BL-4a is intended as a replacement for BL-4 of which the stock is exhausted. It is ore typical of the property of Eldorado Nuclear Limited in Beaverlodge, Saskatchewan, and consists of pitchblende in reddish-brown mylonitized oligoclase saturated with dusty hematite.
The bulk material was dry-ground to minus 74 µm, blended in one lot and bottled in 200-g units. The homogeneity of BL-4a for uranium was confirmed by both neutron activation and fluorimetric procedures performed by two different commercial analytical laboratories.
The recommended value for uranium is the mean of single determinations for each of 25 bottles performed at CANMET by the volumetric umpire method.
INTRODUCTION FOR USE
The recommended value for BL-4a pertains to an "as is" basis.