Paik Samuel Y, Epperson Patrick M, Kasper Kenneth M
a ES&H Directorate, Lawrence Livermore National Laboratory , Livermore , California.
b National Ignition Facility, Lawrence Livermore National Laboratory , Livermore , California.
J Occup Environ Hyg. 2017 Jun;14(6):438-447. doi: 10.1080/15459624.2017.1285495.
This article presents air and surface sampling data collected over the first two years since beryllium was introduced as a target material at the National Ignition Facility. Over this time, 101 experiments with beryllium-containing targets were executed. The data provides an assessment of current conditions in the facility and a baseline for future impacts as new, reduced regulatory limits for beryllium are being proposed by both the Occupational Safety and Health Administration and Department of Energy. This study also investigates how beryllium deposits onto exposed surfaces as a result of x-ray vaporization and the effectiveness of simple decontamination measures in reducing the amount of removable beryllium from a surface. Based on 1,961 surface wipe samples collected from entrant components (equipment directly exposed to target debris) and their surrounding work areas during routine reconfiguration activities, only one result was above the beryllium release limit of 0.2 µg/100 cm and 27 results were above the analytical reporting limit of 0.01 µg/100 cm, for a beryllium detection rate of 1.4%. Surface wipe samples collected from the internal walls of the NIF target chamber, however, showed higher levels of beryllium, with beryllium detected on 73% and 87% of the samples during the first and second target chamber entries (performed annually), respectively, with 23% of the samples above the beryllium release limit during the second target chamber entry. The analysis of a target chamber wall panel exposed during the first 30 beryllium-containing experiments (cumulatively) indicated that 87% of the beryllium contamination remains fixed onto the surface after wet wiping the surface and 92% of the non-fixed contamination was removed by decontaminating the surface using a dry wipe followed by a wet wipe. Personal airborne exposures assessed during access to entrant components and during target chamber entry indicated that airborne beryllium was not present in workers' breathing zones. All the data thus far have shown that beryllium has been effectively managed to prevent exposures to workers during routine and non-routine work.
本文介绍了自铍被用作国家点火装置的靶材以来头两年收集的空气和表面采样数据。在此期间，进行了101次含铍靶材实验。这些数据对该装置的当前状况进行了评估，并为未来的影响提供了基线，因为职业安全与健康管理局和能源部都在提议降低铍的监管限值。本研究还调查了铍因X射线汽化而沉积在暴露表面的情况，以及简单去污措施在减少表面可去除铍量方面的有效性。基于在例行重新配置活动期间从进入部件（直接暴露于靶碎片的设备）及其周围工作区域收集的1961个表面擦拭样本，只有一个结果高于铍释放限值0.2微克/100平方厘米，27个结果高于分析报告限值0.01微克/100平方厘米，铍检测率为1.4%。然而，从国家点火装置靶室内壁收集的表面擦拭样本显示铍含量较高，在第一次和第二次靶室进入（每年进行一次）期间，分别有73%和87%的样本检测到铍，在第二次靶室进入期间，23%的样本高于铍释放限值。对在前30次含铍实验（累计）期间暴露的一个靶室壁板的分析表明，表面湿擦拭后，87%的铍污染仍固定在表面，通过先用干擦拭然后湿擦拭对表面进行去污处理，92%的非固定污染被去除。在进入进入部件期间和靶室进入期间评估的个人空气暴露表明，工人呼吸区内不存在空气中的铍。迄今为止所有数据都表明，在常规和非常规工作期间，铍已得到有效管理，以防止工人接触。
