ML20246E911
| ML20246E911 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 03/31/1989 |
| From: | Oleary A SIEMENS POWER CORP. (FORMERLY SIEMENS NUCLEAR POWER |
| To: | |
| Shared Package | |
| ML14191A412 | List: |
| References | |
| ANF-88-054(NP), ANF-88-54(NP), NUDOCS 8908300062 | |
| Download: ML20246E911 (57) | |
Text
. _ - - - - - - - -
ANF-88-054(NP)
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- 1 y i j ,"
ADVANCED NUCLEAR FUELS CORPORATION' }
I PDC-3: ADVANCED NUCLEAR FUELS CORPORATION POWER DISTRIBUTION CONTROL FOR PRESSURIZED WATER REACTORS AND ,
APPLICATION OF PDC-3 TO H.B. ROBINSON UNIT 2 L
l MARCH 1989 1'
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b ADVANCEDNUCLEARFUELS CORPORATION -:
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ANF-88-054(NP)
)- Issue Date: 3/22/89 I
PDC-3: ADVANCED NUCLEAR FUELS CORPORATION POWER DISTRIBUTION CONTROL FOR PRESSURIZED WATER REACTORS ,
AND APPLICATION OF PDC-3 TO H. B. ROBINSON UNIT 2 l
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t Prepared by-hl 3 A. Hfiton '0' Leary, Team)gsder 3-/J"El j
PWR NeutronicsC/ !
Neutronics and Fuel Management i f Fuel Engineering and Technical Services ;
L March 1989 seg i
CUSTOMER DISCLAIMER ltAPORTANT NOTICE REGARDING CONTENTS AND USE OF THIS {
DOCUMENT FLEASE READ CAREFULLY I
Advanced Nuclear Fuets Corporaton's warranties and representatens con-comng the subpct matter of the document are those set forth m the Agreement betwoon Advanced Nuclear Fuois Corporation and the Customer pursuant to '
whch this document is seued. Accordmgty, except as otherwee expressly pro-vided in such Agreement, neether Advanced Nuclear Fuste Corporaten nor any person aetmg on its bonalf makes any warranty or representaten, expressed or imphed, with respect to the accuracy, comp 6eteness, or usefulness of the mfor-motion contamed in the document, or that the use of any informaton, apparatus. .
method or process decioned in this document wdl not ofnnge prwately owned i rights: or aneumes any habditme with respect to the use of any eformaton, ao-paratus, method or procese disclosed in this document.
The mformanon contamed herem a for the so6e use of Customer, ,
in order to twood impairment of nghts of Advanced Nuc1 ear Fues Corporation in '
l patents or irtwen ons wnch may be meluoed in the informaton contained in this document, the recipient. by its acceptance of this document. agrees not to puOlen or make puche use (in the patent use of the term) of sucn informaton until so authonzed in wntmg Dy Advanced Nuctear Fueis Corporaten or until after six i (6) months followmg termmaton or exosraten of the aforesaid Agreement and any {
I extensen thereof, unless otherwise expresety provided in the Agreemorat. No nghts or licenses m or to any patents are imohed by the fumishmg of this occu-ment.
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i ANF-3145.472A (12/87) 6 9
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ANF-88-054(NP)
. R TABLE OF CONTENTS 1 ,
- b. '
\
PASUL f
1.0 INTRODUCTION
AND
SUMMARY
. . . . . . . . . . . . . . . . . . ... . 'I d 2.0 VERIFICATION ............ 4 2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . ... . . . 4 2.2 Description of the PDC-1 and PDC-2 ... 4 k
.2.3 Description of the PDC-3 ...... 5- '!
2.4 Description of the PDC-3 ........ 6 1.
[ 2.5 PDC-2 Results.. ......... ... 7 3.0 GENERIC PDC-3 METHODOLOGY . . . . . . . . . . . . . . . . . . . . . 15 !
f 3.1 Introduction ........................... 15 3.2 Description of Reactor Operating Modes Analyzed . . . . . . . . . . 15 j 4.0 PDC-3 METHODOLOGY APPLIED.TO H.B. ROBINSON UNIT 2 . . . . . . . . . 24 ;
)
1 4.1 Introduction
.......................,.... 24 l l.
4.2 H.B. Robinson Unit 2 Plant Characteristics and Model Development . 24
- j. 4.3 V(Z) Distribution for 25% Target Axial Offset Band ........ 25 .
i 4.4 V(Z) Distribution for !3% Target Axial Offset Band ........ 26 4.5 Operation Outside the Target Band . . . . . . . . . . . . . . . . . 27 4.6 Implementation of PDC-3 Procedures for H.B. Robinson Unit 2 . . . .
29
5.0 REFERENCES
. . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 I
ANF-88-054(NP)
LIST OF TABLES
.t a n am 2.1 PDC-3 " Sample" Plant Versus PDC-2 " Generic" Plant Charactsr-istics.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.2 PDC-2 Reactor Operating Conditions Analyzed, !5% Target Band . . . . 12-3.1 PDC-3 Versus PDC-2 Reactor Operating Conditions Analyzed (B0C and EOC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 G
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}: -lii-ANF-88-054(NP)
LIST OF FIGURES Fiaure P.Agg 2.1 Comparison Core Average Axial Power Distributions .......................... 13 2.2' -Comparison. .
PDC-2 VZ(Z) Distributions:
15% Target Band ......................... 14 I" 3.1 5 Day 3-6-3-12 Load Follow Cycle . . . . . . . . . . . . . . . . . 21 3.2. 15% Target Axial Offset Band . . . . . . . . . . . . . . . . . . . 22 ,
'3.3 Comparisor .
-PDC-3 VZ(Z) Distribu-tions: 15% Target Band ..................... '23 4.1 H.B. Robinson' Cycle 12 Calculated PDC-3 V(Z) Distribution: 15%
. Target Band . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 l' 4.2 Comparison of H.B. Rot'inson Cycle 8 and " Sample" Plant Calculated PDC-3 VZ(Z) Distributions: 5% Target Band ........... 32 4.3 Comparison of H.B. Robinson Cycle 12 and Cycle B Calculated PDC-3 V(Z) Distributions: 15% Target Band . . . . . . . . . . . . . . . 33 4.4 Effect of Control Rod Worth on H.B. Robinson Cycle 12 Calculated
! PDC-3 V(Z) Distribution: 15% Target Band ............ 34 4.5 Calculated Composite V(Z) Distribution and Limiting PDC-3 V(Z)
Distribution: 15% Target Band . . . . . . . . . . . . . . . . . . 35 4.6 Limiting PDC-3 V(Z) Distribution Versus Current PDC-2 V(2)
Distribution: 5% Target Band . . . . . . . . . . . .'. . . . . . 36 4.7 H.B. Robinson Cycle 12 Calculated PDC-3 V(Z) Distribution: !3%
Target Band ........................... 37 4.8 Effect of Control Rod Worth on H.B. Robinson Cycle.12 Calculated PDC-3 V(Z) Distribution: 3% Target Band ............ 38 t '4.9 Calculated Composite V(Z) Distribution and Limiting PDC-3 V(Z)
Distribution: 13% Target Band .................. 39 4.10 Limiting PDC-3 V(Z) Distribution Versus Current PDC-2 V(Z)
Distribution: 13% Target Band . . . . . . . . . . . . . . . . . . 40 4.11 V-Factor Versus Delta AO, 50% Power, 25% Target Band . . . . . . . 41 l
. ;j
-iv- ANF-88-054(NP) {
LIST OF FIGURES Ficure Pigg 4.12, V-Factor Versus Delta A0, 70% Power, 15% Target Band . . . . . . . 42
) 4.13 V-Factor Versus Delta AO, 90% Power, 5% Target Band . . . . . . . 43 4.14 V-Factor Versus Deita AO, 50% Power, 13% Target Band . .. . . . . . 44 4.15 V-Factor Versus Delta A0, 70% Power, 13% Target Band . . . . . . . 45 i 4.16 V-Factor Versus Delta A0, 90% Power, 13% Target Band . . . . . . . 46 4.17 Allowable Deviation From Target Flux Difference ......... 4,7 4.18 Limiting PDC-3 V(Z) Distributions for 15% and 3% Target Bands .. 48 e
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ANF-88-054(NP)
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' PDC-3: ADVANCED NUCLEAR FUELS COP % RATION f
POWER DISTRIBUTION CONTROL FOR PRESSUR'2ED 4 WATER REACTORS- l AND APPLICATION OF PDC 3-TO H.B. ROBINSON UNIT 2 4 q
F 3 1
j 1.0 ..NTR000CTION AND SUP9mRY 1 Advanced Nuclear Fuels (ANF) reactor power distribution control (PDC)
) proc 6dures have previously been' presented in References 1 through 3. .
' Reference 1 describes a procedure denoted PDC-1. Reference 2 describes a i procedure denoted PDC-2. Reference 3 provides additional information with h respect to PDC-2. This report presents an . extended PDC-2 methodology, >
henceforth ' referred to- as PDC-3. PDC-3 was developed to provide j justification for a .less lfmiting V(Z) distribution through the use of a more ]
conservative analysis. The more conservative analysis allows the final V(Z) I distribution' to be drawn closer to the. calculated distribution. A descrip-tion of the PCC methodology and associated terminology is presented below.
j The basic concept of the PDC procedures is to control the variation in
);
, the core power distribution during reactor operation by controlling the
[ variation in the core power axial offset. The core power axial offset ( AO) ,
is defined as:
/
PT-PB A0 =
P +PB where, PT
=
Power in MWth in the top half of the core l' .PB
=
Power in MWth in the bottom half of the core i.
i f
57 1 1 ',
K
- 2. ANF-88-054(NP) i Thus, the axial offset is the difference in power b'etween the top and 4 bottom halves of the core . expressed as a fraction (or percentage) of the total core p.ower. The above definition may be rewritten as follows:
A0 =
IT-IB AI -
I +I_"
B P/Po
-where, IT PT/Po IB; - Pg/Po AI =
IT-IB = Flux difference Po Rated reactor power-(MWth)
P = Operating reactor power (MWth) l' Under PDC . procedures, a thrget . axial offset is determined at full ;
power, equilibrium conditions. The allowed axial offset (or AI) variation about the target axial' offset is called the target axial offset (or AI) band.
j The major. feature of: the PDC-2 procedure is the V(Z) distribution. The V(Z) distribution-is the ratio of t'he maximum anticipated increase in FgT (z),
total. peaking by plane, during non-equilibrium operation when following PDC-2 procedures, to FgI(Z) corresponding to the target axial offset. PDC-2.V(Z) ,
distributions associated with 25% and 3% target axial offset bands were developed' in References 2 and 3, respectively. The' approved PDC-2 methodology is characterized by six load ^ follow simulations which are used to establish the maximum ' anticipated increases in FgT (Z). The load follow simulations utilize a one-dimensional (ID) XTG model which describes core g average axial behavior. Radial behavior is represented by conservative radial factors, Fxy.
This report presents the PDC-3 methodology, which differs from the current PDC-2 methodology in the generation of the V(Z) distribution. The
- %c' ANF-88-054(NP)' .i V
-generationof the PDC-3 V(Z) . distribution is characterized by the following:
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The
- generic" PDC-3 methodology, characterized by the specific set of load. j j follow simulations used to generate a PDC-3 V(Z) distribution, is presented j in Section 3.0. ;
i
/ The PDC-3 methodology was applied to H.B. Robinson. Unit 2 Cycle 12 in order ~ to generate V(Z) distributions for 5% and 23% target axial offset bands. The results of this appl-ication and the limitations on its use are -)
presented-in Section 4.0.
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!2.0 ! VERIFICATION OF- ;
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' 2 I'- Introduction ~ .l l
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p .The advantages,of a- ' methodology are f..
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2'. 2 Description of the PDC-1 and PDC-2 The principal tool used in PDC-1 and PDC-2 is f..
The calculational model of a typical PWR reload cycle is set up Y
Control rods are represented as accitions of an absorber cross section, a delta cross section, in those assemblies where rods are inserted. Core boundary conditions are described
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ANF-88-054(NP)
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.y This model is then depleted The macroscopic cross section tables as a function of burnup .i i
are constructed The axial plane burnup is obtained in a-completely analogous manner. For a l reload core ,.
1 4
2 In Reference ., model was verified by comparisons against -
reactor measuremen .s (slow transient tests and a xenon buildup following
' shutdown experiment). As a result of these comparisons, i
i 2.3 Description of the PDC-3 The " sample" " model utilized the i development of the " generic" PDC-3 methodology Westinghouse type ,
plant .for which ANF has fuel management responsibilities. This model was (
generated using standard ANF PWR neutronics methodology (6-9) for utilization ,
in standard reload design calculations and has been benchmarked against many I cycles of operating data. The adjustments l'
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'ANF-88-054(NP)-
l L2.5 PDC-2 Results with the' Models-
- j. In Reference 3, the use of
-was established. These y are described in-detail in Section j l
3.2.
I The V(Z) distribution represents Lthe maximum increase in the !
equilibrium FgT(Z) distribution,. at each axial plane Z, which may ' occur when -
a reactor is operated in accordance 'with -PDr. procedures. For each case' j analyzed, - a V(Z) distribution is determined as the ratio of the maximum FgT (Z): which occurs during the reactor operation simulation to the !
equilibrium FnT (Z) distribution associated with the target axial offset, t
i The total peaking factor distri'aution, FgT (Z), is calculated as:
FgI (Z) -
Fz (Z)
- Fxy(Z)
- Ftotal where, FgT (Z) = Total peaking factor at axial location Z Fz (Z) = Relative power at axial location Z '
Fxy(Z) = Peak radial at axial location Z F
total
- All required uncertainties, biases, and engineering factors -
In PDC-2, FgT (Z) is determined ,
The core average axial distribution, Fz(Z), is obtained ,
The radial component, Fxy(2).
_9 1
ANF-88-054(NP).
j 4
Fz(Z).
- Fxy(Z) = Fg N(Z), as well as- each component,-
l The V(Z) ' distribution is then calculated as:
~
i The .V(Z) distribution- -,
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By studying the axial component of the V(2) distribution, f
VI(Z)' represents the maximum increase in the equilibriumz F (Z) distribution,
- at- each axial plane Z, which may occur when a reactor 'is operated in accordance with PDC procedures. For each car,e analyzed, a VZ(Z) distribution is determined as the ratio of the maximum .Fz(Z) which occurs during the reactor operation simulation to the equilibrium Fz (Z) distribution
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The VZ(Z) ' curves cenerated are compared in Figure 2.2.
As shown..
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Small differences between the two curves are due j
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These results demonstrate models are for definina-
.V(Z) distributions. Differences in V(Z) distri.butions, generated L
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ANF-88-054(NP) I TABLE 2.1 PDC-3 " SAMPLE" PLANT-VERSUS PDC-2 " GENERIC" PLANT CHARACTERISTICS PDC-3 PDC-2 Power Density 104.5 kW/ liter- 100 kW/ liter l Nominal Enrichment 3.25 w/o 3.0 w/o .j Active Fuel Height 12 ft. 12 ft. 'i Coolant- Flow Rate 1.119
- 108 lb/hr 1.43
- 108 l b/lir - 3 (3 loop) (4 loop) -l j
Inlet Temperature 546.8'F 545'F l
i Single Centrol Bank Worth 1% Ap 1% Ap l
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T 3 .0_ GENERIC P00-3 METHODOLOGY ,
-3.1' Introduction j
Based upon the results of earlier PDC-2 analyses (2,3) ,
An expanded set has been developed which produces results The V(Z) distribution developed from this' expanded analysis,
} henceforth referred to --as the PDC-3 V(Z) distribution, 'is bounding,- and additional margin is'not required.
,+
It should be noted that PDC-3 operating procedures are analogous to PDC-
- l. ' 2 operating procedures for a given target band. The only differences are F
b 3.2 Description of Reactor Ooeratino Modes Analyzed k The set of load follow cases developed for the PDC-3 methodology are In Reference 2, the sensitivity of the V(Z) distribution to many parameters was studied in detail.
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.-16 ANF-88-054(NP)
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The . reactor operating modes which were considered are characterized by j load follow- operation. Load follow operation implies that the reactor is cycling from one power level to another in a recular oattern. Fiaure 3.1 I shows the tvo* af power cycling considered, I. In this . cycling scheme, the reactor power. ;
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This is the same basic structure.as utilized in previous PDC analyseslI"3) .
In - PDC ' procedures, the plant is required to operate within a given
~
target band'about a target axial offset. This operating range is illustrated I in . Figure 3.2 for a 5% target axial offset band. The. operating modes <
l the extremes of operation within this operating range. They are to be evaluated at both The operating modes are:
(
l' ANF-88-054(NP);
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The need for .became' apparent in the-application of PDC-3 to the H.B. Robinson Unit . 2 Cycle -12 ' blanketed ' core.
(see-Section 4.0). ~In a blanketed core, xenon oscillations are more:
! difficult to initiate and the r
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The HF.A
- . case was included as a corollary to this argument.
U In the PDC-2. methodology, the set of load follow cases considered are
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4 ANF-88-054(NP) ;
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The,
- operating conditions. analyzed in the PDC-2 and PDC-3 methodologies are listed in Table 3.1.
K The PDC-3 V(Z) distribution'is generated' l
The_ V(Z) distribution derived from tnese cases 'is
.theref ore a lso b ounding.- Actual plant operation- would result; in smaller-variations in ' Fg T I (Z)' since it 'is unlikely that the plant. would operate continuously. near the edge of the allowed' operating band. 4 The 15% target band ,VZ(Z) distribution, 1
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The PDC-3 methodology results in a VZ(Z) distributi6n 1
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1 L j An increase in operating margin will be derived frcm the.use of the V(Z) based on the PDC-3 methodology since provides the . justification for drawing a less limiting V(Z) over the region of the core where the axial power distribution peaks occur.
As discussed in Section 2.5, Al values of up to occurred during the simulations.
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the fact that axial region where' I "is.' the. region L between ' the core edge and '. the . point where the ' axtal peak ~
occurs.
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. TABLE 3.1 POC-31VERSUS PO'-2' C REACTOR ..
0PERATING CONDITIONS ANALYZED--(BOC AND-EOC)-
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These cases are described in detail in Section 3.2.
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4 ANF-88-054(NP) 1 4.0 PDC-3..METH000 LOGY' APPLIED TO'H.B. ROBINSON UNIT 2
.l 4.1 Introduction The PDC-3 methodology discussed in Section 3.0 has been applied to H.B.
Robinson Unit 2 -(HBR2) Cycle 12. Plant characteristics of HBR2 are discussed :; in Section 4.2. Also discussed in Section 4.2 is the model used for the HBR2 PDC-3 analyses. The PDC-3 results for t5% and 3% target axial offset bands are presented in Sections 4.3 and 4.4, respectively. The development of axial
= offset . limits for operation outside the target bands is discussed in Section 4.5. The implementation of the'V(2) distributions developed in Sections 4.3 and 4.4 is discussed in Section 4.6.
4.2 H.B. Robinson Unit 2 Plant Characteristics and Model Development Several HBR2 plant characteristics differ from characteristics of the PDC-3 " sample" plant described in section 2.0:
- 1) In HBR2, the nominal power density is 86.6 kW/ liter as compared to 104.5 kW/ liter for the PDC-3 " sample" plant.
I 2) The leading control bank (Bank D) worth in HBR2 is less than 1% ap = 1000 pcm. The worth has generally varied between 600 and 800 pcm in Cycles 8 through 12.
- 3) Beginning in Cycle 10, the fuel loaded into HBR2 has contained natural uranium axial blankets (NUABs) in the top and bottom 6 inches of active j core height. In Cycle 12 all fuel except for 8 twice-burnt assemblies i (out of 157) contain NUABs.
The model used for the HBR2 PDC-3 analyses is the model developed using standard ANF PWR neutronics methodology I0~9) in and has been 7 benchmarked against several cycles of operating data. Unlike the analyses )- performed with the PDC-3 " sample" model, the HBR2 analyses will
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I ANF-88-054(NP)
'(
l 4.3 Vf 7) Distribution for $% Tarcet Axial Offset Band The PDC-3 methodology discussed in Section 3.0 was applied to HBR2 Cycle 12 using the model discussed in Section 4.2 for a 15% target axial offset band. The calculated V(Z) distribution generated j is presented in Figure 4.1. Of these i i V(Z) values. Each of the three. HBR2 plant characteristics mentioned in Section 4.2 (power density, rod worth, axial blankets) affects the shape and magnitude of the HBR2 V(Z) distribution. The effects of power density and axial blankets were analyzed by applying the PDC-3 methodology to HBR2 Cycle 8 for a 15% target band.
- 1) ' The effect of the reduced power density can be seen from a comparison of .
the VZ(Z) distribution's for the PDC-3 " sample" plant and HBR2 Cycle 8 shown in Fiaure 4.2.
- 2) The effect of the blankets can be seen from a comparison of the V(Z) {
distributions for HBR2 Cycle 8 and ' HBR2 Cycle 12 shown in Figure 4.3. The effect of control rod worth on the HBR2 Cycle 12 V(Z) distribution .1 was studied i l 1 ( 4 l l 1
*\
As discussed in Section 2.5, AI values slightly larger than occurred during the simulations. f
ANF-88-054(NP) j i
~
o The rance of control rod worths studied results in V(Z) distributions varying by' Since the control rod worth of HBR2 Cycle 8 is less than that of the PDC-3 " sample" plant and since the control rod worth of HBR2 Cycle 12 is less than that of HBR2 Cycle 8 the differences observed in Figures 4.2 and 4.3 may be partially influenced by control rod worth effects. At each axial level Z, the maximum of the V(Z) distributions in Figure 4.4 was used to generate a composite V(Z) distribution. In Figure 4.5, a limiting V(Z) distribution which bounds the composite V(Z) distribution is I provided. This limiting V(Z) distribution is applicable to blanketed HBR2 cores with Bank D worths bounded by those studied above. A comparison of the PDC-3 V(Z) distribution'n and the PDC-2 V(Z) distribution for the 25% target band is shown in Figure 4.6. 4.4 Vf7) Distribution for 3% Taroet Axial Offset Band The PDC-3 methodology discussed in Section 3.0 was applied to HBR2 Cycle l I 12 using the mode's discussed in Section 4.2 for a 23% target axial offset band. The calculated V(Z) distribution generated 1 The effect of control rod worth on the 23% target band V(Z) distribution 7 i was studied l
- As discussed in Section 2.5, Al values slightly larger than occurred during the simulations.
ANF-88-054(NP) At each axial level Z, the maximum of the V(Z) distributions in Figure 4.8 was used to generate a composite V(Z) distribution. In Figure 4.9, a limiting .V(Z) distribution, which bounds the composite V(Z) distribution is provideo. This limiting V(Z) distribution is epplicable to blanketed HBR2 cores with Baak D worths bounded by those studied above. A comparison of the PDC-3 V(I) distribution and the PDC-2 V(Z) distribution for the 37. target Sand is shown in Figure 4.10. 4.5 Oeeration Outside the Tareet Band In calculating case specific V(Z) distributions (see Section 2.5), FTq(z) is multiplied by the relative power level to account for the increase in T Technical Specification limits on F g(Z) due to a power level decrease. It was found that the maxinium calculated V(Z) distribution (for both the 37. and 15Y, target band cases) was never limited by reduced power cases, i .e. the increase in the Technical Specification limits on FOT(Z) due to a power level decrease was always larger than the increase in FgT (Z) due to a power level decrease when operating within the target band. As a result, operation at axial offsets outside the target band is allowed below 907 power for periods not to exceed I hour in any consecutive 24 hour oeriod. The time outside the band is restricted Allowing the axlas ortset to De outside the target band for short periods of time provides necessary flexibility in plant operation. Operation outside the target bands is allowed during these short periods to the extent that resultant V(Z) distributions are expected to be bounded by the maximum V(Z) distribution. Since the maximum V(Z) distribution
ANF-88-054(NP) The maximum calculated V(Z) distributions, i.e. the compositt V(Z) distributions discussed in Sections 4.3 and 4.4 for 5% and 13% target bands. respectively, were used The limits on operation outside the target band are determined from the relationship between V-factors and AA0 (= axial offset'- target axial offset) for a given power level. In order to establish this relationship The positive and negative AA0 values allowed at a particular power level, as described above, were converted to positive and negative AI
i p , I 1 .
-29 ANF-88-054(NP)-
l The limits on operation outside the 23% target band _were chosen such that the limits: in terms . of flux difference would be 1
-levels.. The. value of' 2% was chosen since.this is the difference between the.
1' L l-
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The restrictions on operation outside the target band are shown in Figure 4.17 for both the.15% and i3". AI target bands. 4.6 Implementation of PDC-3 Procedures for H.B. Robinson Unit 2 The . implementation of PDC-3 operating procedures is identical to the implementation . of PDC-2 opersing procedures. The differences are in the j actual V(Z) distributions to be used and in the axial offset limits 'during ! ! operation outside the target bands. These were di::ussed in detail in Sections 4.3, 4.4, and 4.5. Replacement figures for the current HBR2 Tec,hnical Specification Figures 3.10-4 and 3.10-5 are shown in Figures 4.18 and 4.17, respectively. _l In order to apply the V(Z) dist'ributions developed in Sections 4.3 and ( 4.4 to a given HBR2 cycle, two core configuration characteristics to which l V(2) .is sensitive need to be verified. Specifically:
-l
- 1) The core must be primarily. composed of natural uranium blankets (NUABs) at the top and bottom 6 inches of active core height, and ,y 2)- The Bank 0 worth must be bounded by the worths considered in Sections 4.3 J and 4.4.
l e__=__---___- . _ _ _ _ _ _ _ _
ANF-88-054(NP) In Cycle 12, eight twice-burnt assemblies did not have NUABs. The balance of the assemblies were fully blanketed. Consequently, it is recomended that this bound on the number and type (i.e. twice-burnt) of non-blanketed assemblies be verified in the Safety Analysis Report for each cycle where Figures 4.17 and 4.18 are to be applied. In the Cycle 12 analyses, the ;tandard Bank D worth at the HFP rod insertion limit of 114 steps was calculated to be 418 pcm at 500 mwd /MTU, HFP, . equilibrium xenon conditions. It was found that increasing control rod worth generally increased V(Z) distributions, and Bank D worths as high as were considered in the generation of the V(Z) distributions. Consequently, it is recomended that this bound on the Bank D worth (at the above conditio.ns) be verified in the Safety Analysis Report for each cycle where Figures 4.17 ana 4.18 are to be applied. l l l l l r i i
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5.0 REFERENCES
- 1. J.S. Holm and F.B. Skogen, " Exxon Nuclear Power Distribution Control for P_tgsyurized Water Reactors", XN-76-40(A), Exxon Nuclear Company, Richland, Washington 99352, September 1976.
- 2. J.S. Holm and R;J. Burnside, " Exxon Nuclear Power Distribution Centrol for Pressurized Water Reactors Phase II", XN-NF-77-57 and XN-NF-77-57 Supplement 1 (A), Exxon Nuclear Ccmpany, Richland, Washington 99352, May 1981.
- 3. J.S. Holm, " Exxon Nuclear Power Distribution Control for Pressurized Water Reactors Phase II", XN-NF-77-57 Supplement 2(A) and XN-NF-77-57 Supplement 2 Addendum 1 (A), Exxon Nuclear Compary, Richland, Washington 99352, October 1982.
- 4. M. Todosow, A.L. Aronson, D.J. Diamond, " Axial Power Distribution Control Stratecies for PWRs", BNL-NUREG-28797, Brookhaven National Laboratory, Upton, New York 11973, June 1980.
- 5. R.B. Stout, "XTG: A Two-Groue Three Dimension::1 Reactor Simulator Utilizino Coarse Mesh Soacina (PWR Version)", XN-CC-28, Exxon Nuclear Company, Richland, Washington 99352, January 1975.
- 6. XN-NF-75-27(A), " Exxon Nuclear Neutronics Desian Methods for Pressurized Water Reactors", Exxon Nuclear Company, Richland, Washington 99352, June 1975
- 7. XN-NF-75-27(A) " Exxon Nuclear Neutronics Desian Methods for Pressurized Water Reactors", Supplement 1, Exxon Nuclear Company, Richland, Washington 99352, September 1976 l
- 8. XN-NF-75-27(A), " Exxon Nuclear Neutronics Desion Metho8s for Pressurized Water Reactors", Supplement 2, Exxon Nuclear Company, Richland, Washington 99352, December 1977.
- 9. XN-NF-75-27(A), "{non Nuclear Neutronics Desion Methods for Pressurized Water Reactors", Supplement 3, Exxon Nuclear Company, Richland, l Washington 99352, November 1980.
l l l
ANF-88-054(NP) Issue Date: 3/22/89 PDC-3: ADVANCED NUCLEAR FUELS CORPORATION POWER DISTRIBUTION CONTROL FOR PRESSURIZED WATER REACTORS AND APPLICATION OF PDC-3 TO H. B. ROBINSON UNIT 2 DISTRIBUTION HG Shaw (I) Customer (20) Document Control (5) l l Scg}}