pressure, is allowed to change. Finally, the response of the steam generators to steam valve perturbation is compared for the SIR and the H. Robinson reactors.
98/00363
Feynman-a correlation analysis by prompt-photon detection Hashimoto, K. ef al. Alan. Nitcl. Energy, 1998, 25, (l-3) 13-22. Using the UTR-KINK1 reactor, two-detector Feynman-ru measurements were carried out by detecting high-energy, prompt gamma rays. The reactor is a light-water-moderated and graphite-reflected reactor. The conventional measurements were also performed by detecting neutrons. These measurements were carried out in the subcriticality range from 0 to $1.8. The gatetime dependence of the variance-and covariance-to-mean ratios measured by gamma-ray detection were nearly identical with those obtained using standard neutron-detection techniques. Agreement was found between the prompt-neutron decay constants inferred from the gamma-ray correlation data and those from the neutron data. Furthermore, the correlated-touncorrelated amplitude ratios obtained by gamma-ray detection was dependent on the low-energy discriminator level of the single-channel analyser. The discriminator level was determined as optimum for obtaining a maximum value of the amplitude ratio. The maximum amplitude ratio was much larger than that obtained by neutron detection. The subcriticality dependence of the decay constant obtained by gamma-ray detection was consistent with that obtained by neutron detection and followed the linear relation based on the one-point kinetic model in the vicinity of delayed critical. This gamma-ray correlation technique can be applied to measure reactor kinetic parameters more efficiently.