Real-time reactor coolant system boron concentration monitor utilizing an ultrasonic spectroscpopy system

Abstract

A method and a system for performing real-time, continuous, measurements of the boron concentration in the water entering a nuclear reactor coolant system. The invention utilizes knowledge of the impact that boron contained in liquid water has on the attenuation of acoustic or ultrasonic waves. This information, coupled with radiation damage resistant and high temperature operability capable transmitter and receiver equipment, provides the means to place the measurement system sensors and signal processing electronics on the reactor coolant system charging flow piping or the hot leg or cold leg of the reactor coolant loop. This will allow the reactor operator to directly monitor both the reactor coolant system boron concentration value and detect changes in the reactor coolant system boron concentration relative to a reference value as they occur.

What is claimed is: 
     
         1 . A boron concentration monitor for measuring, in real time, the boron concentration of coolant within a piping servicing a primary loop of a nuclear reactor comprising:
 an acoustic transmitter acoustically coupled to or through the piping operable to transmit an acoustic signal substantially through an interior of the piping;   an acoustic receiver supported at a location around a circumference of the piping that is spaced from the acoustic transmitter, for receiving the acoustic signal;   a communication mechanism in electrical communication with the acoustic transmitter and the acoustic receiver and configured to convey the transmitted acoustic signal and the received acoustic signal to a remote location; and   an analyzer is structured to be in communication with the remote location and is configured to receive the received acoustic signal and the transmitted acoustic signal from the communication mechanism and compare the received acoustic signal and the transmitted acoustic signal and from the comparison determine the boron concentration within the piping.   
     
     
         2 . The boron concentration monitor of  claim 1  wherein the analyzer compares the signal comparison to a standard to determine the boron concentration in the piping. 
     
     
         3 . The boron concentration monitor of  claim 2  wherein the acoustic transmitter and acoustic receiver are at a known linear distance from each other and the standard is established from an experimental determination of the attenuation of an acoustic signal in a borated water solution over the known distance at a plurality of known boron concentrations. 
     
     
         4 . The boron concentration monitor of  claim 1  wherein the communication mechanism comprises:
 a wireless transmitter coupled to the acoustic transmitter and the acoustic receiver and configured to wirelessly transmit both the transmitted acoustic signal and the received acoustic signal to the remote location; and 
 a wireless receiver configured to receive the wirelessly transmitted acoustic signal and received acoustic signal and communicate the transmitted acoustic signal and the received acoustic signal to the analyzer at the remote location. 
 
     
     
         5 . The boron concentration monitor of  claim 4  wherein the acoustic transmitter, the acoustic receiver and the wireless transmitter are powered from a thermoelectric generator having a hot junction in thermal communication with the piping and a cold junction in thermal communication with a surrounding environment. 
     
     
         6 . The boron concentration monitor of  claim 5  wherein the hot junction is in thermal communication with the piping through a heat pipe. 
     
     
         7 . The boron concentration monitor of  claim 4  wherein the wireless transmitter comprises two separate wireless transmitters respectively connected to the acoustic transmitter and the acoustic receiver. 
     
     
         8 . The boron concentration monitor of  claim 1  wherein the acoustic transmitter and the acoustic receiver are supported at substantially diametrically opposite positions around the circumference of the piping. 
     
     
         9 . The boron concentration monitor of  claim 1  wherein the acoustic transmitter and the acoustic receiver employ one or more vacuum micro-electronic devices. 
     
     
         10 . The boron concentration monitor of  claim 9  wherein the solid state vacuum device is a vacuum micro-electronic device. 
     
     
         11 . The boron concentration monitor of  claim 4  wherein the wireless transmitter employs one or more vacuum micro-electronic devices. 
     
     
         12 . The boron concentration monitor of  claim 11  wherein the solid state vacuum device is a vacuum micro-electronic device. 
     
     
         13 . The boron concentration monitor of  claim 1  wherein the acoustic receiver is an ultrasonic energy measurement sensor. 
     
     
         14 . The boron concentration monitor of  claim 1  wherein the piping is a charging line in fluid communication with the primary loop. 
     
     
         15 . The boron concentration monitor of  claim 1  wherein the piping is a hot leg or a cold leg of the primary loop of the nuclear reactor. 
     
     
         16 . The boron concentration monitor of  claim 1  including a temperature sensor for determining a temperature of water flowing in the piping at the location of the acoustic transmitter and acoustic receiver and transmitting a signal representative of the temperature through the communication mechanism to the analyzer which determines the boron concentration as a function of temperature. 
     
     
         17 . The boron concentration monitor of  claim 14  including a pressure sensor for determining a pressure of the water flowing in the piping at the location of the acoustic transmitter and acoustic receiver and transmitting a signal representative of the pressure through the communication mechanism to the analyzer which determines the boron concentration as a function of temperature and pressure. 
     
     
         18 . A method of monitoring a boron concentration of a borated water solution in real-time, comprising the steps of:
 transmitting an acoustic signal through the borated water solution;   receiving the transmitted acoustic signal after the transmitted acoustic signal has passed through at least a portion of the borated water solution, at a known distance between a transmitter structured to transmit the acoustic signal and a receiver configured to receive the transmitted acoustic signal;   comparing the received acoustic signal to the transmitted acoustic signal to determine an attenuation of the transmitted acoustic signal through the borated water solution; and   determining the boron concentration from the attenuation of the transmitted signal.   
     
     
         19 . The method of  claim 18  wherein the determining step compares the attenuation with a standard obtained by chemically analyzing a plurality of different concentrations of boron in borated water solutions and measuring the attenuation over the known distance in each of the plurality of different concentrations of boron. 
     
     
         20 . The method of  claim 18  wherein the determining step comprises:
 obtaining the pressure and temperature of the coolant at a time of transmission of the acoustic signal; and 
 using the attenuation, the temperature and the pressure to mathematically determine the boron concentration in real-time.