WASHINGTON: Inside a nondescript warehouse south of Mannheim, Germany, a dozen robots, ranging in size from a low-slung inspection bot no bigger than a toy wagon to a 22-tonne Caterpillar excavator, stand ready to respond to a nuclear emergency.

With their electronics hardened to withstand radiation, the versatile machines can handle fuel rods as well as monitor doses that would kill a human engineer. A similar robotic quick-response squad is housed near the Chinon nuclear power plant in France.

Married by robot ... a Japanese couple tie the knot. Credit:Reuters

In Japan, where the Fukushima nuclear crisis is three weeks old, the question is: Where are the robots?

The answer is disquieting, say Japan's top roboticists. Instead of building robots that go where humans never could, Japan, renowned for its robotics expertise, invested in machines that do things that humans can already do - such as talk, dance, play the violin and preside over weddings.