As an effort to improve operating margin, an accurate measurement of neutron flux with delayed and prompt self powered neutron detectors has been studied in this paper.
Cobalt and Rhodium has been used as emitters of prompt and delayed detectors, respectively.
For sensitivity calculation, we perform Monte Carlo simulation by considering such aspects as, neutron capture rate, insulator effect, neutron self shielding factor of the emitter, electron escape probability and emitter burnup. Sensitivities from our Monte Carlo simulation show good agreement with those measured or calculated by others.
It is found that a step change of neutron flux, ramp increase of neutron flux and a sinusoidal neutron flux after a long steady state reactor operation are to be measured accurately by the combination of delayed and prompt self powered neutron detectors.
본 논문에서는 Operating margin 을 증가시키고자 delayed 와 Prompt Self Powered neutron detectors 를 같이 사용하여 neutron flux를 보다 정확하게 측정하는 방법에 대하여 연구하였다. Delayed와 Prompts detectors 의 emitter 로서는 각각 Rh 과 Co 를 사용하였다.
Sensitivity 계산에 있어서 우리는 Monte Carlo simulation 을 하였으며 neutron capture rate, insulator effect, neutron self shielding factor, electron escape probability 와 burnup 등을 고려하였다.
한편 Monte Carlo Simulation 을 사용하여 얻은 결과가 실험치와 잘 일치함을 알 수 있었다.
또한 delayed 와 prompt self powered neutron detectors 같이 사용함으로써 neutron flux 가 step 으로 변할 경우, neutron flux 가 일정하게 증가할 경우 그리고 sinusoidal 하게 변할 경우에 neutron flux 를 정확하게 측정할수 있음을 알게 되었다.