If no beneficiary is named on the life insurance policy does it go to life partner or adult children?

A "life partner" has no legal rights under the law unless there is a registered civil union or legal marriage in those states that allow same. That is why it is so important for "life partners" to do estte planning and have wills drafted by a professional. In this case the children would be heirs-at-law unless the decedent had a will that named the life partner as the beneficiary.