A realization method for on-line protection and monitoring of reactor lpd and dnbr

Abstract

The invention discloses a realization method for on-line protection and monitoring of reactor LPD and DNBR, comprising: collecting the measured current of self-powered detector SPND and various measured operating parameters of the main coolant system of the reactor; the collected data are respectively Transmission to the upper-level computing unit and the lower-level computing unit; the upper-level computing unit and the lower-level computing unit perform LPD online calculation and DNBR online calculation; the calculation accuracy of the upper-level computing unit is higher than that of the lower-level computing unit; LDP and DNBR calculation based on the lower-level computing unit As a result, LPD and DNBR protection input signals are provided to the reactor protection system to realize LPD and DNBR protection functions; based on the calculation results of LDP and DNBR of the upper calculation unit, the monitoring of the operating status of the reactor is realized. The method realizes on-line monitoring of the distribution of LPD and DNBR in each axial section of each fuel assembly in the core, and provides LPD and DNBR protection input signals to the reactor protection system, thereby improving the safety and economy of nuclear power plant operation.

Description

technical field [0001] The invention relates to the field of nuclear safety, in particular to an implementation method for on-line protection and monitoring of reactor LPD and DNBR. Background technique [0002] When the pressurized water reactor is in operation, the core is required to work in the mode of nucleate boiling heat transfer, and the heat transfer efficiency is the highest at this time. However, when some transient state causes the local heat flux density in the stack to increase to a certain extent, the bubbles generated on the cladding wall will be connected together before leaving the wall to form a vapor film, which will increase the thermal resistance and reduce the heat transfer coefficient. , causing the cladding temperature to rise sharply, and finally lead to the fuel temperature being too high to melt down. This situation is Deviated Nucleate Boiling (DNB). In order to ensure the safety of the reactor, the maximum heat flux on the surface of the fuel e...

AI Technical Summary

Problems solved by technology

This method can reduce the error of the channel, but it has complex dynamic compensation, and it is necessary to convert the DNB safety limit function into the shutdown setting value of the protection system, and the process is relatively cumbersome.

At the same time, the online monitoring of neutron flux density parameters in the core is only completed by the nuclear instrumentation system outside the reactor, which cannot meet the requirements of reactor protection in terms of calculation accuracy and response time.

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