Kraken Wallet allows only one Secret Recovery Phrase (SRP) at this time. For a single SRP, you can create as many wallets (also known as "accounts") as you like. This article will explain what this means in further detail.
As a reminder, a Secret Recovery Phrase (also known as Seed Phrase) is the series of 12-24 words that represent the private keys to your wallet. Your Secret Recovery Phrase is like a master key that provides full access to your wallet(s), which is why it’s critical that you store it somewhere safe.