The Manhattan Project

John Lithgow

John Mathewson

Christopher Collet

Paul Stephens

Cynthia Nixon

Jenny Anderman

Jill Eikenberry

Elizabeth Stephens

John Mahoney

Lt. Col. Conroy

Richard Jenkins

Radiation Controls Officer

Sully Boyar

Night Guard

Timothy Carhart

Relief Guard

Gregg Edelman

Science Teacher

JD Cullum

Eccles (as John David Cullum)

Abraham Unger

Roland (as Abe Unger)

Robert Sean Leonard

Max

Fred Melamed

Howard

Ned Eisenberg

C-4 Guy (uncredited)

Richard Council

Government Aide

Robert Schenkkan

Government Aide

Steve Blum

Laser Efficiency Kid (as Richard Cardona)

Sarah Burke

Jenny's Parent

Warren Manzi

Day Attendant

Paul Austin

General