the proposed exploration, and in no case for more than 10 years. (e) Permit modification During the term of an exploration permit the permit holder may submit an application to modify the permit. To approve a proposed modification to the permit, the Secretary concerned shall make the same determinations as are required in the case of an original permit, except that the Secretary and the Secretary of Agriculture may specify by joint rule the extent to which requirements for initial exploration permits under this section shall apply to applications to modify an exploration permit based on whether such modifications are deemed significant or minor. (f) Transfer, assignment, or sale of rights (1) No transfer, assignment, or sale of rights granted by a permit issued under this section shall be made without the prior written approval of the Secretary concerned. (2) Such Secretary shall allow a person holding a permit to transfer, assign, or sell rights under the permit to a successor, if the Secretary finds, in writing, that the successor— (A) is eligible to receive a permit in accordance with section 204(d)