I am working in a plant where there is radio active sources. but that area has barricade.is it safe if you are not getting inside that?

Depends on barricade: This is impossible to answer without knowing the type of radiation & type/thickness of the barricade, but materials such as lead will shield most radiation if thick enough. Ask management for info on what the barricade is made of and if they have tested radiation levels outside the barricade. See http://www.Thomasnet.Com/articles/custom-manufacturing-fabricating/radiation-shielding-materials.