The IRS "Where's My Refund" tool does not use the term"accepted." Accepted is an efile term. It's only used to indicate the status of the efile; i.e., it means that the submitted efile was sent in the correct format such that processing could begin. The IRS tool will likely initially say it was "received" and/or "processing." Once processing is finished, the IRS will show if the refund is "approved" or not. And if approved, it will finally indicate "sent" and may show an expected deposit date.
Most Federal refunds are issued within 21 days if efiled and direct deposit is chosen. There are a number of things that can cause delays in processing. Keep watching the IRS WMR tool occasionally for any messages.
https://www.irs.gov/wheres-my-refund