Because Numpy and SciPyY are numerical libraries supported by Python rather than IronPython, they cannot be used with ACT.
Help Doc Link
Numerical library that IronPython supports is Math.net. This library is available for use with ACT and is installed in the following directory:
C:\Program Files\ANSYS Inc\v212\Addins\ACT\bin\Win64\MathNet.Numerics.dll
You can add reference to dll and use them like below:
clr.AddReferenceToFileAndPath("C:\Program Files\ANSYS Inc\v212\Addins\ACT\bin\Win64\MathNet.Numerics.dll")
Please refer for examples in the help doc link above
Futher documentation on the .NET Library: https://numerics.mathdotnet.com/