Changes Uniform Over the Reactor

It will be iiseful to know some of the more probable reactivity variations caused by lattice changes which are made uniformly In each lattice cell The simplest 

The Initial 21 6 Ib/ft fuel element for N Reactor Is not the only fuel choice possible It is a conserva.tive choice one desi ied so that the reactl-y ty transients should be within the capacity. of the horizontal rod system. A heavier fuel element Is not impossible sad may well be charged after the reactor has been operated and the actui reactivity transients and effective control rod strengths determined  

Enrichment and Plutonium Yield as Function of Fuel Weight Uranium Wt/Foot gm Pu/mwD 1200 VSFD/t Bnrlchment Level  

Prob ly on nign sioe Calcuiatea to yiela a minimum e uiribrixim re ActTvfty of Off 

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