Study of emergency unit alarm performance in RSG-GAS operation hall

The RSG-GAS reactor's operation hall is the main room where there are reactor pools and (temporary) used fuel storage ponds. There are always work activities in this room, both in the state of the reactor in operation or not, these activities include: inserting samples and removing various types of irradiation targets in the reactor pool, target handling activities (removal, packaging or releasing) after irradiation, maintenance and repair activities of reactor components (irradiation facilities, neutron detectors, fuel refueling), radioactive waste treatment and others. To ensure safety of reactor's operation and safety of the radiation workers from receiving excessive exposure, this Operation Hall is equipped with 4 radiation protection system. There are gamma dose rate monitoring equipment (coded UJA07 CR001/002/003/004) and an Emergency Unit Alarm (EAU) that installed near the entrance to the Operation Hall. Since the reactor began operating in 1987 the EAU system has never been tested whether the EAU system is functioning, while the other radiation monitoring systems are periodically six months and one year always tested. This is because the EAU system is not included in the maintenance and repair program contained in the MRM (Maintenance and Repair Manual). This was then BAPETEN's discovery because it could not show evidence that the EAU was still functioning when conducting Inspections. This problem was then carried out with regard to the function and testing of the EAU. The study was carried out by tracing the specification's document, the MRM document and the TOP (Turn Over Package) document. From the results of the study and document searching, it is obtained that the EAU system can function if 2 of the 4 gamma dose rate monitoring systems in the Operation Hall show values ≥ 1,10⁴ mR/hour. Then the test is done by simulation using standard sources with the result that the EAU system can operate and function properly. As a follow up, there will be an annual periodic testing and this test will be added to the maintenance and testing Program (MRM) in the RSG-GAS. (author)