A.
First of all, let us check the definition of Fissile Material in DGR 10.3.7.1.1 Fissile Material。It says: "Fissile material is a material containing any of the following fissile nuclides. Uranium-233, Uranium-235, Plutonium-239 and Plutonium-241.”

Thence, we will look at 10.3.7.2 Fissile Excepted for its definition. It says: “Fissile material meeting one of the requirements of 10.3.7.2.1 to 10.3.7.2.6 is excepted from the requirement to be transported in packages that comply with 10.6.2.8 ‘Requirements for Packages containing Fissile Material’ and from the other requirements of these Regulations that apply to fissile material.

This boils down to only six material that will be classified and handled as “Fissile Excepted”. The first 3 items, under 10.3.7.2.1 to 10.3.7.2.3 refer to enriched uranium at 1%, 2% and 5% respectively. The next 2 items, under 10.3.7.2.4 and 10.3.7.2.5 refer to a total mass not exceeding 2g/package and 45g/package, respectively. The last item under 10.3.7.2.6 is different and must meet the requirements of 10.3.7.3, 10.8.7 and 10.9.3.5.3(b). An explanation of the last item, 10.3.7.2.6 will be dealt later.

So, here, I will attempt to first give an explanation on the more simple ones, e.g., Fissile Excepted dealt in 10.3.7.2.1 through 10.3.7.2.5.

Look at Table 10.4.A “Assignment of Proper Shipping Names/UN numbers (10.4.1.1)” and note that there is a small letter (a) printed at the end of some PSNs. The explanation of the small letter (a) is given as a footnote to the Table which reads: “The term “Fissile Excepted” refers to material excepted under 10.3.7.2.” This means those packages with the PSN with a small letter (a) can be used to transport “Fissile Excepted” material. The small letter (a) appears with LSA, SCO, Type A, Type B(U), Type B(M), Type C, Special Arrangement, and UN2978 Uranium Hexafluoride. So, all these packages can be used for Fissile Excepted. However, with UN3507 Uranium hexafluoride, radioactive material, excepted package, there is a small letter (b) which says: “For UN3507, see also Special Provision A194 and PI 603” which must be followed.

As stated, for Fissile Excepted referred to in 10.3.7.2.1 through 10.3.7.2.5, the Activity Value of each material will determine which package is to be used thereby determining the UN number and the PSN. If the Activity is equal to or less than A1 or A2 Value of Table 10.3.A, Type A package can be ued. If the A1 or A2 value exceeds the Activity Value shown on Table 10.3.A, depending on the shipment, you will place an order for Type B(U), Type B(M) or Type C as appropriate. If the Activity Value is in the LSA area, according to the Activity you will classify as LSA-I, LSA-II or LSA-III and thence select from Industrial packages Type 1, Type 2 or Type 3. If it is SCO, you will follow the degree of contamination per 10.3.6 and handle accordingly. For ease in identification, you may enter the light-character printed term “Fissile Excepted” in the Quantity & Type of Packing column of the DGD following the name or symbol of the fissile nuclide.

On the special “Fissile Excepted under 10.3.7.2.6”, the following requirements must be met.
(1) Requirements of 10.3.7.3：
 (a) 10.6.2.8.1.2 (a) : Subcriticality must be maintained during transport.
 (b) 10.6.2.8.3.1 (b) : Must be subjected to 10.6.3.4 package test.
    10.6.2.8.3.2 (b) : More limited drop test than 10.6.3.4.
 (c) 10.6.2.8.2.4 : Must be subcritical under Type C test specified in 10.6.3.7.1
(2) 10.8.7 : Competent authority certificates. 10.3.7.2.6 Fissile material excepted required.
(3) 10.9.3.5.3 (b) : Only one approved fissile material is permitted in the package unless multiple materials are authorized in the certificate of approval.

For documentation, as stated in 10.8.3.9.4 Fourth Sequence – Authorizations Step 10, 8th bullet point, a certification of “fissile material excepted under 10.3.7.2.6” issued by the competent authority must be attached to the DGD.
From the foregoing requirements, I am assuming for Fissile Excepted under 10.3.7.2.6 a Type C package need to be used.