Actually no. The oldest reactor at Fukushima Daiichi, no. 1 was about 40 years old but still operating problem-free and it was likely to get a ten-year licence extension after inspection. The average working life of 1970s-era reactors looks to be about 50 years or more; in a few cases economics and the dash for gas are getting some smaller facilities like Vermont Yankee (a 600MWe single-reactor plant) shut down. Reactors 2, 3 and 4 at Fukushima Daiichi were more modern designs and had at least ten years life left in them before the tsunami hit. Reactors 5 and 6 were built in the 1980s and were totally undamaged but they will be decommissioned as the site is considered inoperable in toto.
As for new modernised reactors designs Japan has three new reactors under construction at various stages of completion and its newest complete reactor came on-line a few years ago (2005, I think). The delay in building new reactors is due to the fact the older models are still operating safely and that reduces the demand for new ones. Gas is cheap at the moment as is coal and that also cripples the case for new nuclear builds because of the very large upfront costs of licencing and building any new reactors (which are expected to have a service life of 60 years).