Abstract: A sensitive and general method of post-separation detection and quantification of chemical compounds is described. The method involves separation of unlabeled compounds by chromatography, electrophoresis or other means and selective binding of the separated compounds to ligands containing highly neutron-activatable elements, followed by neutron irradiation. The neutron-activatable elements are converted to their radiation-emitting isotopes by neutron absorption, and detection is done by autoradiography, fluorography or other means of radiation detection. The theoretical sensitivity of the method is in the attomole (10.sup.-18 mole) range.

Abstract: Closed-loop control law for altering the power level of nuclear reactors in a safe manner and without overshoot and in minimum time. Apparatus is provided for moving a fast-acting control element such as a control rod or a control drum for altering the nuclear reactor power level. A computer computes at short time intervals either the function:.rho.=(.beta.-.rho.).omega.-.lambda..sub.e '.rho.-.SIGMA..beta..sub.i (.lambda..sub.i -.lambda..sub.e ')+l* .omega.+l* [.omega..sup.2 +.lambda..sub.e '.omega.]or the function:.rho.=(.beta.-.rho.).omega.-.lambda..sub.e .rho.-(.lambda..sub.e /.lambda..sub.e)(.beta.-.rho.)+l* .omega.+l* [.omega..sup.2 +.lambda..sub.e .omega.-(.lambda..sub.e /.lambda..sub.e).omega.]These functions each specify the rate of change of reactivity that is necessary to achieve a specified rate of change of reactor power.

Abstract: Closed-loop controller for altering the power level of nuclear reactors in a safe manner and without overshoot. Apparatus is provided for moving a control element such as a control rod or for adjusting the concentration of a soluble neutron absorber (chemical shim) for altering the nuclear reactor power level. A computer computes at short time intervals the two functions [.rho.-.vertline..rho..vertline./.lambda..sub.e ]/.vertline..rho..vertline. and .tau..sub.i 1n(P.sub.F /P.sub.i). The direction of motion of the control element is altered when these two functions become equal thereby resulting in the attainment of a new power level without overshoot. In a preferred embodiment, these two functions are computed at intervals of approximately one second.