ML20136G178
| ML20136G178 | |
| Person / Time | |
|---|---|
| Site: | 05200003 |
| Issue date: | 03/11/1997 |
| From: | Mcintyre B WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP. |
| To: | Quay T NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9703170225 | |
| Download: ML20136G178 (3) | |
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Westinghouse Energy Systems Ba 355 Electric Corporation Pittsburgh Pennsylvania 15230-0355 NSD-NRC-97-5017 DCP/NRC0766 Docket No.: STN-52-003 March 11,1997 Document Control Desk t
U S. Nuclear Regulatory Commission Washington, DC 20555 I
ATTENTION: T. R. QUAY
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SUBJECT:
BREAK EXCLUSION AREA PIPE VOLUMETRIC INSPECTION l
Dear Mr. Quay:
During discussions with the NRC staff on RAI 210.40 which addresses piping in the break exclusion -
area, Westinghouse committed to a volumetric inspection of the piping in the break exclusion area l
equal or greater than 3 inch nominal diameter. This commitment was not included in Westinghouse Letter NSD-NRC-97-4989, dated February 19,1997 nor in Revision 11 of the SSAR. Attached is a markup of subsection 3.6.2.1.1.4 that includes the change. This revision will be included in SSAR Revision 12.
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If you have any questions please contact D. A. Lindgren at (412) 374-4856.
A Brian A. McIntyre, anager
- Advanced Plant Safety and Licensing jml Attachment i
cc:
D. Jackson, NRC (w/ attachment)
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ADOCK : 05200003l.
9703170225 970311 l --
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e Attachment to Westinghouse Letter NSD-NRC-97-5017 j
l 3113a
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- 3. Design of Structures, Components, Equipment, and Systems 3.6.2.1.1.4 Iligh Energy Piping in Containment Penetration Areas The AP600 does not have any ASME Code,Section III Class I pipe in containment penetration areas. Breaks are not postulated in the portions of ASME Code,Section III, Class 2 or Class 3 piping between the containment penetration flued-head and auxiliary building anchor beyond the isolation valve (that is, the break exclusion zone adjacent to the j
containment penetrations) provided subject piping meets the following provisions:
Stresses do not exceed those specified in subsection 3.6.2.1.1.2.
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The maximum stress in this piping as calculated by Equation (9), of paragraph NC-3652 of ASME Code Section III, when subjected to the combined loadings of internal pressure, deadweight, and postulated pipe rupture outside the break exclusion zone, does not exceed 2.25 Sh or 1.8 Sy.
The number of circumferential piping welds is minimized by using pipe bends in place of welding elbows when practicable. There are no longitudinal piping welds in the break exclusion zone. Where guard pipes are used, there are no circumferential or longitudinal welds in the piping enclosed within the guard pipe. Details of the arrangement are shown j
in Figure 3.8.2-4.
When required for isolation valve operability, structural integrity, or containment
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integrity, anchors or five-way restraints capable of resisting torsional and bending moments produced by a postulated pipe break, either upstream or downstream of the piping and valves which form the containment isolation boundary, are located reasonably close to the isolation valves or penetration.
The anchors or five-way restraints do not prevent the access required to conduct in-service inspection examinations specified in Section XI of the ASME Code. In-service examinations completed during each inspection interval provide 100-percent volumetric examination (according to IWA-2400, ASME Code,Section XI) of circumferential pipe welds within the boundary of these portions of piping during each inspection interval.
This volumetric inspection applies to piping that is equal to or greater than a 3 6-inch j nominal diameter.
Welded attachments to these portions of piping for pipe supports or other purposes are avoided. Where welded attachments are necessary, detailed stress analyses are performed to demonstrate compliance with the limits of subsection 3.6.2.1.1 and applicable requirements of Section XI of the ASME Code.
The requirements of ASME Code,Section III, Subarticle NE-ll20, are satisfied for the containment penetration.
Class 3 pipe satisfies the fabrication and inspection requirements for Section III, Class 2 pipe.
W Revision: 12 osua,ni2vnosa ai2-03iio?
Draft,1997 3.6-16 W Westingt100$8
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