18 U.S. Code § 2283 - Transportation of explosive, biological, chemical, or radioactive or nuclear materials
(a) In General.— Whoever knowingly transports aboard any vessel within the United States and on waters subject to the jurisdiction of the United States or any vessel outside the United States and on the high seas or having United States nationality an explosive or incendiary device, biological agent, chemical weapon, or radioactive or nuclear material, knowing that any such item is intended to be used to commit an offense listed under section 2332b (g)(5)(B), shall be fined under this title or imprisoned for any term of years or for life, or both.
(b) Causing Death.— Any person who causes the death of a person by engaging in conduct prohibited by subsection (a) may be punished by death.
(c) Definitions.— In this section:
(1) Biological agent.— The term “biological agent” means any biological agent, toxin, or vector (as those terms are defined in section 178).
(2) By-product material.— The term “by-product material” has the meaning given that term in section 11(e) of the Atomic Energy Act of 1954 (42 U.S.C. 2014 (e)).
(3) Chemical weapon.— The term “chemical weapon” has the meaning given that term in section 229F (1).
(4) Explosive or incendiary device.— The term “explosive or incendiary device” has the meaning given the term in section 232 (5) and includes explosive materials, as that term is defined in section 841 (c) and explosive as defined in section 844 (j).
(5) Nuclear material.— The term “nuclear material” has the meaning given that term in section 831 (f)(1).
(6) Radioactive material.— The term “radioactive material” means—
(8)  Source material.—The term “source material” has the meaning given that term in section 11(z) of the Atomic Energy Act of 1954 (42 U.S.C. 2014 (z)).
 So in original. No par. (7) has been enacted.