The blue chip index continues to be hurt by the crisis in Japan as sentiment remains battered by fears of a nuclear disaster. While off its lows for the day so far, the FTSE 100 still remains over 2% under at around 5,640, a level not seen this year.A third explosion at the Fukushima Daiichi nuclear power plant in Japan has raised concerns of a major radiation leak. People within 30 kilometres of the plant are being told to stay indoors, while a no-fly zone has been set up around the plant to stop the radiation spreading.In London, the biggest fallers in the FTSE 100 are the miners on the back of falling copper prices, with seven out of the 10 worst performers on the index coming from the sector. Eurasian Natural Resources Corp, Fresnillo, Lonmin, African Barrick Gold, Anglo American, Antofagasta and Vedanta Resources are all making losses.Mining giant Rio Tinto is also in the red. The Financial Reporting Review Panel of the Financial Reporting Council (FRC) has had Rio's accounts under review but it says it "regards its enquiries as concluded" after the mining giant added more information on environmental and social issues to its 2010 annual review. A complaint had been made in July 2010 about the lack of this information in the 2008 accounts of Rio Tinto.Shares in Renishaw have taken a sharp dive. More than 10% of the engineer's revenues come from Japan. Car parts maker GKN has warned it may have to cut component manufacturing in response to declining demand from Japan, though its losses today are not so severe. Retailers are among the handful of stocks performing well, with Next, JD Sports and Debenhams making moderate gains.Sales fell at department store Debenhams in the first half, though by a little less than forecast, and headline profit at the department store is expected to beat last year's effort and meet estimates. Like for like sales for the 26 weeks to 26 February fell 1.5% excluding VAT, but were flat including the tax.However, sportswear retailer JJB Sports is unwanted after it confirmed it intends to raise £65m through a new share placing but only if its landlords agree to a new company voluntary agreement.Royal Dutch Shell is lower despite saying it made "good progress" in 2010. The group also said that 2011 has started well, and it is on track to hit its strategic targets by next year. Shell, which hosts its annual Investor Day in London today, is one year in to a three-year strategic plan and should increase cashflow from operations 2009-2012..Security firm G4S notched up its sixth successive year of underlying revenue, profit and dividend growth since the group took on its current incarnation in 2004. Nevertheless investors joined the trend and took profits.Home entertainment products supplier MBL has lost 50% of its value after confirming that Morrisons is terminating two supply agreements in September. MBL has put itself up for sale.