500彩票网

Radiation is encountered in various environments and situations. There is natural radiation, which has existed since ancient times; artificial radiation and radioactive materials, which have been used in the medical and industrial fields in pursuit of better human health and living environments; radioactive waste generated as a result of such activities; and the environment at large, which has been contaminated by radioactive materials that spread as a result of the accident at TEPCO’s Fukushima Daiichi Nuclear Power Plant. In this situation, while we enjoy the convenience of X-rays in airport baggage screening and medical diagnoses in hospitals, we sometimes hear about radiation exposure and are concerned about its effects and risks. When we look back through history, since the discovery of X-rays by Dr. Röntgen in 1895, experts have spent a great deal of time thinking about how to reduce the risk of radiation exposure as much as possible, and have accumulated experience in responding, taking measures, and coming up with ideas. Social confusion caused by the effects of nuclear disasters such as Chernobyl (1986) and Fukushima (2011) on people and the environment has also had a significant impact on the history of these efforts, or the so-called Plan-Do-Check-Act (PDCA) cycle, and discussions by those involved are still ongoing.

This book focuses on artificially sealed sources of radiation. According to the JIS standard (JIS Z 4821), a sealed source is defined as “a radiation source that is encapsulated or bonded to a support material to prevent the dispersal of radioactive material under the conditions of its design, when used as designed.” However, the law (Regulations for the Implementation of the Act on the Regulation of Radioactive Isotopes, etc.) states that “sealed radioactive isotopes (sealed sources) must be used in a state that always conforms to the two conditions of (1) not being likely to be opened or destroyed under normal conditions of use, and (2) not being likely to be contaminated by leakage or permeation of the sealed radioactive isotopes.” As Dr. Röntgen predicted, sealed radioactive sources are used in a wide range of fields, not only for medical examinations and treatments but also for material component analysis and structural analysis; thickness measurements of items such as plating, paper, and metal materials; non-destructive testing; and even sterilization of food and medical equipment. To continue using sealed radiation sources effectively, safely, and stably in situations that directly affect our daily lives, there is a growing need for excellent facility safety managers or radiation protection supervisors who not only understand the nature of such substances and can handle them with confidence, but who can also protect the facilities and people that handle them.
 
We have carefully compiled a qualification test textbook to meet this purpose, and it is written in a way that is easy to understand, so that not just those aiming to become radiation protection supervisors but anyone can understand not only the basics of radiation but also the latest concepts and techniques that are essential to safety management in radiation facilities. I, the writer of this introduction, was in charge of Chapter 4, “Radiation Control Technology,” and I have provided explanations on the motivation and purpose of radiation protection and control, the meaning of the unit of exposure “sievert,” the concept of dose reduction and actual techniques, accident countermeasures, etc. Please refer to it.
 

(Written by IIMOTO Takeshi, Professor, Division for Environment, Health and Safety / 2024)