On June 2, 2018, EOS transitioned from the Ethereum network to the EOS MainNet chain. Kraken fully managed the token swap involved in this transition. All clients with EOS balances in their Kraken accounts did not need to move these tokens nor do anything else in order to have their EOS converted from the Ethereum network to the EOS MainNet.
All Kraken EOS funds are now available for sending and receiving on the EOS MainNet chain.