Angra Unit 1 low power physics tests - rod woth measurements

The Angra Nuclear Power Plant, a Westinghouse PWR, had its first criticality in 1982 and currently has reached ten cycles of operation. During such period, an extensive experience in core design and physics tests was accumulated. This paper evaluates the results of one low power physics test, which verifies that shutdown margin is assured in all expected operating condition. The shutdown margin, among other parameters, is verified by measurement of the reactivity inserted by the control banks. This parameter can be checked by several measurement methods. This paper proposes the use of boron difference to measure the rod worth as equivalent to the measurements made directly by the reactivity computer. (author)