• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文会议>ANS Nuclear Criticality Safety Division topical meeting >DEMONSTRATING COMPLIANCE WITH MODERATOR CONTENT LIMITS IN URANIUM DIOXIDE POWDER UPON LEAVING A FURNACE ENVIRONMENT
【24h】

DEMONSTRATING COMPLIANCE WITH MODERATOR CONTENT LIMITS IN URANIUM DIOXIDE POWDER UPON LEAVING A FURNACE ENVIRONMENT

机译：离开炉膛环境后证明符合二氧化铀粉中的含量限制

获取原文
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

A challenge was posed to the criticality safety consultant to consider whether instrumentation identified by Plant Management in an existing facility could be claimed as appropriate safety measures to ensure compliance with moderator content limits in uranium dioxide (UO_2) powder. During processing of low enriched UO_2, trays of powder are heated in a steam and hydrogen environment in order to reduce fluoride levels. Whilst in the furnace environment criticality safety is ensured by the geometry of the furnace trays used to convey the powder; however, upon leaving the furnace the UO_2 is bulked to a 210 litre drum subject to limited moderation control. Under fault conditions there is a potential that the powder may become wetted due to an imbalance in furnace gas flows resulting in steam condensing in the cooling section of the furnace. Therefore, the safety case methodology followed suggests that two independent and diverse safety measures are provided to terminate the progression of the fault(s) to criticality. The existing criticality safety case credits an infra-red moisture meter as one of two safety measures; however, the calibration procedure required to ensure this device remains suitable is a considerable challenge from a plant operability perspective. As an initial review failed to identify any suitable like-for-like replacement, the National Nuclear Laboratory (NNL) Nuclear Safety Section were requested by the customer to consider the existing criticality safety case and investigate whether any existing instrumentation could be used as an alternative method of detecting conditions in which excess moisture could be present within the furnace trays. A number of solutions were proposed and the benefits and challenges around each are discussed in this paper, concluding with the approach adopted by the project.
机译：关键安全顾问面临一个挑战，即考虑是否可以要求将工厂管理部门在现有设施中确定的仪器声明为适当的安全措施，以确保符合二氧化铀（UO_2）粉末中的缓和剂含量限制。在处理低浓度UO_2的过程中，将粉末托盘在蒸汽和氢气环境中加热，以降低氟化物含量。在炉子环境中，通过用于输送粉末的炉盘的几何形状确保了临界安全性;但是，在离开炉子后，UO_2会散装到210升的转鼓中，并受到有限的适度控制。在故障条件下，由于炉内气流的不平衡，粉末可能会变湿，从而导致蒸汽在炉内的冷却部分凝结。因此，随后采用的安全案例方法表明，提供了两种独立且多样化的安全措施来终止故障发展到严重程度。现有的临界安全案例将红外水分计归功于两个安全措施之一。但是，从工厂可操作性的角度来看，确保此设备保持合适状态所需的校准程序是一个相当大的挑战。由于初步审查未能找到合适的替代产品，因此客户要求国家核实验室（NNL）核安全科考虑现有的临界安全案例并调查是否可以使用任何现有的仪器作为替代品一种检测条件的方法，其中炉盘内可能存在多余的水分。本文提出了许多解决方案，并讨论了每种解决方案的好处和挑战，最后总结了该项目采用的方法。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号