POTENTIAL PROLIFERATION POINTERS FROM THE PAST: Lessons from the British Nuclear Weapons Program, 1952–69

Becoming a nuclear weapon state and sustaining a militarily credible nuclear weapons capability is far from trivial, especially for medium powers. Such a capability is demonstrated by much more than firing a first test or acquiring significant quantities of fissile material; capability is indicated by factors including weaponization, delivery of weapons, reliability and effectiveness of weapons and their delivery systems, fissile material availability, and nuclear and non-nuclear testing. Files in the British National Archives shed considerable light on the problems faced by the nuclear weapon program of the United Kingdom from 1952 through the late 1960s. The question is whether this experience is unique or if it instead offers insights into the potential problems faced by, or facing, other medium or aspiring nuclear weapon states. The proliferation-related topics highlighted include: fissile material production, nuclear testing, the first weapon, weapon delivery rates, non-nuclear testing, delivery platform problems, and long-term maintenance and capability sustainability. Further research could provide clearer insights.     

Deferred verification: the role of new verification technologies and approaches

ABSTRACT

Researchers have recently proposed a new approach to nuclear-arms-control verification, dubbed “deferred verification.” The concept forgoes inspections at sensitive nuclear sites and of nuclear weapons or components in classified form. To implement this concept, a state first divides its nuclear program into a closed segment and an open segment. The total fissile-material inventory in the closed segment, which includes the weapon complex, is known and declared with very high accuracy. Essentially no inspections take place in the closed segment. In contrast, inspectors have access to the open segment, which includes in particular the civilian nuclear sector. The fissile-material inventory in the open segment is known with less accuracy, but uncertainties can be reduced over time using nuclear-archaeology methods. Deferred verification relies primarily on established safeguards techniques and avoids many unresolved verification challenges, such as the need for information barriers for warhead confirmation measurements. At the same time, deferred verification faces some unique challenges. Here, we explore some of these challenges and offer possible solutions; to do so, we examine possible noncompliance strategies in which a state would seek to withhold a higher-than-declared inventory.     

GERMANY'S CURRENT AND FUTURE PLUTONIUM INVENTORY

In the past, Germany reprocessed a significant amount of its spent nuclear fuel, partly on its own territory but mostly as a customer of British and French reprocessing plants. In mid-2005, Germany stopped this practice, banning new transports of spent fuel for reprocessing—although the already-exported material would be allowed to be reprocessed and recycled in German reactors as mixed-oxide (MOX) fuel. In total, about 6,500 tonnes of heavy metal have been contracted for reprocessing, but a significant portion of this material has neither been reprocessed nor recycled as MOX fuel in German reactors. Due to the complex import-export history and the partly nontransparent information policy of the German government and utilities, a comprehensive and up-to-date plutonium balance for Germany is not publicly available. This report provides an assessment of Germany's plutonium inventory (stored domestically or abroad) based on open-source information. Special attention is paid to the issue of whether the entire inventory of separated plutonium can be completely irradiated in German nuclear reactors before the last of them are shut down in 2022. The authors conclude that Germany's stock of plutonium waiting to be recycled was about 12.2 tonnes as of 2010; this plutonium should be completely re-imported from the United Kingdom and France by 2017. Germany's MOX-consumption capacities should be sufficient to irradiate the remaining plutonium, although further delays are expected that could leave Germany with an inventory of separated (unirradiated) plutonium.     

战役级军械维修器材保障决策支持系统设计研究

传统的面向事务的数据处理方法已经无法适应处理大量数据的要求,为解决这一问题,将面向主题的数据仓库技术用于军械维修器材保障决策支持系统的设计,阐述了基于数据仓库的军械维修器材保障决策支持系统需求分析、系统设计和系统实现,讨论了系统设计原则、设计方法、逻辑结构设计、多维数据仓库设计、底层数据库设计、前端用户视图设计等内容,对军械维修器材保障决策支持系统的开发提供了基本思路．     

基于电动增压器的大功率柴油机高原功率恢复研究

高原环境对柴油机的工作性能影响较大,探索在高原环境下柴油机功率的恢复,对车辆在高原地区正常运行具有重要的意义．基于GT-POWER建立某型大功率柴油机整机数值仿真模型,并验证该模型的准确性;确定二级顺序增压系统方案,建立二级顺序增压系统数值仿真模型,通过增加电动增压器实现二级顺序增压的方法恢复柴油机高原使用功率．     

漂浮式微型波力发电装置原理与结构

为了满足偏远岛屿小功率用电保障需求,根据波浪能特点,提出一种新型漂浮式微型波力发电装置。利用重锤惯性定心原理,建立浮动"机架",解决漂浮体内部相对固定问题;采用机-电直接转换系统,提高波浪能的利用效率;研究系统的原理与结构,分析系统的功能特点和主要运动参数。研究结果表明,漂浮式微型波力发电装置具有结构原理新颖、传动效率高、传动质量好与轻巧便携等优点。该研究为漂浮式微型波力发电装置的研发与应用奠定了基础。     

强激光作用充气式轻型仿形诱饵探讨

本文结合充气式轻型仿形诱饵的结构特点,探讨了强激光对轻型仿形诱饵作用的几种效应,以及强激光作用后诱饵运动状态变化的情况,且对由此引起的诱饵轨道偏离进行了数值计算与分析。     

Ku波段高功率TM0n-TM01 混合模式转换器设计

由于过模Ku波段高功率微波返波管通常输出TM0n混合模式,在保证较高能量转换效率的条件下,难以同时兼顾其输出模式的纯度,而辐射终端为达到理想发射效果又要求单一模式馈入,这就给输出混合模式微波源的实际应用带来了困难。针对这一技术难点,提出一种结构紧凑的TM0n-TM01(n≤3)混合模式转换器的设计方法,实现在高功率容量条件下和较宽频带范围内,高效地将TM0n混合模式转换为单一的TM01模,降低了此类高频段高功率微波源模式纯化设计的难度。     

基于CNN的三相逆变器开路故障诊断及其样本条件分析

为了合理选择样本条件以实现高效的智能化诊断,以及克服智能化方法中传统反向传播(back propagation, BP)网络权值较多、局部信息提取能力不足的问题,对基于卷积神经网络(convolutional neural network, CNN)的开路故障诊断方法进行研究,并以典型的三相两电平逆变器为具体对象,着重分析样本时长、样本数量变化时,CNN方法相较于BP网络方法在网络权值数量、训练稳定性、诊断准确率上的量化优势。结果表明,基于CNN的方法可在权值数量远少于BP网络方法的情况下构建深度更深的诊断模型,并在更短样本时长、更少训练样本数量下实现高效、准确的开路故障诊断。     

谈安防系统中的火灾证据和提取方法

近年来,在移动互联网的带动下,面向小微企业、家庭和个人的安防业务步入活跃期,未来以智慧城市为代表的各类物联网项目不断发展,＂数字化、智能化、网络化＂的安防系统将成为趋势。从安防系统的定义入手,论述安防信息在火灾调查中的应用,并针对安防电子证据和视频监控资料的收集方法进行探讨,旨在规范和提高火灾调查人员的火场勘查技术。