> step(nuclear.lm)
Start:  AIC=-107
log(cost) ~ date + log(T1) + log(T2) + log(cap) + PR + NE + CT + 
    BW + log(N) + PT

           Df Sum of Sq      RSS      AIC
- BW        1     0.003    0.571 -108.840
- log(T1)   1     0.004    0.572 -108.787
- log(T2)   1     0.030    0.598 -107.376
<none>                     0.568 -107.002
- PR        1     0.039    0.607 -106.897
- log(N)    1     0.082    0.650 -104.670
- CT        1     0.089    0.657 -104.337
- PT        1     0.091    0.659 -104.260
- date      1     0.278    0.846  -96.254
- NE        1     0.304    0.872  -95.271
- log(cap)  1     0.703    1.271  -83.223

Step:  AIC=-108.84
log(cost) ~ date + log(T1) + log(T2) + log(cap) + PR + NE + CT + 
    log(N) + PT

           Df Sum of Sq      RSS      AIC
- log(T1)   1     0.002    0.573 -110.724
<none>                     0.571 -108.840
- log(T2)   1     0.045    0.616 -108.396
- PR        1     0.046    0.617 -108.355
- log(N)    1     0.080    0.650 -106.664
- CT        1     0.086    0.657 -106.337
- PT        1     0.088    0.659 -106.250
- NE        1     0.305    0.876  -97.142
- date      1     0.322    0.893  -96.517
- log(cap)  1     0.703    1.274  -85.149

Step:  AIC=-110.72
log(cost) ~ date + log(T2) + log(cap) + PR + NE + CT + log(N) + 
    PT

           Df Sum of Sq      RSS      AIC
<none>                     0.573 -110.724
- log(T2)   1     0.044    0.617 -110.380
- PR        1     0.044    0.617 -110.354
- CT        1     0.084    0.657 -108.327
- log(N)    1     0.086    0.659 -108.271
- PT        1     0.088    0.661 -108.132
- NE        1     0.307    0.880  -99.003
- date      1     0.666    1.239  -88.042
- log(cap)  1     0.708    1.281  -86.988

Call:
lm(formula = log(cost) ~ date + log(T2) + log(cap) + PR + NE +     CT + log(N) + PT, data = nuclear)

Coefficients:
(Intercept)         date      log(T2)     log(cap)           PR  
  -15.22561      0.22722      0.30186      0.68246     -0.09336  
         NE           CT       log(N)           PT  
    0.25895      0.11462     -0.07873     -0.21572