CN104332207A - Method for automatically stopping coolant pump under reactor coolant loss accident condition - Google Patents

Abstract

The invention belongs to a coping method for pressurized water reactor nuclear power station accidents and especially relates to a method for automatically stopping a coolant pump under the reactor coolant loss accident condition. The method comprises the following steps: the step 1) triggering a safe injection signal and a reactor coolant pump inlet and outlet pressure difference low logic; and the step 2) when the safe injection signal coexists with the condition of reactor coolant pump inlet and outlet low pressure difference, triggering the reactor coolant pump to stop operation. The method has the advantages that the method can realize automatic shutdown of the reactor coolant pump before reactor core deterioration under the LOCA condition, and the time when operators do not need to intervene the accident is prolonged greatly.

Description

A kind of reactor coolant is automatic stoppage in transit cooling medium pump method under losing accident conditions

Technical field

The invention belongs to a kind of pressurized-water reactor nuclear power plant accident countermeasure, be specifically related to a kind of reactor coolant and lose under accident conditions stoppage in transit cooling medium pump method automatically.

Background technology

The crash analysis result of existing nuclear power station shows, when reacting reactor coolant forfeiture accident (LOCA), primary Ioops reactor coolant is run off fast by cut, primary Ioops pressure and water loading amount reduce, trigger reactor emergency shut-down by voltage stabilizer pressure low signal, the low low signal of voltage stabilizer pressure triggers peace note and drops into.Along with the continuous loss of primary Ioops water loading amount, reactor core is exposed gradually, and the reactor coolant pump that needs to stop transport as early as possible is damaged to prevent reactor core worsening condition from causing fuel can temperature too high.

Domestic active service nuclear power station does not arrange the automatic stoppage in transit reactor coolant pump signal for LOCA operating mode, so just need operator judgement there occurs LOCA after as early as possible manually stoppage in transit reactor coolant pump worsen to prevent reactor core.Because the time interval occurring to reactor coolant pump of must stopping transport from LOCA is shorter, therefore just higher to the requirement of operator, easily there is maloperation.

By arranging reasonably stoppage in transit reactor coolant pump signal automatically, when not having an impact to other accidents, automatically stop transport when LOCA operating mode reactor coolant pump, greatly can extend operator can time of this accident of nonintervention, reduces the error of operator.

Summary of the invention

The object of this invention is to provide a kind of reactor coolant and to lose under accident conditions stoppage in transit cooling medium pump method automatically, it automatically can to stop transport reactor coolant pump before reactor core worsens, thus avoid reactor core to occur worsening, extending operator can time of this accident of nonintervention, reduces the error of operator.

The present invention is achieved in that stoppage in transit cooling medium pump method automatically to be lost under accident conditions by a kind of reactor coolant, and it comprises the steps,

The first step: the triggering of peace note signal and the low logic of reactor coolant pump inlet outlet pressure differential

After LOCA occurs, reactor coolant loop pressure declines rapidly, reactor peace note signal is triggered when pressure drop setting valve low to voltage stabilizer pressure, on the other hand due to cut continue spurt, cause reactor coolant pump pressure reduction to reduce, automatically trigger the low logic of reactor coolant pump pressure reduction when reactor coolant pump inlet outlet pressure differential is reduced to " reactor coolant pump inlet outlet pressure differential is low " setting valve;

Second step: peace note signal and reactor coolant pump inlet outlet pressure differential low meeting trigger reactor coolant pump and stop transport

Exist once peace notes signal and reactor coolant pump inlet outlet pressure differential is low simultaneously, then trigger reactor coolant pump of automatically stopping transport.

Advantage of the present invention is, it can achieve reactor coolant pump of automatically stopping transport before reactor core worsens under LOCA operating mode, and substantially prolongs operator can time of this accident of nonintervention.

Accompanying drawing explanation

Fig. 1 is automatic stoppage in transit cooling medium pump method flow diagram under accident conditions lost by a kind of reactor coolant.

Embodiment

Below in conjunction with drawings and Examples, the present invention is described in detail:

When LOCA occurs PWR nuclear power plant (station), trigger by arranging " safety injection signal and reactor coolant pump inlet outlet pressure differential is low meet " signal reactor coolant pump of automatically stopping transport.This signal automatically will be stopped transport reactor coolant pump before reactor core worsens, afterwards along with the reduction of cut flow, peace beam amount can compensate gradually and exceed cut flow, reactor core water level gos up gradually, finally flood reactor core completely, operator brings reactor into corresponding treatment state according to accident treatment code.

Under LOCA operating mode automatic stoppage in transit reactor coolant pump scheme in the relevant device that relates to comprise steering logic and operator's interface.

The newly-increased steering logic realizing stoppage in transit reactor coolant pump automatically under LOCA operating mode is " safety injection signal and reactor coolant pump inlet outlet pressure differential is low meet " signal.

Operator's interface is to provide instruction and the reseting interface of operator's " safety injection signal and reactor coolant pump inlet outlet pressure differential is low meet " signal.

A kind of reactor coolant is automatic stoppage in transit cooling medium pump method under losing accident conditions, and carrying out practically flow process is as follows:

The first step: the triggering of peace note signal and the low logic of reactor coolant pump inlet outlet pressure differential

After LOCA occurs, reactor coolant loop pressure declines rapidly, triggers reactor peace note signal when pressure drop setting valve low to voltage stabilizer pressure.

On the other hand due to cut continue spurt, cause reactor coolant pump pressure reduction to reduce, automatically trigger the low logic of reactor coolant pump pressure reduction when reactor coolant pump inlet outlet pressure differential is reduced to " reactor coolant pump inlet outlet pressure differential is low " setting valve.

Second step: peace note signal and reactor coolant pump inlet outlet pressure differential low meeting trigger reactor coolant pump and stop transport

Exist once peace notes signal and reactor coolant pump inlet outlet pressure differential is low simultaneously, then trigger reactor coolant pump of automatically stopping transport.

After operator, bring reactor into corresponding treatment state according to corresponding accident treatment code.

Claims (1)

1. an automatic stoppage in transit cooling medium pump method under reactor coolant forfeiture accident conditions, is characterized in that: it comprises the steps,

The first step: the triggering of peace note signal and the low logic of reactor coolant pump inlet outlet pressure differential

After LOCA occurs, reactor coolant loop pressure declines rapidly, reactor peace note signal is triggered when pressure drop setting valve low to voltage stabilizer pressure, on the other hand due to cut continue spurt, cause reactor coolant pump pressure reduction to reduce, automatically trigger the low logic of reactor coolant pump pressure reduction when reactor coolant pump inlet outlet pressure differential is reduced to " reactor coolant pump inlet outlet pressure differential is low " setting valve;

Second step: peace note signal and reactor coolant pump inlet outlet pressure differential low meeting trigger reactor coolant pump and stop transport

Exist once peace notes signal and reactor coolant pump inlet outlet pressure differential is low simultaneously, then trigger reactor coolant pump of automatically stopping transport.