ML20029A639
| ML20029A639 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee  |
| Issue date: | 09/30/1990 |
| From: | Driskell W EG&G IDAHO, INC. |
| To: | NRC |
| Shared Package | |
| ML20029A640 | List: |
| References | |
| CON-FIN-D-6039 EGG-EAST-9403, NUDOCS 9102260356 | |
| Download: ML20029A639 (27) | |
Text
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EGG EASl 9403 q
TECHNICAL EVALVATION REPORT REVIEW OF THE HUXY CODE FOR DETERMINING RADIATION VIEW FACTORS FOR VERMONT YANKEE i
F WALTER E. DRISKELL 4
SEPTEMBER 1990 EG&G' Idaho, Inc.
Idaho Falls, Idaho 83415 Prepared for the U.S. Nuclear Regulatory Comission-Washington D.C. 20555
.Under DOE Contract No. OE AC07 76ID01570 1 FIN No. 06039 l Task Assignment No. 89 2 h o?D b N A max em _. _ _ - - _ - -- - - - - - - - -
- f. ,- 7 ABSTRACT An evaluation of the HUXY code was performed to review the use of this methodology to compute radiation view factors for LOCA' analyses of the Vermont Yankee nuclear plant. A review of the corrections to the valve component subroutines in RELAPSYA code was also performed to verify that the proper updates were incorporated. The updates were taken from corrections to the valve subroutines in the RELAP5/M001 code to correct coding errors in an earlier version upon which the RELAP5YA code was based. Lastly, two typographical errors were identified in the SER documenting the original review of the RELAPSYA code and are also noted.
Based on this review, it is recommended that the HUXY code be accepted for calculating radiation view factors for LOCA evaluations of the Vermont Yankee nuclear plant. The updates to correct errors in the RELAP5YA code were also found to be acceptable and the restrictius placed on_use of the valve components ,
with form loss coefficients is hereby removed.
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SUMMARY
This report documents the review and evaluation of the use of the HUXi code for calculating radiation view factors for performing LOCA analyses of the Vermont Yankee nuclear plant. The use of the HUXY code for computing radiation view factors was submitted to the NRC Office of Nuclear Reactor Regulation for approval for performing LOCA licensing analyses for the Vermont Yankee plant.
The NRC staff requested the assistance of the INEL in reviewing the HUXY code.
The review consisted of evaluating the HUXY code view factor methodology and evaluating a comparison of hand calculated iew factors with that calculated by the HUXY code for a given fuel rod array. The changes to the valve component model in RELAI5YA were also reviewed to verify that the proper updates to RELAP5YA were incorporated to correct errors in the original code version.
Typographical errors were also noted in the SER regarding the original submittal requesting approval of this methodology for the Vermont Yankee plant.
Based on this review, it is recomended that the use of the HUXY code be accepted for calculating radiation view factors for performing LOCA analyses of the Vermont Yankee nuclear power plant. Also, the updates added to the RELAP5YA code to correct errors in the original model were reviewed and are also found to be acceptable. The restriction preventing use of the valve component model in RELAP5YA with form loss coefficients is hereby removed, ii l
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TABLE OF CONTENTS
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ABSTRACT
........................................................ i
SUMMARY
......................................................... 11
- 1. IPTRODUCTION ........................................... 1
- 2. REVIEW 0F METH005 ...................................... 2 2.1 REVIEW OF THE HUXY CODE FOR CALCULATING RADIATION
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VIEW FACTORS .............. ..................... 2 2.2 MODIFICATION TO THE RELAP5YA VALVE SUBROUTINES ..... 4
- 3. RESTRICTIONS .......................................... S
- 4. CONCLUSIONS
.......................................... 6
- 5. REFERENCES
............................................ 7
- 6. APPENDIX A
............................................ A-1
- 7. APPENDIX B ............................................ B-1 111
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TECHNICAL EVALVATION REPORT REVIEW OF THE HUXY CODE FOR GENERATING RADIATION VIEW FACTORS FOR THE VERMONT YANKEE NUCLEAR PLANT
1.0 INTRODUCTION
The HUXY code is used to compute fuel assembly. radiation view factors for use in RELAPSYA LOCA analyses of the Vermont Yankee nuclear plant. The use of the HVXY code for cahulating radiatior, view factors for the Vermont Yankee nuclear plant was submitted to the U.S. Nuclear Regulatory Commission (NRC) by the Yankee Atomic Electric Company (YAEC) for review and acceptance for LOCA licensing analyses.
The NRC Office of Nuclear Reactor Regulation (NRR) is responsible for the evaluation and review of computer codes, analysis methods, and their proposed applications. The NRC requested assistance from the Idaho National Engineering Laboratory (!NEL).to review the YAEC request to.use the HUXY code to calculate ,
radiation view factors for LOCA analyses. Following the review, _ the NRC requested additional information from the YAEC to complete the' evaluation. The INEL reviewed and evaluated the utility responses to.the NRC questions regarding use of the HUXY code. The responses-to the questions are contained in Appendix A._
This Technical Evaluation Report contains the results of the review of the HUXY code for calculating radiation view factors and the methods _ of which are described in' Reference 5.1. A review of modifications to the RELAPSYA was also performed to verify the correct updates were made to correct errors in the valve component model contained-in the previous version of-the code. The YAEC also
-identified typographical errors in the original NRC SER and are noted herein.
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Section 2.0 contains a description of the HVXY code view factor calculation and
" enanges to the RELAP5YA code to correct previous errors in the valve component model.
Section 3,0 itemizes the restrictions regarding use of the HUXY code for LOCA licensing analyses, while Section 4.0 presents the conclusions of this review, t
2.0 REVIEW OF METHODS k
This section presents a brief description of the HUXY code and discusses the method used to verify the ability of this methodology to correctly calculate radiation view factors for use in LOCA analyses of the Vermont Yankae nuclear plant.
{
A description of the updates incorporated into the RELAPSYA code to correct errors in the valve component model is also provided.
2.1 REVIEW 0F THE HUXY CODE FOR CALCULATING RADIATION VIE The HVXY code computes radiation view factors for use in calculating the therma energy transfer between nuclear fuel rods and the channel walls in the Vermont Yankee fuel assembly.
The radiation view factors are calculated for the assembly with the following assumptions:
a.
All rods have equal diameters (0.483") and are positioned in a square array of pitch 0.64". The inside dimension perpendicular to the flat channel wall is 5.278".
b.
The two water rods, with diameters of 0.591" that are located near the center of the assembly, are replaced with fuel rods. This ignores net thermal radiation from neighboring fuel rods to these two potential heat sinks and yields octant svmetry in the radiation enclosure model.
- c. All radiation is assumed to occur in the horizontal plane. !
This assumption neglects axial radiation, j
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To verify the ability of the HUXY code to correctly calculate view factors, the #
view factors calculated by the HUXY code were compared tc hand calculated values for the Vermont Yankee fuel rod array radiation enclosure model. A coraparison of the two methods identified some minor dif ferences, with the largest difference
\ being 22.6%. When this view factor is collapsed into a new set of view factors for use in the RELAPSYA code, the difference is only 0.328%. The reason for these differences i; due to the fact that HVXY only accounts for v12w factors between the source rod and neighboring rods no more than four positions away.
To assess the impact of these differences in response to a request for additional j information documented in Reference 5.2, the YAEC performed a heatup calculation using the view factors computed by hand and by the HUXY code. For the hot rod, the pe:k clad temperature was calculated to be 1658.8'F for the hand calculated view factors while for the HUXY calculated factors the hot rod peak clad temperature was fcund to be 1657.3*F. While this is a negligible difference in L temperature, the difference would be greater for hot rod calculations near the 2200*F limit. When questioned, the YAEC responded that this difference is expected to be less than 50'F. While this difference is negligible for rod temperatures of the order of 1600 to 1700'F, the difference could be much higher at or near 2200*F. As a consequence, should future peak clad temperatures be calculated to be greater than 2150'F, then additional quantitative justification for use of the HUXY code view f actcis will be needed to assure the 2200*F limit E is not exceeded.
Also, the YAEC responded that the VerTnont Yankee plant is not limited by oxidation. As such, the residuals in the HUXY code calculated view factors would not affect oxidation limits.
The radiation view factors also do not take into account rod swelling or t allooning. When questioned, the YAEC stated that rod ballooning is never calculated to occur for peak clad temperatures below 2000*F. As a consequence should future clad temperatures exceed 2000*F, then additional justification would be needed for the view factor calculation.
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The YAEC also stated that rod bow is not accounted for in the view factor calculations.
The NRC staff review of NEDE-2428 P ' Assessment of Fuel Rod Bowing in General Electric Boiling Water Reactors," dated March 8,1983, concluded that significant fuel rod bow in GE BWR fuel is not anticipated and therefore no operational penalties are required.
Lastly, since the channel boxes are not used for a second irradiation, channel box bow is not a consideration for calculating view factors.
i Based on this review, the use of the H0XY code for computing thermal radiation view factors is considered acceptable for LOCA analyses of the Vermont Yankee nuclear power plant with the following restrictions.
1.
If the peak clad temperatures are calculated to be 2150'F or greater, additional justification will be needed to demonstrate that the residuals in the HUXY computed view factors values will not exceed a 50*F increases in temperature.
2.
If the fuel clad temperatures are calculated to exceed 2000*F then justification for the mission of clad swell and ballooning will need to be provided.
2.2 MODIFICATION TO THE RELAP5YA VALVE SUBROUTINES a
To correct errors in the original RELAP5YA code, the YAEC has obtained the RELAP5/M001, cycles 19 to 29 updates from the INEL pertaining to the valve component models. These updates included modifications to correct the errors in the ICOMPH, RVALVE, and VALVE subroutines.
The specific changes are described in Appendix B.
The identified updates were reviewed to verify that they consist of the appropriate upd'ates to RELAPS to correct deficiencies and enable use of the valve component models with form loss coefficients. The correct updates have been identif tett by the YAEC which are necessary to ccrrect the errors in the RELAP5YA
- code.
As a :onsequence, the restriction regarding use of the volve components 4
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with loss coefficients is removed.
I 3.0 -RESTRICTIONS Based on the review of the HUXY code for use in computing radiation view factors for LOCA analyses of the Vermont Yankee nuclear plant, the following restrictions shall be applied.
1.
The use of the HUXY code to compute radiation view factors for the Vermont Yankee nuclear plant shll be limited to the geometry and assumptions for the fuel assembly radiation enclosure model described in Reference 5.3 and the response to Question 2.0 of Appendix A 2.
If the peak clad temperatures are calculated to be 2150'F or greater, additional justification will be needed to demonstrate that the 4
residuals in the HUXY computed view factors values will not exceed a 50*F increase in temperature.
3.
If the fuel clad temperatures are calculated to exceed 2000*F then justification for the-omission of clad swell and ballooning from the view factor calculation will also need to be provided.
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l 4.0 CONCLUMONS i l
) A review of the use of ' 4Y code for computing radiation view factors for j LOCA analyses of the h, n kee nuclear plant was performed. The review i
demonstrates that trae heXY code is acceptable, with the restrictions identified in Section 3.0, for determining the view factors for the specified Vermont Yankee l ,
fuel rod assembly model and whi:h is used in the RELAPSYA code for assessing the effects of rod to rod thermal radiation under LOCA conditions.
I i
The upe;.tes to the RELAPSYA <: ode were also reviewed to verify that the proper coding changes were made to the code to correct errors in the valve component mooi with loss coefficients. The proper changes were made to the RELAP5YA code by ine YAEC, and the restriction preventing use .. the RELAP5YA valve component with loss coefficient is remcved.
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8.0 REFERENCES
5.1 Fernandez, R. T. and H. C. daSilva, " Vermont Yankee BWR Loss of Coolant Accident Licensing Analysis Method," YAEC 1547, Chapter 3. Yankee Atomic Electric Company, June 1986.
5.2 Letter from L. A. Tremblay, Jr. to USNRC, ' Response to Second Request for Additional Information on the Use of RELAPSYA." BVY 90 067, hne 8,1990.
5.3 Letter from R. W. Capstick (YAEC) to V. L. Rooney (USNRC NRR), ' Request for Supplementary Safety Evaluation Report Supporting Use of RELAP5YA for Vermont Yankee Power Station.' FVY 88 006, January 26, 1988.
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' Appendix A VERMONT YANKEE !
NUCLEAR POWER CORPORATION t f
.y y Ferry Road. Stettleboro. VT Os3017D32 (tyU A
ENGtNEERING orr4CE M en... gest (*
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June 8,1990 United States Nuclear Regulatory Commission svy W O67 Document Control Desk j Washington, DC 20555
References:
- a. 1 icense No. DPR 28 (Docket No. 50 271)
- b. Lener, USNRC to VYNPC, NVY 90-068, dated April 5,1990.
- c. Lener, VYNPC to USNRC, FVY 88 006, dated January 26,1990,
- d. Repon YAEC.1300P, R.T. Femandez, et al, dated October,1982.
Subject:
- Response to Second Request for Additional Information on the Use of RELAPSYA c Dear 5ir.
2 By letter dated April 5,1990 [ Reference (b)), NRC requested additional information 4
concerning our rec uest for apprtwal of the use of the HUXY code (Reference (c)) to calculate view factors to be usec. as input to RELAP5YA (Reference (d)). Reference (b) re responses bq submitted to NRC within 60 days from letter rectipt. was Reference received by (b) qu
- Vermont Yankee on April 10,1990.
In accordance with your request, responses to the three (3) questions of Reference (b) are provided as an anachment to this lener. We trust that this informadon satisfactoril concems; bowever, if you have any further questions, please contact this office. y a ,
Very truly yours, VERMONT Y ANKEE NUCMAR POWER COP.PORA110N
- , 0. '
1.conard A. Tremblay, Jr. Y Sen t Ucensin5Engineer oc: USNRC Region I Adtninistrator USNRC Resident Inspector VYNPS '
USNRC Project Manager VYNPS 90 p'Og6120pecx+:.oogop ao r.og i . >
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ATTACHMINT - 1
- YAEC RESPONSE TO ADDI'IO $l NRC OUESTIONS ON HU g APPtICATION TO BWR LOCA ANALYSIS The hand calculated view factors appear te $a more accurate than the view factors calculated by HUXY. This evaluation is based on s
differences in the view factors calculated by HUXY when compared to the hand calculated values, which agree very closely with the TPAC-BF1 calculated facters. It also appears that the hand calculational tec.nique would not significantly increase corr.puter costs if included in the HUXY program. As a consequence, it would st.em reasonable to incorporate the niore accurate hand calculational technique into the HUXY code.
Ouestion i
- 1. Please explain why the more accurate view f actor calculation is not included in the HUXY code, l
Answer 1
- 1. The hand calculated view f actors presented in Reference 2 can be used without incorporating them into the HUXY code. Hence, the inclusion of the more accurate view factor calculation in HUXY (Reference 1) is not needed. We prefer to use HUXY to calculate the view factors mainly for convenience. Whenever there is a change in fuel radius it is easier to use the HUXY code to calcuiate' 41ew 'f actor's" than with the hand calculation method.
In addition, we ha've found that the peak, clad temperatures ir.
LOCA calculations change very little whether the HUXY view f actors or the hand calculated view factors are used as input to PILAP5YA radiation model. This is presented in more detail in the response to Question 2.
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l Questien 2 i
i As noted in the letter, a non-conservative dif ference of 22.6% was observed between HUXY and hand calculated view factors, which is f identified in Table 1.
Tne effect of thi. difference on the radiation heat flux and the hot-rod temperature is difficult to i
assess because the. radiation portion of the heat Clux is dependent i on the difference of absolute tem 7eratures raised to the fourth 4
power, as well as the view factor.
1
- 2. P1, ease provide justification that all nonconservative dif ferences j between HUXY and hand calculated view factors have an
! insignificant effect on the calculated hot-rod temperature response. What may appear as a small error in view factor could translate to a more significant error in radiation heat flux i should the temperature difference between the fuel rods become large. Also, please justify the insignificance of the view factor error in the HUXY code for all intended applications of ,
- the Ht,1XY progra,m.
2 5
Answer 2 The view factors in Table 1 referred to in the question are not i used directly in the REll.PSYA radiation model. This is because the i
HUXY model of the hot channel is different from the MLAPSYA model ,
, of the hot channel. The HUXY view fhetors are collapsed to a new set of view factors before being used in the RELAP5YA model. This process reduces errors considerably, as shewn below.
To address this quest' ion, a sample M1.APSYA,LOCA analysis problem using the hand calculated view factors and the HUXY calculated view t
factors was set up. The sample problem represents n 0.7 ft break 8 in the, recirculation discharge pipe at Vermont Yankee. This case A.2 l
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is close to the limiting LOCA scenario for Vermont Yankee (Reference 3).
In order to understand how the view factors are used, a brief t
description of the Vermont Yankee hot channel model is presented.
In addition, we will present how the view factors are being combined to prepare ,the input for RELAPSYA. We also show that when thus combined, the error is small, as shown in Table 1, attached.
The radiation model option is used in the Vermont Yankee RELAPSYA Hot Channel (HC) Model presented in Reference 4 and approved by NRC in Ref erence '5. 'The HC "model represents one-eighth of the hot assembly and its corresponding fraction of the bypass region. Thus the RELAP5YA HC model represents the tien rods (six full size and four half-size rods) shown in Figure 1(a) . However, the RELAP5YA HC model does not use ten separate heat structure geometries, since this would require excessive computation time. Instead, for the GE Hith Energy Bundle, Rods 1 through 6 and rod 9 are lumped into an average rod and rod 7 is kept as the hot rod. Red 7 was chessn to conservatively represent the hot rod since it " sees" the least of'the water rod and the channel wall. Rod 10 (half size rod) is the-water rod. This arrangement is shown in Figure 1(b) . Hence the RELAPSYA model embodies 4 heat structure geometries: (A)
) channel (box) wall,-- (B) average rod, (C)-hot rod, and (D) water rod. The average rod and the hot red produce the same power. The local peaking f actor in the hot bundle is assumed to be 1.0 in the Vermont Yankee methodology. Hence, both rods will have the sae temperatures if radiation is ign'ored. This answers the reviewer's comment concerning the fact that small error in the view' factor could translate to a more significant errer in radiation heat flux should the temperature difference between the fuel rods become large. Since the " average rod" and the " hot rod" are identical, the only temperature difference between them is due to radiation.
A-3
Tho hot rod is positionod in tho location that will radiato tho l
- Icast to the wall and the water rod. For the configuration presented in Figure 1, the view factors are calculated as follows:
The radiation view f actors f or the PILJJ5YA model are obtained in a two-step process: (1) The view factors for the actual physical rod layout shown in rigure 1(a) are obtained from the t!UXY code (Reference 1) or from the hand calculated view factors (Reference 2), (2) these new factors are " collapsed" into the geometry implemented in the PII.APSYA Het Channel model which is shown in figure 1(b) .
In Step (1), the planar view factors, i.e. the varicus r t o (i " 1 to 11 and $ = 1 to 11, where 11 represents the channel wall (Figure 1(a))) are computed for a given elevation using }{UXY or the hand calculation, method. View f actors between dif ferent elevations are set to :ero for the sake of simplicity. By neglecting interplanar radiation, the heat removal from the hottest heat structure is slightly.less than if such mechanism had been considered. This is a conservative assumption.
In Step (2), the radiation view factors previously computed for heat structure 1 to 11 (Figure 1 (a) ), are used to obtain the view factors for heat structures (A), (B), (C) and (D) shown in Figure 1 (b) . The method used to collapse the view f actors is a direct application of continuity and reciprocity relations.
In the equations that follow, the letter "F" stands for the view factor and "A" for the radiation heat transfer area.. The subscripts, as in Fu, are either the letters A, B, C, D, or numbers 1 to 11 as in figures 1(b) and 1(a) respect 4ve ly .
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The system of equations for the view factor are:
+
Fu =
i Fn.n 6
Fu =
1 Fu.s + Fu.e + f u.e ,
3+1 4
Fu = Fu
- Ac/A i i
F u = F n.i, Fu = F
- A./A, F = 1-(F., + Fx +F) 2 Tx = F.
- Ac /) ,
F., = F ,
- A,/ A,
, Fu = F,.n 6
rn '
= I F,.'3 + r ,.7 + F ,,,
3-1
, Fcc = F ., i .
T o = F ,.i.
Fu = F
- Aa/A, F. = 1-(Fu + Fw + F.)
F = F. -.
- Ac / A, '
T F : = - F u.3, .
Wit a the above equations, the - radiation view f actors computed by th'i.HUXY code and by hand were used to compute the 16 view factors for the RELPASYA h'ot channel model. The results are presented in Table 1, attached.
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The two sets of view factors were implemented in the PILAPSYA models and the sample 1.OCA problem of 0.7 ft' break in the recirculation discharge was calculated.
The radiation model is usert in this sample problem only for rod temperatures greater than 1000'F and void fraction greater than 0.9. Figure 2 compares the clad temperatures et the tottest elevation for the "no radiation" case, "the HUXY calculated view factors" case and the " hand calculated view factors" case. The peak clad temperature for the "no radiation" case was 1729.8'F. The " hand calculated view f actors" case has a PCT of 1658.8'T J 7 the hot rod and a PCT of 1632.2'T for the average red and the "HUXY view factor" case has a PCT of 1657.3'T in the h? rod and a PCT of 1630.6*F in the averags rod.
As can be seen, there is very little difference in the calculated temperatures when the HUXY view factors are used compared with the hand calculated view factors.
The view factor F,.i, identified by the reviewer in Question 2 as showing a dif ference of 22.6%, is incorporated into the view f actor Fn, which has a value of 0.8172223 when the HUXY view factors are used and 0.814544 when the hand' calculated values are used. This gives only a 0.328% difference between the view factors used as input in PILAISYA. Based on this analysis, we conclude that the HUXY calculated view f actors are adequate and there is no need for a new model to be implemented in the code.
Question 3 l
The ability of the HUXY progrNn to accurately calculate radiation I riew factors is based on nominal, as-built fuel geometry. Yuel-assembl,y.and. fuel-rod geometries however, will change due to core l
burnup. Some rods may bow and experience some swelling during full A-6
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y 9 power operation as well as during accider.t conditiens where fuel clad ballooning and/or ciad rupture may occur. *
- 3. Please provide additional inf ormation regarding the method used to accommodate changes in fuel geometry when determining radiation view f actors with the HUXY program. That is, hcw are fuel geometry changes that occur because of burnup and/or accident ccnditions included in the HUXY calculated view f actors?
Answer 3 There are three types of fuel geometry changes which need to be addressed:
a) burnup dependent b) bowing c) clad ballooning and/or rupture a) We take into account the fuel geometry changes due to burn up.
Since both the average red and the hot rod in the hot bundle produce the sue power, the dimensions of the two rods are the same., The fuel dimensions function of burnup are calculated using FROSSTEY-2 (Reference 6) . This fuel radius is used in the HUXY calculation for all the rods in the array.
b) We do not take into account the fuel geometry changes due to bowing for the following reason:
The NRC staff review., of NEDE-24284-P " Assessment of Fuel-Red Bowing in General Electric Boiling Water Reactors," dated March 8,1983, concluded that significant fuel rod bowing in the GE BWR fuel is not anticipated and therefore no operational penalties are required. As such we do not asstune bowing in our view f actor calculation.
A-7
c) The ballooning ef fects on the view f actors can be calculated with the HUXY code. We do not expect ballooning to occur for cladding temperatures belo&: 2 00 0'r . In all our scoping calculations using PILAP5YA, balle aning did not occur. If the cladding temperatures exceed 2000'r we will justify the use of the view f actors used or we wil1 not invoke the radiation option e
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a References -
i
, 1. Steves, L.H. , et al . , HOXY -
A Generalized Multi-Rod Heatue code
, wit h 10CTR50, Appendix x Heatue option User's M a n u a l_ , Exxon Nuclear Company, Inc., XN-CC-33(A), Revision 1, Novernba r 14, j
1975.
?
- 2. Letter, R. W. Capstick (VYNPC) to V. L. Rooney (USNRC), " Request for Supplemental Safety Evaluation Report Supporting the Use of PELAP5YA for Vermont Nuclear Power Station," January 15, 1988 (Docket No. 50-271).
- 3. Letter, L. A. Tremblay, Jr. (VYNPC) to USNRC, " Supplementary Inf ormation- Regarding NRC LOCA Analysis Review Effort," Harch 9, 1990, (Docket No. 50.271).
- 4. R. T . Fernandez and H. C. daSilva, Ve rmont Yankee BWR Less-of-Coolant Accident Licensine Analysis Method, YAEC-1547, YAEC, Framingham, Massachusetts, June 1986 (Docket 50-271) .
P
- 5. Letter, V. L. Rooney (USNRC) to R. W. Capstick (VYNPC), " Approval of Use of Thermal-Hydraulic Code RELAPSYA (TAC No. 60193), Re:
Vermoot Yankee Nuclear Power Station," NVY 87-136, USNRC, date_d August 25, 1987 (Docket No. 50-271).
- 6. Letter, R. W. Cap' stick _(VYNPC) to V. L. _ Rooney (USNRC" " Vermont Yankee LOCA Analysis' Method: FROSSTEY Fuel Performance Code (FROSSTEY-2) , " dated _ December.16, 1987 (Docket No. 50-271).
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. TABLE 1 View Factor Summary PILAPSYA Input view Factors '
Based on Hand View Factor Ensed on HUXY Calculatica Fu 0.0896531 0.0843354 Fo 0.8902789 0.0891942 F, 0.020068 0.021957 F. 0.0 0.0017630 Fu 0.253083 0.253556 T ., 0.57011 0.570394 Fw 0.125726 0.125315 F. - -
0.051081 0.050735 Fu 0.0370811 0.0405714 Fa , 0.817222 0.814544 Fa 0.127156 0.1273608 Fa 0.0185406 0.0175238 Fu 0.0 0.006141 F,. ,
0.625018 0.620791 Fx 0.034902 0.032988 F. 0.34008 0.34008 4
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4 Appendix B Updates to Correct RELAPSYA Valve Subroutines h'RC Question 1.20 in Reference Al provided a sumsaryaofesINEL to upd RELAPS/ MOD 1 to go from Cycle 18, the version used to develop , to RELAP5 Cycle 29, the final version of RELAP$/MODL.
The question asked Yankee Atomic Electric Company (YAEC) to state for each update whether it was (1) incorporated as written by the INEL RELAP5 developers
, (2) incorporated, but in modified formt or (3) not included in RELAP5YA. YAEC's response was provided in Answer 1.20 of Reference A2.
Recently, we have incorporated and tested those INEL updates , contained in Reference A3, that correct and/or clarify the coding for valve subroutines.
The following information identifies the !NEL updates and describes our implementation similar to the format used in our Answer A1 . .
Each item has been given a number that contains the cycle number e left to th of the decimal decimal. and a consecutive number within that update to the e right The INEL summary of the specific update item is given fd11 a owed briet' description of our implementation of that item.
21.7 Valve updates which fix the interpolation over form loss ratheranth CSUBV.
Subroutines modified: ICOMPN, RVALVE, VALVE This update was incorporated as written (AW).
22.1 Corrects input and initialization for check, trip, and swing check valves. Also corrects plot scaling error.
Subroutines modifiedt kCOMPN, RVALVE, VALVE Iv)TS '
All of the uptate changes related to valves (ICOMPN, RVALVE , and VALVE) were incorporated. 1 A'so, a modification in Update 29.1 to correct the l
620lR/20.355 I
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ATHROAT variable for inertial valves i incorporated with this update. n the VALVE subroutine was not implemented; they are not The changes to the PLOT subroutine re we 29.1 related to the valve corrections.
i Fix VOLVEL. calculate momentwn VISC terns i man. .
4 ttore these in DIFVF and DIFNC .
n VOLVEL as derived in the state, and fix inertial valve ATEROAT in VALVEFix indefinite in a .
Subroutine modified:
STATE. VALVE VEXPLT. VOLVtL 4 The update to the VALVE subroutine corrects in Update 22.1.
an error taat was created of Update 22.1 discussed above.This correction was inco ementation related to valves, but vete incorporated in modifi d fT e orm earlier in RELAP3YA as discussed in eour .
erence A2). Answer A120 (R f REFERENCES A1.
Letter. P. Wheatley (INEL) to C. Graves n adS Resulting From the Review of RELAP5YA . " PDW 8 .Cun(NRC)."hest Incorporatedt dated September 4,1986. -86. EC&G Idaho ,
A2.
Letter. R. W. Capstick (YAEC) to V. L Additional NRC Questions on the RELA'SYA C. Rooney (NRC). " Re Yanke'e Atoele Electric Company, dated Novembomputer Code."
No. 50-271). er ~ 1986 (Docket A3.
Letter. E. C. Johnson (INEL) to T. Fernandez (YA EC). "Tr:assittal of RELAP5/PCD1 Updates," ECJ-66-85, EC&G August
- Idahc 19, 1985.- .
rcorporated' dated
- 9 4
6 620lR/20.355 B-2
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