ML20151S351
| ML20151S351 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 08/24/1998 |
| From: | Hughey W ENTERGY OPERATIONS, INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GNRO-98-00067, GNRO-98-67, NUDOCS 9809080034 | |
| Download: ML20151S351 (8) | |
Text
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Entrrgy Operttions, Inc.
j PO. Box 766 Port Gibson, MS 39150 Td 601437-6470 W.K.Hughey Execur August 24, 1998
' ff;" S"'* **' "
f U.S. Nuclear Regulatory Commission Mail Station P1-37 Washington, D.C. 20555 Attention:
Document Control Desk
Subject:
Grand Gulf Nuclear Station Unit 1 Docket No. 50-416 I
License No. NPF-29 Cycle 10 Reload J
Response to NRC Request for submitting Non-proprietary Information for General Electric Company Document,
" Additional Information Regarding the 1.11 Cycle Specific SLMCPR for Grand Gulf Cycle 10"
References:
1.
Entergy Operations, Inc.'s letter dated September 18,1997 (GNRO-97/00087, Proposed Amendment to the Operating License GGNS PCOL-97/003) 2.
Entergy Operations, Inc.'s letter dated February 24,1998 (GNRO-98/00019) " Response to NRC Request for Additional Information Regarding Minimum Critical Power Safety Limit".
3.
NRC Letter GNRI-98/00088 dated July 09,1998 related to the request for withholding information from public disclosure (TAC No. M99639)
GNRO-98/00067 Gentlemen:
Entergy Operations, Inc. via GNRO-97/00087 submitted to the Nuclear Regulatory Commission a proposed amendment to the Operating License (PCOL-97/003) for Grand Gulf Nuclear Station Cycle 10 Reload. The submittal included General Electric Company's proprietary information regarding a 1.11 Cycle Specific SLMCPR for Grand Gulf - Cycle 10. The NRC subsequently via j
GNRI-98/00088 dated July 9,1998 requested Entergy Operations, Inc. to submit General Electric Company's non-proprietary version of the above submitted information.
0, y' 9809080034 980824 PDR ADOCK 05000416 P
PDR G9808201
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i GNRO-98/00067 Page 2 of 2 in response to the above request please find attached General Electric Company's non-proprietary information related 'he Entergy Operations, Inc.'s submittal of GE document "AdditionalInformatior :egarding 1.11 Cycle Specific SLMCPR for Grand Gulf Cycle 10."
Yours truly, WKH/acg 4, attachment: '
General Electric Company's Non-proprietary information to the Additional Information regarding the 1.11 Cycle Specific SLMCPR for Grand Gulf Cycle 10 cc:
Ms. J. L. Dixon-Herrity, GGNS Senior Resident (w/a)
Mr. L. J. Smith (Wise Carter) (w/a) i Mr. N. S. Reynolds (w/a)
Mr. H. L. Thomas (w/o)
Mr. E. W. Merschoff (w/a)
Regional Administrator U.S. Nuclear Regulatory Commission
- Region IV 611 Ryan Plaza Drive, Suite 400 Arlington,TX 76011 Mr. J. N. Donohew, Project Manager (w/2)
Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission p.
Mail Stop 13H3 Washington, D.C. 20555 l
l Dr. E. F. Thompson (w/a)
State Health Officer State Board of Health P.O. Box 1700 Jackson, Mississippl 39205 i
)
i a
i G9808201 i
e Attachment I to GNRO-98/00067 Page 1 of 6 Entergy Operations Inc.
General Electric Company 's Non-proprietary Information related to the Additional Information Regarding the 1.11 Cycle Specific SLMCPR for Grand Gulf Cycle 10 i
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2 a
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Att: chm::t Additi:cIllif:rm:ti:n Reg:rdi g the 1.11 Sept:mber 4,1997 Cycle Specific SLMCPR for Grand Gulf Cycle 10 l
Refer'ences li}
General Electric BWR Thermal Analysis Basis (GETAB): Data. Correlation and Design Application, NEDO-10958-A, January 1977.
l2}
General Electric Standard Application for Reactor Fuel (GESTAR 11), NEDE-240ll-P-A-ll, i
November'1995.
(3}
General Electric Standard Application for Reactor Fuel (GESTAR 11), NEDE-24011 P-A 13, August 1996.
[4]
Gencral Electric Fuel Bundle Designs. NEDE-31152-P, Revision 5, June 1996.
(5}
Afethodology and Uncertainties for Safety Limit AfCPR Evaluations, NEDC-3260lP, Class ill, December 1996.
(6]
R-Factor Calculation biethodfor Gell, GE12 and GE13 Fuel. NEDC-32505P, November 1995.
Comparison of Grand Gulf Cycle 10 SLMCPR versus the Generic Gell Value l
Table I summarizes the relevant input parameters and results of the SLMCPR determination for the j
generic Gell core and the Grand Gulf Cycle 10 core. Both generic and plant / cycle specific evaluations are performed using the methods described in GETABill. The uncertainties applied in this analysis are reported in Table 2. These evaluations yield different calculated SLMCPR values because the inputs that are used are different. The quantities that have been shown to have some impact on the determination of the safety limit MCPR (SLMCPR) are provided. Much of this information is redundant but is provided in this case because it has been provided previously to the NRC to assist them in understanding the differences between plant / cycle specific SLMCPR evaluations and the generic values calculated previously by fuel product line. For example, it can be shown that the SLMCPR can be characterized in terms ofjust two key pammeters:
These two parameters are defined and described below.
Prior to 1996, GESTAR 11 m tipulated that the SLMCPR analysis for a new fuel design be performed for a s
large high power density plant assuming a bounding equilibrium core. The Gell product line generic SLMCPR value of 1.07 was determined according to this specification. Later revisions to GESTAR IIm (see Section 11, " Cycle MCPR Values", of Appendix A of U.S. Supplement to GESTAR II, Revision 13) that have been submitted to the NRC to describe how plant / cycle specific SLMCPR analyses are used to conlirm the calculated SLMCPR value on a plant / cycle specific basis using the uncertainties defined in Reference [4).
In comparing the generic Gell and Grand Gulf Cycle 10 SLMCPR values it is important to note that the Grand Gulf Cycle 10 core is wt an equilibrium core, it is a mixed core with Gell and SPC 9x9-5 fuel. The freshest fuel is the latest batch of Gell, that because of the transition from SPC fuel, comprises of the bundles in the core. Also, the Grand Gulf Cycle 10 core is loaded such that the fresh batch of Gell has the highest enrichment as compared to a core average enrichment of as shown in Table 1. By way of comparison, the generic Gell equilibrium core has batch and core average enrichments of
. Higher enrichment in the fresh fuel for the Grand Gulf Cycle 10 core (compared to the rest of the core) produces higher power in the fresh l
page1of5
~.
l-Att: chart Additir2:1Irf rmitia Regarding the 1.11 September 4,1997 Cycle Specific SLMCPR for Grand Gulf Cycle 10 l
(.
bundles relative to the rest of the core. Rese enrichment differences result in the Gell fresh fuel l
produc'ing a higher relative share of the number af fuel gods calculated to be gusceptible to boiling transition (NRSBT). In fact, the Cycle 10 analysis determined that the NRSBT from the SPC fuel was l
The core MCPR distribution for the Grand Gulf Cycle 10 core is somewhat similar to the core MCPR l-distribution used in the Gell generic analysis. This fact is demonstrated by the
. Ilowever, it is important to note that for the I
Grand Gulf Cycle 10 SLMCPR analysis whereas in the generic Gell analysis only of the bundles within
. By keeping the limiting bundles
. By design, the
. Therefore, the most conservative approach is.to perform the
. His is what was done for the Grand Gulf Cycle 10 analysis and for all other plant / cycle specific analysis performed by GE.
in general, the calculated safety limit is dominated by two key parameters: (1) and (2)
. Greater in either parameter yields more rods susceptible to boiling transition and thus a higher calculated SLMCPR. The Grand Gulf Cyclelo core has a flatter core MCPR distribution than the generic gel l equilibrium core as well as a flatter bundle R-factor distribution.
ne calculated SLMCPR values are strongly correlated to the which -
characterizes the MCPR distribution. GE formally described the use of in evaluating l
core MCPR distributions to the NRC in Reference [5]. Dat information directly relevant to the present discussion is summarized below.
l-values of distributions. The value of
. The value of is proportional to
. It has been normalized to yield a measure of
.The quantity is defined by l-(1)
I i
where is the difference between
. The quantity is the and is the in the core. The function defined by, i
l i
l page 2 of 5 l'
l I
Attachment AdditiorlI;f:rm:ti:2 Reg:rding the 1.11 Sept:mber 4,1997 Cycle Specific SLMCPR for Grand Gulf Cycle 10 (2)
Each is proportional to relative to the as given by The calculated value for the Grand Gulf Cycles 10 core at EOC-lK using the most limiting rod pattern is
.He value for the generic Gell analysis is calculated to be
. Based on a generic Gell value of compared to the value of for Grand Gulf Cycle 10 of at EOC-lK one is led to the conclusion that the core for Grand Gulf Cycle 10 is somewhat The uncontrolled bundle pin-by-pin power distributions were compared between the Grand Gulf Cycle 10 bundles and the GElli bundle used in the generic SLMCPR analysis. Pin-by-pin power distributions are characterized in terms of R-factors using the methodology defined in Reference [ 6]. For the Grand Gulf Cycle 10 bundles, there is a slightly flatter distribution of uncontrolled R-factors for the highest power rods in each bundle, which in the calculation are the rods most likely to be susceptible to boiling transition. This fact is difTicult to ascertain graph:cally since the relative flatnesses are similar and the rods that have an R-factor closer to the R-factor for the lead rod are statistically worth much more than those that have R-factors that are further away.
The flatness of the pin R-factor distribution within a particular bundle is characterized is defined by (3) l l
where is the i
The quantity
. The was defined previously.
l Values of within a bundle.11igher values of j
distributions. For the generic Gell case the value considering all bundles
, For the Grand Gulf Cycle 10 limiting case analyzed at EOC-lK, the was calculated to be page 3 of 5
Att:chmrt Adelitinci Inf:rm: tin Regarding the 1.11 September 4,1997 Cycle Specific SLMCPR for Grand Gulf Cycle 10 These' quantify that the Grand Gulf Cycle 10 bundles are than the bundles used for the generic GEli SLMCPR analysis.
Table 1 Comparison of GEII Generic and Grand Gulf Cycle 10 Core and Bundle Quantities that 7mpact the SLMCPR QUANTITY, DESCRIPTION Generic Gell Grand Gulf Cycle 10 Number of Bundles in Core 764 800 Limiting Cycle Exposure Point Pile EOC-lK Cycle Exposure at Limiting Point [ mwd /STU]--
5500 11960 Latest Reload Batch Fraction %
32.5 %
33.5 %
Latest Reload Average Batch Weight % Enrichment 3.25 %
3.78 %
Core Avera e Weight % Enrichment 3.25 %
3.60 %
Core MCPR (for limiting rod pattern) 1.257 1.2555
% bundles within 0.05 CPR of Core MCPR
% bundles within 0.10 CPR of CoreMCPR
% bundles within 0.20 CPR of Core MCPR
% uncontrolled bundles within 0.20 CPR Maximum Relative Power 1.66 1.57
% bundles within 0.90 of Max Relative Power 12.0 %
14.5 %
Calculated Safety Limit MCPR 1.07 1.11 Table 2 Uncertainties Applied in the Grand Gulf Cycle 10 SLMCPR Evaluation Parameter Uncertainty (%)
Feedwater Flow Feedwater Tem erature Reactor Pressure Core Inlet Tem erature Total Core Flow 2.5 (6.0 for SLO)
ChannelFlow Area Friction Factor Multi lier Channel Friction Factor Multilier TIPReadin TIP Readin Random Uncertaint 1.2 (2.85 for SLO)
Rod F Factor Critical Power Correlation page 4 of 5
Att: chart Additiort Isf:rm:tio3 Regarding the 1.11 September 4,1997 Cycle Specific SLMCPR f2r Graid Gulf Cycle 10 3
l Summary Various quantities have been used over the last year to compare quantities that impact the calculated SLMCPR value. These other quantities have been provided to the NRC previously for other plant / cycle specific analyses using a format such as that given in Table 1. These oder quantities have also been compared for this core / cycle Note that regardless of what comparisons are made, the conclusion is easily reached that the Grand Gulf Cycle 10 core / cycle has a flatter core MCPR distribution and substantially flatter I
in-bundles power distributions than what was used to perform the Gell generic SLMCPR evaluation.
i "the calculated 1.11 Monte Carlo SLMCPR for Grand Gulf Cycle 10 is consistent with what one would i
expect the 1.11 SLMCPR value is appropriate.
Based on all of the facts, observations and arguments presented above, it is concluded that the calculated i
SLMCPR value ofI.ll "or the Grand Gulf Cycle 10 transition core is appropriate. It is reasonable that this l
value is 0.04 higher than the 1.07 value calculated for the genenc Gell equilibrium core.
For single loop operations (SLO) the calculated safety limit MCPR for the limiting case is 1.12 i
I
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i Pre.
by:
Verified by:
+
l 4A.,
i A.F.A K. M. Fawcett TechmcalProject Manager Nuclear Fuel Engineering Grand Gulf Project
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a page 5 of 5
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