胺还原反萃钚的实验。结果表明,钚的收率均可达99.9%以上。在20-24℃时,有机相出口级附近几级的钚浓度较高,实验条件一旦波动,有可能造成钚的流失,且钚在萃取设备中有明显的积累。温度升高,14级反萃(停留时间约18min)时,钚的收率基本得到保证。     

小型分离式混合-离心澄清萃取器

本文介绍了一种小型分离式混合-离心澄清萃取器。它由混合器、澄清器及传动部件等组成。进行了该设备的水力学性能试验和铀、酸传质试验。结果表明,该萃取器的适应范围如下:总流通量10—15毫升/分;相密度比(ρ_o/ρ_a)0.64—0.88;流比(o/a)1/10—10/1。试验还表明,该设备也能在总流通量为5毫升/分条件下稳定运行。酸传质效率为98.5%以上,铀传质效率为99.5%以上。两相混合时间最长可达70秒之久。因此该设备可能作为一种高效、快速的小型逆流萃取实验装置的单元设备,并能适应某些反应速度较慢的过程研究。     

Φ20 mm离心萃取器的水力学性能

为将φ20 mm离心萃取器用于Purex流程2A段的研究中,针对2A段的工艺参数进行了φ20mm离心萃取器的水力学性能研究.固定其重相堰直径为10.8 mm,采用30％ TBP/煤油-HNO3体系,研究了流比(A∶O)、流速、转速变化对两相出口料液的夹带及环隙和转筒内液体体积变化的影响.研究表明:当流比(A∶O)为1∶1、两相总流速小于70.0 mL/min及流比为5∶1、两相总流速小于28.8 mL/min时,当转速大于3000 r/min时,该类型离心萃取器处于稳定可操作区间;此时两相出口料液均不夹带,两相混合区内液体量约为5.1mL,转筒内液体量约为12.3 mL.结合总流速可算出两相接触时间t=5.1×60/vt,vt为总流速.结果表明,该类型离心萃取器可满足Purex流程中2A段工艺实验研究的需要.     

用离心萃取器从动力堆后处理模拟强放废液中萃取铕

本工作用φ10的环隙式离心萃取器检测了30%TRPO-OK萃取硝酸水溶液及模拟强放废液中的铕的传质动力学。结果表明,这种离心萃取器的传质速度快、萃取率高。在一分钟的停留时间内,其传质效率大于98%。在多级连续逆流萃取模拟料液里Eu的传质实验中,Eu的萃取率分别达到99.99%(六级萃取,0.58mol/L的HNO_3料液)和99.83%(十二级萃取, 2.5mol/L的HNO_3料液),验证了原设计的概念流程。     

An industrial-scale annular centrifugal extractor for the TRPO process

Annular centrifugal extractors(ACEs) offer advantages including excellent hydraulic and mass-transfer performance, small hold-up volume, short residence time,and thus low solvent degradation, high nuclear criticality,easy start-up and shut-down, high compact structure.Therefore, ACEs have attracted increasing interest for future nuclear processing schemes, including the partitioning of high-level liquid waste(HLLW). Laboratoryscale and pilot-scale ACEs have been applied in demonstration tests of the trialkyl phosphine oxide(TRPO) process for HLLW partitioning. In this study, an industrialscale ACE(260 mm in rotor diameter) with magnetic coupling and a ‘‘hanging' rotor structure was developed for the TRPO process. Moreover, a series of hydraulic and mass-transfer tests were carried out in the industrial-scale ACE. The maximum throughput can reach 10 m~3/h under suitable operation parameters when kerosene is used as the organic phase, and water is used as the aqueous phase. The influence of the total flowrate, the flow ratio(aqueous/organic, A/O), and the rotor speed on the liquid hold-up volume was determined. The extraction stage efficiency is higher than 98% under test parameters for extraction of Nd~(3+) and HNO_3, using 30% TRPO kerosene as theextractant from an HNO_3 solution containing Nd. All results show good performance of the industrial-scale ACE for the TRPO process.     

Recent advances of annular centrifugal extractor for hot test of nuclear waste partitioning process

Advances are being made in the design of the annular centrifugal extractor fornuclear fuel reprocessing extraction process studies.The extractors have been built and tested.Twelve stages of this extractor and 50 stages are used toimplement the TRPO process for the cleanup ofcommercial and defense nuclear waste liquids,respectively.Following advances are available:(1) simple way of assembly and disassembly between rotor part and housing part of extractor,ease of manipulator operation;(2)automatic sampling from housing of extractor in hot cell;(3) compact multi-stage housing system;(4) easy interstage link;(5) computer data acquisition and monitoring system of speed.     

Hydrodynamic and mass transfer studies of 125 mm centrifugal extractor with 30% TBP/nitric acid system

The Indian nuclear power programme was conceived with a three-stage structure in order to utilize the resources optimally with at most importance to fuel reprocessing for closing the fuel cycle. The first stage of Indian nuclear power programme is based on natural uranium fuelled pressurized heavy water reactors to produce the plutonium (Pu) feed for the second stage. The second stage consists of plutonium fuelled fast breeder reactors to produce U-233 from thorium. The third stage envisages development and deployment of U-233 fuelled reactors. In the fuel cycle operations, solvent extraction is a major step for the recovery of uranium and plutonium. Centrifugal extractors plays a vital role in solvent extraction due to their compact size and high throughput. In the present work, the experimental studies for the hydraulic performance were reported for a single stage annular centrifugal contactor of ϕ125 mm rotor for two-phase flow. Maximum throughput with entrainment less than 1% of one phase to the other, of the centrifugal contactor was measured with the A/O ratio 1 to 6 for the three different bottom vane heights of 6, 8 and 10 mm and also for three different annular gaps of 12, 15 and 18 mm. The centrifugal extractor was operated at different speeds ranging from 1200 to 2200 rpm. In addition, mass transfer performance of the same unit was evaluated with 30% TBP/nitric acid biphasic systems.     

快中子照相的实验研究

快中子照相是一种优良的无损检测技术,它有着X射线、热中子照相等所不具有的独特优势。本文介绍了作者分别采用^241Am-Be同位素中子源和中子发生器进行的快中子照相研究,并利用自制的Gd2O2S：Tb快中子转换发光屏进行探测,成功实现照相。     

A sensitivity study on fast reactor scenarios with various conversion ratios

Korean fast reactor scenarios have been analyzed for various kinds of conversion ratios by the DANESS system dynamic analysis code. The once-through fuel cycle analysis was modeled based on the Korean “National Energy Basic Plan” up to 2030 and a postulated nuclear demand growth rate until 2150. The fast reactor scenario analysis has been performed for three kinds of conversion ratios such as 0.3, 0.61, and 1.0. Through the calculations, the nuclear reactor deployment scenario, front-end cycle, back-end cycle, and long-term heat load have been investigated.     

Experimental study on flow pattern and heat transfer of inverted annular flow

Experimental results are presented on flow pattern and heat transfer in the regions from inverted annular flow to dispersed flow in a vertical tube using freon R-113 as a working fluid at atmospheric pressure to discuss the correspondence between them. Axial distributions of heat transfer coefficient are measured and flow patterns are observed. The heat transfer characteristics are divided into three regions and a heat transfer characteristics map is proposed. The flow pattern changes from inverted annular flow (IAF) to dispersed flow (DF) through inverted slug flow (ISF) for lower inlet velocities and through agitated inverted annular flow (AIAF) for higher inlet velocities. A flow pattern map is obtained which corresponds well with the heat transfer characteristic map.     

Experimental study on fast electron generation during internal crash

Hard x-ray(HXR) burst is found during internal crash in the flat top current stage of experimental advanced superconducting tokamak(EAST) discharges and it is caused by fast electrons. The generated electrons during internal crashes may be an operational safety issue in advanced tokamaks. During an internal crash, locations of fast electron generation from HXR evolution agree with areas of magnetic reconnection from soft x-ray(SXR) tomographic reconstruction. Further statistical analyses show a 27 μs time difference between SXR crashes and HXR bursts, and the agreement between time broadening of HXR bursts and estimated characteristic time of magnetic reconnection in EAST. The magnetic reconnections during internal crash are proved to generate fast electrons, by both spatial and temporal agreements.     

基于MURA编码孔成像测量Pu部件对称性的数值模拟分析

通过分析MURA编码孔成像技术的原理,实现了MLEM重建算法的源物体图像重建。使用数值模拟方法,分析了413keV单能γ面源的MURA编码板成像全过程,通过对比分析重建源物体分布与实际源物体分布,验证了重建算法及程序的正确性。并通过MNCP程序模拟假想的Pu部件模型,在编码孔成像过程中,像平面上射线投影强度分布、直接重建及简单扣本底重建源物体分布,从而论证了MURA编码孔成像测量Pu部件对称性的可行性。数值模拟结果表明,编码孔成像测量Pu部件对称性与小孔成像相比,在保护敏感信息和提高射线利用效率方面,具备一定的优势。