Generator Reactance Values....

in per unit or in % most of these values are nearly same for any generator of given type, like cylindrical rotor, salient pole, diesel generator, etc.

usually the manufacturer will provide the details in technical data sheets.

The appendix in the text book indicated in the following link has significant number of data.

http://as.wiley.com/WileyCDA/WileyTitle/productCd-0471238627.html

Power System Control and Stability, 2nd Edition Paul M. Anderson, A. A. Fouad ISBN: 978-0-471-23862-1 Hardcover 672 pages October 2002, Wiley-IEEE Press There are also open circuit time constants, which is normally used for conservative estimates in calculations. For Hydro generators some of the Q-axis values will not exist.[salient pole alternator]