No abstract available

No abstract available

No abstract available

[en] The analysis of power fluctuation in HWRR-3 is presented. Autopower spectrum densities (APSD) of power signals are analysed for various coolant flow at same power and for various power at same coolant flow rate. The experimental results show that following behaviors: 1. In the case of low power (12 kW) and high flow rate (450 m³h^-1), there are two dominant peaks on the APSD at 0.5 Hz and 2.3 Hz respectively; 2. In the case of power greater than 1000 kW and coolant flow greater than 420 m³h^-1, there are three dominant peaks on the APSD. The frequencys os two dominant peaks of them at 0.5 Hz and 2.3 Hz are hardly changed with coolant flow, but for the third dominant peak, the frquency is changed from 5.5 Hz to 6.7 Hz with coolant flow rates varied from 420 m³h^-1 to 576 m³h^-1; 3. The fluctuation of reactor power is significantly depressed when flow rate is less than 450 m³h^-1, it is hardly changed when flow rate are between 450-540 m³h^-1, but it is increased rapidly when flow rate is greater than 539 m³h^-1

[en] In the heavy water zero power reactor, the neutron temperature and epithermal index under different lattice arrangements and fine distribution of both parameters under one of those arrangements are measured with method of 'pair foils' of ¹⁷⁶Lu-¹⁶⁴Dy and ¹¹⁵In-⁵⁵Mn. The experimental results are compared with the results obtained with 'cadmium radio method'. The agreement between them is satisfactory. The thermal column of swimming pool reactor is used as thermal neutron standard field

[en] The paper gives a description of a noise diagnosis of sodium-water reaction, including the principle, the measurement method and the experimental result. The experiment is made on a sodium-water reaction facility. The amplitude spectrum of Na/H₂O reaction is abstained by frequency spectrum analysis. The result shows that the amplitude of APSD is much higher than that of the background noise

[en] The progress of the research work on sodium boiling noise detection is described. High frequency and low frequency noise signal analysis system with on-line or off-line signal acquisition and processing were set up. The signal processing, accident alarming, failure diagnosis and autoregression model analysis computer soft wares were founded. With these hardware and software, the noise signals of sodium and water boiling were detected and analysed. The results show that the amplitude of APSD of noise signals in boiling status was obviously larger than that in no boiling status. Using distinguishing factor of autoregression model analysis, the on-line and real-time boiling diagnosis and surveillance can be realized

[en] The prompt neutron decay constants measured for Solid Zero Power Reactor by inherent pulsed neutron source method are introduced. Reactor sub-criticality for different assemblies are obtained with prompt neutron decay constants, and some parameters in the measurement are given