Members of the Commission may be allowed travel expenses, including per diem in lieu of subsistence, as authorized by
section 5703 of title 5. A member of the Commission not presently employed for compensation shall be compensated at a rate equal to the daily equivalent of the rate for GS–18 of the General Schedule under
section 5332 of title 5 for each day the member is engaged in the actual performance of his duties as a member of the Commission, not to exceed 90 days of service each year. Except for the purposes of chapter 81 of title 5 (relating to compensation for work injuries) and chapter 171 of title 28 (relating to tort claims), a member of the Commission shall not be considered an employee of the United States for any purpose.