I cannot understand your question.  A power of attorney expires upon the death of the principal.  Therefore, your POA cannot be used.  If you are listed as the beneficiary on his pension, the company will distribute his pension benefits to you without using the POA.  If you are not listed as the beneficiary, the pension benefits will be distributed to the person listed.  If your boyfriend did not name a beneficiary, an estate will be needed.  If he had a will, the beneficiaries will be named in the will.  If he did not have a will, your state's statutes will say who receives his estate.