JPS5853800A - Drain system for reactor circulation pump mechanical seal water - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a nuclear reactor recirculation pump for a nuclear power plant, and particularly to a pump using mechanical sol for the shaft seal.

Conventional reactor recirculation pump mechanical seals drain water into an equipment fin/sump inside the containment vessel. The amount of drain generated by this is 10 tons/day, which accounts for 2/3 of the total amount of drain generated as equipment drain inside the containment vessel. In addition, it accounts for 1/4 of the amount of equipment drainage generated at the power plant as a whole (40 tons/day), and it plays a large role in determining the size of waste treatment equipment, so it is a major factor in increasing costs. This is a contributing factor.

The purpose of the present invention is to reduce the waste disposal capacity, pump capacity, etc. of waste treatment equipment, reduce costs, and construct a closed circuit that returns treated water from the reactor system to the reactor system.
The purpose is to reduce excess water discharged outside the system.

During normal operation of a nuclear power plant, there are various kinds of equipment drains that are continuously generated, such as containment vessel equipment drains and reactor building equipment drains, but among these, the containment vessel equipment drains generate the most amount of drain. . Approximately 15 tons/day of containment vessel equipment drainage is generated continuously, and the majority of this is purge drainage from the mechanical seals of the reactor recirculation pumps. By reducing this wastewater to zero, we aim to reduce the load on waste treatment equipment and reduce costs.

Embodiments of the present invention will be described below with reference to FIG.

Water supplied from a pipe 3 branched from the discharge pipe 2 of the control rod drive pump 1 is supplied to the mechanical seal part 5 of the reactor recirculation pump 4, and the water that has passed there is used as purge water and discharged water. It is discharged out of the reactor recirculation pump 4 through a pipe 6.

In the prior art, waste water was discharged to a drain sump as containment vessel equipment drain, but in the present invention, the waste water is returned to the reactor system. In the embodiment shown in FIG. 1, the next discharge water passing through the discharge water pipe 6 is connected to the suction side pipe 7 of the control rod drive pump 1 to form a closed circuit, so that it is sent as a drain to the containment vessel equipment drain sump. The amount of water discharged can be reduced to zero.

According to the present invention, the following effects can be achieved by recovering water for the mechanical seal of the reactor recirculation pump into the reactor system.

(1) The amount of drain flowing into waste treatment equipment can be reduced. This will help reduce the cost of waste treatment equipment capacity.

(2) Since the amount of treated water in the treatment equipment is reduced, the amount of water discharged outside the power plant as surplus water can be reduced.

(3) Since the amount of condensate that normally flows into the containment vessel equipment drain sump is very small, equipment leakage in the drain sump can be easily detected in the event of abnormal equipment leakage.

[Brief explanation of the drawing]

FIG. 1 shows a system diagram of the purge water for the mechanical seal of the recirculation pump.

Claims (1)

[Claims] 1. A reactor recirculation pump mechanical nord water discharge system characterized by returning the discharged water from the reactor recirculation pump mechanical tar to the suction side of the pump that supplies it.