ML20011A170
| ML20011A170 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 09/30/1981 |
| From: | R Lynne Finch, Hamilton W, Schnatz T MIDDLE SOUTH SERVICES, INC. |
| To: | |
| Shared Package | |
| ML20011A169 | List: |
| References | |
| MSS-NA2-NP, NUDOCS 8110080087 | |
| Download: ML20011A170 (26) | |
Text
{t -
y, se-MSS-NA2-NP ARKANSAS NUCLEAR ONE - UNIT 2 CORE PROTECTION CALCULATOR ADDRESSABLE CONSTANT DETERMINATION !!ETHODOLOGY t
Prepared By:
R. T. Finch W. D. Hamilton Reviewed By:
MN j R. B. LTng Approved By:
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@M T. W.
Schnatz' Assistant Direct r Nuclear Activities' Department MIDDLE SOUTH SERVICES, INC.
225 Baronne Street New Orleans, LA 70161 Se ptember, 1981 8110090087 810930" PDR ADOCK 05000368 P
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% BLE OF COtM NFS l-Page Nanber L
1.0 INTRODUCTION
1 2.0 - SCOPE 2
3.0 IDENTIFICATION OF ADDRESSABIE CDNS'IANIS 3
4.0 ' ADDRESSABIE CONS'IA!TT DUTERMIiATION MU1110DOIDGY
.7 4.1 General 7
4.2 Core Coolant Nuss Flowrate Calibration Constants 7
FCl and FC2
.4.3 CEAC/PSPT Inoperable Flag - CFROP 8
l
-4.4 Azinuthal Tilt Allowance - TR 9
4.5. Wernal Power Calibration Constant - TPC 10 4.6 Neutron Flux Power Calibration Constant - KGL 11 l
~ 4.7 ~ 0NBR and Local Power Density Pretrip Setpoints -
11 l
DNBRPT and LPDPP l
l 4.8 Werna) Power Uncertainty Bias used in f *;dR Calcu-11 lation - BERR0 l
4.9 Power Uncertainty Pactor Used in DNBR thiculation 12 BERR1 4.10 Neutron Flux Power Uncertainty Bias Used in DNBR 13 Calculation - BERR2 l
4.11 Power Uncertainty Factor Used in Local Power Density 13 Calculation - BERR3 4.12 Power Uncertainty Bias Used in Iocal Power Density 14 Calculation - BERR4 l
4.13 End.of Life Flag - IDL 15 4.l_4 Multipliers for Plamr Ibdial Peaking Factors -
15 ARM 1 - ARM 7 L-4.15 Sinpe Annealiry Correction Factors - SCll, SC12, 16 SCl3, SC21, SC22, SC23, SC31, SC32, and SC33
'0, 4
. '. ~
'IABIE OF CXNTErfrS - Cont'd.
Page Nuaber
'4.16 DNBR and LPD CFA Deviation Penalty Factor 17 Correction Multipliers - PFMLTD and PFNLTL t
4.17 Multiplier for CFA Shadowirg Factor - ASM2-ASM7 19 4.18 Tenperature Shadowirg Correction Factor Multiplier 20 00RR1-l 4.19 Bourdary Point Power Correlation Coefficients -
20 BPPCCl - BPPCC4
5.0 REFERENCES
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LIST OF TABES tRNBER TITE PAGE hWEER 3.1 NO-2 CPC TYPE I ADDRESSABE CDt:S'INTIS 4
3.2 ANO-2 CPC TYPE II ADDRESSABE C0t;S1N7PS 5
9 L
.s 1.0 Ih'IPODUCTION Reference 1 and Reference 2 reouested Arkansas Power &
Light Conpany (AP&L) to provide th.luclear Regulatory Comnission (NRC) with a document which describes how the 1
Arkansas Nuclear One - Unit 2 (ANO-2) Core Protection Calculator (CPC) addressable constants are determined. It was i
requested by the NRC that the document be suitable for reference in the NO-2 Technical Specifications.
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1-2.0 SCOPE
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The Core Protection Calculator Syst2m includes a nLmber of addressable constants which are provided to:
a.
Allow periodic mlibration as required by the Techni-cal Specifications or reload analysis report.
b.
Adjust the CEAC inputs used by the CPCs based on CEAC/RSPT (Control Element Asse:tbly Calculator / Reed Switch Position Transmitter) operability.
c.
Apply penalty factors, allowances, etc. based on measured plant (nnditions/ parameters to ensure CPC calculaticn3l conservatism.
d.
Account for mesurement and nodeling uncertainties.
A list of CPC addressable constants is attached (See Tables 3.1 and 3.2).
This document describes the ANO-2 CPC addressable con-stants and the methodology that is used to determine them.
1
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3.0 IDENTIFICATION OF ADDIESSABLE 00NS'I7LVIS
'Ihe ANO-2 CPC addressable contants are grouped as either Type I or Type II. Type I addressable constants are expected to change frequently durirg plant operation while Type II ad-dressable constants are not expected to charge or are expected to change very infrequently during plant operation. Type I constants are entered only via the CPC Operator's nodule. Type II constants can be 1mded from a disk storage unit or from the opea tor's console. The Type II constant 1md from disk feature war inplemented in order to sinplify the enterirg of constants upon CPC roftware relmd after periodic testirg. The ANO-2 CPC Type I addressable constants are presented by Table 3.1 and the Type II constants are presented by Table 3.2.
Each table gives the constant point identification nunber, constant program label and a brief description of the constant..
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TABLE 3.1 m
ARKANSAS NUCLEAR ONE - (*:IT 2 CORE PMITffInN GICUIA'IOR TYPE I ADDRESSABLE CONS' IMPS Point lID
- Program..
Nunbee
-Iabel Description 60 FCl Core Coolant Mass Flow Rate Calibration Constant 61 FC2
. Core Coolant Puss Flow Rate Calibration Constant 62
- CEANOP.
CFAC/RSPT Inoperable Flag 63
'IR Azimuthal Tilt Allowance 64 TPC
'Ibernal Power Calibration Constant 65 KmL Neut ron Flux Power Calibration Constant 66 DNBRPT DNBR Pre-trip Alarm Setpoint e.67:
'LPDPT Im 1 Power Density Pre-trip Alarm Setpoint t
J
- 4. 3,
_4_
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'IABLE 3.2 t
ARKANSAS NUCLEAR ONE - UNIT 2 CORE PRCTTECTION GICULA'IOR TYPE II ADDRESSABLE CONS'IANIS Point ID Program 1
ber-Iabel Description t,s BERR0
'Ihernal Power Uncertainty Bias Used in DhTR
('
Ca1culation.
69 BERR1 Power Uncertainty Factor Used in Dh3R
, Calculation 70 BERR2 Neutron Flux Power Uncerta.inty Bias Used in DNBR Q11culation 71 BERR3 Power Uncertainty Factor Used in Local Power Density. Calculation 72 BERR4 Power Uncertainty Bias Used in Local Power Dansity Calculation 73 EOL End of Life Flag 74 ARM 1 Multiplier for Planar Radial Peaking Factor 75 ARM 2 Multiplier for Planar Radial Peaking Factor
,76 ARM 3 Multiplier for Planar Radial Peaking Factor l
77 ARM 4 Multiplier for Plamr Badial Peakirg Factor 78 ARMS Multiplier for Planar Radial Peaking Factor 79 ARM 6 Multiplier for Planar Radial Peakirg Factor 80 ARM 7 Multiplier for Planar Radial Peakirq Factor 81 SC11 Shape Annealing Correction Factor 82 SCl2 Shape Annealing Correction Factor.
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%BLE 3.2 cont'd.
ARKANSAS NUCLEAR ONE - UNIT 2 (DRE PROTECTION CAILUIA'IOR TYPE II ADDRESSABLE CONSTANIS Point ID Program
~ Nunber Iabel Description 83.
SC13 Shape Annealing Correction Factor 84 SC21 Shape Annealing Correction Factor 85 SC22 Shape Annealirs Correction Factor.
86 SC23 Shape Annealing Correction Factor 87 SC31 Shape Annealing Correction Factor 88 SC32 Shape Annealing Correction Factor 89-SC33 Shape Annealing Correction Factor 90 PFMLTD DNBR Penalty Factor Correction Multiplier 91 PFMLTL LPD Penalty Factor Correction Multiplier 92 ASM2 Multiplier for CEA Shau.
ag Factor 93 AStG Multiplier for CFA Shadowing Factor 94 ASM4 Multiplier for CEA Shadowing Factor 95 ASMS Multiplier for CEA Shadowing Factor
-96 ASM6 Multiplier for CEA Shadowing Factor 97 ASM7 Multiplier for CFA Shadowing Factor 98 CDRR1 Tenperature Shadowing Correction Factor Multiplier 99 BPPCCl.
Boundary Point Power Correlation Coefficient 100 F2PCC2 Boundary Point Power Correlation Coefficient 101 BPPCC3 Bounchry Point Power Correlation Coefficient 102 BPPCC4 Boundary Point Power Correlation Coefficient.
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4.0 ADDIESSABIE GNSTANT DETERMIIRTION MEmiODOIDGY 4.1 General In the followirg sections of this report, Reference 3 was used to describe hcu the CPC addressable constants are used in the CPC System.
References 4 and 5 contain descriptions of tw the " plant measured" addressable constants are determined.
4.2 Core Coolant Mass Flow Pate Calibration Constants - FCl, FC2
'1he CPC addressable constants FCl and FC2 are calibration constants used in the flow algorithm which assure that the CPC normlized measured core coolant mss flow rate is less than the calorimetrically mmsured rate. This clibration is achieved in the CPCs by M = FCl
- Mg + N2 (4.2-1) e where calibrated care coolant nass flow rate (normlized)
M
=
c Madj = normalized CPC measured core coolant nass flow rate and FC1, FC2 = calibration constants (addressable)
It is initially assumed that the CPC movsured flcw rate is equal to the mlorimetric flow rate; that is, FCl and FC2 have initial values of 1.0 and 0.0, respectively.
Cor ection of FCl is nade during startup testing by:
FCl(new) = FCl(old, * (M(calorimetric) - FF)
(4.2-2)
M(t) where M(calorimetric) = nornalized calorimetric total coolant flow rate.
= flow fraction bias applied to accomodate possible instrument drift durirg calorimetric measurements.
FF is equal to.005 at or below 70% power and equal to.0025 above 75% power.
M(t)
= base CPC measured core coolant nass flow rate.
'Ihe value of FC2 rennins equal to 0.0 for ANO-2. '
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4.3 CEAC/RST 2 Inoperable Flag - CEANOD r
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'4.4 Azimuthal Tilt Allowance - TR The azinuthal tilt allowance, 'IR, is used in the UPIRTE and SIATIC
^ algorithms as a nultiplicative factor. In UPIATE:
4 In SIATIC the azinuthal tilt correction is nede by:
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i I [
A value of 1.02 is initially assigned to TR; that is, the azimuthal tilt is assumed to be less than 2%.
If the azimuthal tilt, as periodically calculated (see ANO-2 Technical Specification Section 4.2.3) using incore detectors (excore detectors in the event of incore detector inoperability), is larger than assumed by TR, then TR must be adjusted so that the conversion from average to hot channel heat flux is accurate (if not conservative). Values of TR less tran 1.02 cannot be used without prior approval by the ANO Plant Safety Comttee as required by the ANO-2 Technical Specifications.
4.5 Therral Power Calibration Constant - TPC 4
TPC is given rn initial value of 1.0, thereby assuming that the CPC a
static therral power is egaal to the secondary mlorimetric pwer.
During testing, TPC is corrected by TPC(new) = TPC(old)
- P(ca]orimetric)
BAT where:
P(calorimetric) = plant secondary mlorimetric power if p:uer is greater than or equal to 15% or plant primary calorimetric puer if power is less than 15%.
and updated and previous values 'F '::PC, new, old
=
respectively
7.
4.6 Neutron Flux Pcuer Calibration Constant - KGL a
As with TPC.(Thernal Power Calibration Constant, Section 4.5), KGL is assigned an initial value of 1.0 with the assumption that the neutron flux power calculation is accurate (equal to secondary calorimetric power). KGL is adjusted, if necessary, during testirg by:
KGL(new) = KGL(old)
- P(calorimetric)
(4.6-2) 9GL with
' P(calorimetric) = plant seconchry mlorimetric power if pcuer is greator man or equal to 15% or plant primary calorimetric power if pwer is less than 15%.
and new, old
= updated and previous values of KGL, respectively 4.7 DNBR and Iocal Power Density Pretrip Setpoints - DtBRPT, LPDPT Used in the Trip Sequener portion of the CPCs, DNBRPT and LPDPT are pretrip alarm setpoints for DNBR and local power density which alert operators to potential rector trip events. 'Ihese addressable i
constants nay be adjusted during the cycle according to operatire experience and are given initial values which provide an adequate nargin for response to pretrip alarms, but also alert the operator to undesirable conditions.
4.8 Thernal Power Uncertainty Bias - BERRO.
This offset provides for power measurement uncertainties which include conponents accountiry for:
(1) Secondary mlorimetric uncertainty (2) Bernal power calibration tolerance to secondary calorimetric value (3) hermal power measurement uncertainty (4) Uncertainty due to equipment recalibration or drift correction.
The value of BERR0 determined by a umbimtion of the above compo-nents is determined by the relmd designer, is cycle specific and is not expected to change during each cycle of operation.
4.9 Power Uncertainty Factor Used in DNBR Calculation - BERR1 4
9 2e couponents cf uncertainty included in BERR1 consist of:
(1) Modelling uncertainty (2) Pachine processirg uncertainty (3) Measurement uncertainty (4) Startup test acceptance criteria uncertainty.
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(5) Engineerirg nanufacturing uncertainty (6) During cycle 2 the value of BERR1 will tenporarily be increased to account for additional rod bow pemities pendirg NRC approval of CE's rod bow Topiml Report. (Supplement 3-P to CENPD 225P, " Fuel and Poison Rod Bowirg", June 1979).
'Ihe conbination of these uncertainties in a conservative nanner results in the cuerall uncertainty in BERRl. This value is determined by the reload designer.
4.10 Power Uncertainty Bias Used in DNBR Calculation - BERR2 Similar to other uncertainty factors and biases, BERR2 is cycle specific, is alculated by the reload designer and is not expected to charge durirg operation.
4.11 Power Uncertainty Factor Used in Ircal PoweraDensity Calculation -
BERR3
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We abovs uncertainty components ara determined for various operating conditiu..s and times-in-life (where appropriate) and are conbined in a conservative nenner to produce an overall uncertainty which nay be factored into the [
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We value of BERR3 is determined by the relmd designer, is cycle specific, and is not anticipated to charge durirg cycle operation.
4.12 Power Uncertainty Bias Used in Incal Power Density Calculation -
BERR4 BERR4, the power uncertainty bias used in local pwer density cl-culations is the most conservative uncertainty bias of either thernal or neutron flux pow. r includirg any additional uncertainty which nay be appropriate. 'Ihis power uncertainty bias is independent of the type of m1culation to be cbne - specifically, linear power density or DNBR:
and, because the uncertainty components considered in BERRO and BERR2 are uncharged, the limitirg value is used. [
=
BERR4 is cycle syific, is mlculated by the relmd designer and is not expected to charge durirg operation.
4.13 End-of-Lifa Flag - EOL 4.14 Multiplier for Plamr Radial Peaking Factor - ARM 1 - ARM 7 C
] With the nultipliers initially valued at 1.0, the measured plamr radial peakirg factors are determined with the reactor at steady-state, equilibrium Xenon, for given control rod configurations. We appropriate CPC radial peaking factor nust be greater than or equal to the measured value (to ensure conservatim) or the ARMx addressable constant nust be adjusted as:
ARMx = Fxv(measured)
, (4.14-1) xy(CPC)
- f F
where:
FXY(measured) = measured plamr radial peakire factors
~
,FXY(CPC)
= tabulated CPC radial peakiry factors.
f
= burnup dependent multiplicative correction factor.
We "f" value is cycle specific and is determined by the reload designer.
and ARMg
= planar radial peaking factor multiplier with X dependent on specific control rod configuration as indicated below:
Constant Configuration ARM 1 All Rods Out (AlO)
ARM 2 Part-Iength (PL) CEA inserted ARM 3 Bank 6 inserted ARM 4 Bank 6, PL inserted ARM 5 Banks 6, 5 inserted ARM 6 Banks 6, 5, PL inserted ARM 7 Any other configuration.
4.15 Shape Annaaling Correction Factors - SC11, SC12, SC13, SC21, SC22,
__SC23, dC31, SC32, SC33
. :a
- 2 g.
'Ihe shape annealing natrix is:
S.*
S*H S*H S*13 Sx21 S*22 S*23 (4.15-2)
Sx31 S*32 S*33 For Channel x = A, B, C, D where:
SXij = the measured shape annealirg natrix element for channel x = A, B, C, or D and SXij are defined by the natrix equations:
..g s{
(1*D b2 1
1 3 i1 sL 40b 4N> 4N
<rN
=
" 13-"
sh 90h (N) 4N 4N
i for ' = 1, 2, 3 and x = channel A, B, C, D where D X = the subchannel detector signal from subchannel i
i = 1, 2, 3 of channel x = A, B, C D and P x = the peripheral power integral for the axial elevation i
correspondirg to detector ~ ubchanne; i = 1, 2, 3, in the s
quadrant corresponding to channel x =
2 B,C,D he generation of CECDR peripheral power distributic.
sver a sufficient operating range ensures _ that a sufficient.
' er of chta points are used in the least squares fit. W e resultai.
alculated values o'i the shape annealing natrix are compared with ti... predicted values i.nd replacement is nede if acceptable agreement does not exist.
4.16 DNBR and LPD CEA Deviation Pemity Pactor Correction Multipliers -
/
PFMLTD and PFMLTL 4
4
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6 local Powe[r Density (LPD) penalty factors (PFMLTD and PFMLTL),
respectively) have been adjusted to account for any Tm i
anomlics which my occur durirg a CEA deviation event. Durirg norml operations adjustments for any Tgm nomlies are not required a
since the core average power is determined from the mximum of the thermi power and neutron flux power. Only during a transient condition, especially a CEA Withdrawal event, could a Tgg anomly result.in the determination of a nonenservative core average power. Therefore, to account for this possible non-conservatism, the pemity factor mitipliers have been adjusted to ensure that an i
additional power penalty is applied during a CEA deviation event.
Cycle 1 observations indicate that the eximum temperature deviation from the norml steady state value is 1.50F A power penalty of 3.74% has been determined applicable for this ancnoly and the resultant value for both PFMLTD and PFMLTL is -1.0374. Tm i
anomlies cbserved on the averaged TH inputs to the CPCs of greater than 1.50F require adjustment of t'le addressable PF multipliers as:
Tg g Addressable PF Multiplier 1.754
-1.0439 0
2.00 F
-1.0505 2.250F
-1.0572 0
2.50 F
-1.0639
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- ' ^',
b..
]
r-r 4.17 Multiplifr for_ CFA Shadowing Factor - ASM2 - ASi47 During power escalation testing, the " measured" CFA shadowing fcctors for control rod configuration x are calculated tor each CPC channel:
(A) CFA configurations without Part-Length Group Insertion ED (x) i F(x) 1
- P(ARO)
(4.17-1)
=
ED (ARO)
P(x) i i
and (B) CFA configurations which include Part-Lergth Group Inserticn D (*)
F(x) 2
- P(ARO)
(4.17-2)
=
D (ARO)
P(x) 2 where:
D (x) = excore detector signal at axial level i for CEA i
configuration x, P(x)
=,NSSS ~alorimetric power level for CFA configuration x, F(x)
= CFA shacowing factor, CFA configuration x, and I is wer the three axial excore detectors. The " measured" shadbing factors are then compared to " predicted" values and in the event of non-compliance with specified acceptance criteria the CFA shadowing factor multipliers must be corrected as necessary by:
ASMx = " measured" CFA Shadowire Factor (4.17-3)
" predicted" CE Snadowing Factor The relationship of ASMx with rodded configuration x is as follows:
Addressable CFA Constant Configuration ASM2 Part-Length (PL) CFA inserted ASbG CFA Group 6 inserted ASM4 PL and Group 6 insertei ASM5 Groups 6 and 5 inserted ASM6 PL, Groups 6 and 5 inserted ASM7 All other configurations
If following neasurements the shadowing factors mnnot te 1
acceptably adjusted, then BERR1 and BERR3 must be adjusted. '1he adjustment constants are cycle specific and are determined by the relmd designer.
4.18 Temperature Shadowirs Correction Pactor Multiplier - CORR 1 i
The value of CORR 1 is measured durirg initial plant startup for cycle 1 and is plant - not cycle - specific.
It is anticipated that the cycle 1 value will be used for subsequent cycles.
4.19 Boundary Point Power Correlation Ccefficients - BPPCCl-BPPCC4 6
4 I
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9.
O
-l (P y(L BPPCC1 P P P
L L
BPPCC2
-%'h
%Lh i
L
-l BPPOC3 (P,P (P )
P Y( )
u u
u (4.19-3)
-Qu)
(
BPPCC4 1
where:
BPPCCl-4 = boundary point power correlation coefficients Pu,PL
= core average power fractions for the upper and lower third of the core, respectively y(o),Y(L) = upper and lower core boundary average pwer N
(n) = h I nj over data points measured and
.j=1 We mlues mer a sufficient operatirg mrge ensures that a sufficient number of data points are used in the fit. We resultant measured values of BPPOCl-BPPCC4 are compared with the predicted values and replacement is node if acceptable agreement does not exist..
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5.0 REFERENCES
1.
Letter to Mr. William Cavanaugh from Mr. Robert A. Clark, April 10, 1981.
- 2. -Letter to Mr. William Cavanaugh from Mr. Robert A. Clark May 5, 1981.
3..
CEN-147 (S)-P, " Functional Design Specification for a Core Protection Calculator", Combustion Engineering, Inc., February, 1981.
4.
Letter to Mr. Robert A. Clark from Mr. David C. Trimble, "NRC Request for Information on CPC Addressable Constant Determinations",
May 22, 1981, Letter No. ANO-81-2-0461.
- 5. - "CPC-CEAC System Startup Test Requirements" CEN-63 (A), Combustion Engineering, Inc., July 28, 1977.
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