The department shall, upon individual application, grant special permits to persons, excepting those persons from specific provisions of this chapter or of the regulations issued thereunder, if the department finds to its satisfaction that there is substantial evidence that the people in the locality of this state, in which the exemption is sought, would be denied adequate medical care because of unavailability of certified or certifiable radiologic technologists. Those special permits shall be granted for limited periods of time to be prescribed by the

department in accordance with the purposes of this chapter, and the permits may be renewed.