1 4 The SL-1 reactor was a direct-cycle, boiling water reactor of 3 megawatts gross thermal power using fuel highly enriched in U-235, clad in aluminum, and moderated/cooled by water. On January 3, 1961 it underwent a power excursion that was estimated to have reached a peak power level of 2 x 10 megawatts. The initial asymptotic period (before feedback effects) was estimated to be 4 msec. Use the Inhour equation to determine what step reactivity in dollars would be required to cause a transient with this initial period. Use = 4 x10 seconds and -bar for U-235 = 0.007. Choose the closest value to your result. P= * -5 (a) 0.017 (b) 2.43 (c) 154 (d) 5,000 Taj (Optional & plot Donus question) Knowing the normal power and the peak power achieved in the excursion and knowing the initial asymptotic period (before feedback effects), calculate the approximate time it took for this power excursion to occur. Ref. is Lecture 7 slides and textbook readings.