Deterministic method, computer codes

Analytical methods and computer codes used in the existing deterministic safety analyses and comparable methods for a modern nuclear power plant, including validation. 

Deterministic analysis is usually performed by means of the calculation of plant parameters using complex computer codes. The models and the computer codes used for the deterministic analyses as well as the general assumptions made concerning plant parameters, the operability of systems, including control systems, and the operators actions (if any) in the events should be described. Important simphfications made should be justified. The set of limiting assumptions for safety analysis used in the deterministic safety analyses performed for the different types of PIEs should be described in this section. The methods used to ensure that these assumptions demonstrate that sufficient safety margins are achieved for PIEs of each type should also be described. 

Here, we give a brief review of methods for the analysis of computer experiments, concentrating on statistical approximation of the computer model. Strategies for the design and analysis of computer experiments have been described by many authors, including Currin et al. (1991), Koehler and Owen (1996), Sacks et al. (1989), Santner et al. (2003), and Welch et al. (1992). All these authors take into account the deterministic nature of a code, such as the Wonderland model, and also provide uncertainty measures via a statistical approximation model. 

V11.15. Computational methods that directly solve forms of the Boltzmann transport equation to obtain k j are preferred for use in the criticality safety analysis. The deterministic discrete ordinates technique and the Monte Carlo statistical technique are the typical solution formulations used by most criticality analysis codes. Monte Carlo analyses are prevalent because these codes can better model the geometry detail needed for most criticality safety analyses. Well documented and weU validated computational methods may require less description than a limited-use and/or unique... 

---