Changes in pile operating parameters, such as fuel exposure, paver, and reactivity gain upon water loss affect the potential reactivity of the operating, pile and, therefore, the amount of enrichment required to operate under the desired conditions. Similarly a change in ECT (through enrichment location) changes the amount of enrichment.needed to maintain a constant reactivity. Many of the factors which influence the operating reactivity have quite different effects upon the reactivity of the dry pile with the ball 3X system inserted; therefore, changes in operating parameters may cause sizeable changes in requirements for supplementary control to maintain sub-criticality in the dry pile. It is the purpose of this document to summarize these trends in disaster control requirements for the K piles. The trends are presented as graphs of supplementary control requirements against a single varying parameter. All other parameters are held fixed as specified on each graph. The fuel element (central orifice zone) for all examples is the K-2 slug. In general, the slopes of these curves are only slightly dependent upon the specific values assigned the fixed parameters, although the magnitude of the control requirements may be quite dependent on these values. Unless otherwise noted any dependence of the …