| Popis: |
The neutron and photon flux rates are important parameters for safe reactor operation, refueling and decommissioning, scientific applications and radiation protection. For the Integrated small pressurized water reactor, the advanced reactor core analysis code CORAL, the source calculation code ORIGEN-II and the Monte Carlo code SuperMC are used to establish the reactor flux rate calculation model under normal operation and shutdown refueling condition. The results show that (1) In the normal operation of the reactor, the neutron flux rate is attenuated by 10 orders of magnitude from the outermost component to the inner surface of the pressure vessel, and the shielding effect of the coolant on neutrons is more significant. The neutron flux of the inner surface of the pressure vessel in 40 years is 3.723 × 1014 ncm2; the neutron flux in 60 years is 5.585 × 1014 ncm2. The photon flux rate is reduced by 10 orders of magnitude from the periphery of the core to the outer surface of the pressure vessel. High-quality density materials have better photon shielding effects. (2) In the case of reactor shutdown and refueling, the neutron flux rate is much smaller than the photon flux rate. On the outer surface of the pressure vessel, the maximum neutron and photon dose rates are 7.74 × 10−10 mSv · h−1 and 6.97 × 10−5 mSv · h−1, respectively, which belong to the supervision area. When the cover is opened, the radiation dose value of the workplace at the top of the reactor is less than 0.0025 mSv · h−1, which can ensure the radiation safety of the operation. |
