Reneging a part time job when SF312 is already signed before start date

Received a part time DoD contractor security guard job and signed my SF312 with my EOD expected in a few weeks. Have not been badged or formally indoc’ed into SCI yet.

However, as a college student, I’ve received a internship offer to start this spring at a NGA contractor. I’m aware that I am not allowed to take both offers as they conflict with each other with CACs.

If I decide to go with the internship, and renege this security job before my start date, is there any ramifications on my clearance despite already signing the SF312? Originally, I accepted this part time job to keep my clearance active and to be paid but the other internship offer I’ve received is more fulfilling to my educational and professional interests.

Currently hold active TS/SCI

No, the only issue is with the new agency being able to accept reciprocity if the background investigation has already completed and whether it was favorable adjudicated. Notify the losing agency before your EOD to ensure no misinterpretations of why you declined the opportunity.