Oh they definitely have their own to process, it’s not about that. It’s about false flags. Having other nation’s nuclear material to use on their enemies gives a nuclear signature that ain’t Israeli, so they can maintain plausible deniability after they nuke any nation that pisses them off. We don’t have samples of Israel’s nuclear material so it wouldn’t be easy to say for sure a nuke from their material came from Israel, but if it didn’t match up to any known samples we have, it definitely wouldn’t look good for Israel since there aren’t many governments who have the resources to build nukes