## 4 Discussion  
The ability to shield X-rays and \(\gamma\)-rays used in the diagnostic area of medical institutions depends on the type and thickness of the shielding material [29; 30]. When lead  
Figure 8: Spatial dose distribution inside the imaging room of a medical institution. Figure 7: Enlarged electron microscope images of the fabrics. (**a**) Tungsten powder is not dispersed in the fabric, (**b**) Tungsten powder is dispersed. is used as the main material, yhe X-ray protective clothing used for shielding by medical personnel or patients generally uses 0.25 and 0.50 mm lead thickness. The reported shielding performance of these thicknesses are more than 93.8% at 0.25 mm and 98.9% at 0.5 mm [31]. However, for low-dose radiation shielding, economic, environmental, and personnel activity issues arise because of the excessive protection provided by these lead thicknesses [32]. In this study, a tungsten-based shielding fiber for the efficient shielding of low-dose radiation generated in medical institutions was proposed. In addition, it was attempted to improve the shielding performance by dispersing tungsten nanopowder to remove pinholes between yarns, which are a problem when manufacturing with fibers. Using a large amount of powder increases the shielding effect, but reduces the fiber's flexibility. To retain fiber flexibility, tungsten powder usage was maintained at approximately 8 wt% of the total weight. As a result, the shielding performance was improved by 15% in the low-dose region. The woven shielding fiber can also be used as a lining for special shielding suits such as partial shielding clothing for flight crews and firefighting suits; furthermore, it can be used in medical institutions for protection against scattered rays, rather than direct rays [33]. In the diagnosis area, as shown by the experimental results, shielding using a shielding fiber fabric is possible at a distance of 1.2 m or greater from the X-ray generator in the imaging room. Therefore, although it is insufficient for direct radiation shielding, it could be possible to manufacture a light-weight shielding suit for shielding against scattered rays. In particular, in places where low-dose radiation is used, such as dentistry or veterinary hospitals, the fabric can reduce the hindering effects of heavy shielding clothing on the users' activities [34]. A typical conventional method consists of mixing a resin-based polymer substance and a shielding substance and applying a thin coating on a non-woven fabric. This method increases the strength of the shield more than when it is manufactured in the form of a sheet, but the thin coating results in inconsistent shielding reproducibility, which makes mass production difficult. In addition, continuous use incurs problems such as the separation of the coating from the nonwoven fabric and cracks in the coating, resulting in poor durability of the product [35]. Effective shielding of low-dose radiation generated in medical institutions is closely related to distance, and the micro-design of shielding clothing considering distance is possible. Micro-shielding design can be classified according to the radiation sensitivity of major organs of the human body, and an effective radiation defense plan can be realized through customized shielding for each part [36]. In addition, a safe shielding range should be established to minimize the risk to the human body. Because the use of artificial radiation in medical institutions can control the intensity of energy, it can be used to resolve this risk [37; 38; 39; 40]. Therefore, based on the range of scattered radiation and the amount of scattered radiation presented in the results of this study, the extent of low-dose shielding possible with a 1 kg lightweight shielding suit was determined. In particular, a new process technology for filling pinholes in fibers with nanopowders was also presented. In medical institutions radiation shielding suits are worn by medical staff and patients and the must satisfy the conditions of safety and light weight [41; 42; 43].