There is hereby created the West Virginia Natural Resources Police Officers Retirement System. The purpose of this system is to provide for the orderly retirement of Natural Resources Police Officers who become superannuated because of age or permanent disability and to provide certain survivor death benefits, and it is contemplated that substantially all of the members of the retirement system shall be qualified public safety employees as defined in § 20-18-2 of this code. The retirement system shall come into effect January 1, 2021: Provided, That if the number of members in the system are fewer than 100 on July 1, 2022, then all of the provisions of this article are void and of no force and effect, and memberships in the plan will be merged into the Public Employees Retirement System created in §5-10-1 et seq. of this code. The retirement system constitutes a body corporate. All business of the system shall be transacted in the name of the West Virginia Natural Resources Police Officers Retirement System. The board shall specify and adopt all actuarial assumptions for the plan at its first meeting of every calendar year or as soon thereafter as may be practicable, which assumptions shall become part of the plan.