Thank you for the question, and I definitely understand your concern. The iPhoto application and your iPhoto Library are stored in two different locations, so even if you cannot open iPhoto, your photos are still in their original location.
The version of iPhoto you are currently running is not compatible with Mavericks, but you can upgrade iPhoto to the latest version to access your photos. Follow the steps in the article below to upgrade the iPhoto application:
Once you update iPhoto, you should be able to access your iPhoto Library, but it is always a good idea to have a backup of your photos:
Thank you for using Apple Support Communities.
If you can't get iPhoto open, it's not that you lost all of your photos. The photos are stored in a seperate location on your drive from the iPhoto program itself. Your photos are all still on your computer, you just have to locate where they are on your computer. What happens when you click on iPhoto and try to get it open? Does it do anything?