Abstract: A method for estimating a helium content of the stainless steel core shroud in a boiling water nuclear reactor includes, in an exemplary embodiment, determining a neutron fluence for predetermined areas of the reactor, and estimating a helium content of the stainless steel shroud at predetermined areas of the reactor using the following equation: CHe=1031*(1?e?bj*?j), where CHe is the helium concentration as atomic parts per billion of helium in the stainless steel shroud per weight parts per million of boron in the stainless steel shroud, bj is a value between about 2.50 e?21 and about 5.00 e?21, ?j is fluence expressed as neutrons per square centimeter, and subscript j denotes thermal fluence or fast fluence.