Regulatory Guide 1.142

Safety-Related Concrete Structures for Nuclear Power Plants (Other than Reactor Vessels and Containments)

ML13064A115
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Issue date:	04/30/1978
From:	Office of Nuclear Regulatory Research
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RG-1.142
Download: ML13064A115 (3)

U.S. NUCLEAR REGULATORY

COMMISSION

April 1!978 REGU "LATORnkYk GUIDE OFFICE OF STANDARDS

DEVELOPMENT

REGULATORY

GUIDE 1.142 SAFETY-RELATED

CONCRETE STRUCTURES

FOR NUCLEAR POWER PLANTS (OTHER THAN REACTOR VESSELS AND CONTAINMENTS)

A. INTRODUCTION

ACI Standard 349-76 delineates requirements for the sizing of concrete structural systems and ele-General Design Criteria 1, "Quality Standards and ments, requirements for construction ,etails, and Records," 2, "Design Bases for Protection Against specifications and tests for materials, regulatory Natural Phenomenal" and 4, "Environmental and positions below relate only to Cha through 19 Missile Design Bases," of Appendix A, "General of that standard.

Committee

3 of th merican Design Criteria for Nuclear Power Plants," to 10 Concrete Institute has in p at man itory ap-CFR Part 50, "Licensing of Production and Utiliza- pendices to ACI Standar 3 g thermal ef-tion Facilities," require, in part, that structures, sys- fects, steel embedme , and eci provisions for tems, and components important to safety be de- impulsive and impact cts. gulatory positions signed, fabricated, erected, and tested to quality on these appen s eveloped after their standards commensurate with the importance of the adoption by the ca ncrete Institute.

safety functions to be performed and that they be de-signed to withstand the effects of postulated accidents L TORY POSITION and environmental conditions as well as those effects T ce s and requirements described in ACI associated with normal operating conditions.

This 9-76, "Code Requirements for Nuclear guide describes a method acceptable to the NRC staff d ed Concrete Structures," are generally*Concree Structuf n res,"e aregeerually for complying with the Commission's regulation a p e to the NRC staff and provide an adequate with regard to safety-related concrete structu a for complying with the Commission's regula-(other than reactor vessels and containments)

for -ions with regard to the design of safety-related con-clear power plants. crete structures other than reactor vessels and con-

B. DISCUSSION

tainments, subject to the following:

ACI Standard 3 4 9-7 6 ,1 "Code Require for 1. The applicability of strength design methods to Nuclear Safety Related StrucSJes," was prepared by structures whose principal function is to provide a Committee

349 of the Concrete Institute barrier to contain or retain pressure such as the di-(ACI) and was publish ACI in October vider barrier of the ice-condenser of the PWR con-1976. The standar .s n I Standard 318- tainment or the drywell of the Mark III BWR con-711 (ANSI A89.197 '" Iding Code -Require- tainment is questionable.

Therefore, for those struc-ments for Re o d Co ete," with modifications tures, mere conformance with the requirements*

of to accom at t ings and performance -re- ACI 349-76. is unacceptable to the staff, who will quirements iar to nuclear power plants. ACI continue to review the design of these structures on a Standard 318 long been the basis for the design of case-by-case basis.concrete buildi s in the United States and has been used by the NRC staff as a starting point in evaluat- 2. When concrete structures are used to provide ing the adequacy of concrete structures.

radiation shielding, the provisions of Sections 5.1 and 10 of ANSI Standard N101.6-1972

2 "Concrete Copies may be obtained from the American Concrete Institute, 2 Copies may be obtained from the American Nuclear Society, P.O. Box 4754, Redford Station, Detroit, Michigan 48219. 555 North Kensington Avenue, La Grange Park, Illinois 6052

5. USNRC REGULATORY

GUIDES Comments should be sent to the Secretary of the Commisson, US. Nuclear Rtgu-Regulatory Guides are isued to deIrribe and make available to the public methods latory Commission, Washington, D.C. 20555. Attention:

Docketing and Service acceptable to the NRC staff of imnplementing specific parts of the Commission's Branch.regulations, to delineate techniques used by the staff in evaluating pecific problems The guides are issued in the following ten broad divisions:

or postulated aecidents, or to Provide guidance to applicants.

Regulatory Guides are not iubesitutes for regulations, and compliance with them is not required.

1. Power Reactors 6. Products NMrthods and solutions different from those sat out in the guides will be accept- 2. Research arid Test Reactors 7. Transportation asle if they provide a basis for the findings requisite to the issuance or continuance

3. Fuels and Materials Facilities

8. Occupational Health of a permit or Ic by the Commission.

4. Environmental and Siting 9. Antitrust Review 5. Materials and Plant Protection

10. General Comments and su.ggetions for improvements in these guides ae encouraged at all times, and guides will be revised, as appropriate, to accommodate comments and Requests for single copies of issued guides 1which may be reproduced)

or for place.to reflect new information or experience.

However, comments on this guide,if ment on an automatic distribution list for single copies of fulture guides in specific received within about two months after its iseuance, will be particularly useful in divisions should be made in writing to the US. Nuclear Regulatory Commission.

evaluating the need for an early revision.

Washington.

D.C. 20555. Attention:

Directo,.

Division of Document Control.

Radiation Shields," and those of ANSI Standard N101.4-1972,3 as by Regulatory Guide 1.54, "Quality Assurance Requirements for Protec-tive Coatings Applied to Water-Cooled Nuclear Power Plants," are applicable.

3. ACI Standard 349-76 lacks specific require-ments to ensure ductility of framed structures.

Adherence to the requirements of Appendix A to ACI Standard 318-71 is acceptabie.

4. Section 5.1.2 permits depositing concrete with-out the prior removal of water from the place of de-posit at the discretioni of the owner. Since the pres-ence of water in the place of deposit may seriously affect the strength properties of concrete, it is impor-tant that water be removed before concrete is depos-ited unless a trernie is used.5. Section 5.4.1 allows concrete that has partially hardened or has been contaminated with .foreign ma-terials or remixed after initial set to be reused at the discretion of the engineer.

Such a material would be defective and therefore should not be used.6. in addition to the requirements of Section 1.3.1 of ACI Standard 349-76, the inspectors should have sufficient experience in reinforced and prestressed concrete practice to interpret plans and specifica- tions. The inspectors should be thoroughly familiar with the applicable ACI and ASTM standards.

ACI Standard 311-74,1 "Recommended Practice for Con-crete Inspection," should be followed except where the requirements of Section 1.5 of ACI Standard 349-76 control.7. The frequency of cylinder testing required by Section 4.3.1 of ACI Standard 349-76 is not consist-ent with generally accepted practice.

A test frequency inconformance with ANSI Standard N45.2.5-1974, 4 as endorsed by Regulatory Guide 1.94, '"'Quality As-surance Requirements for Installation, Inspection.

and Testing of Structural Concrete and Structural Steel During the Construction Phase of Nuclear Power Plants," is acceptable.

8. The minimum pressure-testing requirements for embedded piping of ACI Standard 318-71 .have been deleted from ACI Standard 349-76. In order to en-sure that minimum pressure-testing requirements are 3 ANSI N101.4-1972, "Quality Assurance for Proteztive Coat-ings Applied to Nuclear Facilities. " Copies may be obtained from the American Society of Mechanical Engineers, 345 East 47th Street, New York, N.Y. 10017.4 ANSI N45.2.5-1974, "Supplementary Quality Assurance Re-quirements for Installation, Inspection, and Testing of Structural Concrete and Structural Steel During the Construction Phase of Nuclear Power Plants." Copies may be obtained from the Ameri-can Society of Mechanical Engineers.

345 East 47th Street, New York, N.Y.. 10017.met, the pressure tests of embedded pipes in Section 6.3.2.4 of ACI 349-76 should also satisfy the re-quirements of Section 6.3.2.4 of ACI 318-71.9. More- conservative load factors are appropriate in accounting for the effects of normal or shutdown thermal loads, postulated pipe break accidents, and an operating basis earthquake (OBE) in combination with a postulated pipe break. The load factors used in Section 9.3.1 of ACI Standard 349-76 are acceptable-to the staff except for the following:

a. In load combinations

(9), (10), and (11), 1.7 T. should be used in place of 1.4 T,.

b. In load combination

(6), 1.5 Pa should be used in place of 1.25 Pa.

c. In load combination

(7), 1.25 P 5 and 1.25 E 0 should be tised in place of 1.15 Pa and 1.15 E 0 , respectively.

d. In load combinations

(2) and (10), 1.9 E,, should be used in place of 1.7 E,.10. Structures must be able to withstand the effects of differential settlement under environmental loads as well as under abnormal loads. Thus, in Section 9.3.2 of ACI 349-76, consideration of the effects of differential settlement should be included in load combinations (I) (11).11. The provisions of Section 9.3.3 of ACI Stand-ard 349-76 to account for the effects of transitory loads are not sufficiently general. Thus, in Section 9.3.3 of ACI Standard 349-76, when any load re-duces the effects of other loads, the corresponding coefficient for that load should be taken as 0.9 if it can be demonstrated that the load is always present or occurs simultaneously with the other- loads. Other-wise, the coefficient for that load should be taken as zero.12. The provision in Section 9.3.6 of ACI Stand-ard.,349-76 permitting local exceedance of section strength under concentrated dynamic loads does not ensure that the section can withstand the associated distributed loadings.

Thus, if the provision of Section 9.3.6 of ACI 349-76 permitting exceedance of local section strengths is invoked, it should be demon-strated that secion strengths are adequate to accom-modate load combinations

(7) and (8) without the dynamic loads Yj, Yn', and Yr.13. The NRC staff would accept the local excee-dance of section strength for concentrated tornado-generated-missile loading under load combination

(5). However, an analysis should be performed to.demonstrate that section strengths are adequate to ac-commodate load combination

(5) without the dynamic load effect of tornado-generated missiles.1.142-2

14. ACI Standard 349-76 does not address the sub-ject of openings in slabs and footings. -Provisions of Section 11. 12 of ACI 318-71 are acceptable for this purpose.

D. IMPLEMENTATION

The purpose of this section is to provide informa-tion to applicants regarding the NRC staff's plans for using this regulatory guide.Except in those cases in which the applicant pro-poses an acceptable alternative method for complying with specified portions of the Commission's regula.-tions, the method described herein will be used in the evaluation of submittals in connection with construc-tion permit applications docketed after December 15, 1978, unless this guide is revised as a result of suggestions from the public or additional staff re.-view.If an applicant wishes to use this regulatory guide in developing submittals for applications docketed on or before December 15, 1978, the pertinent portions of the application will be evaluated on the basis of this guide.1.142-3/ ,5;/~ A~