Nuclear instrumentation system neutron detectors

Nuclear instrumentation system neutron detectors and ranges of operation. 

The ex-vessel neutron detection equipment consists of fission chamber neutron detectors mounted in six equally spaced vertical wells located just outside the reactor vessel as illustrated in Figure 4.3-4. The signals from these detectors are supplied to the nuclear instrumentation cabinet and Safety Protection Subsystem equipment located primarily in the reactor building. These data are used by the automatic control systems to operate the control rod drives or the reserve shutdown equipment, thereby changing the neutron flux levels within the reactor core. 

The experiments were conducted using trace elements solution containing different concentrations. Each treatment was replicated three times. The rhizome and frond were analyzed for inorganic arsenic. Total arsenic contents in soil and plant were determined by instrumental neutron activation analyses (INAA), Nuclear Reactor lEA-Rlm. The sample irradiation was carried out at the nuclear reactor for 8 h and under thermal neutron flux of 2.7 X 10 ncm s subsequently, a decay time of 3 days and 3 h counting time were employed. The radionuclide activities were measured using a gamma-ray spectrometer comprising a hyper-pure GE detector and associated electronic system. The spectra of the samples were measured under the same experimental conditions of the standard photopeak of 657 keV of As. The amount of anion absorbed was calculated as the difference between the anion concentration before and after reaction with the sod-plant systems. 

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