Reactor Weighting for Production

Since the flux varies from point to point in a reactor the coTicfcnii 5.ti r of products will vary and it is often necessary to define yields averaged over on appropriate reactor volume. The flux varies radially across the fuel element and longitudinally along the fuel column axis. Both variations must be taken into account to obtain a column-averaged yield. Richey s - formulation is used as an example in the case of the Pu concentration y. 

Dm p aMt r Amotion of axlia pooltlon In tlm ooXian, zudUl position 

SroB the axis of tho fool and. Irradiation tins, t. Ona ean wlte 

X distance firont to rear in a column r radial distance from axis of fuel element  

Where 9o(t) t has been taken outside the integral since it is independent of r andJ. The limits in the integrations over r esre the Inner and outer radii of each part of the concentric tube fuel element for example B22 s the outer radius of the outer fuel tube. 

---