The normal limit of 50 milli-sieverts per year is to be eliminated, but 5-year total of 100 milli-sieverts limit remains.
If the limit is eliminated, the workers who will have been exposed to the radiation of more than 50 milli-sieverts but less than 100 milli-sieverts at Fukushima I Nuke Plant will still be able to work at other nuke plants, as long as 5-year total remains under 100 milli-sieverts.
Ministry of Health, Labor and Welfare is for the nuclear industry's health, labor and welfare. Of course, the argument is that unless these workers are able to maintain the power plants (there are 17 of them, with 54 reactors, according to this site), everybody's health, labor, and welfare will be threatened.
From Mainichi Shinbun (3:09AM JST 2/28/2011):
Ministry of Health, Labor and Welfare is considering eliminating the annual radiation exposure limit of 50 milli-sieverts
On April 27, Ministry of Health, Labor and Welfare started to discuss the elimination of the annual radiation exposure limit of 50 milli-sieverts for nuclear plant workers during a normal operation [as opposed to an emergency situation like Fukushima I], while keeping the 5-year limit of 100 milli-sieverts. The nuclear plant workers from all over Japan have been sent to Fukushima I Nuclear Power Plant, and there is a concern expressed by the nuclear industry that there won't be enough workers to do the maintenance work at other nuclear power plants if the current annual limit is kept.
As to the emergency radiation exposure limit, Ministry of Health already raised the 100 milli-sieverts per year limit to 250 milli-sieverts last month, specifically for the work related to Fukushima I Nuclear Power Plant accident.