This video clip is from a news program called "Hodo Station" aired on March 24, 2011.
Other remarks by Dr. Yamashita:
"Radiation won't affect people who are smiling": http://dai.ly/KKj90x
"I can't take responsibility": http://dai.ly/Jb8Rc4
Translation and captioning by tokyobrowntabby, with a help from kna60.