ML20214G604
| ML20214G604 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 08/09/1974 |
| From: | Maccary R US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Deyoung R US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| CON-WNP-0063, CON-WNP-63 NUDOCS 8605220314 | |
| Download: ML20214G604 (3) | |
Text
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1 AUG 9 1974 R. C. DcYoung, Assistant Director for Light Water Reactors, Group 1 Directorate of Licensing EVALUATION OF L"iT-2 PIPE RUP'IURE PROTECTION INSIDE CONTADNEVf (TAR-907)
Plant Sam-
'JPPSS Nuclear Project 'lo. 2 Licenainn Stage: Post CP Docket lM.-
50~397 Responsible tranch and Project Manager: L1R l-2, J. Orndoff Review Status: Avaiting Infornation Report UPPSS-74--2-01 attached to the letter of March 19, 1974 from J. J. Stein of L7PSS to A. Giambu: iso, concernint protection against pipe brea'cs inside containment has been reviewed by the Meenanical En?ineering Branch, Directorate of Licensin;;. Enclosed is our request for additional information.
Drigi5al sig5cd by IL R. Eccary R. R. tiaccary, Assistant Director for Engineering Directorate of Licensin",
cc w/ encl:
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H. ilanauer, DRTA F. Schroeder, L W. R. Butler L J. P. KniP t, L h
J. Orndoff, L S. N. Hou, L cc w/o encl:
A. Giambusso, L W. G. Mcdonald, L Docket Files 50-397 L, Reading File L:MEB File b4 or*nc e *
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MECHANICAL ENGINEERING BRANCH DIRECTORATE OF LICENSING REQUEST FOR ADDITIONAL INFORMATION
" PROTECTION OF PIPE BREAKS INSIDE CONTAINMENT" WNP-2, DOCKET NO. 50-397 1.
Supplement Section 2.1.1 by clarifying the procedures used to calculate the stress intensities for ASME Class 1 piping by which the design basis break locations.are determined. The acceptable approach is to compute the maximum stress range between any two load sets (including the zero load set) by Eq. (10) in Par. NB-3653, ASME Code,Section III, for upset plant conditions including an OBE event.
2.
Supplement Section 2.2.1 by providing the criteria used to identify the most probable type of break based on examination of the state of stress in the vicinity of the postulated break J
location. The acceptable criteria are that if the result of a detailed stress analysis (i.e. finite element analysis) indicates that the maximum stress range in the axial direction is at least twice that in the circumferential alreccion, only a circumferential break.need be postulated, and that if the maximum stress range in the circumferential direction is twice or more than the axial direction, only a longitudinal break need be postulated.
t 3.
Supplement Section 2.2.4 by clarifying your intention to constrain the piping systems such that for circumferential breaks, the free 1
and vill aluays move within a plane formed by the free-end seament and the segment at the first change in direction. In lieu of the above, justify that the possible out-of-plan pipe motion need not be considered.
4.
Supplement Section 3.2.3.6 by describing the methods and procedures used to determine the equivalent static loadings for stiff load transmitting members.
5.
The criteria presented in Section 3.4.1 to account for the rapid strain rate effects are not accaptable. Only 10% increase in minimum yield strength at the specific operation temperature is acceptable. Revise your criteria of strain rate effects or provide justification.
J 6.
Supplement Section 4.3 concerning simplified dynamic analysis by providing the following:
a.
A description concerning the methods and procedures used to deteruine those parameters in the egaatian as shown in Figure 3 for calculating R, such as y,, 'y or p) and k.
1 b.
A 'dnscription concerning the procedures used to check whether the restraint design meets the specified s"-ain er deformation limit.
A justification for neglecting the effects of piping rebound.
c.
4 d.
A justification for using the same F for impulse terms and y
steady state terms as shown in Figure 3.