ML20214P591
| ML20214P591 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 11/20/1986 |
| From: | Adensam E Office of Nuclear Reactor Regulation |
| To: | Farrar D COMMONWEALTH EDISON CO. |
| References | |
| NUDOCS 8612040277 | |
| Download: ML20214P591 (11) | |
Text
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November ~ 20, 1986 DISTRIITION:
@6cket Nos. 50-373/374-
-Docket Nos:'50-373 NRC PDR' and 50-374 Local PDR BWD-3 r/f EAdensam ABournia
'Mr. : Dennis L. Farrar EHylton
= Director of Nuclear Licensing RLi Commonwealth Edison Company Attorney, OGC-P.O. Box 767 EJordan Chicago, Illinois 60690 BGrimes JPartlow
Dear Mr. Farrar:
ACRS (10)
~
Subject:
Additional Information on Operability Assessment Criteria for Piping System - La Salle County Station, Units 1 and 2 By letter dated October 8, 1986, you submitted a request for approval of pro-posed operability assessment criteria for performing piping system evaluations at la Salle County Station, Units 1 and 2.
As a result of our review of your submittal, we find that we need additional infomation in order to complete our review. Enclosed please find the additional information reauested.
If you should have any ouestions, please contact Anthony Bournia, Pro.iect Manager, at (301) 492-8698 Sincerely,
/S/
Elinor G. Adensam, Director BWR Project Directorate No. 3 Division of BWR Licensing
Enclosure:
As stated cc: See next page BVD-3: DBL L
3: DBL D:
DRL ABournia/hmc on EA am 11/f]/86 11/()/86 11/[
86 8612040277 861120 PDR ADOCK 05000373 P
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' Mr. Dennis L. - Farrar la Salle County Nuclear Power Station Commonwealth Edison Company Units 1 & 2 cc:
Philip P. Steptoe, Esquire John W. McCaffrey Suite 4200 Chief, Public Utilities Division One First National Plaza 160 North La Salle Street, Room 900 Chicago, Illinois 60603 Chicago, Illinois 60601 Assistant Attorney General 188 West Randolph Street Suite 2315 Chicago, Illinois 60601 Resident Inspector /LaSalle, NPS U.S. Nuclear Regulatory Commission Rural Route No. 1 P.O. Box 224 Marseilles, Illinois 61341 Chairman La Salle County Board of Supervisors La Salle County Courthouse Ottawa, Illinois 61350 Attorney General 500 South 2nd Street Springfield, Illinois 62701 Chairman Illinois Commerce Commission Leland Buf1 ding 527 East Capitol Avenue Springfield, Illinois 62706 Mr. Gary N. Wright, Manager Nuclear Facility Safety Illinois Department of Nuclear Safety 1035 Outer Park Drive, 5th Floor Springfield, Illinois 62704 l
l Regional Administrator., Region III l
U. S. Nuclear Regulatory Commission 799 Rossevelt Road Glen Ellyn, Illinois 60137 l
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- ATTACHMENT - REQUEST FOR ADDITIONAL INFCRETICH 1.0 GENERAL-QUESTIONS REGARDING THE APPLICABILITY OF THE PROPOSED OPERABILITY CRITERIA 1.
The last sentence of the first paragraph under Section 2.0,
" Background", seems to imply that any evaluation for unanticipated loadings would be limited to only the subsystem in which the loading or support component failure occurs. What evaluations would be performed on branch line systems if, on the run subsystem, an unanticipated loading 1
occurs?
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- 2. Are the proposed operability criteria intended to be used to assess the functional adequacy of valves, pumps, turbines, or other mechanical / electrical equipment?
3.
Will analysis techniques to determine piping systsm responses and support loads be the same as those used for the original design.
calculations? Would independent support motion, ASME Code Case N-411 damping, or response spectra peak shifting (ASME Code Case N-397) be i
utilized in the calculations involving unanticipated dynamic loads?
4.
What course of action is planned if evaluations indicate concern at locations where excessive deformations (i.e. large strains) are not acceptable (e.g. flange leakage, piping components or equipment nozzles deform such that the flow area reduces beyond that required by system performance,etc.)?
5.
Are overpressurization loadings or temperatures beyond design l
- limits included in the definition of unanticipated loadings for the proposed operability criteria?
6.
Will "as-built" piping system data per I&E Bulletin 79-14 requirements be utilized for the reanalysis efforts?
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Please discuss the accuracy of linear elastic analysis techniques in adequately predicting large strains, stresses.significantly beyond the material yield strength, equipment responses, and support loads which may be evaluated under the proposed operability criteria.
8.
After the discovery of an unanticipated loading, what course of action will be followed? The response should include when the discovery is made during operation and during an outage, whether or not examination or component replacement would be made, in what time frame, monitoring programs, etc. What corrective actions would be taken to prevent the recurrence of unanticipated loads?
9.
Would postulated line break locations per SRP 3.6.2 criteria, in-service inspection (ISI) requirements per ASME Section XI, or any other operational requirements change as a result of recalculated stresses or cumulative fatigue values evaluated due to unanticipated loadings? We'.1 d line break locations be postulated for Class 1 and Class 2/3 piping if the evaluated cumulative usage factor exceeds 0.1? Discuss the inten'ded course of action and the impact on operability if the stress limit of 0.8 h + S ) for Class 2/3 piping or the stress limit of 2.4S for (1.2S A
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Class 1 piping is exceeded one or more times?
- 10. What edition and addenda of the ASME Code would be utilized in tne proposed evaluations?
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l 2.0 SPECIFIC QUESTIONS REGARDING CLASS 1 PIPING SYSTEMS AND WELDED ATTACHMENTS OPERABILITY CRITERIA 1.
Does the first sentence under Section 3.1, " Piping and Welded Attachments", imply that the effects of unanticipated loadings must satisfy all the requirements of NS-3600, including stress limits?
If this is not the proper interpretation, are alternate stress limits (if t
applicable, please specify and discuss) proposed for the evaluation of Class 1 piping and welded attachments subjected to unanticipated thermal l
loadings? What course of action (visual examinations, NDE, component
! replacement, etc.) would be follo'wed if either of these stress _ limits are exceeded? If just an evaluation of fatigue life is proposed and no stress limits are implied in the proposed operability criteria for unanticipated thermal loads, please discuss the impact on operability of Class 1 piping and welded attachments subjected to potentially excessive and repetitive thermal gradients, thermal ratchet loadings, elastic fatigue loadings, and l
elastic-plastic fatigue loadings.
2.
What is the impact on operability if the recalculated stresses due to an unanticipated thermal loading exceed 3S, potentially preventing m
elastic plastic shakedown from occurring?
- 3..Will the GE Topical Report NEDO-21985 be utilized for evaluating unanticipated mechanical loadings? What is the intended course of action (visual examination, NDE, component replacement, etc.) if the stress limits specified in that document are exceeded? Will fatigue effects from unanticipated mechanical loadings be incorporated into the cumulative fatigue life? If so, explain the methodology to be utilized.
4.
Per the requirements of the proposed operability criteria, under what circumstances and when would visual examinations of Class 1 piping systems or welded attachments be performed after unanticipated loadings?
I Explain for both mechanical and thermal loadings.
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Per the requirements of the proposed operability criteria, under what circumstances and when would NDE' examinations of Class I piping systems or welded attachments be performed after unanticipated loadings?
Explain for both mechanical and thermal loadings.
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6.
Per the requirements of the proposed operability criteria, under' l
'what circumstances and when would replacement of Class 1 piping system components or welded attachments be performed after unanticipated i
loadings? Explain for both mechanical and thermal loa'ings.
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7.
How are welded attachments to be analytically evaluated under the proposed operability criteria? Would WRC Bulletin 107, ASME Code Cases N-318, N-391, and N-392, or other methodology (please specify) be l
utilized?
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8.
How do ASME Section XI requirements correlate with the proposed
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operability criteria for Class 1 piping systems? Do the inspection i
requirements of 4 and 5 above satisfy Section XI requirements?
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9.
Tests have indicated that the fatigue life of material is dependent
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upon the order and magnitude of cyclic loadings imposed. What effects do unanticipated loadings have on the predicted fatigue life of piping components, especially if the unanticipated loading results in large imposed strains? Is the cumulative usage factor of 1.0 for both design l
and unanticipated loadings technically adequate? Should the cumulative j
usage factor due to unanticipated loadings alone be limited to a value less than 1.0 to minimize potential reductions in the predicted fatigue life?
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l 3.0 SPECIFIC QUESTIONS REGARDING CLASS 2 AND 3 PIPING SYSTEMS AND WELDED ATTACHMENTS OPERA 8ILITY CRITERIA 1.
Regarding the last sentence under Section 3.1, " Piping and Welding l
Attachments", please define for clarity the term " highly stressed areas"?
i 2.
No ASME Code stress limits are implied in the proposed operability criteria for unanticipated thermal loads. Are alternate stress limits (if applicable, please specify and discuss) proposed for the evaluation of Class 2 and 3 piping and welded attachments subjected to unanticipated thermal loadings? What course of action (visual examination, NDE, component replacement, etc.) would be followed if these stress limits are exceeded? If just an avaluation of fatigue life is proposed and no stress limits are implied in the proposed operability criteria for unanticipated thermal loads, please discuss the impact on operability of Class 2,and 3 piping and welded attachments subjected to potentially excessive'and repetitive thermal gradients, thermal ratchet loadings, elastic fatigue loadings, and elastic-plastic fatigue loadings.
3.
What is the impact on operability if the recalculated stresses due to an unanticipated thermal loading exceed 2Sy (taken at operating temperature of the transient), potentially preventing elastic-plastic shakedown from occurring?
4.
Will fatigue effects from unanticipated mechanical loadings be incorporated into the cumulative fatigue life? If so, explain the methodology to be utilized?
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Per the requirements of the proposed operability criteria, under what circumstances and when would visual examinations of Class 2 and 3 piping systems or welded attachments be performed after unanticipated loadings? Explain for both mechanical and thermal loadings.
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6.
Per the requirements of the proposed operability criteria, under what circumstances and when would NDE examinations of Class 2 and 3 piping systems or welded attachments be performed-after unanticipated loadings?
Explain for both mechanical and thermal loadings.
7.
Per the requirements of the proposed operability criteria, under what :ircumstances and when would replacement of Class 2 and 3 piping
' system components or welded attachments be performed after unanticipated loadings? Explain for both mechanical and thermal loadings.
8.
How are welded attachments to be analytically evaluated under the proposed operability criteria? Would WRC Bulletin 107, ASME Code Cases N-318, N-391, and N-392, or other methodology (please specify) be utilized?
i 9.
How do ASME Section XI requirements correlate with the proposed operability criteria for Class 2 and 3 piping systems? Do the ins'ection p
requirements of 5 and 6 above satisfy Section XI requirements?
- 10. What is the intended course of action if the ratio of n/N exceeds 1.07
- 11. What material limitations are implied in the use of the fatigue equation N = (245000/iS)5 cycles?
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- 12. Tests have indicated that the fatigue life of material is dependent upon the order and magnitude of cyclic loadings imposed. What effects do l
unanticipated loadings have on the predicted fatigue life of piping components, especially if the unanticipated loading results in large imposed strains? Is the cumulative usage factor of 1.0 for both design and unanticipated loadings technically adequate, particularly since a l
detailed fatigue evaluation like that required for Class 1 piping would 8
not be performed? Should the cumulative usage factor due to unanticipated loadings alone be limited to a value less than 1.0 to minimize potential i
reductions in the predicted fatigue life?
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4.0 SPECIFIC QUESTIONS REGARDING PIPING SUPPORT COMPONENTS AND
-I STRUCTURES OPERABILITY CRITERIA 1.
Please define " faulted allowables" in terms of stress levels, load combinations, and the applicable criteria document.
2.
The proposed operability criteria states that, if faulted allowables are exceeded, visual examinations will be perforired. Are these visual examinations adequate to insure the continued functionality of the support 1
or structure? What about subsurface cracks resulting from the potential overloadings? With regards to fatigue considerations,.how many times would piping support components or structures be allowed to exceed their initial design stress allowables (normal, upset, emergency, and faulted)?
3.
Per the requirements of the proposed operability criteria, under what circumstances and when would visual examinations of piping s.upport components or structures be performed after unanticipated loadings?
Explain for both mechanical and thermal loadings.
4.
Par the requirements of the proposed operability criteria, under what circumstances and when would NDE examinations of piping support components or structures be performed after unanticipated loadings?
Explain for both mechanical and thermal loadings.
5.
Per the requirements of the proposed operability criteria, under what circumstances and when would replacement of piping system component supports or structures he performed after unanticipated loadings? Explain for both mechanical and thermal loadings.
6.
How would the modeling of pipe supports be reflected in the piping system reanalysis if the pipe support component or structure was sufficiently overloaded to cause plastic yielding, brittle fracturing, or r
l buckling and result in a significant drop of the restraining capability of the support in question?
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How do ASME Section XI requirements correlate with the proposed operability criteria for piping component supports? Do the inspection requirements of 3 and 4 above satisfy Section XI requirements?
i 8.
How would containment penetrations be evaluated when subjected to unanticipated loads?
9.
How will standard pipe support components (catalog-items) be evaluated?
- 10. How will concrete expansion bolts or embedments be evaluated under the proposed operability criteria and the requirements of I&E Bulletin 79-02? Include commentary on load type combinations, load component (axial force, shear force, bending moments, and torsion) combinations, and planned evaluations if the concrete is locally cracked around the concrete expansion bolt (s) or embedments.
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5.0 SPECIFIC QUESTION REGARDING THE SARGENT AND LUNDY ATTAC MENT 1.
In order to clearly understand the intended use of the proposed operability criteria, please explain the terms " transient stresses" and "IE Bulletin No. 79-14 allowables" found in the last sentence of the second paragraph of Section 1.0, " Introduction". A similar coment regarding I&E Bulletin 79-14 allowables also appears in Section 7.0,
" Conclusions".
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