Use and application of ANSI/ANS 51.1 and 58.14

[pxp]

I have a question regarding use and application of ANSI standards. If the components, systems of structures are classified in accordance with ANSI/ANS 18.2 1973 »Nuclear Safety Criteria For The Design Of Stationary PWRs«, and this standard is referenced in USAR, are you allowed to use ANSI/ANS 58.14 »Safety and Pressure Integrity Classification Criteria for Light Water Reactors«. Are you allowed to declassify some parts of systems for minor modifications? ANSI/ANS 58.14 is currently not referenced in USAR. My second question is, what is the correlation between ANSI/ANS 18.2 and ANSI/ANS 51.1 »Nuclear Safety Criteria for the Design of Stationary Pressurized Water Reactor Plants«? In foreword of ANSI/ANS 51.1 is stated that is complete revision of ANSI/ANS 18.2. In this case are you allowed to apply this standard instead of ANSI/ANS 18.2, which is referenced in USAR.

 

[racookpe1978]

Once declassified, it would be nearly impossible to return the component to its current (original) certification.

 

[Mr168]

In regards to your 51.1 question, in my experiences, we could not justify the use of an alternate standard, even if superseding an original, without a licensing amendment. Doing so would be the equivalent to committing to an earlier code year/addenda in your USAR, and then trying to invoke a later code year in design/operation. Your experience may differ.

 

[pxp]

If the plant is licensed in accordance with ANSI/ANS 18.2, and ANSI/ANS 51.1 is complete revision of 18.2, it is not allowed to use it without a licensing amendment. Therefor application of ANSI/ANS 58.14 standard which has no direct link to ANSI/ANS 18.2 is not permitted. Is my thinking OK?