Software engineering in the SCEPTRE code

The SCEPTRE radiation transport code suite is a relatively young development effort motivated by the need for coupled photon-electron transport analyses at Sandia National Laboratories. It contains multiple discretizations of both the first-and second-order forms of the Boltzmann transport equations. Although any of these capabilities May be used separately, they also May be used in a complementary manner in the same analysis for computational efficiency. Reliable development and use of these inter operable capabilities is a complex task. Therefore the SCEPTRE project relies on various software engineering methods to manage this complexity. These methods include a modular, levelized design, generic programming, and object-oriented programming. We describe several specific examples of the application of these techniques, particularly those that enable hybrid capabilities. The result is a reliable and flexible code base that can be adapted to multiple needs. (authors)