United States Nuclear Regulatory Commission - Protecting People and the Environment

Licensee Qualification for Performing Safety Analyses in Support of Licensing Actions (Generic Letter No. 83-11)


                               UNITED STATES 
                       NUCLEAR REGULATORY COMMISSION 
                          WASHINGTON, D. C. 20555 

                              February 8, 1983 

TO ALL OPERATING REACTOR LICENSEES 

SUBJECT:  LICENSEE QUALIFICATION FOR PERFORMING SAFETY ANALYSES IN SUPPORT 
          OF LICENSING ACTIONS (Generic Letter No. 83-11) 

Gentlemen: 

The purpose of this letter is to inform you of the current NRR practice 
regarding licensee qualification for performing safety analyses in support 
of licensing actions. 

Over the past few years, the number of licensees electing to perform their 
own safety analyses to support reload applications, technical specification 
amendments, etc... rather than contract the work out to their NSSS vendor or
other organizations has increased substantially. We encourage utilities to 
perform their own safety analyses since it significantly improves their 
understanding of plant behavior. 

NRC's experience with safety analyses using large, complex thermal-hydraulic
computer codes such as RELAP and TRAC has shown that a large percentage ,of 
all errors or discrepancies discovered in safety analyses can be traced to 
the user rather than to the code itself. This realization has led NRR to 
place additional emphasis on assuring the capabilities of the code users as 
well as on the codes themselves. For example, for the past two years NRR has
been working with the Vendor Inspection Branch in Region IV to inspect the 
acceptability of the QA procedures used for code development, verification, 
use, and maintenance for all licensees and vendors involved with safety 
analysis codes presently under staff review. While this aspect of our review
focuses primarily on the competence of the licensee and vendors regarding 
quality assurance practices, the technical competence of the licensees and 
vendors with respect to their ability to set up an input deck, execute a 
code, and properly interpret the results must also be assured. NRR obtains 
this assurance by reviewing the code verification information submitted by 
the licensee or vendor. The information we look for includes comparisons 
performed by the user of the code results to experimental data, plant 
operational data, or other benchmarked analyses. 

We are concerned however, that some licensees planning to perform their own 
safety analyses may not intend to demonstrate their ability to use the code 
by performing their own code verification. Rather, they plan to rely on the 
code verification work previously performed by the code developer or others.




8302080304 
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NRR does not consider this acceptable and each licensee or vendor who 
intends to use a safety analysis computer code to support licensing actions 
should demonstrate their proficiency in using the code by submitting code 
verification performed by them, not others. 

In order to eliminate problems on future licensing submittals, I request 
that you factor this into your future licensing submittal plans. 

                                   Darrell G. Eisenhut, Director 
                                   Division of Licensing 
Page Last Reviewed/Updated Wednesday, June 19, 2013