Solutions and Radioactive Shipments

Critical Interaction Potentials of Water-Moderated UFe Arrays, C. E. Newlon (UCNC) 

The critical spaclngs of individually subcritical units in large arrays may be computed by use of an interaction potential method which lsl)ased on the solid angle of neutron interaction. The method has been written in a Fortran code for two- or three-dimensional arrays for use with the IBM-7090. 

When two or more identical subcrits are considered as an Meracting array, their nuclear reactivity may be expressed as an interaction potential Im, 

At criticality, the Interaction potential of the subcrits Iin must equal the neutron leakage probability Ig of u n-unit array, which is given as  

TABLE I. Nuclearly Safe Units For UF Systems (Optimum water moderation and reflection .  

---