As used in this act:
a. "Certificate of handling" means a written document issued by the Department of Environmental Protection pursuant to the terms of P.L.1977, c. 233 (C. 26:2D-18 et seq.), approving the use of certain specified New Jersey highways for the transport of specified quantities of radioactive materials.
b. "Certificate number" means the number associated with the certificate of handling issued by the Department of Environmental Protection.