Software used for safety review of nuclear facilities

Reliability of simulation models for nuclear installations, which are realized applying computer codes, has a vital importance for the safe use of nuclear energy. In the process of development of software that allows forecasting to the last detail of nuclear installations behavior in various operation conditions, as well as in case of an accident, the results of the advanced scientific researches are used. The most remarkable mathematicians, physicists, experimentators and software programmers take part in software development, and all components of the nuclear industry innovative development are involved. It is evident, that soundness of simulation models shall be evaluated and verified at the equally high level which is observed in the process of the software development.

Since 1991, Rostechnadzor applies in its regulatory activity the unique practice of software review, which is implemented by the SEC NRS. Since the very beginning of establishing of the software evaluation system there appeared understanding of the necessity of the open and transparent cooperation among all teams, participating in the development, verification and use of the software applied in the process of safety analysis. That is why the results of the review of such codes shall be definitely the subject to the review by the Expert Council in charge of computer codes certification under the aegis of Rostachnadzor, which includes representatives from more than 40 enterprises of the nuclear industry in Russia. The procedure for the software review was initially forethought to be a free from subjectivity team work of highly qualified specialists in the field of nuclear energy use. The solutions taken by the Expert Council are always based on the cumulative experience and knowledge of the whole scientific and technical society of the Russian nuclear industry, and represent the driving force for the development of innovative projects related to creation of new generation simulation tools and conduct of necessary experimental studies. In 2018, the more than a 25-year successful practice of computer codes review was settled by law, and the relevant amendments were introduced into the Federal Law “On the Use of Atomic Energy”.

Currently, among the most significant challenges in the context of scientific and technical aspects of computer codes development, verification and validation are as follows:

  • updating of the requirements to verification (validation) of computer codes, upgrading of the criteria and forming of approaches to evaluation of the current computer codes (including multi-physical simulation, creation of codes for CFD-DNS type PCs) and digital technologies (artificial neural networks, virtual NPPs and etc.);
  • development of recommendations on estimation of errors and uncertainties of the simulation results (preparation of the draft first revision of the relevant Guide has been planned for the year 2019);
  • the system development of the experimental base and creation of the unified digital base of the evaluated experimental data, which can be used in the process of verification (validation) of the modern computer codes in the field of use of nuclear energy;
  • evolvement of the approaches to rating of computer code users qualification.

 

Contact
Sergey SHEVCHENKO,
Scientific and Engineering Centre for Nuclear and Radiation Safety (SEC NRS)
sshevchenko@secnrs.ru