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• This course is intended for personnel who:– Perform Safety Analyses– Review or control the vendor who performs the Safety Analyses– Perform or review any portion of the core reload process– Licensing personnel who are charged with identifying the need
for NRC submittals and preparing them, if necessary
and
– the supervision of the personnel above.
• This is intended to be a “Master-Level” class• Potential student population is typically limited to 20 to
• Three detailed examples have been developed. These examples– illustrate the learning objectives – provide a forum for answering student questions– require about four to five hours on the first day
• The Summary Flowcharts illustrate the three examples– The course teaches the students to use the Summary
Flowcharts on their own
• The second day is dedicated solely to review pre-prepared exercises and any situations the students wish to resolve– Students typically can answer their own questions on day #2
Click here to view a few simple, selected course slides
Comanche Peak has recovered their containment liner with the coating described in Example #1. This was inadvertently treated as a simple maintenance activity. Now the liner recoating is complete and the calculations described in Example #2 have subsequently shown that the maximum, post-accident containment pressure is over the containment design limit by 0.3 psig. Their current outage is scheduled to be complete in three weeks, making any extensive licensing action problematic. As a result, Westinghouse Electric Company, LLC has been contacted for their assistance.
The examples consist of a series of questions and answers that
illustrate the learning objectives. The answers are presented
Under what conditions, if any, can “margin be created” to resolve Comanche Peak’s concerns?
The flowchart on the next slide summarizes the overall process.
This example will explore both the flexibility and the restrictions associated with the new 10 CFR 50.59 process. A summary of these features and where they will be illustrated follows the flowchart.
This refers to one of the Summary Flowcharts previously described.
A review of the the major containment structures and components has identified that the concrete missile blocks that sit on top of the CRD booster fans, pressurizer coffin, and the Reactor Coolant Pumps have not been included in the structural heat loss calculations. Specifically, a comparison of the actual analysis inputs, Table 6.2.1-6, and a field walk-down has identified these blocks.
Can they be included in the structural heat loss calculation to reduce the peak pressure? Should they be evaluated as “Input Parameters” or as a “Method of Evaluation”?
To “Input Parameters vs Method of Evaluation” flowchart
Yes. They can be included. The modeling of the concrete blocks would qualify as altering an “Input Parameter”.
There is no discussion in UFSAR Section 6.2.1.1.3.7(page 6.2.5) regarding the extent, or absence, of modeling these blocks. Contrast that wording with the language of Section 6.2.1.5.6 (page 6.2-26). In that section, the assertion is made that the selection of “surface areas and thicknesses were … conservatively high.”
The calculation being described in 6.2.1.5.6 is intended to result in the smallest peak pressure.
Note that in all cases, 10 CFR 50, Appendix B, Criterion 3 would apply. That is, these are all “Quality”, Design Bases calculations that require the use of accurate information. This includes use of calculations to develop the value of the “Input Parameter”. (Calculations may be used to determine the value of an “Input Parameter”.)
Note that the thermal properties of the coating itself may also hold some potential for refinement here.