ML20054E814

Forwards Requests for Addl Info from Reactor Sys Branch,To Permit Completion of OL Application Review

ML20054E814
Person / Time
Site:	Waterford
Issue date:	06/07/1982
From:	Miraglia F Office of Nuclear Reactor Regulation
To:	Maurin L LOUISIANA POWER & LIGHT CO.
References
NUDOCS 8206140274
Download: ML20054E814 (13)

Text

3 o-4 p

9 JUN 7 1982 DISTRIBUTION:

Document Control (50-382)

NRC PDR L PDR LB#3 Rdg.

CMiles, OPA Docket Hol 50-382 TERA FMiraglia NSIC JLee SBlack iW.

L. V. Maurin JRutberg, OELD Vice President - Nuclear Operations Louisiana Power & Light Company hitzman,AIG 142 Delaronde Street Attorney, OELD New Orleans, Louisiana 70174 ABrauner, NRR

, ASLBP

Subject:

Request for Additional Information - Waterford Stean Electric Station, Unit No. 3 We have determined that certain additional information is required in order to permit us to complete our review of your application for an operating license for Waterford Steam Electric Station, Unit Ho. 3.

The enclosed round two requests for additional infomation were prepared by the Reactor Systeus Branch and are numbered 440.1 through 440.68.

Please provide responses to the enclosed request by August 1,1932.

If you require any clarification, please contact the project manager Suzanne Black on (301) 492-7702.

Sincerely, Original Signed P/t Frank J. Miraglia, Chief Licensing Branch No. 3 m

e Division of Licensing 3

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OFFICIAL RECORD COPY

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Mr. L. V. Maurin Vice President - Nuclear Operations Louisiana Power & Light Company 142 Delaronde Street New Orleans, Louisiana 70174 cc:

W. Malcolm Stevenson, Esq.

Monroe & Lemann 1423 Whitney Building New Orleans, Louisiana 70130 Mr. E. Blake Shaw, Pittman, Potts and Trowbridge 1800 M Street, NW Washington, DC 20036 Gary L. Groesch 2257 Bayron Road New Orleans, Louisiana 70119 Mr. F. J. Drummond Project Manager - Nuclear Louisiana Power & Light Company 142 Delaronde Street New Orleans, Louisiana 70174 Mr. D. B. Lester Production Engineer Louisiana Power & Light Company 142 Delaronde Street New Orleans, Louisiana 70174 Luke Fontana, Esq.

824 Esplanade Avenue New Orleans, Louisiana 70116 Stephen M. Irving, Esq.

535 North 6th Street Baton. Rouge, Louisiana 70802 Resident Inspector /Waterford NPS P. O. Box 822 Killona, Louisiana 70066 Dr. D. C. Gibbs Middle South Service, Inc.

P. O. Box 61000 New Orleans, Louisiana 70161

CONFIRMATORY QUESTIONS REGARDING CESEC*

Section 1.0 440.1 Describe in detail the relationship between CESEC-SAR, CESEC-ATWS, CESEC-SLB and CESEC-III with an emphasis on the differences.

440.2 There is no discussion of DNBR calculations.

If tiie code does compute DNBR, provide details.

440.3 Describe the self-initialization procedure.

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How is the closure head bubb'le modelled?

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440.4 Section 2.0 440.5 Does assumption (1) of Appendix B, assuming pressure to be spa-tially unifonn throughout the entire primary coolant syster imply that no differentiation is made between pressurizer pressure and system pressure in the derivation of the T/H equations, eq. (B-30) through eq (B-78)? Where and how is each pressure used?

Section 3 440.6 How are the crossflows, bypass flows, mixing flows, head flows and leak flows incorporated into eq. (3-1), the equation for the pump flow?

440.7 How does the inertia tem in eq. (3-1) take account of the now split for parallel pumps?

Section 4 440.8 Justify the use of the Semiscale degraded two phase pump data to model CE pumps.

• Note: Questions are organized in Sections, corresponding to CENPD-107, "CESEC."

Section 6.0 440.9 Describe how the level in the pressurizer is determined and how the external heat transfer / mass flow terms are divided between the steam region and the liquid region.

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Section 7.0 J

440.10 Why does the gravity tenn in the surge line momentum equation, eq.

(7.1) centain expressions for the pressurizer when the inertia term is written only for the surge line?

440.11 Show the table of f values used in eq. (7-1) when Re > 15000.

Section 8.0 440.12 Why is the pressurizer pressure time derivative and not the RCS pressure time derivative used in eq. (8-1)?

Section 9.0 l

440.13 Are the 13 nodes referred to in the wall heat transfer model radial nodes?

Provide a figure for the model to illustrate it.

440.14 How is heat conduction through the steam generator tubes modelled?

440.15 Is eq. (9-2) for the shroud heat capacity solved simultaneously with the thermal hydraulic equations of Appendix B?

Section 10.0 440.16 For the Doppler and the moderator reactivity feedback calculation does the core have only one axial node? How is the split core ac-counted for?

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--- - -,.- - - - ___ -_---_w

440.17 How is the moderator temperature / density calculated for the reac-tivity feedback?

4 440.18 How is the fuel temperature for the Doppler feedback calculated?

440.19 Describe in detail the 3<< reactivity feedback model used for -

steam line breaks.

440.20 Explain the homogenization procedure for the third radial node of the fuel rud heat conduction model.

440.21 Is the heat transfer correlation, given by eq. (10-1), for the clad-coolant interface, actually used for all pressures and temp-eratures?

440.22 What is the difference between T and Twi in Fig. 10-6?

y 440.23 Is Qw in Fig.10-6 the source term used in the thermal-hydraulic equations of Appendix B?

Section 11.0 440.24 Is the letdown fluid temperature at the heat exchanger user input l

l as stated by 511.0 or calculated in accordance with eq. (F-3)?

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440.25 In the iterative procedure described in Appendix F is the critical flow set equal to the D' Arcy flow? Why assume saturation at the RHX exit?

440.26 Wnat is the database for the heat transfer correlation given by eq. (F-6)?

.o Section 13.0 440.27 (a) Why does the suppression factor S, given by eq. (13-9) not i

correspond with the formula given in Table 2 of the Hoeld paper referenced?

(b)

Provide references / explanation for the difference in func-tional dependence between Chen's suppression factor

[f(Re F.25)) and Hoeld's expression [f(1 - x) Re F-1.253, 1

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(c)

Justify the choice of Hoeld's formula for the Reynold's number factor, r, eq. (13-8) over the original Chen values.

440.28 Justify the use of the Dittus-Boelter correlation, eq. (13-3) for film heat transfer.

440.29 (a) Justify the assumption of two phase flow with condensation in the steam generator primary for all cases of forward heat I

transfer.

(b)

Explain why the extrapolation of the Akets, Deans, and Crosser correlation to the water system is valid.

440.30 (a)

Present the database for CE's modification of the Rohsenow pool boiling correlation, eq. (13-10), and discuss the range of talidity.

(b)

Should the tem (P - 800) be (P

- 800) in the second sec expression for KR on page 13-57 440.31 Justify the assumption of free convection in the steam generator l

secondary during reverse heat transfer.

l i

A. Hoeld, "A Theoretical Model for the Calculation of Large Transients in Nuclear Natural Circulation U-Tube Steam Generators (Digital Code UTSG),"

Nuclear Eng. and Design, 4_7_, pp. 1-23, 1978.

J. C. Chen, " Correlation for Boiling Heat Transfer to Saturated Fluids in Convective Flow," I&EC Process Design'and Development, 5_, pp. 322-329.

Section 15.0 440.32 Is flow through the valves of the~ steam system assumed to be, choked even when the sink pressure is higher than the throat pressure?

440.33 Justify the expression for ATUB in Fig. 15-1A.

440.34 Correct the equation for Wgt in Fig.15-1 A.

Section 16.0 440.35 Justify the use of CRITCO for steam discharge flow when the refer-ence+ quoted in the CESEC report is for two phase mixtures.

440.36 Is an orifice coefficient used in eq. (16-4) only when the steam generator tube rupture option is selected?

Section 17.0 440.37 Show why the steam generator load dependency of the steam gener-ator water level, required in the steady state situation, is not needed to determine level during transients.

Appendix B 440.38 Equations (B-31),'(B-33), (B-35) and (B-54) should be corrected.

l 440.39 Is reverse flow allowed in the core?

440.40 Is W25 = 2W25,7 7 i

+

A. N.Nahavandi and M. Rashevsky, " Computer Program for Critical Flow Discharge of Two Phase Steam-Water Mixtures," CVNA-128, February,1962.

6 440.41 Describe the algorithm CESEC uses to trace the state of the pres-surizer and to maintain continuity as the state changes.

Is there

.j an automatic time step adjuster?

440.42 Justify the identification, in state 8, of Wg with the vapor por-tion of the critical flow through the pressurizer valve. How is this consistent with the absence of W in state 7?

B 440.43 Provide references for the two phase pressure drop correlations, eqs. (C-1) - (C-5) and a comparison with the Baroczy+ or Chisholm*

correlation.

440.44 Are the CEFLASH-4A water properties applicable to the supercriti-cal region? Provide a copy of the report

• Appendix D 440.45 Explain why eq. (D-12A) can be neglected.

440.46 (a)

How is the reference exit temperature in the steam generator node calculated and how is it used?

(b)

How is the exiting enthalpy computed?

Appendix E 440.47 Prove that eq. (E-4) converges.

+

C. J. Baroczy, "A System Correlation for Two Phase Pressure Drop," ATChE reprint #37.

Paper presented at the 8th Nat. Heat Transfer Conf., Los Angeles, Aug.1965.

D. Chisholm, "The Influence of Mass Velocity on Frictional Pressure Gradients During Steam-Water Flow," Paper 35 presented at the 1968 Themodynamics and Fluid Mechanics Convention, Bristol,1968.

CENPD-133, "CEFLASH-4A, A FORTRAN IV Digital Computer Program for Blowdown-Analysis," August,1974.

)

440.48 How is the moderator feedback divided between the void feedback and the density feedback?

440.49 (a)

Provide additional infomation about the core coolant flew and temperature calculation as the connection between COREQ and LOOPEQ is not clear. Which moderator temperature and density is used for the reactivity feedback?

(b) What fraction of instantaneous core power is absorbed by the coolant?

440.50 Justify the reactivity flux weighting method (i.e., flux or fl ux**2 ).

440.51 Why does the void reactivity calculation employ static quality when the Martinelli-Nelson correlation + referred to uses flowing quality?

440.52 (a)

Is the quantity Q used in Teff for the Doppler an input constant?

(b)

How is it determined?

440.53 Justify the CESEC/PDQ-TH calibration scheme for weighting fac-tors.

440.54 Explain why in the formulation of the T/H nodal equations the pressure p is used but in the determination of water properties the pressure p + ApSqge is utilized.

440.55 Present the derivation / assumptions used to reduce the T/H nodal equations to a 19 equation set.

+

N. C. Sher, " Review of Martinelli-Nelson Pressure Drop Correlation,"

Westinghouse Electric Corp. Report WAPD-TH-219 (July 1956).

440.56 In the T/H model is the instantaneous core power entirely ab-3 sorbed by the coolant with no heating of the fuel?

440.57 Are the sprays 1007, efficient?

440.58 Discuss the DNBR calculation in more detail; in particular the open/ closed channel aspect.

440.59 Describe the modelling of the steam bubble.

What effect does the assumption of a unifonn RCS pressure have?

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440.60 Is there only boiling heat transfer on the secondary side of the steam generator and only film heat transfer on the prima'y ' side?

r 440.61 (a)

Explain the steam generator dryout heat transfer criterion and the calculation of UA.

(b)

How is the steam flow calculated?

(c)

How is tube heat transfer area related to the mass inven-i tory, the recirculation flow, and the quality calculation?

(d)

How is quality calculated?

440.62 Is it correct that the heat transfer in the steam generator is

' UA(T -T) i s

UA = 1.0 UA forward transfer (T -T)

= input reverse transfer 9

"(T -T) o s

Q=

when T > T and T

<T T

+T UA(

-T,)

with UA = 0.8 UA of 2

previous timestep s

where UA = overall heat transfer coefficient Tj = primary side inlet temperature T = primary side outlet temperature o

T = secondary side temperature I

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440.63 (a)

Does the code use the cold edge temperature or the c,old leg temperature for the moderator feedback?

(b)

How is the cold edge temperature. calculated?

440.64 Is there an iteration between the pump flow calculation and the c

energy / mass balance calculations?

440.65 (a)

How is the input flow fraction for the outlet plenum to closure head flow determined?

(b)

Are the plena crossflows or the bypass flows user specified? ;If so what is the basis for the input values?

440.66 How is the UA parameter used in the steam generator heat transfer determined at the minimum mass inventory?

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440.67 I

It is our intent that CESEC-III be used for future analyses instead of CESEC-I or CESEC-II.

Please demonstrate that CESEC-III is capable of perform-ing the required analyses by submitting an analysis of the following tran-sients for the CESSAR design using CESEC-III:

(1) steanline break, (2) feedwater line break, (3) loss of, feedwater ATWS, and y

b (4) steam generator tube rupture.

The results obtained with CESEC-III should be over1 aid with the results ob-tained with CESEC-1 and CESEC-II.. -

440.68 In general, it is our ineression that the dataIII presented by Fla. P.8L.

is insufficient to support a general nixing andel since only one flow condi-tion was measured.

Furthermore, the particular flow condition chosen has a Reynolds. number nearly one full order of magnitude belcw operating conditions.

The expertsent represented each core assembly by a single flow tube and used air as its simulant fluid.

502 was injected ipto the air flow of one (of

4) reactor vessel inlet nozz!es on a roughly 1/4 scale model. The 502 e neen-tration was measured at the exit of each of the " core tubes" and in each of the two reactor vessel outlet nozzles.

Although the scethod appears reasonable for obtaining inforration on reactor vessel outlet ficw, unfortunately, data is presented for only one operating condition. Furthercore, we are concerned about the icpect of constraining the core flow in tubes when substantial cross -

ficw is to be expected.

Thus it is our general opinion that this single data point is not an

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adequate basis upon which to build a co=puter code model intended to model a

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wide. range of flow conditions.

The' following specific questions shodld be addressed by the applicant.

1)

This data is only'for one Re nu=ber, representing only one operating condition.

Upon what gro-Jnds does CE utilize this data for other flow conditicas such as purp coastde-vn or loss of one pump.

2)

Hex was this data icipleWnted in the CESEC ccrpster codes, justify and explain in depth.

3)

Discus: the frpact of having done these experifants in a gacuatry which prchibits cross ficw betwen acre-blids.

Hcw is the cross fica expected to impact the flew split in the exit nozzles.

(1)

"Tc-t P.e;;;rt en Fluid Ml:f r.g in c Scs. lad hscter '.'essal Flcw Model,"

CEM-159(L)-P, July,1981, CecSustica Engin22 ring.

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Further:cre, hw does this lack of cross flow frpect the accu-racy of simulation of core mderator temperature during a return to power?

4)

Discuss accuracy of the experiments - what are the fractional errors in the 1 of flow throu5,- the various " core tubes"?

h The total 5 of flow yJing into the two outlet nozzles is 38% +

14% = 52% - why is it not 50 7 What were the experirental errors?

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