Values in italics are calculated, other cells suitable for direct entry of values
Unmanned NEP moonbase delivery vehicle
Assuming SDV lift capability of 80t to LEO:
First launch - entire vehicle (80t) apart from payload, propellant and prop. tank.  Optionally, uranium may be launched separately.
Second launch - 80t payload module, this mass includes engines and propellant for lunar landers etc.  No maneuvering capability.
Third launch - propellant module consisting of 64t xenon propellant, 7t tank, 9t temporary hardware and rendezvous propellant *(see bottom)
used to dock with payload module, then tug it to the main vehicle (this hardware is discarded after docking)
Configuration is [Engines/main vehicle]-[Propellant module]-[Payload module]
so the propellant provides some shielding for the payload to avoid scrambling chips etc.  Reactor still needs some shielding to
prevent the propellant module becoming radioactive by neutron activation, since the propellant module will re-enter.
Trip: 3 to 4 months spiralling out (then in to lunar orbit), detach payload module, 2 to 3 months return to a 650km circular Earth orbit. 
Empty propellant module is then discarded and allowed to re-enter.
650km orbit is chosen so that in case the ion drives cannot be restarted for whatever reason, the orbit doesn't decay quickly and drop a nuke in our laps:
we have several years to fix it or boost the vehicle to a high graveyard orbit or escape.  Easiest (but expensive) way to do this would be to attach 
another identical vehicle to it, along with a propellant module, then just lift it to escape velocity.
Repeat 2nd and 3rd launches for lifetime of vehicle, perhaps 10-20 cycles.  
Probably would use two or three of these vehicles simultaneously, requiring 5 to 7 launches a year for a delivery rate of 200 to 300t/year to lunar orbit.
Reactor core lasts for lifetime of the engines without needing to be refueled.  Refueling would be a big hassle (because of difficulty to shield from the really-hot old core)
so on the last run, instead of returning to LEO the engine is used to enter a heliocentric orbit that does not intersect the Earth's.
Power
Drive 1800 kW three sets of 600kW propulsion system
Other 100 kW
Total 1900 kW
generator efficiency (heat->electricity) 15 %
This is probably roughly right for a first-generation spaceborne reactor, no big deal if the efficiency is a bit less - just use a few more kg fuel
Thrust 90 N three sets of 600kW propulsion system
Mass Structure/systems 20 t <--}
Engines/reactor 60 t <--}- are these numbers sane?
Prop. Tank (empty) 7 t <--}
Payload 80 t
Uranium 100 kg elec. energy  15000 MWd (1 gram produces approx 1MWd thermal)
Total dry 167.1 t
Propellant 64 t <--xenon
Total 231.1 t
Mass fraction 1.4
Isp 2200 seconds <-- realistic?
dV
To lunar orbit Return to LEO Total over whole trip
dV required 4500 m/s 4500 m/s 9000 m/s
apollo used about 4050 but some extra required due to spiral trajectory?  
       
Initial mass 231.1 t 107.6 t 231.1 t
Final mass 187.6 t 87.3 t 87.3 t
Propellant used 43.5 t 20.3 t 63.8 t
Propellant remaining 20.5 t 0.20 t 0.20 t
Initial acc 3.89E-04 ms^-2 8.37E-04 ms^-2  
Final acc 4.80E-04 ms^-2 1.03E-03 ms^-2  
Burn duration 119.8 d 55.8 d 175.6 d
Coast time 70 d 40 d 110 d
really not sure about coast times      
     
Total time 189.8 d 95.8 d 285.6 d
6.2 months 3.2 months 9.4 months
               
Prop. Flow rate 4.2 g/sec            
Energy req'd 360.7 MWd            
               
Trips on one uranium load 41.6              
Delivery rate to lunar orbit, per vehicle
102.3 tonnes per year
* Rendezvous propellant calculations:
The SDV must be able to lift 80 tonnes to a 500km orbit.  The main vehicle is initally launched from this altitude, but
returns to a higher 650km circular orbit for safety reasons (orbit has a long decay time).
The payload module and propellant module are lifted to coplanar 500km orbits by the SDV.
The propellant module is active; it must rendezvous with the payload module, dock, then lift both to the 650km orbit
for rendezvous and docking with the main vehicle.  For this it uses conventional propellant.
Propellant module mass 80 t
Payload module mass 80 t
Isp 320 seconds
dV Payload module rndvz. 40 m/s (no significant overall change in altitude or plane change)
(including docking)
mass after procedure 158.99 t
Lift from 500km circ. orbit 85 m/s
to 650km circ. orbit
mass after procedure 154.73 t
Main vehicle rndvz. 40 m/s
(including docking)
mass after procedure 152.77 t
Total propellant req'd 7.23 t
Thrusters, nav. 
computer etc (disposable) 1.5 t
Total  8.73 t