ML14138A082

Forwards Revision 1 to 820626 re-evaluation Guideline - Seismic Criteria for SEP Group II Plants (Excluding Structures),Per SEP Topic III-6, Seismic Design Considerations

ML14138A082
Person / Time
Site:	San Onofre
Issue date:	09/20/1982
From:	Paulson W Office of Nuclear Reactor Regulation
To:	Dietch R SOUTHERN CALIFORNIA EDISON CO.
References
TASK-03-06, TASK-3-6, TASK-RR LSO5-82-09-060, LSO5-82-9-60, NUDOCS 8209270289
Download: ML14138A082 (15)

Text

September 20, 1982 Docket No. 50-206 LS05-82-09-060 Mr. R. Dietch, Vice President Nuclear Engineering and Operations Southern California Edison Company 2244 Walnut Grove Avenue Post Office Box 800 Rosemead, California 91770

SUBJECT:

SEP TOPIC 111-6, SEISMIC DESIGN CONSIDERATIONS, STAFF GUIDELINES FOR SEISMIC EVALUATION CRITERIA FOR THE SEP GROUP II PLANTS -

REVISION 1 On June 26, 1982, we forwarded criteria acceptable to the staff for your seismic analysis of systems and components entitled, "Reevalua tion Guideline Seismic Criteria for SEP Group II Plants (Excluding Structures)." Based upon discussions of this criteria with the licensees for Haddam Neck, Yankee and San Onofre 1, and further review of the criteria by the staff and its consultants, we have determined that some aspects of these guidelines require clarification and that a revision is warranted. The revision 1) clarifies the intent of certain load combinations; 2) provides criteria for both Class 1 and Class 2 supports and mechanical equipment; 3) references the ASMIE Code for scope and evaluation criteria for pump and valve S#t structural integrity and 4) limits active component deformation evaluations for valve operators, pump internals and similar mechanical components (e.g., CRDs) to items contained in safe shutdown systems.

UDID Other methods or approaches to seismic reanalysis of systems and com ponents may be acceptable, however, they will require specific a

justification and will be reviewed on a case-by-case basis.

Sincerely, Walt Paulson, Project Manager 8209270289 820920 Operating Reactors Branch No. 5 PDR ADOCK 05000206 J

Division of Licensing PDR

Enclosure:

Reevaluation 0f:BC

.DL MEB: DE Guideline for SEP Group DCrutchfield glia RBosnak II Plants (Excluding Structures) h 9/1/82 Al 2

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.Mr. R. Dietch cc Charles R. Kocher, Assistant General Counsel James Beoletto, Esquire Southern California Edison Company Post Office Box 800 Rosemead, California 91770 David R. Pigott Orrick, Herrington & Sutcliffe 600 Montgomery Street San Francisco, California 94111 Harry B. Stoehr San Diego Gas & Electric Company P. 0. Box 1831

.San Diego, California 92112.

Resident Inspector/San Onofre NPS c/o U. S. NRC P. 0. Box 4329 San Clemente, California 92672 Mayor City of San Clemente San Clemente, California 92672 Chairman Board of Supervisors County of San Diego San Diego, California 92101 California Department of Health ATTN: Chief, Environmental Radiation Control Unit Radiological Health Section 714 P Street, Room 498 Sacramento, California 95814 U. S. Environmental Protection Agency Region IX Office ATTN:

Regional Radiation Representative 215 Freemont Street San Francisco, California 94111 Robert H. Engelken, Regional Administrator Nuclear Regulatory Commission, Region V 1450 Maria Lane Walnut Creek, California 94596

• ALUATION GUIDELINE SEISMIC CRITERIA FOR SEP GROUP II PLANTS (EXCLUDING STRUCTURES)

INTRODUCTION In support of NRC's Systematic Evaluation Program (SEP) for Group II Plants, the following Reevaluation Criteria have been established. These criteria include recommended load combinations with allowable stresses and/or loads for piping systems, component supports, concrete attachments, and equipment. These criteria are based on linear elastic analyses having been performed. The acceptance criteria are generally based on the ASME Code. For situations not covered by these criteria, (i.e. items constructed of cast iron) compatible criteria shall be developed by the licensee and will be reviewed on a case-by-case basis. The licensee is requested to justify major deviations in criteria which appear less conservative than those specified herein.

DEFINITIONS Code ASME Boiler and Pressure Vessel Code,Section III, "Nuclear Power Plant Compnnents," 1980 Edition, Winter 1980 Addenda.

am General membrane stress.

This stress is equal to the average stress across the solid section under consideration, excludes discontinuities and concentrations, and is produced only by mechanical loads.

ob

=

Bending stress. This stress is equal to the linear varying portion of the stress across the solid section under consideration, excludes discontinuities and concentrations, and is produced only by mechanical loads.

PD Design or maxi7 :m operating pressure loads and design mechanical loads.

1

SSE

=

Inertial loads due to Safe Shutdown Earthquake (SSE) and design mechanical loads where applicable.

T

=

Loads due to thermal expansion of attached pipe (constraint of free end displacement).

W

=

Loads due to weight effects.

AM

=

Loads due to SSE anchor movement effects.

S Critical buckling stress.

bk S

=

Allowable stress intensity at temperature listed in ASME Code.

m S

=

Yield strength at temperature listed in ASME Code.

y S

=

Ultimate tensile strength at temperature listed in ASME Code.

u

-=

Local membrane stress.

This stress is the same as a except that it includes the effect of discontinuities.

S

=

ASME Code Class 2 allowable stress value. The allowable stress shall correspond to the metal temperature at the section under consideration.

P=

General Primary Membrane Stress Intensity. This stress m

intensity is derived from the average value across the thickness of a section of the general primary stresses produced by design internal pressure and other specified Design Mechanical Loads, but excluding all secondary and peak stresses. Averaging is to be applied to the stress components prior to determination of the stress intensity values.

2

P

=

Local Membrane Stress Intensity. This stress intensity is the same'as P except that it includes the effects of m

discontinuities.

P=

Primary Bending Stress Intensity. This stress intensity is b

derived from the linear varying portion of stresses across the solid section under consideration produced design pressure and other specified design mechanical loads.

Secondary and peak stresses are not included.

SPECIAL LIMITATIONS

1. Critical buckling loads (stresses) must be.determined taking into account combined loading (i.e., axial, bending,-and shear), initial imperfections, residual stresses, inelastic deformation, and boundary conditions.

Both gross and local bucklin.g must be evaluated.

Critical buckling loads (stresses) shall be determined using accepted methods such as those contained in NASA Plates and Shells Manual or ASME Code Case N-284.

2.

Where stresses excecd material yield strength, it shall be demonstrated that brittle failures and detrimental cyclic effects are precluded, and that dynamic analysis assumptions. are not nonconservatively affected. Where significant cyclic effects are identified, it shall be demonstrated that the structure or component is capable -of withstanding ten full peak deformation cycles.

3. Where results of analysis indicate that the allowable stresses of the original construction code are exceeded in any of the load combinations specified herein, it shall be demonstrated that the in-situ item was designed and fabricated using rules compatible with those required for the appropriate ASME Code Class (Subsection NX2000, 3

4000, 5000, and 6000). In cases where compatibility with the appropriate ASME Code Subsections was not substantially achieved, appropriate reductions in these limits shall be established, justified, and applied.

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ACCEPTANICE CRITERIA FOR PIPING.

Using Code(a) Class 2 analytical procedures [Equation (9),

1 NC-3653.1], the following stresses are not to be exceeded for the specified pip i ng:

Class 1:

P + PfW

+ PD+ ISSE < 1.8 S m

b Class 2:

P + P = W + P ISSE?< 2.4 S The effects of thermal expansion must meet the requirements of Equation (10) or (11) of NC-3653, including moment effects of anchor dis placements due to the SSE if anchored displacement effects are omitted from 1

Equation (9) of NC-3653.

Class 1 analytical procedures (NB-3600) can also be utilized if appropriate allowable stresses specified in NB-3650 are used.

Branch lines shall be arilyzed including the incrtial and displacement input due to the response of the piping to which it is attached at the attachment point,

a.

The references to ASME Code equation and paragraph numbers on this page correspond to the 1980 edition of the code, 1981 winter addenda.

This was done in order to avoid confusion introdu-ced by the initial 1980 edition of the code which renumbered the equations di: l.rently from 'ast and present editions of the code.

Equation numbers pr..sented on this page reflect common onienclature utilized in the rnuclear industry.

ACCEPTANCE CRITERIA FOR CLASS 1 COMPONENT SUPPORTS Acceptance Critpria(a)

Imposed Load (b)

Combinations Linear Plate and Shpll The higher of:

IW + PD Pm 1.0 Sm Code Subsection NF or Design, Level A, and Level B Limits 1W

+ PD +

P2*Pb.

5 11 The higher of:

1W + PD1 + ISSE

+ IAMi Pm < 1 5 Sm or Code Subsection NF 1.2 Sy c) or Level D Limits not to exceed 0.7 Su W + P

+ T

+ ISSE

+Al Pz + Pb$2.25 Sm or 1.85 Sy (c) not to exceed 1.05 Su In addition to the above criteria, the allowable buckling stress shall be limited to 2/3 S bk where Sbk is determined in accordance with Special Limitation 1.

a. These load combinations shall be used in lieu of those specified in ASME Code Subsection NF.

In addition, for brittle types of-matrial not specified in the Code, appropriate stress intensification factors for notches and stress discontinuities shall be applied in the analysis.

b.

The 1.5 Sm value from NB 3221 on which these are based (Code Appendix F 1323.1) shall be limited by Code Section NB 3221.3.

c. Use larger of.

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ACCEPTANCE CRITERIA FOR CLASS 2 COMPONENT SUPPORTS Acceptance Criteria(a)

Imposed Load Combinations Linear Plate and Shell The higher of:

1W + PO

< 1.0 5 Code Subsection NF or Design, Level A, and Level B Limits 1W P

+

a +

T1

< 1.5 S The higher of:

W + PD +

S

+AM

< 1.5 S or p

sCode Subsection NF or Level 0 Limits 0.4 S (b) jW + P0 + Tj + I

+SI AMI 0 b

_ 2.25 S or 0.6 Su (b)

In addition to the &bove crit.ria, the allowable buckling stress shall be limited to 2/3 Sbk' where Sb is determined in accordance with Special Limitation 1.

a.

These load combinations shall be used in lieu of those specified in ASME Code Subsection NF.

In addition, for brittle types of material not specified in the Code, appropriate stress intensification factors-for notches and stress discontinuities shall be applied in the analysis.

b. Use lesser of.

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ACCEPTANCE CRITERIA FOR CONCRETE ATTACHMENTS (a)

1. Concrete Expansion Anchor Bolts Load Combinations:

Same as for component supports.

(b)

Acceptance Criteria:

Wedge type:

1/4 ultimate as specified by manufacturer.

Shell type:

1/5 ultimate as specified by manufacturer.

11.

Grouted Bolts:

Replace(a),(b) (c)

(a)

III. Concrete Embedded Anchors Load Corbinations:

Same as for component suppnts.

(h)

Acceptance Criteria

0.7 S

a. Base plate flexibility effects must be considered.

b. Both pullout and shear loads must be considered in combined loading situations.

c. Unless stresses in the bolts and structure to which they are attach2d are shown to be sufficiently low to preclude concretc/grout/steel interface bond failures. Load combinations are the same as threse for component supports.

ACCEPTANCE CRITERIA FOR CLASS 1 MECHANICAL EQUIPMENT (b)

Cr te i (d) (g)

Component Loadinq Combination iteria Pressure vessels W + PDI+ISSEI+ Nozzle Loadsj m < 2.4 Sm or 0.7 Su (e) and heat-exchangers Mor P.) + Pb :S3.6 Sm or 1.05 Su (e)

Active pumps and W + PDI+ISSE+i Nozzle Loads PIm. 1.2 Sm or Sy (f) other mechanical (Pm or PZ) + Pb :.1.8 Sm components(a),(c),(d) or 1.5 Sy

)

Inactive pumps and w + PDI+ISSEI+!Nozzle Loadsj Pm. 2.4 Sm or 0.7 Su (e) other mechanical (Pm or P9) + Pb

. 3.6 Sm components(c) or 1.05 Su (e)

Active

)

W P1 JSSEt-lNoz7.le Loads P m < 1.2 S.< or Sy (f) valVes(a)

(c)

(d (Pm or PZ) +

< 1.8 Sm or 1.5 Sy i)

Inactive valves(c) t + PDI

+ SSE +Nozzle Loads Pm. 2.4 Sm or 0.7 Su (e)

(Pm or PL) + Pb <.3.6 Sm or 1.05 Su (e)

(e)

Bolt stress shall be limited to:

Tension Sy or 0.7 Su Shear 0.6 Sy or 0.42 Su

a. Active pumps, valves, and other mechanical components (e.g., CRDs) are defined as those that must perform a mechanical motion to accomplish a system safety function.

b. Nozzle loads shall include all piping loads (including seismic and thermal anchor movement effects) transmitted to the component during the SSE.

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c. Scope and evaluation of pumps and valves are to be in accordance with NB 3411, NB 3412, and NB 3546 of the Code, including seismic and thermal anchor movement effects.

d. For.active mechanical equipment contained in safe shut down systems, it shall be demonstrated that deformation induced by the loading on these pumps, valves and other mechanical components (e.g., CRDs) do not introduce detrimental eFfects which would preclude function of this equipment following a postulated SSE event. For valve operators integrally attached to valve bodies, binding can be considered precluded if stresses in the valve body and operator housing and supports are shown to be less than yield.

In these evaluations, all loads (including seismic ahd thermal anchor.moveme2nt effects) shall be included.

e.

Use lesser of two values.

f.

Use greater of two values.

g. The 1.5 Sm value from NB 3221 on which these are based (Code Appendix F 1323.1) shall be limited by Code Section NB 3221.3.

10

ACCEPTANCE CRITERIA FOR CLASS 2 MECHANICAL EQUIPMENT Component Loading Combination (b)

Criteria(d)

Pressure vessels (W + PO +jSSE + Nozzle Loads Im < 2.0 S and heat-exchangers (am or aL) + ub S 2.4 S Active pumps and W + POl+ISSEI+?Nozzle Loadsl am < 1.5 S other mechanical (am or ap) + 9b < 1.8 S components(a),(c),.(d)

Inactive pumps and jW + PDj+ISSE + Nozzle Loadsj am < 2.0 S other mechanical (cm or a.) + ab < 2.4 S components(c)

Active

+ PDI+ISSEI+INozzle Loads am < 1.5 S valves(a),(c),(d)

(am or a)

+ ab < 1.8 S Inactivc valves(c)

IW pD + S'j N

(am or a2 ) + Pb < 2.4 S Bolt stresses shall be limited to:

Tension = Sy or 0.7 S(e)

Shear = 0.6 Sy or 0.42 Su

a. Active pumps, valves, and other mechanical components (e.g., CRDs) are defined as those that must perform a mechan cal motion to accomplish a system safety function.

b. Nozzle loads shall include all p-ipinq loads (including seismic and thermal anchor movement effects) transmit-ed to the component during the SSE.

c. Scope and evaluation of pumps and vlves are to he in accordance with NC 3411, NC 3412, and NC 3521 of the CoJe, including scismic and thermal anchor movement effects.

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d. For active mechanical equipment contained in safe shut down systems, it shall be demonstrated that deformation induced by the loading on these pumps, valves and other mechanical components (e.g.,

CRDs) do not introduce detrimental effects which would preclude function of this equipment following a postulated SSE event. For valve operators integrally attached to valve bodies, binding can he considered precluded if stresses in the valve body and operator housing and supports are shown to be less than.

yield. In these evaluations, all loads (including seismic and thermal anchor movement effects) shall be included.

e. Use lesser of two values.

12

ACCEPTANCE CRITERIA FOR TANKS

.Load Combinations:

1W

+ PDI+jSSE!

+ Dynamic Fluid Pressure Loads(a)

Acceptance Criteria:

Smaller of S or 0.7 S.

In addition, the y

u allowable buckling stress shall be limited to 2/3 Sbk where Sbk. is determined in accordance with Special Limitation 1

a. Dynamic fluid pressure shall be considered in accordance with accepted and appropriate procedures; e.g., USAEC TID-7024. Horizontal and'vertical loads shall be determined by appropriately combining the loads due tn vertical and horizontal earthquake excitation considering that the loads are due to pressure pulses within the fluid. These loads shall also be applied, in combination with other loads, in tank support evaluations.

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