ML18081B336
| ML18081B336 | |
| Person / Time | |
|---|---|
| Issue date: | 04/14/1979 |
| From: | Moseley N NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | Engelken R, Grier B, James Keppler, James O'Reilly, Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I), NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II), NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III), NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV), NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| Shared Package | |
| ML18081B337 | List: |
| References | |
| NUDOCS 7907180613 | |
| Download: ML18081B336 (3) | |
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UNITED STAT=S NU-Ct:EAi~ REGULATORY CO!'J!MISSION W.l!.!.'MINGTON, Il. C. 2~~
April 14. 1979 M8>10RANDIJM FOR:
B. H. Grier. Director 7 RI J. P. O'Reilly, Director, RII J. G.
Keppler~ Director, RIII K. V. Seyfrit, Director, RIV R. H. Engelken, Director~ RV FROM:
Norman C. Moseley, Director, Division of Reactor Operations Inspection, OIE
SUBJECT:
IE EULLETIN 79-07, SEISMIC STRESS ANl\\LYSIS OF S,>1.FETY-RELATED PIPING The subject IE l3u11etin shou1d be dispatched for action by Apr11 14, 19799 to an power reactor facilities with.:ni operating license or con-s*truction pel41lit.
The text of the Bulletin and a draft letter to the 1 icensee are enclosed for this purpose.
Enc1osures:
L Draft Transmitta1 Letter.
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Nonnan C. Moseley Director Division of Reactor Operations Inspection Office of Inspection and Enforcement to all 1icensees and Permit Holders
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IE Bull et in No. 79-07 CONTACT:
E. L. Jordan, IE 49-28180
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{D'f'ti.ft let.tar to ;.11 power reactor facilities with an operating 1icense or a construction pennit}.
IE Bulletin No. 79-07 Addressee:
Enclosed is IE Bulletin No. 79-07 \\'jhich requires action by you with regard to your power reactor facility(ies) with an operating license or a construction permit.
Should you have any questions regarding this Bulletin or the actions required by you, please contact this of*fice.
Sincerely, Signature (Regional Director)
Enclosure:
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IE Bulletin No. 79-07 April 14, 1979 Page 2 of 3 Although the greatest differences in predicted loads would tend to be limited to localized stresses in pipe supports and restraints or in weld attachments to pipes, there could be a substantial number of areas of high stress in piping, as we1l as a number of areas in which there is potential for damage to adjacent restraints or supports.
Any of these situations could have significant adverse effects on the ability of the piping system to withstand seismic events.
The NRC staff has not yet determined that all of the p1p1ng systems important to safety that were designed using a piping analysis computer code which contains the algebraic summation error, have been identified.
Certain information is needed in order to make this determination.
Action To Be Taken By All Licensees and Pennit Holders:
For all power reactor facilities with an operating license or a construction permit:
(1)
Identify which, if any~ of the methods specified below were employed or were used in computer codes for the seismic anulysis of safety related pipin.g in you~ plant and provide a 1ist of safety systems (or portions thereof) affected:
Response Spectrum Model Analysis:
- a.
Algebraic (considering signs) summatio~ of the cadirectional spatial components (i.e., algebraic suJJ'lttlation of the maximum values of the codirectional responses caused by each of the components of ea\\*thquake motion at a particular point in the mathematical model).
- b.
Algebraic (considering signs) summation of the codirectional inter model responses (i.e., for the number of modes considered, the maximum values of response for each mode summed algebraically).
Time History Analysis:
- a.
Algebraic summation of the ccdirectiona1 maximum responses or the time dependent responses due to each of the components of earthquake motion acting simultaneously when the earthquake directional motions are not statistically indep~ndent.