Nuclear power plant closed circulation system backwashing device and backwashing method

Abstract

The invention discloses a nuclear power plant closed circulation system backwashing device, which comprises a first short pipe and a second short pipe; the first short pipe is provided with a filter screen provided with a front end and a rear end, at least a first open hole is arranged at the periphery of the first short pipe, and a water inlet pipe with a flushing valve is installed at the firstopen hole; and the second short pipe is connected with the first short pipe, the second short pipe is provided with a second open hole, and a drain pipe with an isolation valve is arranged at the second open hole. Compared with the prior art, the nuclear power plant closed circulation system backwashing device can connect a backwash water source with pressure to a closed circulation system, flushing water backwashes the filter screen from the rear end of the filter screen to the front end of the filter screen, sediments in the filter screen flow out of the filter screen along with the flushingwater and are discharged through the drain pipe at the front end of the filter screen, and therefore online backwash without disassembling the filter screen can be achieved.

Description

technical field [0001] The invention belongs to the field of nuclear power plant debugging, and more specifically, the invention relates to a backwashing device and a backwashing method for a closed circulation system of a nuclear power plant. Background technique [0002] As a unique system for nuclear power plants, the containment and spent fuel pool medium and long-term waste heat removal system (SEU) belongs to the mitigation measures for beyond-design-basis accidents under the condition of losing the final heat sink. The SEU system does not perform operating functions during the normal operation of the nuclear power unit, does not directly participate in the realization of reactivity control, and does not directly participate in the realization of radioactive material containment. The residual heat of the core and the spent fuel pool is discharged under the condition of small loop loss of water accident (small LOCA), and the waste heat of the spent fuel pool is exported...

AI Technical Summary

Problems solved by technology

[0012] After the filter is cleaned, it is necessary to fill and exhaust the inlet and outlet of the pump, and the operation of filling and exhausting water needs to be repeated many times, so there is a risk of insufficient water filling and exhaust at the inlet and outlet of the pump, resulting in the risk of cavitation damage to the pump

[0013] The most direct results of the above three defects are: increased investment in manpower and material resources for washing work, increased risk of equipment damage and safe operation of the system; the indirect results are the prolongation of the commissioning cycle of nuclear power plants, which ultimately leads to increased construction costs of nuclear power plants

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