Approximation critical method of pressurized water reactor first furnace reactor core without additional primary neutron source

Abstract

The invention belongs to the field of reactor engineering design and operation, and relates to an approximation critical method for a pressurized water reactor first furnace reactor core without an additional primary neutron source. The method comprises the following steps of: 1, installing a neutron detector monitoring device; 2, confirming the channel neutron counting response performance of a source range detector monitoring device and a high-sensitivity neutron detector monitoring device; 3, carrying out critical safety supervision parameter calculation and alarm function setting on a secondary instrument in an out-of-reactor high-sensitivity neutron detector monitoring device; 4, confirming the effectiveness of the protection function of the source range detector monitoring device; 5,adding a critical safety supervision key parameter monitoring and alarming function to a digital distribution control system of a power station; 6, heating and boosting a reactor; 7, adding a small-flow dilution control conversion point and dilution interval control; 8, isolating and controlling equipment influencing the subcritical degree of the reactor; and 9, guiding the reactor core without the additional primary neutron source to transit from a deep subcritical state to a critical state.

Description

Technical field [0001] The invention belongs to the technical field of reactor engineering design and operation, and specifically relates to a method for approaching criticality without an external primary neutron source in the core of the first furnace of a pressurized water reactor. Background technique [0002] Looking at the world today, the vast majority of pressurized light water reactors that use square fuel assemblies are loaded with low-cost reactor cores when they are newly built. 235 The new fuel assembly with U enrichment degree, so at the beginning of the core life (Beginning Of Life, abbreviation: BOL), cold shutdown (Cold Zero Power, abbreviation: CZP), all rod clusters (All Rod Clusters In, abbreviation: ARI), k when the core is fully loaded when the core is filled with 2300ppm boron-containing coolant eff (I.e. the effective multiplication coefficient of a finite-size reactor) is much lower than 0.85. In order to satisfy the requirement that the reactor core is i...

AI Technical Summary

Problems solved by technology

This puts forward higher requirements for the transportation of primary neutron source, assembly and storage of primary neutron source components, etc., which increases the cost of manpower, material resources, radiation protection, and the risk of personnel exposure;

[0006] 2. During the use of the primary neutron source components in the reactor, there is a phenomenon that the cladding of the primary neutron source rod is damaged, which will lead to an increase in the radioactive level of the reactor coolant system, and increase the exposure dose of the staff and equipment;

[0007] 3. The primary neutron source assembly is only used for the first fuel cycle, and the primary neutron source assembly is no longer used after the reactor core is refueled

[0008] 4. The high cost of purchasing a primary neutron source increases the construction cost of nuclear power projects

If an external neutron detector with the same performance as the active core (i.e. the source-range detector of the external nuclear measurement system) is used, the external neutron detector will not be able to obtain effective neutron count rate signal, resulting in the "blind zone" of neutron fluence rate monitoring

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