ML20134G790: Difference between revisions

From kanterella
Jump to navigation Jump to search
(StriderTol Bot insert)
 
(StriderTol Bot change)
 
Line 1: Line 1:
{{Adams
#REDIRECT [[NSD-NRC-96-4879, Summarizes What Westinghouse Has Chosen to Do Re Updating AP600 HCLPF Values for Seismic Margins Assessment]]
| number = ML20134G790
| issue date = 11/06/1996
| title = Summarizes What Westinghouse Has Chosen to Do Re Updating AP600 HCLPF Values for Seismic Margins Assessment
| author name = Mcintyre B
| author affiliation = WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP.
| addressee name = Quay T
| addressee affiliation = NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
| docket = 05200003
| license number =
| contact person =
| document report number = NSD-NRC-96-4879, NUDOCS 9611130356
| document type = CORRESPONDENCE-LETTERS, INCOMING CORRESPONDENCE
| page count = 2
}}
 
=Text=
{{#Wiki_filter:.        .                                                            .                                  ..    .    .
        ~ ,                                                                                  fx
    ~
(          \
g%/j
                          .                                                                      =
e Westinghause                Energy Systems                                    Bu 355 I                                                                                              Pittsbwgh Pennsylvania 15230-0355 Electric Corporation NSD-NRC-96-4879 DCP/NRC0655 Docket No.: STN-52-003 November 6,1996 Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555 ATTENTION:                T.R. QUAY
 
==SUBJECT:==
AP600 SEISMIC MARGIN HCLPF METHODOLOGY
 
==Dear Mr. Quay:==
 
The NRC performed an audit of the Westinghouse AP600 seismic margin high-confidence / low-probability of failure (HCLPF) calculations on February 8 and 9,1995, and issued meeting minutes in a letter dated March 6,1995. Westinghouse responded to the open items presented in the NRC meeting minutes and provided a written methodology of how to revise the seismic margin HCLPF valves to address the NRC open issues. This information was transmitted to the NRC in Westinghouse letter NTD-NRC-96-4625, dated January 17, 1996.
The calculated AP600 seismic margins HCLPF values were originally estimated using the median shape review level earthquake from NUREG/CR-0098, similar to the HCLPF analysis of another evolutionary plant analysis since approved by the NRC. During the February 1995 audit, it was strongly suggested to Westinghouse by the NRC staff to use the one-sigma (84-percentile) spectra rather than the median shape for NUREG/CR-0098, similar to that approved for one of the evolutionary plants. Thus, in the methodology Westinghouse issued in January 1996, the 84th-percentile was preposed to be used when the HCLPF values for AP600 were updated.                                    ;
Several telecons between Westinghouse and NRC occurred since the January 1996 Westinghouse submittal, and the NRC issued RAls about the proposed methodology. In the most recent telecon                      ;
l (June 28,- 1996), the NRC staff strongly suggested Westinghouse use the AP600 response spectrum curve rather than the previously suggested NUREG/CR-0098 84th-percentile curve.
The purpose of this letter is to summarize what Westinghouse has chosen to do concerning updating the AP600 HCLPF values for the seismic margins assessment. Specifically:
!                          Westinghouse is revising the calculated AP600 HCLPF values for the seismic margins assessment. Fol!owing the NRC staff position put forth during the June 28,1996 telecon, Westinghouse veill determine HCLPF values based on the latest AP600 seismic response
_                        spectra.
O g CDAj _
a 1300y 9611130356 961106 PDR      ADOCK 05200003 A                        pog ,
 
!          NSD-NRC-96-4879 l          DCP/NRC0655                                                                        November 6,1996 i
HCLPF values will be calculated using the log-normal fragility formulation procedure for the following buildings / structures:
                          .        shield building roof i
e        containment vessel
                          .        interior containment structure which includes modular conatruction
                          .        containment baffle support a        primary component supports for the reactor pressure vessel, pressurizer, and steam generators.
Westinghouse will define HCLPF values for equipment based on its design margin as defined by qualification analyses, design requirements, and test programs. HCLPF values will be defined from applicable generic information for those items that sufficient design information is not available.
l It is noted that no HCLPF value will be determined for the shield building walls, or for the Auxiliary Building walls or floors since these structures are not the controlling HCLPF values l                          for the associated buildings. This is consistent with an NRC staff statement put forth during the June 28,1996 telecon.
Finally, in response to an NRC question posed during the June 28,1996 telecon, the turbine
                        - building collapse and its effect on the nuclear island will be addressed in the seismic margin assessment.
The HCLPF values are scheduled to be updated and available for NRC to review by January 1997.
;          Cindy Haag will contact Ms. Diane Jackson, NRC, to set the agenda and schedule the meeting.
Please contact Cynthia L. Haag on (412) 374-4277 if you have any questions or disagreements concerning this approach.
A Brian A. McIntyre, Manager Advanced Plant Safety and Licensing
            /nja Enclosure cc:          D. Jackson, NRC T. Martin, NRC N. J. Liparulo, Westinghouse (w/o enclosure) 2993A I
l}}

Latest revision as of 16:59, 14 December 2021

Redirect to:

Retrieved from "https://kanterella.com/w/index.php?title=ML20134G790&oldid=3378506"