Patent Number: 039322114
Section: claims

1. A method of on line monitoring the normal power operation of a nuclear reactor using a movable in-core neutron detector comprising the steps of: automatically inserting and withdrawing the detector respectively into and out of the reactor core region, during normal power operation, at predetermined, staggered, intermittent, time, programmed, sequence intervals;  moving the detector, upon insertion, through the core region along a fixed predetermined path; and  recording the output of the detector as a function of core location. 2. A method of claim 1 including the step of storing the detector within the reactor thermal environment outside the reactive core region in a prearranged storage location prior to insertion into the core and wherein the fixed predetermined path of movement of the detector terminates at the storage location. 3. The method of claim 1 wherein a plurality of movable in-core detectors are employed to monitor the normal power operation of the nuclear core and wherein said moving steps moves the detectors along separate corresponding predetermined paths through the core. 4. The method of claim 3 wherein the detectors are arranged in groups and wherein the groups of detectors are alternately inserted into the core region of the reactor according to the predetermined time program. 5. The method of claim 4 wherein four-in-core detectors are employed to monitor the reactor, arranged in groups of two detectors each. 6. The method of claim 1 including the step of periodicaly repeating the predetermined time sequence. 7. The method of claim 6 wherein the predetermined sequence is repeated every eight hours. 8. The method of claim 1 wherein the reactivity of the core is alterable by control means, including the step of reinitiating the time sequence automatically upon a given change in reactivity of the core caused by the control means. 9. The method of claim 8 wherein the control means comprises control rods and the time sequence is reinitiated upon a given movement of the control rods within the core. 10. The method of claim 1 including the step of automatically calculating the peak to average value of the neutron flux as indicated by the detector output. 11. The method of claim 1 wherein the fixed predetermined path of the detector is linear.