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No, it is not because you have over 60k photos. In fact your iPhoto can hold more than that without any issues. This usually happens if there is any issue with the iPhoto Library, like corruption of library or other glitches. We can rebuild your iPhoto library.
Close iPhoto if it is open. Hold down the Command and Option keys on the keyboard and open iPhoto. Keep the keys held down until you are prompted to rebuild the library. A dialog will appear with rebuild options. Select all the options/checkboxes Click Rebuild. This may take a while to complete.
After rebuilding, iPhoto will open.
If it is still crashing after rebuilding, then we have to rebuild the iPhoto library using a third party application named iPhoto Library Manager. Download and install it from here (use the trial version) : http://www.fatcatsoftware.com/iplm/
Open iPhoto Library Manager. Select your iPhoto Library, click on Library menu in the top and select Rebuild Library. This will verify the library. Then click the Rebuild button on the right.
After rebuilding, open iPhoto. Does it crash now ?
Please let me know if that didn't work, so we can continue troubleshooting.