**4.3 Leakage tests**

Radioactive sources that are used for medical treatments, industrial radiography, and nuclear batteries are routinely leak tested at the time of manufacture and, in some cases, during the lifetime of the sources. The various leak test procedures are designed to detect the presence of leak paths in the containment walls of sources through which radioactive material might escape to the surroundings. Shielding harboring liquid radioisotopes, such as Mo99/Tc99m generators are also leak tested. There are several requirements for the tests and they are presented in the ISO 2919 [55] and ISO 9978 [56].

A series of classification steps must be performed so a classification code can be emitted. Each of the tests (temperature, pressure, impact, vibration, and punching) corresponds to a specific digit in the product classification code, and can assume different values (1 to 6), according to the required performance level. The classification result will be an alphanumeric code that characterizes the product according


#### **Table 2.**

*Acceptable dose limits separated by ICRP's publications [50].*

#### **Figure 12.**

*Sealed source classification accordingly with the ISO 2919 standard. The numbers are the classification obtained.*

#### *Radiopharmaceuticals - Current Research for Better Diagnosis and Therapy*


#### **Table 3.**

*All recommended leakage tests. Numbers in () refers to the standard subtitles where the test description can be found.*

to the ISO 2919 standard. **Figure 12** shows an example of a sealed source classification.

The ISO 9978 standard establishes the conditions and procedures for carrying out leakage tests on sealed radioactive sources, presenting various methods for inspecting these sources. Appendix A presents a guide for choosing the type of test, depending on the type of source to be controlled. Basically, they are (**Table 3**).

The test choice and performance level depend on the source being evaluated and its use. A source is considered leak thigh if less than 185 Bq (5nCi) is detected.

#### **5. Conclusion and future perspective**

The future perspective is that research in the different fields will increase. In the medical field new forms of treatment are being developed. Two new of interest are the lutetium-177 radiopharmaceuticals and nanobrachytherapy. Accordingly with Banerjee et al. [57] research with 177Lu-based radiopharmaceuticals has demonstrated spectacular growth in recent years. 177Lu Radiolabeling was performed with monoclonal antibodies, peptides, phosphonate ligands, particulates, steroids, and other small molecules. High success was achieved on treating neuroendocrine tumors with 177Lu-labeled DOTA-Tyr3 -octreotate (DOTA-TATE). Nanobrachytherapy is a new form of brachytherapy that uses radioactive nanoparticles. The major advance is the small size makes it possible to penetrate tumor vascularity and cell barrier, delivering the treatment directly into the target

*Start Here When Performing Radiochemical Reactions DOI: http://dx.doi.org/10.5772/intechopen.98766*

[35]. Works with gold-198, palladium-103, indium-111, and lutetium-177 are currently being investigated. In industrial applications, one major area that can be highlighted is nuclear power systems, more specifically, nuclear batteries. Withing this, Radioisotope Thermoelectric Generator and betavoltaic batteries. The first mode converts the decay heat to power by using the seebeck effect. Efforts are being made in several countries such as South Korea using strontium-90 for space exploration, Brazil using strontium-90 for oil extraction, and Europe using americium-241 for space exploration. The second mode uses beta decay (electron) to generate power directly. They are used in micro sensors and random number generators. Betavoltaic batteries using diamond are being developed in Russia and the UK. In South Korea, a p-i-n diode Nickel-63 beta battery is under development.

With research increasing at a fast pace, new students are starting in radiation chemistry, more collaborations are being signed, and the field is becoming more multidisciplinary in nature. This chapter created a guide by summarizing the basic chemistry, concepts, and steps to be consider to achieved the expected results when performing a radioactive reaction. The focus is, through knowledge and practical examples, in achieving high degree of success, protecting the operator, and the environment.

## **Author details**

Carla Daruich de Souza\*, Jin Joo Kim and Jin Tae Hong Korea Atomic Energy Research Institute, Daejeon, South Korea

\*Address all correspondence to: carla@kaeri.re.kr; carladdsouza@yahoo.com.br

© 2021 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
