During the Arkansas Nuclear One Unit 2 (ANO-2) initial power ascension, four system transient tests were conducted. The four tests were:

  1. turbine trip from 98.2% power
  2. total loss of flow from 81% power
  3. a full-length control element assembly (CEA) drop from 49.4% power
  4. a part length CEA drop from 49.2% power.
Middle South Services has undertaken a project to benchmark RETRAN-02 against these ANO-2 startup tests. The primary purpose of this project is to develop validated RETRAN-02 models of ANO-2, which give a good prediction of the measured data. The RETRAN model used is a two-loop representation of ANO-2, with a point kinetics representation of the core. For the turbine trip test, the comparison of RETRAN-02/MOD001 predictions against test data indicates that RETRAN-02 properly predicts the significant test events and agrees well with test data.