Regulatory Guide 1.48
| ML12298A124 | |
| Person / Time | |
|---|---|
| Issue date: | 05/31/1973 |
| From: | Office of Nuclear Regulatory Research |
| To: | |
| References | |
| RG-01.048 | |
| Download: ML12298A124 (8) | |
May 1973 U.S.
R~GULATO
ATOMIC ENERGY COMMISSION
GiE
DIRECTORATE OF REGULATORY STANDARDS,
REGULATORY GUIDE 1.48 DESIGN LIMITS AND LOADING COMBINATIONS
FOR SEISMIC CATEGORY I FLUID SYSTEM COMPONENTS
A. INTRODUCTION
loading combinations for design or for identifying Seismic Category I fluid system components. The lack of General Design Criterion 2, "Design Bases for adequate guidance: for selecting loading combinations is Protection Against Natural Phenomena," of Appendix A apparent from. a review of recent construction permit to 10 CFR Part 50, "General Design Criteria for Nuclear applications which :reflect design requirements, as Power Plants," requires, in part, that the design bases for contained in the code design specifications. For structures, systems, and components important to safety e~sentially identical components designed for the same reflect appropriate combinations of the effects of plant conditions (i.e., operating conditions of the plant normal and accident conditions with the effects of categorized as normal, upset, emergency, and faulted natural phenomena such as earthquakes. This guide plant conditions) and specified seismic events (i.e.,
delineates acceptable design limits and appropriate one-half the Safe Shutdown Earthquake (SSE) and the combinations of loadings associated with normal SSE) the. loading combinations and asso'ciated design operation, postulated accidents, and specified seismic limits, vary considerably : among applications for events for the design of Seismic Category I fluid system construction permits. Regulatory Guides 1.26 and 1.29 components (i.e., water- and steam-containing (Safety Guide 26 and 29) entitled "Quality Group components). This guide applies to light-water-cooled Classifications and Standards" and "Seismic Design reactors. The Advisory Committee on Reactor Classification," respectively, provide acceptable bases for Safeguards has been consulted concerning this guide and classifying fluid system components in relation to has concurred in the regulatory position. applicable national codes (e.g.,Section III of the ASME
Code) and for-identifying th6se striuctures, systems and
B. DISCUSSION
' components that: should be designed to remain functional under the effects Of the SSE (i.e., Seismic The design conditions and functional requirements Category I structures, systems, and components).
of fluid system components important to safety in nuclear power, plants should be reflected in the To further provide a consistent basis for design of application of appropriate design limits (e.g., stress or fluid system comipoiient's important to safety, this guide strain limits) for the most adverse combination of delineates acceptable design limits and appropriate loadings to which these components may be subjected in combinations' of, loadings associated with applicable service. plant conditions arid specified seismic events. The approach set' forth in this guide is directly related to For components that are constructed in accordance Section III of the ASME Code. Design limits as specified with Section III of the American Society of Mechanical in Section III are extensively utilized to provide Engineers (ASME) Boiler and Pressure Vessel Code, assurance of ýthie pressure-retaining integrity of vessels, provision of a design specification which stipulates the piping, non:active pumps, and non-active valves of each design requirements for the component: (i.e., the Code class; however',: for the particular case of active mechanical and 'operational loadings) and the Code pumnIps and valves (i.e.,`pumps and valves that must classification of the component (e.g., Code Class 1, 2, or performs a mechanical motion during' the course of
3) is required. However, neither Section III nor any accomplishing a 'syst'eni safety function), special design other published national code or standard provides limits and supplemental requirements are specified to adequate guidance for selecting code classifications and provide assurance of operability. These special design USAEC REGULATORY GUIDES Copies of published guides may be obtained by request indicating the divisions desired to the US. Atomic Energy Commission, Washington, D.C. 20545, Regulatory Guides are issued to describe and make available to the public Attention: Director of Regulatory Standards. Comments and suggestions for methods acceptable to the AEC Regulatory staff of implementing specific5parts of improvements in these guides are encouraged and should be sent to the Secretary the Commission's regulations, to delineate techniques used by the staff in of the Commission, US-: Atomic Energy Commission, Washington, D.C. 20545, evaluating specific problems or postulated accidents, or to provide guidance to Attention: Chief, Public Proceedings Staff.
applicants. Regulatory Guides are not' substitutes for regulations and compliance - "
with them is not required. Methods and solutions different from those set out in The guides are issued in the following ten broad divisions:
the guides will be acceptable if they provide a basis for the findings requisite to the issuance or continuance of a permit or license by the Commission. 1. Power Reactors
6. Products
2. Research and Test Reactors
7. Transportation
- 3. Fuels and Materials Facilities a. Occupational Health Published guides will be revised periodically, as appropriate, to accommodate 4. Environmental and Siting 9. Antitrust Review comments and to reflect new information or experience. 5. Materials and Plant Protection 1
0. General
limits and supplemental requirements are provided for for all classes of components (e.g., the dynamic loadings active pumps and valves because the rules for associated with the faulted plant condition may not be constructi6n of Section II1 apply to the assurance of present for all Code Class 2 and 3 components because pressure-retaining integrity but do not assure that pumps piping ruptures may be postulated to occur only- for and valves designated to perform a system safety certain Code Class 2 and 3 piping). However, a failure in function will operate when required. This conclusion is any system or component should be evaluated for its supported by B-1223.4(b) of Appendix B to Section III, .effects on all other systems and components.
"Owner's Design Specification;' which states, "Although Code requirements for the acceptability of a component ASME Code Class 1 Components are not intended to assure the functional adequacy of the component, the higher stress limits permitted for Code Class I components, except for pumps and Emergency and Faulted Condition evaluation may result valves, benefit from the most complete design coverage in deformations which preclude operability during or that Section III of the ASME Code provides. Design after the event. The. Owner may wish to provide more rules and design limits are available for other than the restrictive limits for components which require close normal plant condition (e.g., for the severe loadings dimensional control and which must operate during and associated with the emergency and faulted plant after the event. Such requirements are beyond the scope conditions and specified seismic events). These severe loadings are accomodated by application of the design of this Section (i.e., Section I11)." Footnote 1 to limits for the emergency and faulted operating condition NB-35 10 of Section III also expresses this limitation by stating that, "These requirements for the acceptability categories (as defined in NB-3113 of Section 111) which of a valve design are not intended to assure the permit design limits in excess of those allowed for the functional adequacy of the valve." normal operating condition category. Loadings associated with the normal plant condition and loadings In addition, design limits augmenting Section III of associated with the upset plant condition (i.e.,
the ASME Code are selected for Code Class 2 and 3 anticipated operational occurrences as defined in components and certain Code Class 1 components in the Appendix A to 10 CFR Part 50) are sustained by absence of design limits for other than the normal plant application of the design limits specified for the normal condition (e.g., the emergency and faulted plant operating condition category and the upset operating conditions). It is emphasized that the design limits condition category of Section III, respectively.
delineated in this guide are intended to apply to all fluid ASME Code Class 1 Vessels and Piping system components (vessels, piping, pumps, and valves)
that are relied upon to cope with the effects of specified plant conditions. To provide assurance of pressure-retaining integrity, the upset, emergency, and faulted operating condition Loading combinations are defined as those loadings category design limits given in NB-3200, "Design by or combinations thereof-that are associated with each Analysis," and NB-3600, "Piping Design," of Section III
plant condition or specified seismic event. These of the ASME Code should be applied to design vessels loadings result from'the various transients or events that and piping for the combination of loadings delineated in are included within each plant condition and the regulatory positions l.a., 1.b., and l.c., respectively.
magnitude of the specified seismic events associated with the nuclear power plant site. Identification of the Non-Active ASME Code Class 1 Pumps and Valves particular transients or events to be evaluated for each (Designed by Analysis)
plant condition will be addressed in a future guide;
however, only the most adversejloadings resulting from As permitted by Section III of the ASME Code those transients or events associated with each plant within the limitations of NB-3400 and NB-32 11, Code condition and specified seismic event as combined herein Class I pumps may be designed by analysis (i.e., the should be considered for design (e.g., those design procedures specified in NB-3200 of Section III).
combinations of loadings that result in the limiting or Case 1552 (Interpretations of ASME Boiler and Pressure controlling design condition). The combinations of Vessel Code) allows design by analysis of Code Class I
loadings are based upon information contained in recent valves if additional requirements are met. Non-active applications for construction permits, the anticipated pumps and valves are those pumps and valves thatare sequence of' occurrences which produ'ce loadings, and ,pot required to perform a mechanical motion during the the most limiting combination of low-probability -course of accomplishing a system safety function. Since postulated accidents or events (i.e., the concurrent -non-active pumps and valves need only be assured of loadings associated with the normal plant condition, the pressure-retaining integrity, the upset, emergency, and vibratory motion of the SSE, and the dynamic system faulted operating condition category design limits of loadings associated with the faulted plant condition). NB-3200 should be designated for the combination of Although the loadings associated with each plant loadings delineated in regulatory positions 2.a., 2.b., and condition and specified seismic event delineated in this 2.c., respectively.
guide are combined in the same maniner for all classes of components, the design limits 'and specific loadings associated with each plant condition-are not the same Non-Active ASME Code Class 1 Valves (Designed by Standard or Alternative Design Rules). 0
1.48-2
Standard or alternative design rules for Code Class 1 Active ASME Code Class 1 Valves (Designed by valves are specified by, NB-3512 and NB-3513 of Section Standard or Alternative Design Rules)
III of the ASME Code. These design rules encompass the use of pressure-temperature ratings of valves. The design To provide greater assurance of operability, the limits specified in, this guide are in terms of Pr which primary pressure rating (Pr) for Code Class 1 active differs from the definition given by Section III in that Pr valves designed by standard or alternative rules should is related to maximum transient temperature in lieu of not be exceeded when the valve is subjected to the the design temperature.. Pr is defined in this guide. as the combination of loadings delineated in regulatory primary-pressure rating corresponding to the maximum positions 5.a.(1), 5.a.(2), and 5.a.(3). This design limit is transient temperature for each plant condition as selected on the same basis as that designated for active specified in Tables NB-3531-1 to NB-3531-7 of Section. pumps and valves that are designed by analysis and is III..Therefore, the maximum transient temperature for analogous to design limits specified for the normal each plant condition should be determined before the operating condition category of Section III of the ASME
pressure rating of, the valve is. selected (e.g., Class 600, Code. Note 6 to the regulatory position also applies.
900, or 1500). In order to provide assurance of However, in the case of pressure-related valves, Note 6 pressure-retaining integrity, Pr should not be exceeded, states that the primary-pressure ratings (Pr) for by more than 10, 20, and 50 percent when the valve is non-active valves designed by standard or alternative subjected. to the combination of loadings delineated in design rules may be used for the applicable loading regulatory positions 3.a., 3.b., and 3.c., respectively. One combinations if appropriate testing demonstrates that hundred ten percent and 120 percent ,of Pr, respectively, operability is not impaired when the valve is so rated.
are analogous to the upset and emergency operating Since detailed analytical techniques are not used to condition category limits of NB-3200 of Section III. One design pressure-temperature rated valves, demonstration hundred fifty percent of Pr is analogous to the of operability by test is'indicated.
hydrostatic test pressure specified for Code Class 1 valves in Section III. ASME Code Class 2 and 3 Components Active ASME Code Class 1 Pumps and Valves (Designed With one exception, no distinction is made between by Analysis) Code Class 2 and 3 components since the design requirements of Section III of the ASME Code are the The normal operating condition category design same for both classes of components. The design rules limits given by NB-3222 of Section III should be applied for Code Class 2 and 3 components do not provide for to design active pumps and valves for the combination of design by analysis (except for Code Class 2 vessels loadings delineated in regulatory positions 4.a.(l), designed in accordance with Section VIII, Division 2, of
4.a.(2), and 4.a.(3). The design limits of NB-3222 are the ASME Code) and do not yet provide any design rules selected because the primary stress intensities associated for pumps. Furthermore, no design limits for other than with those limits are in the elastic range and thus provide the normal plant condition are available (the one greater assurance of operability for pumps and valves exception to this is piping). Generally, Class 2 and 3 (i.e., less probability of unacceptable deformations that components are of somewhat lower quality as related t0'
would impede or prevent operation) than the design material, fabrication, and. nondestructive examination limits for the upset, emergency, and faulted operating requirements than Code Class I components. Because of condition categories of Section Ii. Secondary effects less stringent design requirements and a lower quality (stresses and deformations,) in components whosc *"" level in comparison to Code Class 1 components; the function is pressure retention are not usually evaluated design limits selected for Code Class 2 and 3 non-active for the loading combinations delineated in regulatory components are, on a comparable basis, lower for the positions '4.a.( 2 ) and 4.a.(3). However, these effects combination of loadings associated With the emergency should be considered for active Class I pumps and valves and faulted plant conditions than for Code Class 1 so that unacceptable' deformations do not result. Local non-active components. The same considerations that effects (peak stresses) 'need not be evaluated for these apply to Code Class I active pumps and valves apply to loading combinations. In addition to compliance with Code Class 2 and 3 active pumps and valves.
the design limits specified, demonstration of operability as outlined by Note 6 to the regulatory position should ASME Code Class 2 and 3 Vessels (Designed to Division also be provided. Note 6 suggests appropriate testing,
1 of Section VIii)
analysis, or combinations of those measures that should be implemented to demonstrate the operability of active pumps and valves under all design loadinig'combinations. To provide assurance of pressure-retaining integrity However, Note 6 states that the design limits for for Code Class 2 and 3 vessels, the allowable stress value non-active pumps and valves designed by analysis may be S should not be exceeded by more than 10 percent for used if assurance is provided by detailed stress and the combination of loadings delineated' in 'regulatory deformation:analyses that operability is not impaired positions 6.a.(1), and 6.a.(2), and S should not be when designed to these limits. exceeded by more than 50 percent-for the combination
1.48-3,
of loadings specified by regulatory position 6.b. One bending stresses should not be exceeded by more than hundred ten percent of S is analogous to the upset 65 percent of S for the combination of loadings operating condition category design limitsspecified for delineated in regutlatory positions 9.a.(]), and '9.a.(2).
Code Class I components, while 150 percent of S is The primary membrane stress and thfe surn of the comparable to the membrane stress that would occur in primary membrane plus primary bending stresses should a cylindrical or spherical shell during hydrostatic testing. not be exceeded by nlore than 20 percent and 80
Both limits are within the elastic stress range for ferritic percent of S. respectivel'. for the combination of materials. If a more detailed analysis is performed. noloe loadings delilneated in regulatory position 9.b.
9 to the regulatory position provides limits for prinoary membrane and primary bending stresses. Active ASME Code Class 2 and 3 Pumps ASME Code Class 2 Vessels (Designed to Division 2 of For active Code Class 2 and 3 pumps the primary Section VIII) llemllbrane stress should not exceed S. and tile surn of the primary membrane plus primary bending stressesSection III of the ASME Code allows Code Class 2 should not be exceeded by more than 50 percent vessels to be designed in accordance with the rules of of S fbr the combination of loadings delineated in Division 2 to Section VIII of the ASME Code. Division 2 regulatory positions 10.a.( I), 10.a.(2), and 10.a.(3).
to Section VIII provides rules for design by analysis that These limits are analogous to tile normal operating are equivalent to those of Section III for Code Class I condition category design limits of NB-3200 of Section vessels. In addition, the quality level for Division 2 Ill of the ASME Code and thus provide increased vessels is comparable to that for Code Class I vessels of assurance that unacceptable deformations affecting Section III. Therefore, the design limits for the loading operability of active Code Class 2 and 3 pumps will not combinations delineated in regtilatory position 7. should result. In addition to compliance with the design limits be tile same as those for Code Class I vessels in specified. demonstration- of operability as outlined by regulatory position I. Note I1 to tl1e reCulatory position should also be provided. Note II is identical to Note 6 to the ASME Code Class 2 and 3 Piping regulatory position except that the design limits for non0-active pumps and valves may be used for the NC-3600 of Section ill of the ASME Code land by applicable loading combinations if appropriate analyses reference ND-3600) provides design limits for piping and/or testing confirnms that operability will not be under "Upset Conditions" and "Emergency Conditions" impaired when the component is designed to these which are analogous to tile upset and emergency limits.
operating condition category design lilmits specified in NB-3600 for Code Class I piping. In utilizing these Non-Active ASME Code Class 2 and 3 Valves design limits'for assurance of pressure-retaining integrity, the "Upset Condition" limits should not be exceeded for The design of Co de Class 2 and 3 valves the combination of loadings delineated in regulatory encompasses the use of pressure-temllperature ratings.
positions 8.a.(I), and 8.a.(2). and the "Emnergency The design limits (Oven herein are in terms of Pr which is Condition" limits should not be exceeded for the the prinlary-pressure rating corresponding to the combination of loadings specified in regulatory position maximunm transient temperature for each plant
8.b. However, only equation 9 of NC-3651 need he met condition as specified in NC-3511 and ND-351 I for for the loadings designated in regulatory position 8.a.(2) Code Class 2 and 3 valves, respectively. This definition since thermal expansion effects of piping are not usually 'of Pr differs froim the Section III of the ASME Code evaluated for these loadings. definitiot*i of Pr in tile same manner 'as that for Code Class I valves and the same considerations apply. To Non-Active ASME Code Class 2 and-3 Pumps assure pressure-retainiung integrity, the limits for Pr are lower than those given for Code Class 1 valves for the Design limits were selected for Code Class 2 and 3 same loading combinationis involving emergency and pumps in the absence of Section III of the ASME Code faulted plant conditions. Pr should n6t be exceeded by design rules for these components. These design limits more than 10 percent for the combination of loadings relate to both primary membrane and primary bending delineated in regulatoiy positions I i.a.(1), and I l.a.(2),
stresses~and are derived on a basis that is comparable to and Pr should not be exceeded by more than 20 percent the design limits for Code Class I components designed for the combination of loadings delineated in regulatory by analysis. One hundred ten percent of S and 120 position 1I .b.
percent of S (and the limilts for primary membrane plus primary bending) are analogous to the design limits for Active ASME Code Class 2 and 3 Valves the upset operating condition category and the emergency operating condition category, respectively, To provide greater assurance of operability for given in NB-3200 of Section 11I. Therefore, to assure active valves of Code Class 2 and 3, Pr should not be pressure-retaining integrity, the primary membrane stress exceeded for the comnbination of loadings delineated in -
should not be exceeded by more than 10 percent of S, regulatory positions 12.a,(i), 12.a.(2), and 12.a.(3).
and the sumn of the primary membrane plus primary Note I I to ,ie regulatory position applies. However, as I .48-4
allowed! by' Note 11, if the design limits for non-active b. Pr should not be exceeded by more than 20
valves are used, appropriate testing should demonstrate percent when the component is subjected to the loadings operability in lieu of analysis since detailed analytical associated with the emergency plant condition.
techniques are. not applied to design c. Pr should not be exceeded by more than 50
pressure-temperature rated valves. percent when the component is subjected to concurrent loadings associated with the normal plant condition, the
C. REGULATORY POSITION
vibratory motion of the SSE, and the dynamic system loadings associated with the faulted plant condition.
Seismic Category I fluid system components should be designed to withstand the following loading 4. Active ASME Code Class 1 pumps and valves 4 that combinations within the design limits ' specified. are designed by analysis:
a. The design limits 6 specified in NB-3222 5 7,8 of
1. ASME Code 2 .Class 1 vessels and piping: the ASME Code should not be exceeded when the a. The design limits specified in NB-3223 and component is subjected to either (1) concurrent loadings NB-3654 of the ASME Code for vessels and piping, associated With either the normal plant condition or the respectively, should not be exceeded when the upset plant condition and the vibratory motion of 50
component is subjected to concurrent loadings percent of the SSE, or (2) loadings associated with'the associated with either the normal plant condition or the emergency plant condition, or (3) concurrent loadings"
upset plant condition 3 and the vibratory motion of 50 associated with the normal plant condition, the'
percent of the Safe Shutdown Earthquake (SSE). vibratory motion of the SSE, and the dynamic system b. The design limits specified in NB-3224 and loadings associated with the faulted plant condition.
NB-3655 of the ASME Code for vessels and piping, respectively, should not be exceeded when the 5. Active ASME Code Class 1 valves that are designed component is subjected to loadings associated with the by standard or alternative design rules:
emergency plant condition. a. The primary-pressure rating Pr 6 should not be'
c. The design limits specified in NB-3225 and exceeded when the component iý subjected to either (1)
NB-3656 of the ASME Code for vessels and piping, concurrent loadings associated with either the normal respectively, should not .'be exceeded when the plant condition or the upset plant condition and the'
component is subjected to concurrent loadings vibratory motion of 50 percent of the SSE, or (2)
associated with the normal plant condition, the loadings associated with the emergency plant condition, vibratory motion of the SSE, and the dynamic system or (3) concurrent loadings associated with the niormal'
loadings associated with the faulted plant condition. plant condition, the vibratory motion of the SSE, and'
4 the dynamic system loadings associated with the faulted'
2. Non-active ASME Code Class 1 pumps and valves plant condition.
that are designed by analysis:
a. The design limits specified in NB-3223s of the ASME Code should not be exceeded when the 6. ASME Code Class 2 and 3 vessels 'designed to.
component is subjected to concurrent loadings Division 1 of Section VIII of the ASME Code:
associated with either the normal plant condition or the a. The allowable stress value S9 should not be upset plant condition and the vibratory motion of 50 exceeded by, more than 10 percent when the component percent of the SSE. is subjected to either (1) concurrent loadings associated.
b. The design limits. specified in NB-3224 of the with either the normal plant condition or the upset plant ASME Code should not be exceeded when the condition and the vibratory motion of 50 percent of the..
component is subjected to loadings associated with the SSE, or (2) loadings associated with the emergency plant emergency plant condition. condition.
c. The design limits specified in NB-3225 of tile b. S should not be exceeded by more than 50
ASME Code should not be exceeded when the percent when the component is subjected to concurrent component is subjected to concurrent loadings loadings associated with the normal plant condition, the associated with the normal plant condition, the vibratory motion of the SSE, and the dynamic system vibratory motion of the SSE, and the dynamic system loadings associated with the faulted plant condition.
loadings associated with the faulted plant condition.
7. ASME Code Class 2 vessels designed to Division 2 of
3. Non-active ASME Code Class 1 valves that are Section VIII of the ASME Code:
designed by standard or alternative design rules: a. The design limits specified in NB-3223 of the a. The primary-pressure rating Pr should not be ASME Code should not be exceeded when the exceeded by more than 10 percent when the component component is subjected to concurrent loadings is subjected to concurrent loadings associated with either associated with either the normal plant condition or the the normal plant condition or the upset plant condition upset plant condition and the vibratory motion of 50
and the vibratory motion of 50 percent of the SSE. percent of the SSE.
1.48-5
b. The design limits specified in NB-3224 of the associated with the normal plant condition, the ASME Code should not be exceeded when the component is subjected to loadings associated with the emergency plant condition.
c. The design limits specified in NB-3225 of the vibratory motion of the SSE, and the dynamic system loadings associated with the faulted plant condition.
10. Active ASME Code Class 2 and 3 pumps:
0
ASME Code should not be exceeded when the a. The primary membrane stress should not component is subjected to concurrent loadings exceed the allowable stress value S, and the sum of the associated with the normal plant condition, the primary membrane and the primary bending stresses'
should not be exceeded by more than 50 percent of S
vibratory motion of the SSE, and the dynamic system when the component is subjected to either (1)
loadings associated with the faulted plant condition.
concurrent loadings associated with either the normal plant condition or the upset plant condition and the
8, ASME Code Class 2 and 3 piping:
vibratory motion of 50 percent of the SSE, or (2)
a. The design limits specified in loadings associated with the emergency plant condition, NC-361 1.1(b)(4)(c)(b)(1) of the ASME Code should not or (3) concurrent loadings associated with the normal be exceeded when the component is subjected to either plant condition, the vibratory motion of the SSE, and
(1) concurrent loadings associated with either the the dynamic system loadings associated with the faulted normal plant condition or the upset plant condition and plant condition.
the vibratory motion of 50 percent of the SSE, or (2)"0
loadings associated with the emergency plant condition. 11. Non-active ASME Code Class 2 and 3 valves:
b. The design limits specified in a. The primary-pressure rating Pr should not be NC-361 1 .1(bX4Xc)(b)(2) of the ASME Code should not exceeded by more than 10 percent when the component be exceeded when the component is subjected to is subjected to either (1) concurrent loadings associated concurrent loadings associated with the normal plant with either the normal plant condition or the upset plant condition, the vibratory motion of the SSE, and the condition and the vibratory motion of 50 percent of the dynamic system loadings associated with the faulted SSE, or (2) loadings associated with the emergency plant plant condition. condition.
b. Pr should not be exceeded by more than 20
9. Non-active ASME Code Class 2 and 3 pumps: percent when the component is subjected to concurrent a. The primary membrane stress should not be loadings associated with the normal plant condition, the exceeded by more than 10 percent of the allowable vibratory motion of the SSE, and the dynamic system stress value S, and the sum of the primary membrane loadings associated with the faulted plant condition.
and primary bending stresses should not be exceeded by more than 65 percent of S when the component is 12. Active ASME Code Class 2 and 3 valves:
subjected to. either (1) concurrent loadings associated a. The primary-pressure rating Pr 1 ' should not be with either the normal plant condition or the upset plant exceeded when the component is subjected to either (1)
condition and the vibratory motion of 50 percent of the concurrent loadings associated with either the normal SSE, or (2) loadings associated with the emergency plant plant condition or the upset plant condition and the condition. vibratory motion of 50 percent of the SSE, or (2)
b. The primary membrane stress should not be loadings associated with the emergency plant condition, exceeded by more than 20 percent of S, and the sum of or (3) concurrent loadings associated with the normal the primary membrane and primary bending stresses plant condition, the vibratory motion of the SSE, and should not be exceeded by more than 80 percent of S the dynamic system loadings associated with the faulted when the component is subjected to concurrent loadings plant condition.
1.48-6
DEFINITIONS
Active Pumps and Valves. Components that must and shutdown other than upset, emergency, or faulted.
perform a mechanical motion during the course of plant conditions.
accomplishing a system safety function.
Plant Conditions. Operating conditions of the plant Allowable Stress Value (S). As specified in Appendix I categorized as normal, upset, emergency, and faulted.
of Section III of the ASME Boiler and Pressure Vessel plant condtions.
Code.
Design by analysis for Class 1 Pumps and Class 1 Valves. Primary-Pressure Rating (Pr). The primary-presstire For Class 1 pumps, the design procedures specified in rating corresponding to the maximum transient NB-3200 of the ASME Boiler and Pressure Vessel Code, temperature for each plant condition, as specified in Section III. For Class, I valves, the requirements of Case Section III of the ASME Boiler and Pressure Vessel
1552 of Interpretations of ASME Boiler and Pressure Code, Tables NB-3531-1 to NB-3531-7, for Code Class 1 Vessel Code. -valves or as specified in NC-3511 and ND-3511 for Code Class 2 and 3 valves, respectively.
Dynamic System Loadings Associated with the Faulted Plant Condition. Refers to those dynamic loadings which Safe Shutdown Earthquake (SSE). That earthquake result from the occurrence of a postulated rupture (e.g., which produces the vibratory ground motion for which complete severance or equivalent longitudinal break structures, systems, and components important to safety area) of any reactor coolant pressure boundary piping or are designed to remain functional.
of any other piping not a part of the reactor coolant pressure boundary. Seismic Category I. Those structures, systems, and components that are designed to remain functional if the Emergency Plant Condition. Those operating conditions SSE occurs.
which have a low probability of occurrence.
Standard or Alternative Design Rules for Class 1 Valves.
Faulted Plant Condition Those operating conditions As specified in NB-3512 and NB-3513 of the ASME
associated with extremely-low-probability postulated Boiler and Pressure Vessel Code,Section III.
events.
Upset Plant Condition. Those deviations from the Normal Plant Condition. Those operating conditions in normal plant condition which have a high probability of the course of system startup, operation, hot standby, occurrence.
NOTES
Applies to all components (vessels, piping, pumps, and b. full-scale prototype testing.
valves) that are relied upon to cope with the effects of specified c. reduced-scale prototype testing plant conditions. d. detailed stress and deformation analyses (includes experimental stress and deformation analyses).
2 In the performance of tests or analyses to demonstrate Section III of the American Society of Mechanical operability, the structural interaction of the entire assembly Engineers Boiler and Pressure Vessel Code including the 1972 (e.g., valve-operator assembly and pump-motor assembly) should Winter Addenda thereto. be considered. If superposition of test results for other than the combined loading condition is proposed, the applicability of
'Identification of the specific transients or events to be such a procedure should be demonstrated. The design limits for considered under each plant condition will be addressed in a non-active pumps and valves designed by analysis may be used future regulatory guide. for the applicable loading combinations if assurance is provided
4 by detailed stress and deformation analyses that operability is The requirements of the Case 1552 (Interpretations of not impaired when designed to these limits. Similarly, the ASME Boiler and Pressure Vessel Code) should be met for all primary-pressure ratings Pr for non-active valves designed by sizes of Code Class 1 valves designed by analysis.
standard or alternative design rules may be used for the applicable loading combinations if appropriate testing
'The provisions of NB-3411 and NB-3413 may be applied demonstrates that operability is not impaired when the valve is for all sizes of Code Class 1 pumps designed by analysis.
so rated.
6
'Inaddition to compliance with the design limits specified, assurance of operability under all design loading combinations 7 should be provided by an appropriate combination of the Secondary effects (stresses and deformations) should be following suggested measures: evaluated for the loading combinations designated by regulatory a. in situ testing (e.g., preoperational testing after the positions 4.a.(2) and 4.a.(3). Local effects (peak stresses) need component is installed in the plant). not be considered for these loading combinations.
1.48-7
I
8Table 1-3.0, "Permanent Strain Limiting Factors," of " For the loadings designated in regulatory position 8.a.(2),
Appendix I of the ASME Boiler and Pressure Vessel Code, onlyequation 9 of NC-3651 need be met.
Section III, may be used as an aid in determining the relationship between design stress and deformation (see note 2 to Table 1-1.2, In addition to compliance with the design limits q of Sectiori Ill of the ASME Code). specified, assurance of operability under all design loading combinations should be provided by any appropriate
9 Division 1 of Section VIII of the ASME Boiler and combination of the following suggested measures:
Pressure Vessel Code does not provide rules for design by a. in situ testing (e.g., preoperational testing after the analysis. If a detailed analysis is performed, Division 1 vessels component is installed in the plant).
should meet, as a minimum, equations a and b below. which arc b. full-scale prototype testing.
applicable to regulatory positions 6.a. and 6.b., respectively. c. reduced-scale prototype testing.
d. detailed stress and deformation analyses (includes experimental stress and deformation analyses).
a. om < 1.IS > m 1.5 +Ob In the performance of tests or analyses to demonstrate operability, the structural interaction of the entire assembly am < 1.5S > Om +o b (e.g., valve-operator and pump-motor assembly) should be b.
in 1.5 considered. If superposition of test results for other than the combined loading condition is proposed, the applicability of where: such a procedure should be demonstrated. The design limits for urn = primary membrane stress; non-active pumps and valves may be used for the applicable ob = primary bending stress; loading combinations if appropriate analyses and/or testing S = allowable stress value as specified in Appendix I of cooifirms that operability is not impaired when designed to these Section III of the ASME Boiler and Pressure Vessel Code. limits.
1.48-8