ML20028B784

Structural Engineering Branch Criteria for Safety-Related Masonry Wall Evaluation

ML20028B784
Person / Time
Site:	Rancho Seco
Issue date:	07/31/1981
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20028B783	List: ML20028B782 ML20028B784
References
IEB-80-11, TAC-42918, NUDOCS 8212060027
Download: ML20028B784 (8)

Text

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SEB CRITERIA FOR SAFETY-RELATED MAS 0!1RY WALL EVALUATIO:4 B

JULY 1981 8212060027 821122 PDR ADOCK 05000312 p

PDR

TABLE OF CONTENTS 1.

General Requrirements 2.

Loads and Load Combinations a.

Service Load Conditions b.

Extreme Environmental, Abnormal, Abnormal / Severe Environmental, and Abnormal / Extreme Environmental Conditions 3.

Allowable Strerses 4.

Design and Analysis Considerations t

5.

References l

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1.

General Requirements The materials, testing, analysis, design, construction and inspection related to the design and construction of safety-related concrete I

masonry walls shall conform to the applicable requirements contained in Unifor Building Code - 1979, unless specified otherwise, by the j

f provisions in this criteria.

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The use of other standards or codes, such as ACI-531, ATC-3 or NCMA are also acceptable. However, when the provisions of these codes are less conservative than the corresponding provisions of the criteria,

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their use should be justified.cn a case-by-case basis.

In new construction, no unreinforced masonry wall will be permitted.

4 For operating plants, existing unreinforced walls will be evaluated by the provisions of this criteria.

Plants applying for cperating l.

license which have already built unreinforced masonry walls, will be evaluated on a c.ase-by-case basis.

2.

Loads and Load Combinations The loads and load tumbinations shall include consideration of normal l

loads, severe environmental leads, extreme environmental loads, and l

abnormal loads. Specifically, for operatiTig plants the lcad combinations provided in plant's FSAR shall govern.

For mperating license appliIations, i

the follo. sing load combinations shall apply (for definition of load terms,

.see SRP Section 3.8.411-3).

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(a) Service Load Conditions (1) D+L (2) D+L+E (3) D+L+W f

If thermal stresses due to T and R are present, they should be included o

o in the above combinations, as follows:

(la) D + L + T + P o

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(2a) D + L + T + P + E o

o (3a) D + L + T + P + W o

o Check load combination for controlling condition for maximum

'L' and for no 'L'.

(b)

Extre :e Environmental, Abnormal, Abnormal /Servere Environmental f

and Abnormal / Extreme Environmental Conditions (4)

D+L+T+P+E o

o (5) D+L+To+R+Wt o

(6) D + L + T + R '+ 1. 5 P a

a a

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(7)

D + L + T + R + 1. 25 P + 1. 0 (Y + Yj + Ym ) + 1. 25 E a

a a

p (8) D + L + T + R + 1. 0 P + 1. 0 (Y + Y + Ym ) + 1. 0 E '

a a

a p

j In ccmbinations (6), (7), and (8) the maximum val,ues of Pa, T P > Yj,* Y, and Ym, including an appropriate dynamic a

a r

load factor, shcruld be used unless a time-history analysis is' performed to justify otherwise.

Combinations (5), (7) and (8) and the corresponsing structural acceptance criteria should be satisfied first without the tornado missile load in (5) and without Yr, Yj, and h in (7) and (8). When censidering these l

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3 loads, local section strength capacities may be exceeded under these concentrated loads, provided there will be no loss of function of any safety-related system.

Both cases of L having its full value or being completely absent should be checked.

l 3.

Allowable Stresses Allowable stresses provided in ACI-531-79, as supplemented by the following modifications / exceptions shall apply.

(a) When wind or seismic loads (0BE) are considered in the loading combinations, no increase in the allowable stresses in permitted.

(b) Use of allowable stresses corresponding to special inspection

l category shall be substantiated by demonstration of compliance with the inspection requirements of the SEB criteria.

(c) When tension perpendicular to bed joints is used in qualifying the unreinforced masonry walls, the allowable value will be justified by test program or other means pertinent to the plant and loading l

conditions.

For reinforced masonry. walls, all the tensile stresses i

I will be resisted,by reinforcement.

(d) For load conditions, which represent extreme environmen al, abnormal, abnormal / severe environmental, and abnormal / extreme environmental conditions the allowable working stresses ny be multipli,ed by the factors shown in the following table:

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4 TYPE OF STRESS FACTOR Axial or Flexural Compression -(1)

2. 5 Bearing

2. 5 Reinforcecent 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 1.3 Masonry tension perpendicular to bed joint for reinforced masonry 0

for unreinforced masonry (2) 1.3 1

1 Notes (1) When anchor bolts are used, design should prevent facial spalling of masonry unit.

(2) See 3 (c).

4.

Design and Analysis Considerations (a) The analysis should follow established principles of engineering

.:echanics and take into account sound engineering practices.

(b) Assumptions and modeling techniques used shall give proper considerations to boundary conditions, cracking of sections, if-any, and the dynamic behavior of masonry walls.

i (c) Damping values to be used for dynamic analysis shall be those for reinforced concrete given in Regulatory Guide 1.61.

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In general, for operating plants the seismic analysis and

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i Category I structural requirements of FSAR shall apply.

For other plants, corresponding SRP requiraments shall apply. The seismic analysis shall account for the variations and uncer-tainties in mass, materials and other pertinent parameters used.

(e) The analysis should consider both in-plane and out-of-plane loads.

(f)

Interstory drift effects should be considered.

(g) In new construction, grout in concrete masonry walls, whenever i

l used, shall be compacted by vibration.

(h) For masonry shear walls, the minimum reinforcement requirements of ACI-531 shall apply.

(i) Special constructions (e.g. multiwythe, composite) or other items not covered by the code shall be reviewed on a case-by-case basis for their acceptance.

(j) Licensees or ap'plicants shall submit" QA/Q'C information, if

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available, for staff's review.

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i In the event, QA/QC information is not available,'a fid1d survey a

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and a test program reviewed and approved by tiie staff shall 6e

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-- m implemented to ascertain the conformance of masonry construction

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to design drawings and specifications (e.g. rebar and grouting).

(k)

For masonry walls requiring protection from spalling and scabbing due to accident pipe reaction (Y ), jet impingement (Yj) and r

missile impact (Y ), the requirements similar to those of m

SRP 3.5.3 shall apply. However, actual review will be conducted on a case-by-case basis.'

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5.

References (a) Uniform Building Code - 1979 Edition (b)

Building Code Requirements for Concrete Masonry Structures ACI-531 - 79 and Commentary ACI-531R - 79.

(c) Tentative Provisions for the Development of Teismic Regulations '

for Buildings - Applied Technology Council ATC 3-06.

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(d) Specification for the Design and Construction of Load-bearing

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Concrete Masonry - NCMA August,1979.~

(e) Trojan Nuclear Plant Concrete Masonry Design Criteria Safety Evaluation Report Supplement - November, in 3.

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