On a quarterly basis on and after January 1, 1980, there shall be levied and the department shall collect a charge of five cents per pound on each pound of uranium or thorium compound milled out of the raw ore. All moneys paid to the department from these charges shall be deposited in a special security fund in the treasury of the state of Washington to be known as the "radiation perpetual maintenance fund." This security fund shall be used by the department when a licensee has ceased to operate and the site may still contain, or have associated with the site at which the licensed activity was conducted in spite of full compliance with RCW
70A.310.030, radioactive material which will require further maintenance, surveillance, or other care. If, with respect to a licensee, the department determines that the estimated total of these charges will be less than or greater than that required to defray the estimated cost of administration of this responsibility, the department may prescribe such an increased or decreased charge as is considered necessary for this purpose. If, at termination of the license, the department determines that by the applicable standards and practices then in effect, the charges which have been collected from the licensee and earnings generated therefrom are in excess of the amount required to defray the cost of this responsibility, the department may refund the excess portion to the licensee. If, at termination of the license or cessation of operation, the department determines, by the applicable standards and practices then in effect, that the charges which have been collected from the licensee and earnings generated therefrom are together insufficient to defray the cost of this responsibility, the department may collect the excess portion from the licensee.