GB1352126A - Monitoring systems - Google Patents

Abstract

1352126 Controlling reactors UNITED KINGDOM ATOMIC ENERGY AUTHORITY 28 July 1971 [28 July 1970] 36584/70 Heading G6C A monitoring system, e.g. a BCD system for a nuclear reactor, particularly a fast neutron reactor cooled by liquid sodium, operates to feed quantities to be monitored, such as samples of coolant discharging from fuel element channels, to manifolds which group the quantities into overlapping fractions, and embodies means for monitoring the group quantities and means for identifying abnormal quantities by analysis of the output from the monitoring means. As an example, the 16-sample BCD system shown provides manifolds 12-A1, 12-A2 &c. into each of which eight sample outlets flow. In all there are sixteen outlets 11-1, 11-2 &c. from the reactor 10. Each manifold has an associated monitor 13-A1, 13-A2 &c. which exhaust with a ring manifold 14; electrical outputs 15-A1, 15-A2 &c. from the monitors are fed to a computer which derives a vector dimension from each monitor output pair 15- A1 and 15-A2, 15-B1 and 15-B2 &c. The four vectors are then added vectorially and the resultant analysed in respect of its magnitude and direction in a 4-dimensional solid angle. If a certain magnitude is exceeded and the resultant lies in a specified angle, an alarm is caused to operate and reactor shut down initiated. In order to reduce the probability of error arising from the reliance upon overlapping signals, it is possible to incorporate a switching system which temporarily "cencentrates" the analysis in a group of outlets showing an alarm condition, at the expense of "diluting" the analysis of the remaining outlets. Although the disclosure is concerned mainly with "halved" overlapping fractions, suitable modifications are indicated which will allow the use of overlapping quarters. The monitoring system also may be used in aircraft location from fixed aerials, or in conjunction with a power station.