expired industrial gamma projectors and its impact on the safety and performance

Gamma-ray industrial radiography is performed with the help of a gamma projector, and a gamma projector is a device in which a radionuclide source produced according to the standard (ISO 2919) is placed inside a shield (often depleted of uranium) and equipped with equipment and Appropriate accessories, while keeping the safe during industrial radiography work, provide the possibility of transferring the source to the radiation point, by remotely. There are two categories of direct crossing channels and S-shaped channels. In direct channel , it is possible for the holder containing the source to come out of the gamma projector due to defects in the gamma projector, such as a broken gamma projector lock, which can lead to accidents during transport and radiography operations.Due to the portable use of this type of gamma projectors , this type of gamma projectors are mainly used as a B (U) transport package and the terms and conditions related to this type of indoor radioactive package are mandatory for them.
The reasons for expiring this type of gamma projectors are as follows:
1. Non-compliance of gamma projectors with direct radiation source channel with the latest requirements of ISO-3999 standard
2. expiring the design certificate of B (U) type packages of this type of gamma projectors
Based on the decision of the regulatory body on 07/11/1394, it was decided that from the mentioned date, purchase, sale, transfer and international transportation of all gamma projectors:
A- Gammamat projectors TI, TIF, TIFF, S models
B- Tech-ops 660 and Gammarid 
C- Gammavolt SU-50, SU-100
Banned and companies with TI, TIF, TIFF, S gamma projector models for 2 years and companies with gamma projector SU-50, SU-100 and Tech-ops 660 and Gamarid for 3 years are allowed to use In industrial radiography operations and then they have to drop the mentioned gamma projectors.
According to the statistics of accidents in the country's radiography activity, which were mostly related to gamma projectors with direct radiation passage channel, the expiring of this type of non-standard projectors resulted in a decrease in accidents in radiography activities, especially accidents related to radiography equipment errors.
Also, the evaluations made regarding the ratio of the number of loaded projectors that are used in the country to the total number of projectors in the country before the implementation of the decree and its comparison with the same ratio after the implementation of the decree, show that expiring this number of projectors has not led to a shortage of projectors in use in the country and also this issue has not caused a disruption in the amount of radiography work of related companies in the country.