Classification of nuclear material according to its physical form; material can be either in item form or in bulk form. Material is in item form as long as it consists of individually identifiable units (e.g., fuel assembly, bundle, pin, plate or coupon) that are kept intact during their stay in a material balance area. Bulk material is material in loose form, such as liquid, gas or powder, or in a large number of small units (e.g., pellets or pebbles) that are not each individually identified for nuclear material accountancy purposes.