ML19347E776
| ML19347E776 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 05/08/1981 |
| From: | Clark R Office of Nuclear Reactor Regulation |
| To: | Withers B PORTLAND GENERAL ELECTRIC CO. |
| References | |
| TAC-12369, NUDOCS 8105130371 | |
| Download: ML19347E776 (14) | |
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/pu utuq'o, UNITED STATES NUCLEAR REGULATORY COMMISSION
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WASHWGTON, D. C. 20$$$
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MAY 0 8 1981
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tb Docket No. 50-344 9
- d o' Y-g.V n ' p, Mr. Bart D. Withers
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Vice President Nuclear Portland General Electric Company 121 S. W. Salmon Street Portland, Oregon 97204
Dear Mr. Withers:
In conducting'our review of your letter of October 23, 1980 relati masonry wall design at Trojan Nuclear Plant, we have determined th,ng to at we will need the additional information identified in the enclosure to continue our review.
'de have also enclosed a copy of "SEB Interim Criteria for' Safety-Related Masonry Wall Evaluation" for your information and to assist you in preparing your response.
In order.for us to maintain our review schedule, your response is requested within 30 days of your receipt of this letter.,
Please contact us if you haye any questions co.ncerning this request.
Sincerely, v+~lA 6~'
Robert A. Clark, Chief Operating Reactors Branch #3 Division of Licensing
Enclosures:
1.
Request for Additional Information 2.
SEB Interim Criteria cc w/ enclosure:
See next page 1-
- h 8105130b11 P
Portland General Electric Company cc: Mr. J. W. Durham, Esquire Vice President and Corporate Counsel Portland General Electric Company 121 S. W. Salmon Street Portland, Oregon 97204 Multnomah County Library Social Science and Science Department 801 S.W.10th Avenue Portland, Oregon 97205 Michael Malmros, Resident Inspector U. S. Nuclear Regulatory Commission i
Trojan Nuclear Plant:
P. O. Box 0 Rainier, Oregon 97048 Robert M. Hunt, Chairman Board of County Commissioners Columbia County St. Helens, Oregon 97501 Director, Criteria and Standards Division Office of Radiation Programs ( ANR-460)
U. S. Environmental Protection Agency Washington, D. C.
20460 Donald W. Godard, Supervisor Siting and Regulation Oregon Department of Energy Labor and Industries Building Room 111 Salem, Oegor 97310
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1
a REQUEST FOR ADDITIONAL INFORMATION 1.
The licensee should confirm that the inspection methods used during construction at Trojan are in conformance with the provisions c,f "Special Inspection" requirements of UBC.
2.
With respect to the use of load factors in conjunction with increased allcwable stresses in the masonry wall evaluation, the licensee should eithe.- demonstrate the equivalency between the staff's interim criteria and the Trojan criteria or quantify the safety margins resulting from the use of Trojan criteria.
Some of the safety margins can probably be quantified by the use of existing test data with Trojan-specific calculations. For this purpose,-
the most critical of all the three types of walls (single-wythe, double-wythe, and composite) should be considered for each o' the safety-related structures and the calculations should be provided for the staff's review. Where test data is inadequate or non-existent, the licensee should conduct tests. The possibility of a long-term confirmatory testing program was discussed with the licensee as early as December, 1979 and was agreed to by the licensee in a December 31, 1979 letter. Earlier SERs were based on the assumption that the licensee would demonstrate the existance of adequate safety-margin in its criteria.
3.
Our position with regard to the Trojan FSAR is that, for the shear wall load combinations, the same load factor values should be considered for both in-plane and out-of-plane loads. The licensee should use the same load factor or provide justification beyond that submitted for not doing so.
t 2-4.
With respect to Table 1 of Attachment 2:
a.
The licensee should clarify whether or not the factor of safety of 2 mentioned in Note 1 applies to the modulus of rupture values for cell concrete; and b.
It is our position that the licensee should not use the values given in this table to evaluate the resistance of walls to applied loads. ValuesgiveninthistablearetobeusedonlyforstiffNess evaluation and load determination. Particularly, in accordance with the UBC Code and the staff's interim criteria, for reinforced masonry flexural design the tensile forces are resisted only by the tensile reinforcement.
Earlier SERs and NRC consultant's reports are also written based on the,above consideration 5.
The licensee should evaluate the impact of using a 4% damping value i
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instead of the 5% damping value used, and submit this informatien for staff review.
6.
The licensee has not addressed the criteria for determining the overall structural response from missile impact. Either these criteria should be provided'or justification for not considering the response should be provided.
In addition, during the recent phone conversation with the licensee it was indicated that the licensee may not have considered the combined effects of tornado wind load and pressure drop loads as indicated in Attachment 1 to the October 23, 1980 letter. Our position is that all e
of the above three effects are to be combined (tris is in conformar.:e with the FSAR; earlier SERs relied on the compliance with FSAR provisions).
The licensee shou'ld comply with the above criteria or provide justification for not doing so.
7.
The FSAR spectra of tornado generated missiles consists of only 3 missiles. -
The licensee should assess the impact of considering the missile spectra given in Standard Review Plan Section 3.5.1.4., and provide the.information for staff's review.
8.
The licensee should clarify, with regard to missile protection, whether the masonry missile barriers protecting single trains of safety-related systems were evaluated to determine their design adequacy.
If this was not done, provide the basis and justification.
9.
The licensee should upgrade the missle.,rotection at locations identified in Attachment 2 to its October 23, 1980 letter. The upgrading should be based on agreed-upon criteria between the NRC staff and the licensee.
As general guidance, the SRP Section 3.5.3 criteria should suffice for the upgrading work.
- 10. With regard to the use of expansion anchor bolts and local load capacity, the licensee has made references to currently ongoing test programs by other organizations. The licensee should submit these test results 7
along with the justification for, their applicability to situations at Trojan to confirm the conservatism of its criteria.
SEB INTERIM CRITERIA FOR SAFETY-RELATED MASONRY WALL EVALUATION G
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e 6
TABLE OF CONTENTS 1.
General Requirements 2.
Loads and Load Combinatimtr a.
Service Load Conditions b.
Extreme Environmental, Abnormal, Abnormal / Severe Environmental, and Abnormal / Extreme Environmental Conditions 3.
Allowable Stresses 4.
Design and Analysis Considerations 5.
Revision of Criteria 6.
References h
9 6
6
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1.
General Recuirements The materials, testing, analysis, design, construction and inspection related to the design and construction of safety-related concrete masonry walls, hall confom to the applicable requirements contained in Unifonn Building Code - 1979, unless specified otherwise, by the provisions in this criteria.
The use of other industrial codes, such as ACI-531, ATC-3 or NCMA is also acceptable. However, when the provisions of these codes are less conservative than the correspending provisions of the interim criter a, their use should be justified on a case-by-case basis.
c 2.
Leads and Load Cc.binations The leads and lead combinations shall include consideration of normal loads, severe environmental load, extr.eme environmental load, and abncmal leads.
Specifically, for operating plants the load combinations provided in plant's FSAR shall govern.
For operating license applications, the felicwing icad combinations shall apply (for definition of Icad tems, see SRP Section 3.8.4.11-3).
(a) Service Load Conditions
'l)
D+L (2)
D+L+E (3)
D+L
'd If tnemal stresses due to T and R are present, they should be included
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in the above combinations, as follows:'
E00R BRIGinnc
2 (la)
D+L+T+Ro o
(2a) D + L + T,+ R,+
E (3a)
D + L + T,+ R,+ W Check load combination for controlling condition for maximum
'L' and for no 'L'.
(b) Extreme Environmental, Abnormal, Abnormal / Severe Environmental and Abnonnal/ Extreme Environmental Conditions (4)
D + L + T,+ R,+ E
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(5)
D+L+T+R+W J-o o
t (6)
D + L + T,+ R,+ 1.5 P, (7) D + L + T,+ 1.25 P,+ 1.0 (Y
- Y
- Y ) + 1.25 E + R, r
j m
e (8) D + L + T,+ R,+ 1.0 P,+ 1.0 (Y ' Y + Y ) + 1.0 E r
j m
In combinations (6),. (7), and (8), the. maximum values of P,, T,, R,, Y), Y, and Y, including an accropriate dynamic r
load factor, should be used unless a time-history analysis is performed to justify otherwise. Combinations (5), (7) and (8) and the corresponding structural acceptance criteria should be satisfied first without the tornado missile lo'ad in (5) and without Y,,
Y,, and Y_in (7) and (8).
'n' hen considering these loads, local section strength cacacities may be exceeded under these concentrated loads, provided there will be no loss of functien' of any safety-related system.
Both cases.cf L havtng its full' value or being completely absent should~ be checked..
P00R 0RIGINAl.
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3.
Allewable Stresses Allowable stresses provided in Chapter 24 of UBC-79, as supolemented by the following modifications / exceptions shall apply.
(a) When wind or ssismic loads (DBE) a-e considered in the leading combinations, no increase in the alicwable stresses is permitted.
(b) Use of.allowabl.e stresses corresponding to special inspection
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category shall be substantiated by cemenstration of compliance with the inspection requirements of the NRC c-iteria.
(c) No tension perpendicular to bed joints of either. einforced or unreinfor:ed masonry walls is allowed, except in the evaluation of unreinforced masonry walls of operating-plants.
In such cases, the allowable values of USC-79 ca'n be used, if justified by test program or other means.
(d) For load conditions, which represent extreme environmental, abnormal, abnormal / severe environrental, and abnormal / extreme environmental conditions the allowable working stresses may be multiplied by the fa'ctors shown in the following table:
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PDDR ORIGINAL
TYPE OF STRESS FACTOR (1)
Axial or Flexural Compression 2.5 Bearing 2.5 Reinforcement stress except shear 2.0 but not to exceed 0.9 fy Shear reinforcement and/or bolts 1.5 Masonry tension parallel to bed joint 1.5 Shear carried by masonry 1.0 Masonry tension perpendicular to bed joint for reinforced masonry 0
for unreinforced masonry (2) 1.0 Notes (1) When anchor bolts are used, design should prevent facial spalling of masonry unit.
(2)
See 3 (c).
4.
Desian and Analysis Considerations j
(a)
The analysis should follow established principles of engineering mechanics and take into account sound engineering practices.
(b)
Assumptions and modeling techniques used shall give proper considerations to boundary. conditi:ns, cracking of secticns, if any, and the dynamic behavier of masonry walls.-
(c)
Damping values to be used for dynamic analysis shall be those -
for reinf:rced c:ncrete given S..egulat ry Guice 1.61 c
P00R ORIGINR
5 (d)
In general, for cperating plants,the seismic analysis and Category I structural requirements of FSAR shall apply. For other plants, corresponding SRP requirements shall apply.
(e) The analysis shculd censider both in-plane and out-or. plane loads.
(f)
Interstory drif t ef fects should be censidered.
(g)
In new construction, no unreir. forced masonry wall is pemitted, also all grout in concrete masonry walls shall be compacted by vibration.
(h) For masonry shear walls, the minimum reinforcement requirementc of ACI-531 er ATC-3 shall apply.
(i)
Special censtructions (e.g. multiwythe, ccrnposite) or other items not covered by the cede shall be revieaed en a case-by-case b'a. sis for their acceptance.
(j ) 1.icensees or applicants shall submit QA/0C infomation, if available, for staff's review.
In the event, CA/0C infomation is not available, a field survey and a test program reviewed and approved by the staff shall be implemented to ' '
ascertain the confcmance of masenry construction to design drawings and specifications (e.g. re'bar. and grouting).
(k) Fcr ma'sen y walls recuiring prctection from spalling and scabbing due te accicent pioe reaction (Y l' d't
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and mi ssile imcact r
j (Y,.), the recuiremen s cf SP.? 3.5.3 shall a;cly.
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CRP 3.5.3 shall ce revie-ed and approvac cn a case-by-case basis.
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5.
Revision of Criteria The criteria will be revised, as appropriate, based on:
(a) Design review meetings with the selected licensees and their A/E's.
(b) Experience gained during review.
(c) Additional. infomation develeped through testing and researches.
6.
References (a)
Unifor n Building Code - 1979 Editien (b) Building Code Requirements for Concrete Masonry Structures ACI-531 - 79 and Commentary ACI-531R - 79.
(c) Tentative Provisions for the Deveicpment cf Seismic Re.gulations for Buildings - Applied Technelegy Ocuncil ATC 3-06.
(d) Specification for the Design and Ocnstruction of Load-bearing Concrete Masonry - NCMA August,1979.
(e) Trejan Nuclear Plant Cencrete Masonry Design Criteria Safety Evaluation Report Supplement - November,1980.
POOR ORIGINAL
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