Reactor start-up physics test standards for PWRs - An overview for the '90s

In 1985, a working group (ANS 19.6.1) of the Standards Committee of the American Nuclear Society (ANS) developed and issued a standard set of start-up physics measurements that would confirm that the characteristics of a reload pressurized water reactor (PWR) core were the same as expected from design calculations. This paper describes the purpose of start-up physics testing, identifies some of the reasons why this standard has been widely accepted and used by the nuclear utility industry, reviews the bases for and describes the different tests that are part of the standard, and suggests how the criteria for some of the tests could be lowered in the future without jeopardizing the start-up program. Some of the criteria currently being used for the above tests could probably be lowered based on expected differences using state-of-the-art calculational methods such as CASMO-3/SIMULATE-3. The paper compares typical differences (1σ) from CASMO-3/SIMULATE-3 versus the test criteria from the standard