10 C.F.R. § 75.22 – Accounting records.

(a) The accounting records required by § 75.21 shall include, for each IAEA material balance area:
1. (1) All inventory changes, so as to permit a determination of the book inventory at any time;
2. (2) All measurement results that are used for determination of nuclear material quantities; and
3. (3) All adjustments and corrections that have been made with respect to inventory changes, book inventories and physical inventories.
(b) The records shall show, for each batch of nuclear material: material identification, batch data and source data. The batch data means a separate listing of the total weight of each element of nuclear material (including, as specified in the license conditions, isotopic composition for special nuclear material) with plutonium and enriched uranium measured in grams and natural or depleted uranium and thorium measured in kilograms. The source data are the data, recorded during measurement or calibration or used to derive empirical relationships, which identify nuclear material and provide batch data.
(c) For each inventory change, the records shall show the date of the inventory change and, when appropriate, (1) the originating IAEA material balance area or the shipper, and (2) the receiving IAEA material balance area or the recipient.