iPhoto won't open

I am currently running iPhoto ver 9.1 however when I updated my system to Mavericks I cannot open iPhoto (it has a grey circle over the icon)

The App store won't update iPhoto successfully - says there is a problem updating.

I think I need to buy iPhoto again but the app store is only allowing an update because I have the application on this computer.

If I need to delete iPhoto is there a way to secure the photos in it?

Thanks in advance😕