ML19221A981
| ML19221A981 | |
| Person / Time | |
|---|---|
| Issue date: | 11/24/1975 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| References | |
| NUREG-75-087, NUREG-75-087-03.2.1, NUREG-75-87, NUREG-75-87-3.2.1, SRP-03.02.01, SRP-3.02.01, NUDOCS 7907120124 | |
| Download: ML19221A981 (5) | |
Text
. epa.f cq%e NUREG 75/087 O'*
U.S. NUCLEAR REGULATORY COMMISSION
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%*%'M STANDARD REVIEW PLAN OFFICE OF NUCLEAR REACTOR REGM ATION
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SECTIOa 3.2.1 SEISMIC CLASSIFICATION REVIEW RESPONSIBILITIES Primary - Reactcr Svstems Branch (RSB)
Secondary - Containnent Systens Branch (CSB)
Auxiliary and Power Conversion Systems Branch (APCSB)
Ef fluent Treatment Systems Branch (ETSB)
I.
AREAS OF REVIEW Nuclear power plant structures, systems, and components irportant to safety should be designed to withst.nd the effects of earthquakes without loss of capability to perfom necessary safety functions. Information presented by the applicant identifying those struc tures, systems, and components (including their foundations and supports) which are irpor-tant to saf'ty ard are designed to withstand, without loss of function, the effect of a safe shutdown earthquake (SSE) is reviewed. The SSE is based upon an evaluation of the naximum earthquake potential and is that earthquake which produces the maximun vibratory ground notion for which structures, systers, and componente important to safety are cesigned to remain functional. Those structures, systens, and components that are designed to remain functional if the SSE occurs are designated seismic Category 1.
The RSB reviews the classification of thuse plant features (excluding electrical features) specified as scismic Category I by the applicant in his safety analysis report (SAR).
Where required, specific information or assistance may be obtained from the EICSB to review classification of electrical and instrumentation systems. This review is done for both construction permit (CP) and operating license (OL) applications.
The applicant's prcposed classifications nay oe presented in the form of a table which identifies structures and fluid systems that are seismic Category I.
Where portions of structures and fluid s,'tems are seismic Category I they also nust be clearly identified.
For fluid systems important to safety, the classification tables in the application should identify syste:n components tuch as presture vessels, heat exchangers, stor' age tanks, pumps, piping, and valves, h3ve suitable footnotes defining interfaces, and be in sufficient detail so that there is a clear understanding of the extent of those portions of the system that are classified as seismic Category I.
USNRC STANDARD REVIEW PLAN
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Alternately, such inforration ray be presented on suitable pipinq and instrunentation diagrams, or ray be conbined with the information presented in SAR Section 3.2.2, in which case it may be cross-referenced rather th3n repeated here.
The CSB reviews, in SAR Section 6.2.5, the datailed systen design of seismic Category I fluid systems that are provided for the control of corbustible g3s concentrations in con-tainrent following a lcss-of-coolant accident.
The APCSB reviews, in SAR Sections 9 and 10, the detailed systen design of auxiliary fluid systems important to safety that are desic;nated seisnic Category I.
The ETSB reviews, in SAR Sections 11.2 and 11.3, the detailed systen design of seismic Category I liquid, gaseous, and solid radioactive waste systems that are provided to reduce the radioactivity to levels which will not be in excess of the appr, ate limits.
In the event a branch that has secondary review respvnsibility identifies other plant features important to safety that have not been previously identified by the R$3, this information should be Lransmitted to the RSB.
II.
ACCEPTMCE CRITERI A 1.
10 CFR Part 50, Apoendix A, General Design Criterion 2.
This cr'*erion requires that structures, systems, and components important to safety shall be designed to
'ithstand the effects of natural pheno ena such as earthquakes without loss of tapability to perform necessary safety functions.
2.
Regulatory Guide 1.29 " Seismic Design Classification." This Regulatory Guide describes an acceptable method of identifying and classifying those plant features that should be designed to withstand the effects of the SSE.
III. REVIEW PROCEDURES Selection and emphasis of various aspects of the areas covered by this review plan will be made by the reviewer on each case. The judgenent on the areas to be given attention during the review is to be based on an inspection of the material presented, the similarity of the material to that recently reviewed on other plants, and whether itens of special safety significance are involved.
Regulatory Guide 1.29, which ider.tifies structures, systems, and components of light-water-cooled reactors on a functianal basis, is the principal document used for identi-fying those plant features important to safety which, as a mininum, should be designed to seismic Category I requireme,ts.
The staf f review should establish whether the applicant has indicated compliance with Regulatory Guide 1.29 in the SAR. Where there are differences with respect to the Guide, these dif ferences should be identified.
The infomation supplied by the applicant identifying seisnic Category I structures, systems, and components is reviewed for conpleteness and to assure there is suf ficient detail to permit identification of specific equiprent. Where portions of a system are 2.2.1-2 146 053
classified seismic Category I, the boundary limits of that portion of the system designed to Category I requirements should be identified on the pipinq and instrtrientation diagrams.
In additica, where portions of a structure are classified seisnic Category 1, those portions of the building foundations and supports desiqned to Category I requirements should be identified on the plant arrangenent drawings. The interfaces between corponents and associated support structures designed to seismic Category I requirenents are then checkcd to assure conpatability.
For systens which are partially seisnic Category I, the Category I portion of the systen should extcnd to the first seisnic restraint beyond the isolation valves which isolate that pai' which is Category I fron the non-seisnic portion of the systen.
In the eve-t an applicant intends to take exception to Regulatory Guide 1.29 and has not provided an adequate justification for his proposed seisnic classification, questions are prepared by the staff which nay require additional documentation or analysis to establish an acceptable basis for his proposed seismic classification. Staf f corrents nay also be prepared requesting clarification in order to assure a clear understanding of the seisnic classification assigned to a systen by the applicant.
If the staff's cuestions are not resolved in a satisf actory nanner, a staff position is taken requiring confornance to Regulatory Guide 1.29.
IV.
EVf?_UATION FINDINGS The staff's review should verify that adequate and sufficient infor ation is contained in the SAR and anendnents to arrive at conclusions of the following type, which are to be included in the staff's safety evaluation report:
" Structures, systers, and conponents incortant to safety that are required to with-stand the effects of a safe shutdown earthquake and renain functional have been properly classified as seismic Category I itens. These plant features are those necessary to assure (1) the integrity of the reactor coolant pressure boundary, (2) the capability to shut down the reactor and maintain it in a safe shutdown condition, and (3) the capability to prevent or nitigate the consequences of acci-dents which could result in potential offsite exposures comparable to the guideline exposures of 10 CFR Part 100.
"All other structures, systens, and conponents that may be required for operation of the facility are designed to other than seismic Category I requirements.
Included in this classification are those portions of Category I systems which are not required to perform a safety functi.
Structures, systems, and co ponents inportant to safety that are designed to withstand the effects of a safe shutdown earthquake and remain functional Nye been identified in an acceptable nanner in Tables 3.X.X and 3.X.X, and on systen piping and instrumentations diagrams.
"The basis for acceptance in the staff's review has been conformance of the appli-cant's designs, design criteri? and design bases for structures, systems and con-ponents important to safety with the Comission's regulatiens as set forth in General Design Criterion 2, and to Regulatory Guide 1.29, staff technical positions, and industry standards."
3.2.1-3 146 054
V.
REFERENCES 1.
10 CFR Part 50, Appendix A, General Design Criterion 2, " Design Bases for Protecticn Against Natural Phenomena."
2.
10 CFR Part 100, Appendix A. " Seismic and Geologic Siting Critaria for Nuclear Power Plants."
3.
Regulatory Guide 1.29, " Seismic Design Classification."
4.
ANSI N18.2a-1975, Revision and Addenda to ANSI N18.2, " Nuclear Safety Criteria for the Design of Stationary Pressurized Water Reactor Plants," American National Standards Institute (1973).
5.
ANS N212, " Nuclear Safety Criteria for the Design of Stationary Boiling Water Reactor Plants,' Draf t No. 4, Rev. 2, April 1974, ANS Standard Issued for Trial Use and Cocrent, American Nuclear Society (1974).
6.
ANS N213. " Nuclear Safety Criteria for the Design of Stationary Gas Cooled Reactor Plants," Draft No. 9, Rev. 2, January 1974, ANS Standard Issued for Coment, Amer'can Nuclear Society (1974).
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3.2.1-4 146 055
CONTAINMENT QUALITY GROUP D OUALITY GROUP D QUALITY QUALITY OR CERTIFICATION GROUP A GROUP B l
TURBINE BUILDING h
AUXILIARY BUILDING
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[ MAIN STEAM LEAD 5 y
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BRANCH LINE d 1
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CONDENSER d
d SHUTOFF VALVES
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TURBINE BY-PASS '
VALVE ISOLATION VALVES TRACEj l
p SEISMIC CATEGORY I NON-SEISMIC CATEGORY I c
STRUCTURES, SYSTEMS & COMPONENTS STRUCTURE, SYSTEMS & COMPONENTS QUALITY GROUP D
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GS CD Figure 3-2.1 AEC Quality Group and Seismic Category Classifications Applicable to Power Conversion Ln System Components in BWR/G P! ants.
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