What is meant by "nickle workers"? Are they the same as Chinese 50 centers?

They are the same but also different. Our comrades in the CPC-PRC only accepts Chinese 50 cents or wu mao, hence the name "wu mao dang" or 50 cent party. Nickel workers are an improvement, a new name in replacement but nickels are American currency, my comrades cannot use US currency in China. lol