Fritz Bradley G, Barnett J Matthew
*Pacific Northwest National Laboratory, P.O. Box 999, MSIN K7-68, Richland, WA 99352.
Health Phys. 2015 Nov;109(3 Suppl 3):S200-4. doi: 10.1097/HP.0000000000000325.
Clause 6.4.4 in the American National Standard ANSI/HPS N13.1 standard "Sampling and Monitoring Releases of Airborne Radioactive Substances From the Stacks and Ducts of Nuclear Facilities" addresses the internal smoothness of sample transport lines present between the nozzle and the analyzer (or collector). The appropriateness of this clause is evaluated by comparing roughness length of various materials against the required relative roughness and by conducting computational fluid dynamic modeling. The results indicate that the inclusion of numerical criteria for the relative roughness of pipe by the ANSI/HPS N13.1-2011 (clause 6.4.4) is not appropriate. Recommended alternatives would be elimination of the numerical criteria or modification of the standard to include a variable criterion for relative roughness.
美国国家标准ANSI/HPS N13.1“核设施烟囱和管道中空气传播放射性物质的采样与监测排放”中的第6.4.4条涉及喷嘴与分析仪（或收集器）之间的样品传输线的内部光滑度。通过将各种材料的粗糙度长度与所需的相对粗糙度进行比较，并进行计算流体动力学建模，来评估该条款的适用性。结果表明，ANSI/HPS N13.1 - 2011（第6.4.4条）中纳入管道相对粗糙度的数值标准是不合适的。建议的替代方案是取消数值标准，或修改标准以纳入相对粗糙度的可变标准。
