That's 904 workers out of 24,118 who have worked at Fukushima I Nuclear Power Plant since March 2011, up to September this year.
It's still over 5-fold increase, though. Originally when Prime Minister Noda declared a "cold shutdown state" to the ridicule of the world on December 16, 2011, only 167 workers who had exceeded the cumulative radiation of 100 millisieverts one day prior were to be fully covered by the national government for annual cancer screening for life, but no one else.
In August this year, TEPCO (at that time already effectively nationalized) was kind enough to lower the limit to 50 millisieverts, but the exposure should have been sustained by December 16, 2011 to qualify for the free checkups.
How much does a cancer screening test cost? About 50,000 yen (US$610). 45.2 million yen (about US$549,000) per year for 904 people, instead of 1.2 billion yen (US$15 million) per year for 24,118 people.
The Japanese government is paying 22 trillion yen (US$268 billion), or about a quarter of the annual budget, in interest payments for its enormous debt. "We owe it to ourselves", say the Japanese citizens, analysts, politicians alike.
I guess they don't feel they owe it to the subcon workers at Fukushima I Nuke Plant.
From Asahi Shinbun (11/22/2012; part):
(Report by Miki Aoki) It has been revealed that only 904 workers, or 3.7% of the 24,118 workers who have worked at Fukushima I Nuclear Power Plant since the start of the accident up to September this year will be able to receive free cancer screening tests from the national government and TEPCO. It is because the national government and TEPCO will allow free cancer tests only to workers who had already received more than 50 millisieverts of radiation by the December  declaration by the Noda administration that the accident was over. TEPCO says the workers who are worried can still talk to the company by calling 03-3597-0741 to speak with [TEPCO's] attorney.
Even after the declaration that the nuclear accident is over, the work at Fukushima I Nuclear Power Plant is carried out in a high radiation environment. For example, 24 workers exceeded cumulative radiation exposure of 50 millisieverts just this September. However, except for 2 TEPCO employees who are exempt [from the government/TEPCO rule], 22 workers won't be eligible for free cancer screening tests.
Ministry of Health, Labor and Welfare set up the system last October which designated the workers at Fukushima I Nuclear Power Plant as "workers engaged in emergency work" and allowed them to receive annual cancer screening tests for free for life if their cumulative radiation level exceeded 100 millisieverts.
The cost (about 50,000 yen [US$610]) would be borne by the employers, and if the workers quit, the national government would pay the cost.
However, when the Noda administration declared the end of the nuclear accident on December 16 last year, Ministry of Health decided that the emergency work was now basically over and limited the number of workers eligible for the free annual cancer checkups to 167 who had already exceeded 100 millisieverts as of December 15, 2011, one day prior to the declaration.
This August, TEPCO announced the remedial measures whereby 663 workers who had exceeded 50 millisieverts by the time of the declaration would be added to the workers who could receive free checkups. In addition, some TEPCO employees who carry out particular work will receive free checkups even if they exceed 50 millisieverts after the declaration, and there are 74 such employees so far.
At Fukushima I Nuke Plant, in September alone, 27 workers were exposed to 10 to 20 millisieverts of radiation, which is very high, as evidenced by the 20 millisieverts per year standard used by the companies that work in nuclear power plants. There are workers at Fukushima I Nuke plant who say all workers should be included in the program [of free annual cancer screening tests]. If this health management problem is underestimated, workers may start avoiding the work at Fukushima I Nuclear Power Plant, causing the delay in decommissioning which is estimated to last for more than 40 years.
40 years. That's why some right-wing politicians (including the vice governor of Tokyo) have been talking about reinstating the draft and send young people to work at the plant, willing or not.
As you see, the declaration in December last year that the cold shutdown "state" was achieved and the nuclear accident was over was made so that the national government would not need to spend extraordinary amount of money on the workers at the plant and to the residents in Fukushima who were displaced by the nuclear accident. Instead, the government have been generously giving money to general contractors doing the "decontamination" and transporting disaster debris full of asbestos and heavy metals as well as radioactive materials to be burned and buried in faraway places like Osaka and Kitakyushu.
LDP politicians, already planning for their administration (or at least how to spend more taxpayers' money once they get there, which they have no doubt about), wants to have a supplementary budget to the tune of 5 trillion yen or more right after the election. You can bet none of the money is going to Fukushima I Nuke Plant workers.