10 CFR §709.13

1. (a)Subject to § 709.14 of this part, a covered person may refuse to take a polygraph examination pursuant to § 709.3 of this part, and a covered person being examined may terminate the examination at any time.
2. (b)If a covered person terminates a polygraph examination prior to the completion of the examination, DOE may treat that termination as a refusal to complete a CI evaluation under § 709.14 of this part.