ITER双功能液态锂铅实验包层系统PIE-PIT分析

ITER要求各参与国的实验包层模块在实验前必须提交安全分析报告(含确定论分析和概率论分析),进而获取安全许可证.结合中国双功能锂铅实验包层模块的具体特点,采用了假设始发事件-潜在影响表(PIE-PIT)分析方法对DFLL-TBM进行了安全评估与分析,已验证确定论安全分析所选择的三个参考事件是否可包络PIE-PIT分析得到的严重事故序列.     

聚变实验堆ITER实验包层瞬态热工安全分析

在中国向ITER(International Thermonuclear Experiment Reactor)实验包层工作组提交的双功能锂铅实验包层模块(DFLL-TBM)设计分析的基础上,通过对DFLL-TBM系统相关的瞬态事故如真空室内部冷却剂泄漏、TBM(实验包层模块)内部冷却剂泄漏以及真空室外部冷却剂泄漏事故进行计算分析,评价DFLL-TBM对ITER在热工方面对安全的影响.结果表明:当发生瞬态事故时,DFLL-TBM有能力通过热辐射将余热排出,且包层结构不会熔化.DFLL-TBM可满足ITER在热工方面对安全的要求.     

基于RELAP5的双功能液态锂铅实验包层模块安全分析

利用嵌入了液态锂铅（LiPb）的热工水力子模块的系统程序RELAP5/MOD3,对双功能液态锂铅（DFLL）实验包层模块（TBM）的安全特性进行评价。对DFLL-TBM及其辅助冷却系统的稳态运行工况、预期运行事件和相关事故工况进行了建模、计算和分析。计算结果表明,稳态运行时第一壁（FW）结构材料表面最高温度低于允许值550 ℃。事故工况下氦气泄漏引起的ITER真空室（VV）、窗口设备室（port cell）以及托卡马克冷却水系统大厅拱顶（TCWS vault）的增压均低于ITER要求的限值0.2 MPa。实验包层钢结构不会熔化且可通过辐射换热有效地导出衰变余热。DFLL-TBM的设计可满足ITER对其热工水力安全方面的要求。     

中国双功能锂铅实验包层系统在ITER赤道窗口的界面设计

中国双功能锂铅实验包层模块(DFLL-TBM)是中国计划在国际热核实验堆(ITER)进行氚增殖包层实验的两个候选概念之一.实验包层系统(TBS)与ITER界面设计关系到TBS能否在ITER装置有限空间内安装和实验,是ITER国际组关注的重点.本文根据ITER对TBS的设计要求、DFLL-TBS概念设计,结合中国与印度TBS在实验窗口的功能、安全和空间分配的定义,利用CATIA三维设计软件进行了DFLL-TBS在ITER窗口塞、管林区、窗口室的界面设计,初步设计可以满足ITER实验窗口空间要求.     

ITER中国液态锂铅实验包层模块氦气冷却系统初步设计研究

氦气冷却系统是ITER中国液态锂铅实验包层模块(DFLL-TBM)在ITER装置内进行实验的重要辅助系统.根据ITER运行时的热工条件、安全要求、空间要求,分析了DFLL-TBM氦气冷却系统的功能,确定氦气冷却系统的设计原则和要求,在此基础上给出氦气冷却系统的初步设计方案和设备布置.该氦气系统的特点体现在:双功能,即有宽的裕量满足SLL-TBM和DLL-TBM实验;两条氦气回路共享压力控制单元和氦气净化子系统;旁路设计调节TBM和热交换器氦气的出口温度.     

ITER中国液态锂铅实验包层模块结构热应力数值模拟

使用有限元程序对中国向国际热核实验堆ITER实验包层工作组提交的双功能锂铅实验包层模块(DFLL-TBM)的两种结构设计方案即双冷LiPb包层DLL和单冷准静态LiPb包层SLL进行热应力数值模拟,在包层结构设计、热工水力学设计和中子学计算基础上,给出包层结构温度场和应力场分布,依据ITER高温结构设计标准,进一步对包层高温部件进行力学性能分析.根据这些模拟结果,分析两种结构基本设计方案的合理性和可行性,并作为进一步优化分析的基础.     

ITER中国液态锂铅实验包层模块结构设计与加工

根据ITER实验包层的发展目标,实验要求,限制条件,结合聚变发电反应堆FDS-Ⅱ DLL/SLL包层方案设计了DFLL-TBM原型结构,给出了加工工艺和装配序列方案.该实验模块特点是极向LiPb流道易于布置FCI流道插件,"]"型隔板和"盒形"背板式联箱简化冷却方案和结构.这种简单的结构易于加工制造,易于派生出在ITER不同运行阶段实验的系列模块,符合在ITER进行SLL-TBM和DLL-TBM两种包层模块实验的策略.     

ITER中国液态锂铅实验包层模块液态金属流动MHD效应数值模拟

为研究国际热核聚变实验堆(ITER)的中国双功能锂铅实验包层模块(DFLL-TBM)中液态金属磁流体动力学(MHD)效应,对在强磁场环境下磁流体动力学效应对液态金属LiPb流动和传热的影响进行数值模拟和分析.主要包括三部分:(1) 建立模拟液态金属磁流体的磁感应方程数学模型和程序简介;(2) 对液态LiPb MHD流体在全模块内流动的数值模拟,给出了速度场和压力场分布,重点考察和分析局部的流动特点和对传热的影响;(3) LiPb在进口供给联箱内的流场的数值模拟,对供给联箱的分流作用给出了初步的估算和评价.     

基于氘氚聚变中子源的双功能锂铅包层(DFLL-TBM)模型中子学实验

为了验证双功能锂铅实验包层模块(DFLL-TBM)的中子学设计,中国科学院核能安全技术研究所·FDS凤麟核能团队利用14 MeV中子源开展了DFLL-TBM模型的中子学实验。实验中分别利用In、Al、Nb活化片和~6Li玻璃探测器测量了DFLL-TBM中子学实验模型中不同深度3个位置的活化反应率和产氚率。并利用蒙特卡洛模拟程序Super MC和FENDL3.1数据库进行了相应的模拟计算,计算值和实验值比较在10%以内吻合。结果表明计算值与实验值符合较好,所采用的计算程序和数据库适用于DFLL-TBM的计算设计。     

中国氦冷固态增殖剂实验包层模块材料研究进展

在未来核聚变反应堆中,为补充氚的消耗,需要在核聚变堆的包层中进行氚的在线增殖,以维持核聚变反应的持续进行。为验证这一关键技术,在国际热核聚变实验堆(ITER)上开展了ITER TBM计划(实验包层项目)。作为ITER计划成员方之一,中方以中国氦冷固态增殖剂实验包层模块(HCCB TBM)概念参与ITER TBM计划。HCCB TBM现今进入初步设计阶段,而材料的制备技术和性能数据是支撑其结构设计、安全分析和服役工况评估的基础。本文综述和分析了HCCB TBM结构材料低活化铁素体/马氏体钢(RAFM钢)与功能材料氚增殖剂和中子倍增剂的研究现状,并对这些材料下一步的研究方向进行了展望。     

Failure Modes and Effects Analysis on ITER DFLL-TBM system

As required for licensing process, accident analyses of International Thermonuclear Experimental Reactor (ITER) accounting for site specifications and design changes will be updated. Chinese Dual-Functional Lithium-Lead-Test Blanket Module (DFLL-TBM) system is a key safety-related component of ITER, its detailed safety analysis, which was designated to demonstrate the integrated technologies of both Helium single coolant (SLL) blanket and Helium-LiPb dual coolant (DLL) blanket, was performed. Failure Modes and Effects Analysis (FMEA) was applied to perform the safety analysis of DFLL-TBM. This study described the process of FMEA studies on DFLL-TBM system. All safety-related Postulated Initiating Events (PIEs) was identified. And a set of PIEs recommended to be taken into account in the further deterministic transient analyses were defined for both SLL and DLL blanket concepts separately.     

Preliminary thermal-hydraulic and safety analysis of China DFLL-TBM system

China has proposed the dual-functional lithium-lead (DFLL) tritium breeding blanket concept for testing in ITER as a test blanket module (TBM), to demonstrate the technologies of tritium self-sufficiency, high-grade heat extraction and efficient electricity production which are needed for DEMO and fusion power plant. Safety assessment of the TBM and its auxiliary system should be conducted to deal with ITER safety issues directly caused by the TBM system failure during the design process. In this work, three potential initial events (PIEs) – in-vessel loss of helium (He) coolant and ex-vessel loss of He coolant and loss of flow without scram (LOFWS) – were analyzed for the TBM system with a modified version of the RELAP5/MOD3 code containing liquid lithium-lead eutectic (LiPb). The code also comprised an empirical expression for MHD pressure drop relevant to three-dimensional (3D) effect, the Lubarsky–Kaufman convective heat transfer correlation for LiPb flow and the Gnielinski convective heat transfer correlation for He flow. Since both LiPb and He serve as TBM coolants, the LiPb and He ancillary cooling systems were modeled to investigate the thermal-hydraulic characteristic of the TBM system and its influence on ITER safety under those accident conditions. The TBM components and the coolants flow within the TBM were simulated with one-dimensional heat structures and their associated hydrodynamic components. ITER enclosures including vacuum vessel (VV), port cell and TCWS vault were also covered in the model for accident analyses. Through this best estimate approach, the calculation indicated that the current design of DFLL-TBM and its auxiliary system meets the thermal-hydraulic and safety requirements from ITER.     

Preliminary tritium safety analysis on China DFLL-TBM for ITER

The dual-functional lithium-lead test blanket module (DFLL-TBM) system was proposed to be tested in ITER. A tritium permeation model of the entire DFLL-TBM system was developed, and the tritium permeation and inventory in DFLL-TBM system were done based on the model during normal operation. Three classes of off-normal situations had been preliminarily analyzed, i.e. in-vessel TBM coolant leaks, in-TBM breeder box coolant leaks and ex-vessel TBM ancillary coolant leaks. The results showed that some issues required significant R&D effort to guarantee the tritium release to the environment below the allowable level, such as the tritium extraction from LiPb and helium coolant and very efficient detritiation system. And more analyses would be carried in the future to further assess the safety of DFLL-TBM.     

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.     

Potential failure mode and effects analysis for the ITER NB injector

The failure mode and effects analysis (FMEA) is a widely used analytical technique that helps in identifying and reducing the risks of failure in a system, component or process.The application of a systematic method like the FMEA was deemed necessary and adequate to support the design process of the ITER NBI (neutral beam injector). The approach adopted was to develop a FMEA at a general “system level”, focusing the study on the main functions of the system and ensuring that all the interfaces and interactions are covered among the various subsystems. The FMEA was extended to the whole NBI system taking into account the present design status. The FMEA procedure will be then applied to the detailed design phase at the component level, in particular to identify (or define) the ITER Class of Risk.Several important failure modes were evidenced, and estimates of subsystems and components reliability are now available. FMEA procedure resulted essential to identify and confirm the diagnostic systems required for protection and control, and the outcome of this analysis will represent the baseline document for the design of the NBI and NBTF integrated protection system.In the paper, rationale and background of the FMEA for ITER NBI are presented, methods employed are described and most interesting results are reported and discussed.     

Software safety analysis application of safety-related I&C systems in installation phase

This work performed a software safety analysis (SSA) in the installation phase of the Lungmen nuclear power plant (LMNPP) in Taiwan, under the cooperation of INER and TPC. The US Nuclear Regulatory Commission (USNRC) requests licensee to perform software safety analysis (SSA) and software verification and validation (SV&V) in each phase of software development life cycle with Branch Technical Position (BTP) 14. In this work, 37 safety grade digital instrumentation and control (I&C) systems were analyzed by Failure Mode and Effects Analysis (FMEA), which is suggested by IEEE Standard 7-4.3.2 (2003). During the installation phase, skew tests for safety grade network and point to point tests were performed. The FMEA showed all the single failure modes can be resolved by the redundant architecture. The common mode failures can be resolved by operator manual actions via the diverse displays.