That is correct, no appeal is possible under the ICSID Additional Facility Rules.

Moreover, the ever present jurisdiction "issue" always raised by Venezuela and now just tossed into the body of arbitration cases is a canard: Article XII, § 5 of the Canada - Venezuela BIT states, "Each Contracting Party hereby gives its unconditional consent to the submission of a dispute to international arbitration in accordance with the provisions of this Article." My added emphasis.