Nuclear Techniques ›› 2015, Vol. 38 ›› Issue (4): 40605-040605.doi: 10.11889/j.0253-3219.2015.hjs.38.040605

• NUCLEAR ENERGY SCIENCE AND ENGINEERING • Previous Articles     Next Articles

Methods for calculating the release to birth ratio of volatile fission products

XU Rui1 DONG Bing1 FU Yaru2 MEI Qiliang2 WANG Dezhong1   

  1. 1(Shanghai Jiao Tong University, Shanghai 200240, China) 2(Shanghai Nuclear Engineering Research & Design Institute, Shanghai 200233, China)
  • Received:2014-12-26 Revised:2015-02-05 Online:2015-04-10 Published:2015-04-09

Abstract: Background: A large quantity of fission products would be produced when the nuclear reactor runs. These fission products would be released to the pellet-rod gap and then to the primary circuit while the fuel rod is broken. The fission products in the primary circuit become the main source term of the reactor. Purpose: This study aims to analysis the source term accurately by calculating the release to birth ratio (RBR) of volatile fission products precisely. Methods: After researching American NRC ANSI/ANS-5.4 methods and French methods for calculating the RBR of volatile fission products, we calculated the RBR of volatile fission products of a fuel rod at different power and different burn-up by these methods, and made some comparison and analysis of these results. Results: Computation results showed that the RBR of volatile fission products would increase with the power and burn-up of the fuel rod. Compared with the ANSI/ANS-5.4-2011, the French method is more conservative whilst the ANSI/ANS-5.4-1982 is the most conservative among these methods. Conclusion: ANSI/ANS-5.4-2011 is the best method among these three methods and it can be used to calculate the release to birth ratio of volatile fission products with good results.

Key words: Fuel rod, Fission products, Release to birth ratio, ANSI/ANS-5.4, METEOR1.5