Regulatory Guide 1.125

Physical Models for Design and Operation of Hydraulic Structures and Systems for Nuclear Power Plants

ML13350A272
Person / Time
Issue date:	03/31/1977
From:	NRC/OSD
To:
References
RG-1.125
Download: ML13350A272 (3)

t yR REG&, 90U.S. NUCLEAR REGULATORY COMMISSIONMarch 1977REGULATORY GUIDEOFFICE OF STANDARDS DEVELOPMENTREGULATORY GUIDE 1.125PHYSICAL MODELS FOR DESIGN AND OPERATIONOF HYDRAULIC STRUCTURES AND SYSTEMS FOR NUCLEARPOWER PLANTS

A. INTRODUCTION

Paragraph (a) (3) (ii) of §50.34, "Contents of Ap-plications; Technical Information," of 10 CFR Part50, "Licensing of Production and UtilizationFacilities," requires that the Preliminary SafetyAnalysis Report (PSAR) include information on thedesign bases of the facility and the relation of thedesign bases to the principal design criteria.Paragraph (a) (4) of §50.34 requires, in part, a pre-liminary analysis of the adequacy of structures,systems, and comnonents orovided for the preventionExamples of types of physical modeling studies in-clude, but are not confined to, the following:I. Intake structures.2. Discharge structures.3. Energy dissipation structures.4. Spillway and tailwater ratings for (dWrs (water-level discharge relations).5. Release of water resulting from daiii'lures.6. Wave runup, including ounaAi',effect'7. Erosion from waves..and,.rtbilaotin therefrom.8. Erosion and deppo8io'n in.i and othersysems and component prvie for. --.h- .. .....'-. ..... aenb desadtrt toohenoof accidents and the mwttgation of the consequences ...... and ..r: , *th eerom .of accidents. mittonfts 9. Flow pattersand d(pettion of heated or con-taminated i&"recci'6ing water bodies.10. Heat'Al'sý IK n-" receiving water bodies.This guide describes the desired coordination of an 10. Ha .rapplicant with the NRC staff and the detail and ex eerience of the NRC staff thatdocumentation of data and studies that. an applicant sozpe ' ican6 have not furnished sufficientlyshould include in the PSAR to support the use of detidic "'i.r' mation on physical hydraulic modelphysical hydraulic model testing for predicting per the staff to perform an adequate review. Informance of hydraulic structures and systems t.so~,-4instances, staff involvement in the early plan-nuclear power plants. The regulatory position of i~is "T,%ing of a mcdel study would have resulted in savingsguide is applicable only to physical mo~elt"Osedlo, gOf both NRC and applicant funds and time in thepredict the action or interaction of su .Uce waterV` review and acceptance of the results.with features located outside of contaiihtent.1Therecommendations of this guide are not ppo a e to Accordingly, the regulatory position details theinternal plant systems or stuctures. documentation that should be furnished and the typeof coordination between the staff and the applicantthat should minimize the time necessary for accep-,,.tance of the results of model studies.Physical hydr 1i ml els' te often used to predict The information described in the regulatory posi-prototype o nce. hey are particularly useful tion should be incorporated in the PSAR. However,where h a res and systems are of un- the staff recognizes that it will not always be possibleusual de or configuration and hydraulic to incorporate such information in the initial applica-parameters not be adequately evaluated by state- tion for a construction permit since studies of thisof-the-art analytical methods. Hydraulic models may type may not be undertaken until after the PSAR isalso be used to establish conservative and reasonable submitted. Such information may, therefore, be add-design or operating bases for sites, structures, or ed to the PSAR by amendment, either by reference tosystems involving thermal and erosional problems. separate reports or by insertion into the PSAR.USNRC RE.GUL.ATORY GUIDES Cotenmeeet. %hureild bee wnt to t he S--Cletry eII IIe- Creen,e,,eoy.ree US. Ni.1a -,ijRegutlatory Guidieae d.C twed to iesvrilte antd malte availablte to the, ptublic method, Ilaoty Ce,e .... ...awo. Vi,)Ii tee,', D.C. 7D~bV,. Ate .,I,ete L)-e 1e,nel, Ntn eedacceptable to the NRC staff ol imtlementie'j uiiecetec parts of the Cenlor,$inss~~, feeeregulIatieons, to deliea~tetdt Ichetetteecl ,tivdl Ityth! stalfi cc tvalai nat stjwtecol c problemees Theuiesa sejtc t. ttecvt eeteetlIvieccor postolittO accidenti. or itt ittovde! guitdance to .tttttlicints. R. rgulatory Guide% h-qi.sie"uII n ol~- eareC not substnlesu for *eifulmitons. and ConneteleieCe Withe them, is not triltuirtd. I Pectvt Iie-ectnr G midc,ele;roMetthods atot solntlotv' dillefecnt from lholit, set ou!to i c M jetguide% will hee Ancmil- Ffesi,...icnited Tot tetecci 1. ' awer~ltcable .1 they ttoe idt, a1 btasis It the. findeings rentuisite In, the ifsueinci!et Col co~ntnance. V fl Ite ,ecc.1,,!mt lst F.1,tcttin, w% Qe8 ccttet I t.01throf a Petmit or license by the Comcmission. .1, Erivifortcnce-mtit ctl adSt tnq f) ete t lc,-"e5r Mate, e.0,ine Ptan)t NolvotC "~Cormnians antd suggestions for itilltrnvetntent% in theso (euieetle ntt! etcncuraged at ;,I[gitime's, .ntrw goiei "Melt It evi"Icl .s in te, ltnuette.tt, to atcecrtto,ilitt ctttlflenrtt and~t tle4tectt Iwe lecele ccitfe te seee Mteej, t4erhe cee.e hi.e~eeute or let, tela,;'to rei edl fee. intotint Ieon ot et !I net'C,, Hoeweve~r, cornenerreot th!itts luetle., it eeee~t 'ten tee iutomtmtc n:e dt ieteeul etetetlee I ecte Cite'! ' tet leeee! n.e'ett lt itne , eefiteceivedl vvethin abeout ty. ioi ,,~hs titer its oletincc. vvil lee ttaelicntar,tl eestt~le to tleeeetoet quittet Itw netteo in eteteti tee tte U S. ~tel-ec.,,, tllqeetdnty CetettcowaeeeeevileeetetIltnatl It e *.tyttefUt Vdtlitnhmtttt, D.C. 205fbh. At t,-niut .e Deeq fe or. Dionuienr etf Uttinpritn Cultecto

C. REGULATORY POSITION

Because all hydraulic design problems cannot beresolved by the mechanics of similitude and becausethere are limitations to hydraulic modeling.'the NRCstaff should be furnished with certain documentation* for any structural, thermal, erosional,I or otherphysicalhydraulic models used by the applicant to es-tablish design or operating bases. The regulatory* position contained in this guide applies only to'physical models used to predict the action or interac-tion of surface waters with features located outside ofcontainment.Generally, regulatory positions I and 3 describe in-formation that should be furnished prior to actualmodel testing., and regulatory positions 4 through 6describe information needed after testing is com-pleted. Additionally, partial test results should be* provided for staff review and acceptance during the* course of testing to ensure reconsideration of* parameters whose importance becomes apparent onthe basis of partial data collection. After completingthe entire study, all the information should be con-solidated either (1) as a separate report with ap-* propriate reference added in the PSAR or (2) for in-sertion into the PSAR.1. Prior to construction of the model, the appli-* cant should submit information outlining (a) the* problem to be resolved, (b) reasons for selecting thehydraulic model chosen to resolve the problem, (c)* expected results to be obtained, (d) a detailed descrip-tion of the model, including a description of.materials, methods used to measure parameters, scalerelations, and other physical characteristics of themodel, (e) methods that will be used to analyze the* data obtained from the model studies, and (0 aschedule of expected tests, proposed completiondates, and estimated dates for submittal of informa-* tion for NRC staff review.2. Staff views and recommendations should besolicited prior to model construction and followingor coincident with the submittal of the information* listed in regulatory position 1, and arrangementsshould also be made for appropriate members of thestaff to be present periodically during model opera-tion to observe the actual performance of the model.3. Documentation should be furnished on how thevarious conditions of geometric, kinematic, dynamic,and thermodynamic.similitude that take into account.the physical properties and flow state of the fluid (i.e,.Froude, Reynolds, Euler, Cauchy, Weber, and otherrelated numbers) have been considered. Because-cer-tain forces may act differently in a model than in aprototype, documentation should be provided tojustify the neglect of any forces by showing that theseforces (a) are of negligible magnitude, (b) compensatefor other neglected forces in such a manner that theeffects of both are negligible, or (c) are such that theirneglect leads to conservative model results and es-tablishmen.t of conservative 'design or operatingbases.Documentation should be furnished on themethods used to satisfy the equations of similitude inthe model. The effects of scale distortions on data ob-tained from the model studies should be documented.Where applicable, model adjustment and verificationprocedures should be described, and informationshould be furnished on the validity of the model overa range of likely flow conditions, heat regimes, at-mospheric conditions, and other physical parameters.Where applicable, it should be demonstrated that themodel will simulate known flow conditions; this ver-ification should be provided when historical data areavailable.4. Where full-scale structures or systems havingcharacteristics similar to those being modeled existand information relative to the observed or measuredperformance of the existingstructures or systems isavailable, the physical model results should be com-pared with the available information generated by theexisting structures. Testing performed on existingfull-scale structures or systems and the results ofthese tests should be described. The applicability ofsuch tests to the problem in question should bedocumented, and any conclusions derived from thetests should be discussed. If the results of other modeltests are used by the applicant, justification for theuse of these results and verification of the ability ofthese other models to reproduce or predict prototypeperformance should also be provided.Detailed documentation of data obtained fromexisting full-scale structures and systems should beprovided, including (a) instrumentation used, (b)description of the data collection network, (c) fre-quency of collection,. (d) methods of collection, and(e) physical parameters existing at the time of collec-tion, such as heat regimes, flow conditions, and at-mospheric conditions.5. Any changes to the original design of theprototypes as a result of the model test should be dis-cussed. The designs that were modeled and the basisfor modifying the design should be documented.Undesirable flow characteristics or failure modes forthe design tested, as well as any oiihcr problems,should be discussed.-6. Figures. drawings, photographs, and text sub-mitted as documentation for regulatory positions 3,4, and 5 should be provided in sufficient detail to al-low the staff to evaluate independently the ap-plicability of the model to the design problem inquestion. (A typical model investigation report aspublished by the U.S. Army Waterways ExperimentStation has been found acceptable in the past.) Bases01.125-2 for the interpretation of model results and for anyconclusions reached should be provided. In many in-stances, it may be advisable to provide partial testresults for review. The models should not be dis-mantled until the staff has reviewed the submittals.

D. IMPLEMENTATION

The purpose of this section is to provide informa-tion to license applicants regarding the NRC staff'splans for implementing this regulatory guide.Except in those cases in which the applicantproposes an acceptable alternative method for com-plying with specified portions of the Commission'sregulations, the method described herein will be usedin the evaluation of submittals for construction per-mit applications docketed after November 1, 1977. Ifan applicant wishes to use this regulatory guide indeveloping submittals for construction permit ap-plications docketed on or before November 1, 1977,the pertinent portions of the application will beevaluated on the basis of this guide.1.125-3