Regulatory Guide 1.72

Spray Pond Piping Made from Fiberglass-Reinforced Thermosetting Resin

ML13038A106
Person / Time
Issue date:	11/30/1978
From:	Office of Nuclear Regulatory Research, NRC/OSD
To:
References
RG-1.072, Rev. 2
Download: ML13038A106 (7)

&3&ws~stsn I Revision 2 November 1978 U.S. NUCLEAR REGULATORY

COMMISSION

REGULATORY

GUIDE OFFICE OF STANDARDS

DEVELOPMENT

REGULATORY

GUIDE 1.72 SPRAY POND PIPING MADE FROM FIBERGLASS-REINFORCED

THERMOSETTING

RESIN

A. INTRODUCTION

General Design Criterion 1, "Quality Stand-ards and Records," of Appendix A, "General Dtsign Criteria for Nuclear Power Plants," to 4' y -O CFR Part 50, "Domestic Licensing of Pro-duction and Utilization Facilities," requires that structures, systems, and components important to safety be designed, fabricated, erected, and tested to quality standards com-mensurate with the importance of the safety functions to be performed.

Appendix B, "Qual-ity Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants," to 10 CFR Part 50 requires that measures be established to ensure materials control and control of special processes such as resin molding.Section 50.55a, "Codes and Standards," of 10 CFR Part 50 requires that design, fabrica-tion, installation, testing, or inspection of the specified system or component be in accordance with generally recognized codes and standards.

Footnote 6 to § 50.55a states that the use of specific Code Cases may be authorized by the Commission upon request pursuant to § 50.55a (a)(2)(ii), which requires that proposed alter-natives to the described requirements or por-tions thereof provide an acceptable level of quality and safety.This guide describes a method acceptable to the NRC staff for implementing these require-ments with regard to the design, fabrication, and testing of fiberglass-reinforced thermo-setting resin (RTR) piping for spray pond applications.

This guide applies to light-water- cooled and gas-cooled reactors.

The Advisory Committee on Reactor Safeguards has been con-sulted concerning this guide and has concurred in the regulatory position.Lines indicate substantive changes from previous issue.

B. DISCUSSION

The ASME Boiler and Pressure Vessel Com-mittee publishes a document entitled "Code Cases."' Generally, a Code Case explains the intent of rules in the ASME's Boiler and Pressure Vessel Code (the Code)1 or provides for alternative requirements under special circumstances.

Most Code Cases are eventually superseded by revisions to the Code and then are annulled by action of the ASME Council.Code Case N-155-1 (1792-1), referred to in this guide, is limited to Section III, Division 1, of the Code and is oriented toward design and fabrication of RTR piping. The Code Case does not prescribe a lower temperature limit, prima-rily because the American Society for Testing and Materials (ASTM) specifications do not contain a lower temperature limit, but RTR piping systems would normally be qualified for the intended service temperature condition.

It is planned that after Revision 2 of this guide is issued, the acceptability of future minor revisions to Code Case N-155 (1792) will be noted in Regulatory Guide 1.84, "Design and Fabrication Code Case Acceptability--ASME

Section III Division I." Major revisions to the Code Case will, however, result in a revision to this guide (1.72). Filament-wound struc-tures have mechanical properties superior to fiberglass-filled laminates, and they are con-sidered more desirable when intended for.safety-related pressure components.

The Code Case obtains an allowable design stress from the hydrostatic design basis (HDB)strength as derived from either Procedure A 1 Copies may be obtained from the American Society of Mechan-ical Engineers, United Engineering Center, 345 East 47th Street, New York, New York 1001

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or for Comments and suggestions for improvements in these guides are encouraged at placement on an automatic distribution list for single copies of future guides all times, and guides will be revised, as appropriate, to accommodate comments in specific divisions should be made in writing to the U.S. Nuclear Regulatory and to reflect new information or experience.

This guide was revised as a result Commission, Washington, D.C. 205&5, Attention:

Director, Division of of substantive comments received from the public and additional staff review. Technical Information and Document Control.

point B), constitut,;

the acceleration region of the horizontal Design Response Spec-tra.

For frcquencies higher than 33 cps. the maximum ground acceleration line thc Design RCeptm.c Spcctra.lie vertical cuomponent Design Response Spectra corresponding to the maximum horizontal ground auceicru/ahm of 1.0 g are shown in Figure 2 of this guide.The numerical values of design displacements, velocities, and accelerations in these spectra arc obtained by iultiplying the corresponding values of the maximum horrn tai ground motion (acceleration

= 1.0 g and displacement

= 36 in.) by the factors given in Table II of this guide. The displacement region lines of the Design Response Spectra are parallel to the maximum ground displacement line and are shown on the left of Figure 2.The velocity region lines slope downward from a frequency of 0.25 cps (control point D) to a frequency of 3.5 cps (control point C) and are shown at the top.The remaining two sets of lines between the frequencies of 3.5 cps and 33 cps (control point A), with a break at I %e frcquency of 9 cps (control point B), constitute the acceleration region of the vertical Design Response Spectra. it should be noted that the vertical Design Response Spectra values are 2/3 those of the horizontal Design Response Spectra for frequencies less than 0.25;tor frequencies higher than 3.5, they are the same, while the ratio varies between 2/3 and I for frequencies between 0.2S and 3.5. For frequencies higher than 33 cps. the Design Respone Spectra follow the maximum ground acceleration line.The horizontal and vertical component Design Response Spectra in Figures 1 and 2, respectively, of this guide correspond to a maximum horizontal ground acceleration of 1.0 g. For sites with different acceleration values specified for the design earthquake, the Design Response Spectra should be linearly scaled from Figures I and 2 in proportion to the specified maximum horizontal ground acceleration.

For sites that (1) are relatively close to the epicenter of an expected earthquake or (2) have physical characteristics that could significantly affect the spectral pattern of input motion, such as being underlain by poor soil deporits.the procedure described above will not apply. In these cases, the Design Response Spectra should he developed indivdually according to the site characteristics.

C. REGULATORY

POSITION 1. The horizontal component ground Design Response Spectra, without soil-structure interaction effects, of the SSE, 1/2 the SSE, or the OBE on sites underlain by rock or by soil should be linearly scaled from Figure 12 in proportion to the maximum horizontal ground acceleration specified for the earthquake chosen. (Figure 1 corresponds to a maximum horizontal ground acceleration of 1.0 g and accompanying displacement of 36 in.) The applicable multiplication factors and control points are given in Table 1. For damping ratios not included in Figure I or Table I, a linear interpolation should be used.2. The vertical component ground Design Response Spectra, without soil-structure interaction effects, of the SSE, 1/2 the SSE, or the OBE on sites underlain by rock or by soil should be linearly scaled from Figure 2 in proportion to the maximum horizontal ground acceleration specified for the earthquake chosen. (Figure 2 is based on a maximum honzmtal round accekration of 1.0 g and accompanying displacement of 36 in.) The applicable multiplication factors and control points an given in Table 11. For damping ratios not included in Figure 2 or Table II, a linear interpolation should be used.2 This does not apply to sites which (I) are reattwely clom to the epicenter of an expected earthquake or (2) which hav physical characteristies that could apuficntly affect the spectra tmbmiatton of input motion. The D=srp Respons Spectra for such sites sould be dveioped on a bets.1.60-2 DEFINITIONS

Response Spectrum mcans a plot (4 Ihc maximuin response (acceleration, velocity.

or displaceennt)

of a family of idealized single-degice-of-frcedin, damped oscillators as a function of natural frequencies (or periods) of the oscillators to a specified vibratory motion input at their supports.

When obtained from a recorded earthquake record, the response spectrum tends to be irregular, with a number of peaks and valleys.Delip Respim Spectrum is a relatively smooth relatlionship obtained by analyzing, evaluating, and statistically combining a number of individual response spectra derived from the records of significant past earthquakes.

Maximum (peak) Ground Azcceierltion specified for a gwen site means that value of the acceleration which corresponds to zero period in the design response spectra for that site. At zero period the design response spectra acceleration is identical for all damping values and is equal to the maximum (peak) ground acceleration specified for that sit

e. TABLE I HORIZONTAL

DESIGN RESPONSE SPECTRA RELATIVE VALUES OF SPECTRUM AMPLIFICATION

FACTORS FOR CONTROL POINTS Pero t Amplifitimtlon Factors for Control Points of. ..CrOtf imiraion Oispliammanth

2 iticei Dmping A(33 cps) 8(9 qos) C(2.5 qu I0(0.26 qCR 0.5 1.0 4.96 5.95 3.20 2.0 1.0 3.54 4.25 2.50 5.0 1.0 2.61 3.13 2.05 7.0 1.0 2.27 2.72 1.88 10.0 1.0 1.90 2.28 1.70'Maximum ground displacement is taken proportkma to maximn gpound acoilwation, and is 36 in. for pound accel ation of 1.0 gravity.'A6meimtion and displacement amplificition factors ame taken ftom reconumaenitions given in reference

1.1.60-3 VERTICAL DESIGN RESPONSE SPECTRA RELATIVE VALUES OF SPECTRUM AMPLIFICATION

FACTORS FOR CONTROL POINTS Percnt Amplification Factors. for Control Points of Critical Acceleration'

2 Displacements I oemping A(33 cps) B(9 cps) C(3.5 cps) D10.25 CpS)0.5 1.0 4.96 5.67' 2.13 2.0 1.0 3.54 4.05 1.67 5.0 1.0 2.61 2.98 1.37 7.0 1.0 2.27 2.59 1.25 I0.0 1.0 1.90 2.17 1.13'Maximum ground dispiaoCCncnt is taken proportional to maximum ground acceleration and is 36 in. for ground accelcratin of 1.0 gravity.' Accelcration anipl-aticaton factors for the verti'al design v.sXmnne spectra arc equal to those for uorizontal design rcsponse spectra at a given frequency.

whereas displacement amplification factors are 2/3 those for hori-r ,lial design response spectra. Thesc ratios between the amplification factors for the two desin response spcctra are in aprcement with those recommcnded in reference

1.'Thewe values were changed to make this table consistent with the dis.Luimmin of vertical components in Section 8 of this guid

e. REFERENCES

I. Newmark, N. M., John A. Blume, and Kanwar K.Kapur, "Design Response Spectra for Nuclear Power PIlnts," ASCE Structural Engineering Meeting, San Francisco.

April 1973.2. N. M. Newmark Consulting Engineering Services, "A Study of Vertical and Horizontal Earthquake Spectra," Urbana, Illinois, USAEC Contract No.AT(49-5)-2667.

WASH-1255, April 1973.3. John A. Blume & Associates, "Recommendations for Shape of Earthquake Response Spectra," San Francisco, California, USAEC Contract No.AT(49-5)-301

1, WASH-1254, February 1973.1.60-4 I--0.1 0.2 0.5 1 2 5 10 20 50 100 FRF IUENCY, qu FIGURE

1. HORIZONTAL

DESIGN RESPONSE SPECTRA -SCALED TO lg HORIZONTAL

GROUND ACCELERATION

low0 q~4b 10 KK 0.1 0.2 0. 1 2 5 10 20 50 100 FREQUENCY, q FIGURE 2. VERTICAL DESIGN RESPONSE SPECTRA -SCALED TO 1g HORIZONTAL

GROUND ACCELERATION

UNITED STATES NUCLEAR REGULATORY

COMMISSION

WASHINGTON, D.C. 20555 FIRST CLASS MAIL POS1 AGE & FEES PAID USN RC WASH D C PE RMIT No .Jil OFFICIAL BUSINESS PENALTY FOR PRIVATE USE. $300