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)

yRt REG&, 9

0 U.S. NUCLEAR REGULATORY COMMISSION March 1977 REGULATORY GUIDE

OFFICE OF STANDARDS DEVELOPMENT

REGULATORY GUIDE 1.125 PHYSICAL MODELS FOR DESIGN AND OPERATION

OF HYDRAULIC STRUCTURES AND SYSTEMS FOR NUCLEAR

POWER PLANTS

A. INTRODUCTION

Examples of types of physical modeling studies in- clude, but are not confined to, the following:

Paragraph (a) (3) (ii) of §50.34, "Contents of Ap- plications; Technical Information," of 10 CFR Part I. Intake structures.

50, "Licensing of Production and Utilization 2. Discharge structures.

Facilities," requires that the Preliminary Safety 3. Energy dissipation structures.

Analysis Report (PSAR) include information on the 4. Spillway and tailwater ratings for (dWrs (water- design bases of the facility and the relation of the level discharge relations).

design bases to the principal design criteria. 5. Release of water resulting from daiii'lures.

Paragraph (a) (4) of §50.34 requires, in part, a pre- 6. Wave runup, including ounaAi',effect'

liminary analysis of the adequacy of structures, 7. Erosion from waves..and,.rtbilaotin therefrom.

systems, and comnonents orovided for the prevention 8. Erosion and deppo8io'n in.i *6trecamiis and other sysems and component --.

of accidents and the mwttgation of the consequencesprvie .. . for.

.... h- '-. ..... aenb . .....

desadtrt and r: ..

tooheno eerom ., *th of accidents. mittonfts 9. Flow pattersand d(pettion of heated or con- taminated

10. Heat'Al'sý effluerit*i IK i&"recci'6ing n-" receivingwater water bodies.

bodies.

This guide describes the desired coordination of an 10. Ha . r applicant with the NRC staff and the detail and eerienceex of the NRC staff that documentation of data and studies that. an applicant sozpe ' ican6 have not furnished sufficiently should include in the PSAR to support the use of detidic "'i.r' mation on physical hydraulic model physical hydraulic model testing for predicting per sd*iiA*r the staff to perform an adequate review. In formance of hydraulic structures and systems 4*r 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 savings guide is applicable only to physical mo~elt"Osedlo, gOf both NRC and applicant funds and time in the predict the action or interaction of su .Uce waterV` review and acceptance of the results.

with features located outside of contaiihtent.1 The recommendations of this guide are not ppoa e to Accordingly, the regulatory position details the internal plant systems or stuctures. documentation that should be furnished and the type of coordination between the staff and the applicant that 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 possible usual 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 this of-the-art analytical methods. Hydraulic models may type may not be undertaken until after the PSAR is also 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 to systems 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.reeUS. Ni.1a -,ij Regutlatory Guidieaed.C twed to iesvrilte antdmalte availablte to the, ptublic method, Ilaoty Ce,e ....... awo. Vi,)Ii tee,', D.C. 7D~bV,. Ate.,I,ete Ntn eed L)-e 1e,nel, acceptable to the NRC staff ol imtlementie'j uiiecetec parts of the Cenlor,$inss~~, feee regulIatieons, to deliea~tetdt Ichetetteecl ,tivdlItyth! stalfi cc tvalai nat stjwtecolc problemees Theuiesa sejtc t. ttecvt eeteetlIviecc or postolittO accidenti. or itt ittovde! guitdance to .tttttlicints. R.rgulatory Guide% h-qi.sie"uII n ol~- e areC not substnlesu for *eifulmitons. and ConneteleieCe Withethem, is not triltuirtd. I PectvtIie-ectnr G midc,ele;ro Metthods atot solntlotv' dillefecnt from lholit, set ou!to i Mc jetguide%will hee Ancmil- Ffesi,...icnited Tot tetecci 1. ' awer~ltc able .1 they ttoe idt, a1btasis It the.findeings rentuisite In, the ifsueinci!et Col co~ntnance. V fl ,ecc.1,,!mt Ite lstF.1,tcttin, w% Qe8 ccttet I t.01thr of a Petmit or license by the Comcmission. .1, Erivifortcnce-mtit adSt ctl tnq ete t f)lc,-"e

5r Mate, e.0,ine Ptan)tNolvotC "

~Cormnians antd suggestions for itilltrnvetntent% in theso (euieetle ntt! etcncuraged at ;,I[

gitime's,.ntrwgoiei "Melt It evi"Icl .s te, in ltnuette.tt, to atcecrtto,ilitt ctttlflenrtt and~t tle4tectt Iwe lecele ccitfe te seee tMteej,

4 erhe cee.ehi.e~eeute or let, tela,;'

to rei edl fee. intotint Ieon ot et !I net'C,, Hoeweve~r, cornenerreotth!itts luetle.,it eeee~t 'ten teeiutomtmtc n:e dtieteeul etetetlee I ecte Cite'! ' tet leeee! n.e'ett ltitne, eefi teceivedlvvethin abeout ty. ioi ,,~hs titer its oletincc. vvil lee ttaelicntar,tl eestt~leto tleeeetoet quittet Itw netteoin eteteti tee tte U S. ~tel-ec.,,,

tllqeetdnty Cetettcowaeeee evileeetetIltnatl It e *.tyttefUt Vdtlitnhmtttt, D.C. 205fbh. At t,-niut .e Deeq feor. Dionuienr etf Uttinpritn Cultectol.

C. REGULATORY POSITION

effects of both are negligible, or (c) are such that their neglect leads to conservative model results and es- Because all hydraulic design problems cannot be tablishmen.t of conservative 'design or operating resolved by the mechanics of similitude and because bases.

there are limitations to hydraulic modeling.'the NRC

staff should be furnished with certain documentation Documentation should be furnished on the

• for any structural, thermal, erosional,I or other methods used to satisfy the equations of similitude in physicalhydraulic models used by the applicant to es- the model. The effects of scale distortions on data ob- tablish design or operating bases. The regulatory tained from the model studies should be documented.

• position contained in this guide applies only to Where applicable, model adjustment and verification

'physical models used to predict the action or interac- procedures should be described, and information tion of surface waters with features located outside of should be furnished on the validity of the model over containment. a range of likely flow conditions, heat regimes, at- mospheric conditions, and other physical parameters.

Generally, regulatory positions I and 3 describe in- Where applicable, it should be demonstrated that the formation that should be furnished prior to actual model will simulate known flow conditions; this ver- model testing., and regulatory positions 4 through 6 ification should be provided when historical data are describe information needed after testing is com- available.

pleted. Additionally, partial test results should be

• provided for staff review and acceptance during the 4. Where full-scale structures or systems having

• course of testing to ensure reconsideration of characteristics similar to those being modeled exist

• parameters whose importance becomes apparent on and information relative to the observed or measured the basis of partial data collection. After completing performance of the existingstructures or systems is the entire study, all the information should be con- available, the physical model results should be com- solidated either (1) as a separate report with ap- pared with the available information generated by the

• propriate reference added in the PSAR or (2) for in- existing structures. Testing performed on existing sertion into the PSAR. full-scale structures or systems and the results of these tests should be describe

d. The applicability of

1. Prior to construction of the model, the appli- such tests to the problem in question should be

• cant should submit information outlining (a) the documented, and any conclusions derived from the

• problem to be resolved, (b) reasons for selecting the tests should be discussed. If the results of other model

.

hydraulic 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, scale tests are used by the applicant, justification for the use of these results and verification of the ability of these other models to reproduce or predict prototype performance should also be provided.

0

relations, and other physical characteristics of the model, (e) methods that will be used to analyze the Detailed documentation of data obtained from

• data obtained from the model studies, and (0 a existing full-scale structures and systems should be schedule of expected tests, proposed completion provided, including (a) instrumentation used, (b)

dates, and estimated dates for submittal of informa- description of the data collection network, (c) fre-

• tion for NRC staff review. quency of collection,. (d) methods of collection, and (e) physical parameters existing at the time of collec-

2. Staff views and recommendations should be tion, such as heat regimes, flow conditions, and at- solicited prior to model construction and following mospheric conditions.

or coincident with the submittal of the information

• listed in regulatory position 1, and arrangements 5. Any changes to the original design of the should also be made for appropriate members of the prototypes as a result of the model test should be dis- staff to be present periodically during model opera- cussed. The designs that were modeled and the basis tion to observe the actual performance of the model. for modifying the design should be documented.

Undesirable flow characteristics or failure modes for

3. Documentation should be furnished on how the the design tested, as well as any oiihcr problems, various conditions of geometric, kinematic, dynamic, should be discussed.

and thermodynamic.similitude that take into account

.the physical properties and flow state of the fluid (i.e,. -6. Figures. drawings, photographs, and text sub- Froude, Reynolds, Euler, Cauchy, Weber, and other mitted as documentation for regulatory positions 3, related numbers) have been considered. Because-cer- 4, and 5 should be provided in sufficient detail to al- tain forces may act differently in a model than in a low the staff to evaluate independently the ap- prototype, documentation should be provided to plicability of the model to the design problem in justify the neglect of any forces by showing that these question. (A typical model investigation report as forces (a) are of negligible magnitude, (b) compensate published by the U.S. Army Waterways Experiment for other neglected forces in such a manner that the Station has been found acceptable in the past.) Bases

1.125-2

for the interpretation of model results and for any Except in those cases in which the applicant conclusions reached should be provided. In many in- proposes an acceptable alternative method for com- stances, it may be advisable to provide partial test plying with specified portions of the Commission's results for review. The models should not be dis- regulations, the method described herein will be used mantled until the staff has reviewed the submittals. in the evaluation of submittals for construction per- mit applications docketed after November 1, 1977. If

D. IMPLEMENTATION

an applicant wishes to use this regulatory guide in developing submittals for construction permit ap- The purpose of this section is to provide informa- plications docketed on or before November 1, 1977, tion to license applicants regarding the NRC staff's the pertinent portions of the application will be plans for implementing this regulatory guide. evaluated on the basis of this guide.

1.125-3