Використання лічильника Гейгера-Мюллера для визначення аварійного парогенератора під час міжконтурної течі в реакторних установках типу ВВЕР-1000

• Дата: 2020
• Автори: Fylonych, Yu., Zaporozhan, V., Balashevskyi, O., Gerlyga, V., Tarasov, V.
• Формат: Стаття
• Мова: Ukrainian
• Опубліковано: State Scientific and Technical Center for Nuclear and Radiation Safety 2020
• Онлайн доступ: https://nuclear-journal.com/index.php/journal/article/view/679
• Назва журналу: Nuclear and Radiation Safety

The main indicator of a primary-to-secondary leakage in WWER-1000 is the increased secondary side activity. Activity can be detected by radiation devices. Accordingly, the online monitoring of the secondary side activity allows the reactor operator to successfully determine the affected steam generator and implement appropriate actions to transfer the reactor in a safe state. The detectors are supposed to be installed behind the steam generator pipelines outside of the containment. The scattered photon spectrum, formed from N-16 decay in the detection area, is analyzed. The possibility of using a detection unit with a Geiger-Muller counter to register particles with energies that exceed the device energy range, which is indicated in the technical specifications, is confirmed. The paper indicates that the detector response is determined by two different approaches. In the first case, the absorbed dose rate is calculated by the energy deposition method (KERMA factor), and in the second case, the detector count rate is calculated by taking into account the secondary ionization processes. The calculation results of the detector response taking into account the dead time are presented. The dead time effect on the absorbed dose rate registered by the counter is analyzed. The calculated response coefficients of the detector for the main reference radionuclides of the primary side, which could be potentially transported into the detector’s registration volume, is obtained. Additionally, the paper provides for the maximum limit of the detected absorbed dose rate of BDMG-04-02B. The calculations were carried out using MCNP6 neutronic code focused on the analysis of the elementary particle interaction with surrounding materials.