ML20034D446
| ML20034D446 | |
| Person / Time | |
|---|---|
| Issue date: | 07/29/1992 |
| From: | Rosalyn Jones Office of Nuclear Reactor Regulation |
| To: | Tritch S WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP. |
| References | |
| NUDOCS 9208030276 | |
| Download: ML20034D446 (3) | |
Text
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g July 29, 1992
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S. R. Tritch, Manager i
Engineering Technology i
Westinghouse Electric Corporation P.O. Box 355 Pittsburgh, PA 15230-0355
Subject:
Request for Additional Information on Topi:a1 Report WCAP-13060-P,
" Westinghouse Fuel Assembly Reconstitution Evaluation Methodology" l
I
Dear Mr. Tritch:
The review of topical report WCAP-13060-P is currently in progress. During the I
course of our review, the staff has identified the need for some additional information as irdicated in the enclosure.
Please contact E. D. Kendrick of my staff on (301) 504-2891 if there are any questions concerning this request.
Sir.cerely, p/
Robert C. Jones, Chief Reactor Systems Branch Office of Nuclear Reactor Regulation Encicsure:
As stated l
DISTRIBUTION Central Files SRXB R/F RJones LPhillips EKendrick EKendrick R/F I
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t 0FFICIAL RECORD COPY Document Name: WESTRAII.EDK l
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l OUESTIONS ON VESTINGHOUSE FUEL RECONSTITUTION REPORT (WCAP-130601 i
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What is the maximum number of replacement rods that Westingnol 1.
place in a reactor core?What is the maximum number of fuel assemblies allowed l
per assecoly?
What is the maximum number of replacement rods that with filler rods?
Please provide justification for j
may be placed in adjacent positions?
these numbers based on the departure from nucleal f
Replacing fuel rods with solid filler rods will lower the bundle power i
slightly (on the average, approximately 0.5 per rod) but it will f
2.
increase local radial peaking in surrounding rods.
f What is the maximum possible increase in local power on a neigh-boring fuel rod due to the insertion of a) one adjacent solid l
2a.
filler rod, and b) two adjacent solid filler rods?
Will the departure from nucleate boiling correlation selected for On the analysis apply to the new radial power peaking pattern?
I 2b.
what basis will this be determined?
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Are quadrant power tilts considered when several reconstituted l
2c.
assemblies are placed in a given quadrant?
i On Page H, Section 4.2.1, a sample calculation is pj l
3.
fuel assembly results in an increase in the departure from nucleate t
boiling argin.
What was the baseline reference for this calculation?
3a.
l What assumotions were made about the effect of the replacement i
On the radial power distri-35.
rc:s en the assembly total power?
bution withie *he assembly?
I Wnat departure from nucleate boilino corre.lation was used in the f
Were the Does the analysis model cold-wall effects?
j 3c.
local ccnditions within the range of the correlation's data base, analysis?
e.g., ratio of hot-to-cold surf ace area and pin radial power factors?
Was this the ' worst case' for the effect of reconstituted l If so, on what basis were they 3d.
local hot channel conditions?
determined to be the ' worst' conditions?
Please provice critical heat flux data to substant 4.
l lower enthalpy rise due to the replacemeat of heated fuel rods with l solid filler (non-heated) rods in a subchannel particularly when two or l l
1 l
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more of the filler rods are adjacent to each other.
Is this data Which applicable for assemblies with and without mixing-vane grids?
critical heat flux correlations will be applied to which fuel designs and do any of these correlations explicitly model the cold-wall effect?
If these correlations do not model the cold-wall effect, how can the analyses consider this effect?
What critcria will Westinghouse use to determine that all future 5.
reconstituted assemblies are bounded by the departure from nucleate For example, shouldn't the boiling ratio analyses in WCAP-13060?
following minimum evaluations be performed for each reconstituted assembly:
a) applicability of the reconstituted geometry to the data base of the critical heat flux correlation used, b) the effect of reconstitution en local rod peaking and on bundle and core powers, and c) the effect of reconstituted rods on hot channel conditions in the rod?
What is the gap between the upper tie plate of the reconstituted 5.
assembly and the top of the solid filler rods at beginning-of-life and end-of-life? Also, how is the end-of-life gap determined?
Section 2.3.2 does not appear to discuss lateral stiffness of the 7.
Please provide a comparison of the lateral reconstituted assembly.
stiffness of a reconstituted assembly to a non-reconstituted assembly.
This section only provides a comparison of grid impact forces from a reconstituted assemoly to those from a non-reconstituted assembly at a What is the impact of a reconstituted assembly at peripheral location.
an interior core location on surrounding non-reconstituted assembly components including the fuel rod impact forces?
2