An inmate who escapes from lawful custody while undergoing a sentence of imprisonment is liable upon recapture to undergo the punishment which he or she was undergoing at the time of his or her escape and in addition for a further term equal to the period during which he or she was absent from the correctional facility after the escape and before the expiration of the term of his or her original sentence whether or not at the time of his or her recapture the term of the original sentence, has expired.