ML18102B546
| ML18102B546 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 08/31/1997 |
| From: | Wathey T WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP. |
| To: | |
| Shared Package | |
| ML18102B545 | List: |
| References | |
| WCAP-14963, NUDOCS 9709020239 | |
| Download: ML18102B546 (60) | |
Text
\\*;
WESTINGHOUSE NON-PROPRIETARY CLASS 3 WCAP-14963 Conditional Extension of the Rod Misalignment Technical Specification for Salem Units 1 and 2
. August, 1997 T. R. Wathey Verified: I/. J. '}3-~
- lFettermall Core Analysis C Approved: -a.~
B.fo~er Core Analysis C Westinghouse Electric Corporation Commercial Nuclear Fuel Division P. 0. Box355 PittSburgb, Pennsylvania 15230 970-9020239-97oa25---***----,
PDR 'ADOCK 05000272 P
© 1997 Westinghouse Electric Corporation, All Rights Reserved
WESTINGHOUSE NON-PROPRIETARY CLASS 3 LIST OF TABLES Table 3.1 Design Models Used in Rod Misalignment Analyses................... 5 Table 3.2 Summary of Misalignment Cases Analyzed.......................
8 Table 3.3.1 Summary of 6 Additional Step Hot Full Power Rod Misalignment Cases Analyzed.. 14 Table 3.3.2Summary of 6 Additional Step Part-Power Rod Misalignment Cases Analyzed..... 32 Table 3.3.3Summary of 3 Additional Step Rod Misalignment Cases Analyzed........... 37 0
WESTINGHOUSE NON-PROPRIETARY CLASS 3 LIST OF ILLUSTRATIONS Figure 3.1 [
Figure 3.2 [
Figure 3.3 [
Figure 3.4 [
Figure A.1 [
Figure A.2 [
Figure A.3 [
Figure A.4 [
Figure A.5 [
Figure A.6 [
Figure A.7 [
Figure A.8 [
] a 'c...............................
11
] a ' c................................
13
] a., c............... 14
....... 15
] a ' c........... 47
] a, c
....................... *.. 48
] a ' c........... 49
] a ' c
........................... 50
] a ' c
............ 51
] a, c
......................... 52
] a ' c........... 53
] a ' c
- ........................... 54
-1
WESTINGHOUSE NON-PROPRIETARY CLASS 3 TABLE OF CONTENTS 1.0 2.0 3.0 3.1 3.2 3.3 3.4 3.5 4.0
5.0 INTRODUCTION
1 DESCRIPTION OF CONTROL ROD SYSTEM FAILURES..............
2 ANALYSES SUPPORTING NORMAL OPERATION.................
4 ANALYSIS METHODOLOGY................................ 4 CORE MODELS USED FOR ANALYSIS..........................
5 MISALIGNMENT CASES ANALYZED..........................
6 ANALYSIS RESULTS....................................
7 PROPOSED TECHNICAL SPECIFICATION CHANGES..................
9 SAFETY ANALYSIS IMPACTS.............................
40 CONCLUSIONS.......................................
41 REFERENCES............................................ 42 APPENDIX.............................................. 43
-2
WESTINGHOUSE NON-PROPRIETARY CLASS 3 ACKNOWLEDGEMENTS The author gratefully acknowledges the following individuals for their contributions to the completion of this report: C. R. Tuley, R. A. Holland, R. J. Fetterman, T. R. Wathey, K. R. Robinson, and K. W.
Bonadio.
-3
WESTINGHOUSE NON-PROPRIETARY CLASS 3 ABSTRACT This report proposes modifying the Technical Specification for allowable rod misalignment from the current +/-12 steps indicated to a value up to a maximum of +/-18 steps indicated, depending upon the minimum available peaking factor margin.
Such a Technical Specifications change is sought to minimize disruptions to normal plant operations due to frequent and erroneous indications 9f rod misalignment from the Analog Rod Position Indicator (ARPI).
The required margins to the hot rod and hot spot peaking factor (F AfI and FQ) limits will be determined by examining the changes in these peaking factors between similar cases with misalignments of +/-12 and +/-18 steps indicated. These resulting required margins will be determined such that they are cycle independent for Salem Units 1 and 2. It will also be shown that plant safety will not be compromised by this Technical Specifications change.
-4
WESTINGHOUSE NON-PROPRIETARY CLASS 3
1.0 INTRODUCTION
The current Westinghouse licensing basis supports an indicated rod misalignment of +/-12 steps for any rod(s) within a bank from the bank demand position.
As the analog rod position indication system (ARPI) has an uncertainty of 12 steps, the actual misalignment may be as large as +/-24 steps. In most cases, these indicated misalignments are false readings caused by fluctuations in the temperature of the control rod drive shafts. For example, such fluctuations can occur after rod control cluster assemblies (RCCAs) are withdrawn from the core during startup. However, when an indication of a misalignment does occur, false or otherwise, the reactor operator must take corrective action per the Technical Specifications.
Increasing the maximum allowable indicated misalignment to +/-18 steps (actual misalignment of +/-30 steps) will provide relief to the aforementioned conditions of false misalignment indications from the ARPI. For real misalignments, increasing the misalignment by 6 steps generally yields a small but acceptable increase in the hot rod and hot spot peaking factors, Fm and FQ. This report will briefly review the feasible single failures of the rod control system that could yield misalignments of single and multiple rods. These feasible single failures will then form the basis for the cases analyzed and documented in this report to support the increase in the misalignment permitted by th~ Technical Specifications.
1
WESTINGHOUSE NON-PROPRIETARY CLASS 3
2.0 DESCRIPTION
OF ROD CONTROL SYSTEM FAILURES To determine the misalignment cases to be analyzed for this Technical Specification change, an evaluation of the rod control system was performed, drawing from the Failure Mode and Effects Analysis (FMEA) documented in Reference 1. This evaluation considered single failures within the rod control system logic cabinets, power cabinets and the control rod drive mechanisms (CRDMs).
This evaluation also considered the impacts of the revised current order timing previously documented in Reference 2.
This evaluation has determined that a single failure of the rod control system can result in six categories of failure mechanisms within the system:
A.
[
B.
[
- c.
[
D.
[
2
WESTINGHOUSE NON-PROPRIETARY CLASS 3 E.
[
F.
[
3
WESTINGHOUSE NON-PROPRIETARY CLASS 3 3.0 ANALYSES SUPPORTING NORMAL OPERATION For the remainder of this report, the failure mechanisms discussed in Section 2 will be referred to by the letter they are listed as; i.e. failures A through F. When analyzing these failure mechanisms for peaking factor impacts, the following cabinet configurations must be considered:
- 1.
- 2.
2AC: groups CA2, CC2, SA2
- 3.
- 4.
2BC: groups CB2, CD2, SB2
- 5.
SCD: groups SC, SD The above configurations are also illustrated in Figures 3. I and 3.2. The group nomenclature used to describe the power cabinets is defined as follows: the first letter (C or S) refers to a control or shutdown bank; the second letter (A, B, C or D) refers to the bank; the number (1 or 2) refers to the group number.
For example, power cabinet IAC controls group CAI, which is group I of control bank A. Power cabinet 2BC controls group SB2, which is group 2 of shutdown bank B.
[
3.1 ANALYSIS METHODOLOGY The failure mechanism categories described in Section 2 will be analyzed using the USNRC-approved PHOENIX-P/ANC core design system documented in References 3 and 4. For each failure analyzed, calculations are performed for misalignments of +/-24 and +/-30 steps and compared to the corresponding non-misaligned reference case.
The F ~H and FQ for these cases are calculated and compared [
4
WESTINGHOUSE NON-PROPRIETARY CLASS 3 3.2 CORE MODELS USED FOR ANALYSIS To petform the analysis of the possible rod misalignments, two different ANC models of the Salem core were used. The first model is the currently planned Salem Unit 2 Cycle 10 core loading pattern, and represents the current Salem Units 1 and 2 licensing basis for fuel products and peaking factor limits.
The second model used is intended to represent a "bounding" future cycle; that is, higher enrichments and higher peaking factors. These two models are summarized in Table 3.1 below:
Table 3.1: Design Models Used in Rod Misalignment Analyses Design Parameter Current Future Cycle Cycle Cycle Length (End of Full Power 485 500 Capability, EFPD)
No. of Feed Assemblies 28 fresh, 64 64 "slightly burned"*
No. Feeds Under Lead Bank 0
8@ 4.80 (No. @ w/o U235)
Feed Enrichments 20@ 4.0, 8@
24@ 4.40 (No. @ w/o U235) 4.4, 52 "slightly burned"@ 4.0, 40@ 4.80 12 "slightly burned" @ 4.4 Burnable Absorbers 4928 spent*,
6144 IFBA, (No. I Type I Length) 2624 fresh IFBA, 132" centered; 132" centered; 48 Pyrex, 144" 320 spent*, 192 fresh Pyrex, 144" Fm Limit 1.55 1.65
- The Current Cycle contains 64 slightly burned assemblies, 4928 spent IFBA and 320 spent Pyrex rods that were fed into the Cycle N-1 which shutdown at a cycle burnup of 3130 MWD/MTU.
5
WESTINGHOUSE NON-PROPRIETARY CLASS 3 3.3 MISALIGNMENT CASES ANALYZED For the failure mechanism categories listed in Section 2, several distinct subsets of cases are analyzed in ANC. These cases are considered at beginning of cycle life (BOL, 150 MWD/MTU), middle of cycle life (MOL), and end of cycle life (EOL).
Most of the calculations are performed assuming the reference condition as hot full power (HFP) with rods at the insertion limit (RIL); the Salem Units 1 and 2 RILs are illustrated in Figure 3.3. Several of these cases are repeated at other reference rod conditions above the RILs, and at part power conditions such as 85% and 50% rated thermal power. The subsets of cases analyzed are summarized below:
- 1.
[
- 2.
[
- 3.
[
- 4.
[
- 5.
[
- 6.
[
6
WESTINGHOUSE NON-PROPRIETARY CLASS 3
- 7.
[
- 8.
[
The specific cases analyzed for an additional 6 steps of misalignment are summarized in Table 3.3.1.
The "Failure Mechanisms" listed in Table 3.3.1 are described in Section 2. The "Demand Position" is the desired rod configuration of the RCCA(s) in the precondition case. All other rods are ARO (222 steps withdrawn) unless otherwise stated. The "Rod(s) Misaligned" column provides the configuration of the misaligned rod(s) from the precondition case stated in the "Demand Position" column. Thus for Case Number 8 in Table 3.3.1, the precondition is D bank in at 170 steps and all other banks at 222 steps withdrawn (ARO). "Subgroup D2 In" means that group D2 of D bank is inserted to 146 (170 -
- 24) steps and then 140 (170 - 30) steps, while subgroup Dl remains at 170 steps and all other banks remain at 222 steps. The "Peaking Factor % Increase" column is the percent increases in F ~H and FQ from the misalignment at 24 steps to the misalignment of 30 steps for an additional 6 step misalignment.
Additional cases were also performed at part power conditions as listed in Table 3.3.2. Finally, several misalignment cases, primarily the limiting of the 6 step additional misalignment cases, were repeated with only 3 steps of additional misalignment (+/-27 steps total) as listed in Table 3.3.3. The performance of the part power cases and 3 step misalignment cases provide completeness and verify the bounding nature of the evaluation process utilized in this report. Results from these three tables are also summarized in Table 3.2.
3.4 ANALYSIS RESULTS A complete description of all cases analyzed is presented in Tables 3.3.1 through 3.3.3. A summary of all cases analyzed and the limiting results to support the rod misalignment Technical Specifications change is given in Table 3.2. This data is presented as the change in the peak Fm and FQ for an increase in the rod misalignment beyond the current licensing basis of +/-24 steps.
Note that with the current F ~H' FQ, and Fxy Technical Specifications, margins to the limits generally increase as power level decreases:
pLIMIT -
pHFP[l + 0 3(1-P)J
~H f:.H (1) 7
WESTINGHOUSE NON-PROPRIETARY CLASS 3 (2)
(3)
Then, since peaking factor margins are usually a minimum at HFP, the amount of margin required to allow the permissible indicated misalignment to be increased from +/-12 to +/-18 steps will be determined based on the HFP data for the additional +/-6 step misalignments from Table 3.3.1 and summarized in Table 3.2. For all HFP +/-6 step misalignment cases, the 95/95 increases in F AH and FQ are [
]a,c and [
]a,c respectively, and the maximum increases in F AH and FQ are [
]a,c and [
]a,c respectively. These results can be conservatively bounded by required F AH and FQ margins of [
p,c and [
]a,c, respectively, for increased rod misalignment of +/-6 steps. Note that these required margins are an increase of [
]a,c and [
p,c respectively over the 95/95 values and an increase of
[
]a,c and [
p,c respectively over the observed maximum values for all HFP +/-6 step cases.
8
WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 3.2: Summary of Misalignment Cases Analyzed; Change in Peak F MI and F Q for Increased Misalignment Beyond +/-24 Steps Cases Dist.
Mean (x)
Std. Dev.
95/95 Max.%
Peak Value No. Points Function (cr), %
(Case No.)
HFP+/-6 FAH Beta 0.4 0.4 1.5 1.8 (100) 159 FQ Exponential 0.9 0.9 3.4 3.3 (101)
Part Power FAH Beta 1.0 0.7 2.3 2.4
+/-6 (185,188) 31 FQ Beta 1.8 0.9 3.4 3.6 (172)
HFP+/-3 FAH Beta 0.4 0.3 1.0 0.9 (196) 17 FQ Beta 1.1 0.6 1.8 1.8 (195,198, 203)
Examining the +/-3 step misalignments from Table 3.3.3, and summarized in Table 3.2, the 95/95 increases in F AH and FQ are 1.0% and 1.8% respectively, and the maximum increases in F AfI and FQ are 0.9% and 1.8% respectively. These results are reasonably approximated by required FAH and FQ margins of 1.0% and 1.75% respectively.
The analysis approach of the +/-3 step cases is also conservative in that most of the cases analyzed (17 +/-3 step cases versus 159 +/-6 step cases) were chosen based on which cases provided limiting results in the +/-6 step analysis. If all 159 +/-6 step cases were repeated with only +/-3 steps of rod misalignment, it is expected that the 95/95 results shown in Table 3.2 would decrease and that the maximum observed values would not increase.
Therefore, the proposed F AfI and FQ margins for an additional 3 steps of misalignment are half of the limits proposed for an additional 6 steps. This would suggest that margin required for an increase in the permissible misalignment can then be specified as a linear function of the available peaking factor margin, with the misalignment increase being determined from the minimum of the available F AH or FQ margin.
9
WESTINGHOUSE NON-PROPRIETARY CLASS 3 Examining the +/-6 step part-power misalignments from Table 3.3.2, and summarized in Table 3.2, the 95/95 increases in F AH and FQ are 2.3% and 3.4% respectively, and the maximum increases in F AH and FQ are 2.4% and 3.6% respectively. The part-power 95/95 F AH increase is 0.8% larger than the HFP-only +/-6 step 95/95 F AH increase. The part-power 95/95 FQ increase is the same as the HFP-only +/-6 step increase. However, by 85% power, the Technical Specification F AH and Fxy limits have increased by 4.5% and the FQ limit has increased by 18%. By 50% power, the F AH and Fxy limits have increased by 15% and the FQ limit has increased by 100%. Since the limits are increasing much faster than the required margins, the misalignment Technical Specification change can be written in two parts:
the first part is applicable for the majority of normal operation, 85% to 100% power, with allowable misalignment as a linear function of minimum available F AH or minimum available FQ or Fxy margin as discussed above; the second part is applicable for operation below 85% to 0% power, including reactor criticality and start-up, with an allowable indicated misalignment of +/-18 steps.
3.5 PROPOSED TECHNICAL SPECIFICATION CHANGES A graphic representation of the proposed Technical Specification discussed in Section 3.4 is shown in Figure 3.4. The amount of available margin must be determined at least once every 30 EFPD during normal incore flux map surveillance. For Salem Units 1 and 2, the amount of Fxy margin will be based on Fxy surveillance methodology (Reference 5), and the amount of FQ margin will be based on the FQ surveillance methodology (Reference 6). Currently, the Salem plants use Fxy surveillance. Future cycles may possibly implement FQ surveillance.
10
WESTINGHOUSE NON-PROPRIETARY CLASS 3 FIGURE 3.1 Salem Unit 1 Control and Shutdown Rod Configuration By Group and Power Cabinet R
90° p
N M
L Cl A2 SAl Al in
- -* ~
SB.1 SA2 SC Bl SB2 D2 A2 SAl Cl Al D CABINET SCD D
CABINET lAC D CABINET lBD K
J D2 SB2 SD C2 SD SA2 si;i1 Dl H
G F
SC Pl SBl B2 SA2 C2 SD D2 C2 C2 SD B2 SB2 SC D2 E
D c
Al Cl SAl A2 SB2 Bl, SA2 s!ll Al SAl A2 Cl D
CABINET 2AC D
CABINET 2BC B
A D2 SC Dl
-1
-2
-3
-4 5
6 7
-8 9
10
-11 12 13
-14 15 11
WESTINGHOUSE NON-PROPRIETARY CLASS 3 "This page intentionally blank."
12
WESTINGHOUSE NON-PROPRIETARY CLASS 3 FIGURE 3.2 Salem Unit 2 Control and Shutdown Rod Configuration By Group and Power Cabinet R
p N
M L
K J
H G
F E
D c
B A
SA2 D2 E!l.
pl SAl SD SB2 SBl SC SAl Cl A2 Cl SA2 SC SD p~
B2 C2 B2 D2 sin SB2 90° Bl Al C2 D2 C2 A2 in SB2
- SBl, D2 B2 C2 B2 1)1 SD SC SA2 Cl Al Cl SAl SC
~B.J.
SB2 SD SAl l;>l
]31 D2 SA2 oo D
CABINET SCD D
CABINET 2AC D
CABINET lAC D
CABINET 2BC
~
CABINET lBD 1
2 3
4 5
6 7
-8
-9 10 11 12 13 14 15 13
WESTINGHOUSE NON-PROPRIETARY CLASS 3 Figure 3.3 Salem Units 1 and 2 Control Rod Insertion Limits 14 220 200 180 a 160
- r-1
.w
- r-1 Ol 0
P-i A
140 Q) 120
.I-)
(/)
~
Q 100 cd r:x:t re 0
80
~
60 40 20 0
V 10 1.1s,2221 I
0.68,2221 I
v I
BANK B I
I I
I I
I/ 10.0,1061 I/
/
ll.0,1701 I
/
v I
)
I I BANK C I
)I I
I I
v I
I I
!/
/
I v
I I
I I
I I I BANK D I
10.o,s01 I
I I
f
)
I v I0.29,0I I
0.0 0.2 0.4 0.6 0.8 1.0 Fraction of Rated Thermal Power
WESTINGHOUSE NON-PROPRIETARY CLASS 3 Figure 3.4 Permissible Increase in Rod Misalignment Vs. Available F MI and Available FQ or Fxy Margin a,c 15
Table 3.3.1: Summary of 6 Additional Step Hot Full Power Rod Misalignment Cases Analyzed (Sheet 1 of 18)
Peaking Factor %
Increase for Case Burnup Power Cycle Failure Demand Rod(s) Misaligned Additional 6 Steps No.
Mechanism Position F~H FQ
- a,c 1
BOL HFP Future B
D at 170 Subgroup Dl Out 2
EOL HFP Future B
D at 170 Subgroup Dl Out 3
BOL HFP Future B
D at 170 Subgroup Dl In 4
EOL HFP Future B
D at 170 Subgroup Dl In 5
BOL HFP Future B
D at 170 Subgroup D2 Out 6
EOL HFP Future B
D at 170 Subgroup D2 Out 7
BOL HFP Future B
D at 170 Subgroup D2 In 8
EOL HFP Future B
D at 170 Subgroup D2 In 9
BOL HFP Future D
D at 170 K-02 Out 10 EOL HFP Future D
D at 170 K-02 Out 11 BOL HFP Future A
D at 170 K-02 In 12 EOL HFP Future A
D at 170 K-02 In
Table 3.3.1: Summary of 6 Additional Step Hot Full Power Rod Misalignment Cases Analyzed (Sheet 2of18)
Peaking Factor %
Increase for Case Burn up Power Cycle Failure Demand Rod(s) Misaligned Additional 6 Steps No.
Mechanism Position F~H FQ 13 BOL HFP Future D
D at 170 K-02,P-10,H-08 Out a,c 14 EOL HFP Future D
D at 170 K-02,P-10,H-08 Out 15 BOL HFP Future A
D at 170 K-02,P-10,H-08 In 16 EOL HFP Future A
D at 170 K-02,P-10,H-08 In 17 BOL HFP Future D
D at 170 K-02,B-06 Out 18 EOL HFP Future D
D at 170 K-02,B-06 Out 19 BOL HFP Future A
D at 170 K-02,B-06 In 20 EOL HFP Future A
D at 170 K-02,B-06 In 21 BOL HFP Future D
D at 170 H-08,K-02 Out 22 EOL HFP Future D
D at 170 H-08,K-02 Out 23 BOL HFP Future A
D at 170 H-08,K-02 In 24 EOL HFP Future A
D at 170 H-08,K-02 In
Table 3.3.1: Summary of 6 Additional Step Hot Full Power Rod Misalignment Cases Analyzed (Sheet 3of18)
Peaking Factor %
Increase for Case Burn up Power Cycle Failure Demand Rod(s) Misaligned Additional 6 Steps No.
Mechanism Position F~H FQ 25 BOL HFP Future D
D at 170 H-08 Out a,c 26 EOL HFP Future D
D at 170 H-08 Out 27 BOL HFP Future A
D at 170 H-08 In 28 EOL HFP Future A
D at 170 H-08 In 29 BOL HFP Future D
D at 170 K-02,P-10,F-14 Out 30 EOL HFP Future D
D at 170 K-02,P-10,F-14 Out 31 BOL HFP Future A
D at 170 K-02,P-10,F-14 In 32 EOL HFP Future A
D at 170 K-02,P-10,F-14 In 33 BOL HFP Future A
D at 170 K-02,F-14,H-08,B-06 In 34 EOL HFP Future A
D at 170 K-02,F-14,H-08,B-06 In 35 BOL HFP Future c
D at 170 All D Bank In
Table 3.3.1: Summary of 6 Additional Step Hot Full Power Rod Misalignment Cases Analyzed (Sheet 4of18)
Peaking Factor %
Increase for Case Burn up Power Cycle Failure Demand Rod(s) Misaligned Additional 6 Steps No.
Mechanism Position F~H FQ 36 EOL HFP Future c
D at 170 All D Bank In a,c 37 BOL HFP Future E
D at 170 Subgroup D2 Out, Unit 1 Subgroup B2 In 38 EOL HFP Future E
D at 170 Subgroup D2 Out, Unit 1 Subgroup B2 In 39 BOL HFP Future E
D at 170 Subgroup D2 Out, Unit 2 Subgroup B2 In 40 EOL HFP Future E
D at 170 Subgroup D2 Out, Unit 2 Subgroup B2 In 41 BOL HFP Future E
D at 170 Subgroup Dl Out, Unit 1 Subgroup Bl In 42 EOL HFP Future E
D at 170 Subgroup Dl Out, Unit 1 Subgroup Bl In 43 BOL HFP Future E
D at 170 Subgroup Dl Out, Unit 2 Subgroup Bl In
N 0
- Table 3.3.1: Summary of 6 Additional Step Hot Full Power Rod Misaligrument Cases Analyzed (Sheet 5of18)
Peaking Factor %
Increase for Case Burnup Power Cycle Failure Demand Rod(s) Misaligned Additional 6 Steps No.
Mechanism Position F.1.H FQ 44 EOL HFP Future E
D at 170 Subgroup Dl Out, a,c Unit 2 Subgroup B 1 In 45 BOL HFP Future E
D at 170 Subgroup D2 Out, Subgroup SB2 In 46 EOL HFP Future E
D at 170 Subgroup D2 Out, Subgroup SB2 In 47 BOL HFP Future E
D at 170 Subgroup Dl Out, Subgroup SBl In 48 EOL HFP Future E
D at 170 Subgroup Dl Out, Subgroup SBl In 49 BOL HFP Future F
D at 170 BankD Out, Bank SB In 50 EOL HFP Future F
D at 170 BankD Out, Bank SB In
Table 3.3.1: Summary of 6 Additional Step Hot Full Power Rod Misalignment Cases Analyzed (Sheet 6of18)
Peaking Factor %
Increase for Case Burn up Power Cycle Failure Demand Rod(s) Misaligned Additional 6 Steps No.
Mechanism Position F~H FQ 51 BOL HFP Future A
D at 170 Unit 1 Subgroups a,c C2,SA2,A2 In Except N-11 52 EOL HFP Future A
D at 170 Unit 1 Bank SC,SD In Except F-06 53 BOL HFP Future A
D at 170 Unit 2 Subgroups Cl,SAl,Al In Except M-08 54 EOL HFP Future A
D at 170 Unit 2 Subgroups C2,SA2,A2 In Except H-10 55 BOL HFP Future A
D at 170 Unit 1 Subgroups C2,SA2 In 56 EOL HFP Future A
D at 170 Unit 1 Subgroups Cl,SAl,Al In 57 BOL HFP Future A
D at 170 Unit 2 Subgroups C2,A2 In
~
Table 3.3.1: Summary of 6 Additional Step Hot Full Power Rod Misalignment Cases Analyzed (Sheet 7 of 18)
Peaking Factor %
Increase for Case Burnup Power Cycle Failure Demand Rod(s) Misaligned Additional 6 Steps No.
Mechanism Position F.!lu FQ
~
58 EOL HFP Future A
D at 170 Unit 2 Subgroups a,c SBl,Bl Dl In 59 BOL HFP Future A
D at 170 Unit 2 Subgroups D2,SB2,B2 In Except P-10,N-09,K-06,K-10 60 MOL HFP Future A
D at 170 Unit 2 Subgroups D2,SB2,B2 In Except P-10,N-09,K-06,K-10 61 EOL HFP Future A
D at 170 Unit 2 Subgroups D2,SB2,B2 In Except P-10,N-09,K-06,K-10 62 BOL HFP Future A
ARO at222 Unit 1 Subgroups D2,B2,SB2 In Except B-06,C-07 63 MOL HFP Future A
ARO at222 Unit 1 Subgroups A2,C2,SA2 In Except C-05
Table 3.3.1: Summary of 6 Additional Step Hot Full Power Rod Misalignment Cases Analyzed (Sheet 8 of 18)
Peaking Factor %
Increase for Case Burnup Power Cycle Failure Demand Rod(s) Misaligned Additional 6 Steps No.
Mechanism Position FAH FQ 64 EOL HFP Future A
ARO at222 Unit 1 Subgroups a,c D2,B2,SB2 In Except B-06,C-07 65 BOL HFP Future A
ARO at222 Unit 2 Subgroups D2,B2,SB2 In Except B-06,C-07 66 MOL HFP Future A
ARO at222 Unit 2 Subgroups D2,B2,SB2 In Except B-06,C-07 67 EOL HFP Future A
ARO at222 Unit 2 Subgroups D2,B2,SB2 In Except B-06,C-07 68 BOL HFP Future A
ARO at222 Unit 1 Subgroups C2,SA2 In 69 MOL HFP Future A
ARO at222 Unit 1 Subgroups C2,SA2 In 70 EOL HFP Future A
ARO at222 Unit 1 Subgroups C2,SA2 In
~
Table 3.3.1: Summary of 6 Additional Step Hot Full Power Rod Misalignment Cases Analyzed (Sheet 9of18)
Peaking Factor %
Increase for Case Burnup Power Cycle Failure Demand Rod(s) Misaligned Additional 6 Steps No.
Mechanism Position FL\\H FQ 71 BOL HFP Future A
ARO at222 Unit 2 Subgroups a,c A2,C2 In 72 MOL HFP Future A
ARO at222 Unit 2 Subgroups A2,C2 In 73 EOL HFP Future A
ARO at222 Unit 2 Subgroups A2,C2 In 74 BOL HFP Future A
ARO at224 K-02,P-10,H-08 In 75 EOL HFP Future A
ARO at224 K-02,P-10,H-08 In 76 BOL HFP Future A
ARO at224 K-02,H-08 In 77 EOL HFP Future A
ARO at224 K-02,H-08 In 78 BOL HFP Future A
D at 197 K-02,P-10,H-08 In 79 EOL HFP Future A
D at 197 K-02,P-10,H-08 In 80 BOL HFP Future A
D at 197 K-02,H-08 In 81 EOL HFP Future A
D at 197 K-02,H-08 In
N Vt Table 3.3.1: Summary of 6 Additional Step Hot Full Power Rod Misalignment Cases Analyzed (Sheet 10 of 18)
Peaking Factor %
Increase for Case Burn up Power Cycle Failure Demand Rod(s) Misaligned Additional 6 Steps No.
Mechanism Position FAH FQ 82 BOL HFP Future D
D at 193 K-02,P-10,H-08 Out a,c 83 EOL HFP Future D
D at 193 K-02,P-10,H-08 Out 84 BOL HFP Future D
D at 193 K-02,H-08 Out 85 EOL HFP Future D
D at 193 K-02,H-08 Out 86 BOL HFP Current A
D at 170 H-08 In 87 BOL HFP Current A
D at 170 K-02 In 88 BOL HFP Current A
D at 170 K-02,H-08 In 89 BOL HFP Current A
D at 170 K-02,H-08,B-06,F-14 In 90 BOL HFP Current A
D at 170 K-02,B-06,F-14 In 91 BOL HFP Current D
D at 170 K-02 Out 92 BOL HFP Current D
D at 170 K-02,H-08 Out
~
Table 3.3.1: Summary of 6 Additional Step Hot Full Power Rod Misalignment Cases Analyzed (Sheet 11 of 18)
Peaking Factor %
Increase for Case Burnup Power Cycle Failure Demand Rod(s) Misaligned Additional 6 Steps No.
Mechanism Position FAH FQ 93 BOL HFP Current D
D at 170 K-02,H-08,B-06,F-14 a,c Out 94 BOL HFP Current D
D at 170 K-02,B-06,F-14 Out 95 BOL HFP Current D
D at 170 K-02,B-06 Out 96 BOL HFP Current B
D at 170 Subgroup Dl In 97 BOL HFP Current B
D at 170 Subgroup Dl Out 98 BOL HFP Current B
D at 170 Subgroup D2 In 99 BOL HFP Current B
D at 170 Subgroup D2 Out 100 BOL HFP Current A
D at 170 Unit 2 Subgroups
(*)
D2,B2,SB2 In Except P-10,N-09,K-10 101 BOL HFP Current A
D at 170 Unit 2 Subgroups
(*
D2,B2,SB2 In Except P-10,N-09 102 MOL HFP Current A
D at 170 H-08 In
Table 3.3.1: Summary of 6 Additional Step Hot Full Power Rod Misalignment Cases Analyzed (Sheet 12 of 18)
Peaking Factor %
Increase for Case Burnup Power Cycle Failure Demand Rod(s) Misaligned Additional 6 Steps No.
Mechanism Position F~H FQ 103 MOL HFP Current A
D at 170 K-02 In a,c 104 MOL HFP Current A
D at 170 K-02,H-08 In 105 MOL HFP Current A
D at 170 K-02,H-08,B-06,F-14 In 106 MOL HFP Current A
D at 170 K-02,B-06,F-14 In 107 MOL HFP Current D
D at 170 H-08 Out 108 MOL HFP Current D
D at 170 K-02 Out 109 MOL HFP Current D
D at 170 K-02,H-08 Out 110 MOL HFP Current D
D at 170 K-02,H-08,B-06,F-14 Out 111 MOL HFP Current D
D at 170 K-02,B-06,F-14 Out 112 MOL HFP Current D
D at 170 K-02,B-06 Out 113 MOL HFP Current B
D at 170 Subgroup Dl In
N 00
- Table 3.3.1: Summary of 6 Additional Step Hot Full Power Rod Misalignment Cases Analyzed (Sheet 13 of 18)
Peaking Factor %
Increase for Case Burn up Power Cycle Failure Demand Rod(s) Misaligned Additional 6 Steps No.
Mechanism Position FAH FQ 114 MOL HFP Current B
D at 170 Subgroup Dl Out a,c 115 MOL HFP Current B
D at 170 Subgroup D2 In 116 MOL HFP Current B
D at 170 Subgroup D2 Out 117 MOL HFP Current A
D at 170 Unit 2 Subgroups D2,B2,SB2 In Except P-10,N-09,K-10 118 MOL HFP Current A
D at 170 Unit 2 Subgroups D2,B2,SB2 In Except P-10,N-09 119 EOL HFP Current A
D at 170 H-08 In 120 EOL HFP Current A
D at 170 K-02 In 121 EOL HFP Current A
D at 170 K-02,H-08 In 122 EOL HFP Current A
D at 170 K-02,H-08,B-06,F-14 In 123 EOL HFP Current A
D at 170 K-02,B-06,F-14 In
N
\\0 Table 3.3.1: Summary of 6 Additional Step Hot Full Power Rod Misalignment Cases Analyzed (Sheet 14of18)
Peaking Factor %
Increase for Case Burnup Power Cycle Failure Demand Rod(s) Misaligned Additional 6 Steps No.
Mechanism Position F~H FQ 124 EOL HFP Current D
D at 170 H-08 Out a,c 125 EOL HFP Current D
D at 170 K-02 Out 126 EOL HFP Current D
D at 170 K-02,H-08 Out 127 EOL HFP Current D
D at 170 K-02,H-08,B-06,F-14 Out 128 EOL HFP Current D
D at 170 K-02,B-06,F-14 Out 129 EOL HFP Current D
D at 170 K-02,B-06 Out 130 EOL HFP Current B
D at 170 Subgroup DI In 131 EOL HFP Current B
D at 170 Subgroup Dl Out 132 EOL HFP Current B
D at 170 Subgroup D2 In 133 EOL HFP Current B
D at 170 Subgroup D2 Out 134 EOL HFP Current A
D at 170 Unit 2 Subgroups D2,B2,SB2 In Except -
P-10,N-09,K-10
w 0
- Table 3.3.1: Summary of 6 Additional Step Hot Full Power Rod Misalignment Cases Analyzed (Sheet 15of18)
Peaking Factor %
Increase for Case Burn up Power Cycle Failure Demand Rod(s) Misaligned Additional 6 Steps No.
Mechanism Position
(
FAH FQ 135 EOL HFP Current A
D at 170 Unit 2 Subgroups a,c D2,B2,SB2 In Except P-10,N-09 136 BOL HFP Current A
ARO at222 Unit 2 Subgroups D2,B2,SB2 In Except P-10,N-09 137 MOL HFP Current A
ARO at222 Unit 2 Subgroups D2,B2,SB2 In Except P-10,N-09 138 EOL HFP Current A
ARO at222 Unit 2 Subgroups
(*)
D2,B2,SB2 In Except P-10,N-09 139 BOL HFP Current E
D at 170 Subgroup D2 Out, Unit 1 Subgroup B2 In 140 MOL HFP Current E
D at 170 Subgroup D2 Out, Unit 1 Subgroup B2 In 141 EOL HFP Current E
D at 170 Subgroup D2 Out, Unit 1 Subgroup B2 In -
Table 3.3.1: Summary of 6 Additional Step Hot Full Power Rod Misalignment Cases Analyzed (Sheet 16 of 18)
Peaking Factor %
Increase for Case Burn up Power Cycle Failure Demand Rod(s) Misaligned Additional 6 Steps No.
Mechanism Position F~H FQ 142 BOL HFP Current E
D at 170 Subgroup D2 Out, a,c Unit 2 Subgroup B2 In 143 MOL HFP Current E
D at 170 Subgroup D2 Out, Unit 2 Subgroup B2 In 144 EOL HFP Current E
D at 170 Subgroup D2 Out, Unit 2 Subgroup B2 In 145 BOL HFP Current E
D at 170 Subgroup Dl Out, Unit 1 Subgroup Bl In 146 MOL HFP Current E
D at 170 Subgroup Dl Out, Unit 1 Subgroup Bl In 147 EOL HFP Current E
D at 170 Subgroup Dl Out, Unit 1 Subgroup B 1 In 148 BOL HFP Current E
D at 170 Subgroup Dl Out, Unit 2 Subgroup Bl In -
Table 3.3.1: Summary of 6 Additional Step Hot Full Power Rod Misalignment Cases Analyzed (Sheet 17of18)
Peaking Factor %
Increase for Case Burn up Power Cycle Failure Demand Rod(s) Misaligned Additional 6 Steps No.
Mechanism Position FilH FQ 149 MOL HFP Current E
D at 170 Subgroup Dl Out, a,c Unit 2 Subgroup B 1 In 150 EOL HFP Current E
D at 170 Subgroup Dl Out, Unit 2 Subgroup B 1 In 151 BOL HFP Current E
D at 170 Subgroup D2 Out, Subgroup SB2 In 152 MOL HFP Current E
D at 170 Subgroup D2 Out, Subgroup SB2 In 153 EOL HFP Current E
D at 170 Subgroup D2 Out, Subgroup SB2 In 154 BOL HFP Current E
D at 170 Subgroup Dl Out, Subgroup SBl In 155 MOL HFP Current E
D at 170 Subgroup Dl Out, Subgroup SBl In
Table 3.3.1: Summary of 6 Additional Step Hot Full Power Rod Misalignment Cases Analyzed (Sheet 18 of 18)
Peaking Factor %
Increase for Case Burn up Power Cycle Failure Demand Rod(s) Misaligned Additional 6 Steps No.
Mechanism Position F~H FQ 156 EOL HFP Current E
D at 170 Subgroup Dl Out, a,c Subgroup SBl In 157 BOL HFP Current F
D at 170 BankD Out, Bank SB In 158 MOL HFP Current F
D at 170 BankD Out, Bank SB In 159 EOL HFP Current F
D at 170 BankD Out, Bank SB In
(*)
Signifies that plots of peaking factors and increases due to additional 6 steps of misalignment are included in the Appendix of this report.
Table 3.3.2: Summary of 6 Additional Step Part-Power Rod Misalignment Cases Analyzed (Sheet 1of5)
Peaking Factor %
Increase for Case Burn up Power Cycle Failure Demand Rods Misaligned Additional 6 Steps No.
Mechanism Position F~H FQ 160 EOL 85%
Future D
D at 170 K-02 Out a,c 161 BOL 85%
Future E
D at 170 Subgroup Dl Out, Unit 1 Subgroup B 1 In 162 EOL 85%
Future E
D at 170 Subgroup Dl Out, Subgroup SBl In 163 BOL 85%
Future A
D at 170 Unit 2 Subgroups D2,SB2,B2 In Except P-1 O,N-09,K-06,K-10 164 EOL 85%
Future A
D at 170 K-02,P-10,H-08 In 165 BOL 85%
Future A
D at 170 K-02,F-14,H-08,B-06 In 166 EOL 85%
Future D
D at 134 K-02 Out 167 BOL 85%
Future E
D at 134 Subgroup Dl Out, Unit 1 Subgroup B 1 In
Table 3.3.2: Summary of 6 Additional Step Part-Power Rod Misalignment Cases Analyzed (Sheet 2 of 5)
Peaking Factor %
Increase for Case Burnup Power Cycle Failure Demand Rods Misaligned Additional 6 Steps No.
Mechanism Position F~H FQ 168 EOL 85%
Future E
D at 134 Subgroup Dl Out, a,c Subgroup SBl In 169 BOL 85%
Future A
D at 134 Unit 2 Subgroups D2,SB2,B2 In Except P-10,N-09,K-06,K-10 170 EOL 85%
Future A
D at 134 K-02,P-10,H-08 In 171 BOL 85%
Future A
D at 134 K-02,F-14,H-08,B-06 In 172 EOL 85%
Future A
ARO at222 Unit 2 Subgroups D2,B2,SB2 In Except B-06,C-07 173 EOL 85%
Future A
D at 200 Unit 2 Subgroups B2,SB2,D2 In Except C-07,B-06 174 EOL 85%
Future A
ARO at224 K-02,P-10,H-08 In 175 BOL 85%
Future A
ARO at224 K-02,F-14,H-08,B-06 In
Table 3.3.2: Summary of 6 Additional Step Part-Power Rod Misalignment Cases Analyzed (Sheet 3 of 5)
Peaking Factor %
Increase for Case Burnup Power Cycle Failure Demand Rods Misaligned Additional 6 Steps No.
Mechanism Position FL1H FQ 176 BOL 85%
Current A
D at 140 Unit 2 Subgroups a,c D2,B2,SB2 In Except P-10,N-09 177 MOL 85%
Current A
D at 140 Unit 2 Subgroups D2,B2,SB2 In Except P-10,N-09 178 EOL 85%
Current A
D at 140 Unit 2 Subgroups D2,B2,SB2 In Except P-10,N-09 179 BOL 50%
Current A
D at 50, Cat Unit 2 Subgroups 176 Cl,Al,SAl In Except D-02,M-12 180 MOL 50%
Current A
D at 50, Cat Unit 2 Subgroups 176 Cl,Al,SAl In Except D-02,M-12 181 EOL 50%
Current A
D at 50, Cat Unit 2 Subgroups 176 Cl,Al,SAl In Except D-02,M-12
Table 3.3.2: Summary of 6 Additional Step Part-Power Rod Misalignment Cases Analyzed (Sheet 4 of 5)
Peaking Factor %
Increase for Case Burn up Power Cycle Failure Demand Rods Misaligned Additional 6 Steps No.
Mechanism Position F~H FQ 182 BOL 50%
Current A
D at 50, Cat Unit 1 Subgroups a,c 176 Cl,Al,SAl In Except N-13,L-13,M-12 183 BOL 50%
Current A
D at 50, Cat Unit 1 Subgroups 176 C2,A2,SA2 In Except H-10,J-ll 184 BOL 50%
Current A
D at 50, Cat Unit 2 Subgroups 176 D2,B2,SB2 In Except P-10,N-09 185 MOL 50%
Current A
D at 50, Cat Unit 1 Subgroups 176 Cl,Al,SAl In Except N-13,L-13,M-12 186 MOL 50%
Current A
D at 50, Cat Unit 1 Subgroups 176 C2,A2,SA2 in Except H-10,J-11 187 MOL 50%
Current A
D at 50, Cat Unit 2 Subgroups 176 D2,B2,SB2 In Except P-10,N-09
w 00
- Table 3.3.2: Summary of 6 Additional Step Part-Power Rod Misalignment Cases Analyzed (Sheet S of 5)
Peaking Factor %
Increase for Case Burnup Power Cycle Failure Demand Rods Misaligned Additional 6 Steps No.
Mechanism Position F.!lH FQ 188 EOL 50%
Current A
D at 50, Cat Unit 1 Subgroups a,c 176 Cl,Al,SAl In Except N-13,L-13,M-12 189 EOL 50%
Current A
D at 50, Cat Unit 1 Subgroups 176 C2,A2,SA2 In Except H-10,J-11 190 EOL 50%
Current A
D at 50, Cat Unit 2 Subgroups 176 D2,B2,SB2 In Except P-10,N-09
Table 3.3.3: Summary of 3 Additional Step Rod Misalignment Cases Analyzed (Sheet 1 of 3)
Peaking Factor %
Increase for Case Burnup Power Cycle Failure Demand Rods Misaligned Additional 3 Steps No.
Mechanism Position F.1H FQ 191 BOL HFP Current A
D at 170 Unit 2 Subgroups a,c D2,B2,SB2 In Except P-10,N-09 192 MOL HFP Current A
D at 170 Unit 2 Subgroups D2,B2,SB2 In Except P-10,N-09 193 EOL HFP Current A
D at 170 Unit 2 Subgroups D2,B2,SB2 In Except P-10,N-09 194 BOL HFP Current A
ARO at222 Unit 2 Subgroups D2,B2,SB2 In Except P-10,N-09 195 MOL HFP Current A
ARO at222 Unit 2 Subgroups D2,B2,SB2 In Except P-10,N-09 196 EOL HFP Current A
ARO at222 Unit 2 Subgroups D2,B2,SB2 In Except P-10,N-09
Table 3.3.3: Summary of 3 Additional Step Rod Misalignment Cases Analyzed (Sheet 2 of 3)
Peaking Factor %
Increase for Case Burn up Power Cycle Failure Demand Rods Misaligned Additional 3 Steps No.
Mechanism Position F~H FQ 197 BOL HFP Current E
D at 170 Subgroup D2 Out, a,c Unit 2 Subgroup B2 In 198 MOL HFP Current E
D at 170 Subgroup D2 Out, Unit 2 Subgroup B2 In 199 EOL HFP Current E
D at 170 Subgroup D2 Out, Unit 2 Subgroup B2 In 200 BOL HFP Future A
ARO at224 K-02,P-10,H-08 In 201 EOL HFP Future A
ARO at224 K-02,P-10,H-08 In 202 BOL HFP Future A
ARO at222 Unit 2 Subgroups D2,B2,SB2 In Except B-06,C-07 203 EOL HFP Future A
ARO at222 Unit 2 Subgroups D2,B2,SB2 In Except B-06,C-07 204 BOL HFP Future D
D at 170 K-02 Out 205 EOL HFP Future D
D at 170 K-02 Out
Table 3.3.3: Summary of 3 Additional Step Rod Misalignment Cases Analyzed (Sheet 3 of 3)
Peaking Factor %
Increase for Case Burn up Power Cycle Failure Demand Rods Misaligned Additional 3 Steps No.
Mechanism Position FL'lH FQ 206 BOL HFP Future E
D at 170 Subgroup Dl Out, a,c Unit 1 Subgroup B 1 In 207 EOL HFP Future E
D at 170 Subgroup Dl Out, Unit 1 Subgroup B 1 In
WESTINGHOUSE NON-PROPRIETARY CLASS 3 4.0 SAFETY ANALYSIS IMPACTS Section 3 discussed the effects of increased misalignment on the normal operation peaking factors.
This section will address the effects on safety analysis inputs used for the reload safety evaluation.
An increase in rod misalignment does not have a significant impact on any of the moderator or Doppler reactivity coefficients or defects, nor on the reactor kinetics data. An increase in the rod misalignment also will not adversely affect the boron worths or data generated for the evaluation of boron dilution nor the boron system duty.
Analyses of Condition II transients such as rod out of position, dropped rod and single rod withdrawal assume an initial condition of either all rods out (ARO) or rods at the insertion limit (RIL) and are based on the motion of a control rod or control bank. These are considered fully misaligned rod transients caused by a single failure of the rod control system.
Thus, the proposed changes to the rod misalignment Tech Spec do not have an adverse impact on the safety analysis inputs for these accidents, or the DNB analysis results.
A possible impact of the increase in the rod misalignment is an increase in the rod insertion allowance (RIA), the worth of the rods at their insertion limits or RIL's. The RIA has a direct impact on the available trip reactivity and the shutdown margin (SDM) assumed in several transient analyses including steamline break. The maximum effect on the RIA would be caused by a misalignment of all of the RIL rods inward by an additional 6 steps. This was examined at HFP, HZP and part-power conditions for both of the cycles listed in Table 3.1 and the maximum increase in the RIA was found to be [
]a,c. For application of this Technical Specification change, the RIA calculated as pait of the reload safety evaluation must be conservatively increased by [
p,c to account for an additional 6 step misalignment if a cycle-specific calculation is not performed. This bounding value is
[
]a,c larger than the maximum calculated value.
Condition Ill and IV events which assume Condition I initial power distributions skewed to the peaking factor limits or assume the highest rod fully misaligned out of the core are not impacted. Other safety analyses inputs that would be affected by an increase in the allowable misalignment are the rod ejection FQ, ejected rod worth ~PEJ and the available trip worth following a rod ejection.
The rod ejection parameters can be affected by an increased rod misalignment in two ways:
a misalignment of any number of RIL rods during the last 30 effective full power days (EFPD) of the rodded depletion; or a misalignment of the RIL rods at HZP prior to the ejection. For the first scenario, only the last 30 EFPD of the rodded depletion are assumed to have a misalignment, since flux maps are required every 30 EFPD and any significant misalignment would be detected and corrected. For both scenarios, misalignments of individual rods, bank groups and entire banks were considered to determine the limiting effects on FQ and ~PEJ* Calculations were also performed for both cycles described in Section 3. Results of these calculations show for an additional 6 steps of rod misalignment maximum increases of [
]a,c in FQ and [
]a,c in ~PEJ* For application of this Technical Specification change, the FQ and ~PEJ calculated as part of the safety evaluation must be increased by factors of 1.085 and 1.065, respectively, to account for an additional 6 step misalignment if a cycle-specific analysis is not performed.
42
WESTINGHOUSE NON-PROPRIETARY CLASS 3 The safety analysis of the rod ejection transient also assumes a certain amount of available trip worth following the rod ejection. Since the ejected rod is assumed to damage a neighboring RCCA drive housing, the trip worth for this transient is defined as the change in core reactivity between the HZP, RIL condition and the HZP, all rods inserted (ARI) minus the ejected rod and the neighboring rod. For this part of the rod ejection transient, the limiting misalignment will be the deeper insertion of all control banks C and B (recall from Figure 3.3 that the HZP RILs permit control bank D to be fully inserted). Thus, for inserting control banks C and B an additional 6 steps, the calculated available trip worth must be decreased by 100 pcm before comparing to the value assumed in the safety analysis.
This value was chosen to bound future analyses based on the calculated values of [
p,c for the future cycle model and [
]a,c for the current cycle model.
43
WESTINGHOUSE NON-PROPRIETARY CLASS 3
5.0 CONCLUSION
S An extension of the allowable indicated rod misalignment of +/-12 steps to +/-18 steps may be permitted as long as it is demonstrated that sufficient peaking factor margin is available. To increase the allowable indicated misalignment by 6 steps for operation above 85% of rated thermal power, 3.5% FQ or Fxy margin and 2.0% F LlH margin must be available. The amount of required margin is also linearly dependent upon the amount of additional misalignment desired, as shown in Figure 3-4. Indicated misalignments of up to 18 steps are also permitted for all powers below 85 % of rated thermal power.
The analysis documented in this report has been performed such that the above mentioned excess peaking factor margin required for additional indicated rod misalignment is cycle independent for Salem Units 1and2.
The analysis documented in this report is conservative and appropriate based on the following assumptions on rod insertion:
- The rod insertion limits (RILs) shown in Figure 3-3 determine the maximum bank demand position as a function of core power;
- The all rods out (ARO) position can be as deep as 222 steps withdrawn.
The results of this report are also conservative and appropriate for any future change in the RILs that would reduce the maximum allowable rod insertion and for any ARO position above 222 steps withdrawn. Any future change to the RILs or the ARO position that would permit deeper rod insertion would also require an evaluation of the results of this report.
As part of the reload specific safety evaluation, design calculations will include the following additional conservatisms, if a cycle-specific analysis is not performed, to bound an additional 6 steps of rod misalignment any time during the cycle:
44
- The calculated ejected rod worth, ApEJ, will be multiplied by 1.065 as part of the uncertainty rack-up.
- The calculated ejected rod peak, FQ,EJ* will be multiplied by 1.085 as part of the uncertainty rack-up.
- The available trip worth following an ejected rod ApEJ, will be reduced by 100 pcm as part of the calculation procedure.
- The calculated RIA used in reload safety evaluations will be increased by 120 pcm as part of the calculation procedure.
WESTINGHOUSE NON-PROPRIETARY CLASS 3 REFERENCES
- 1. Shopsky, W. E., Failure Mode and Effects Analysis (FMEA) of the Solid State Full Length Rod Control System, WCAP-8976, Rev. 0 (Non-Proprietary Class 3), August 1977.
- 2. Baker, T., et. al., Rod Control System Evaluation Program, WCAP-13864, Revision 1-A (Non-Proprietary Class 3), November 1994.
- 3. Nguyen, T. Q., et. al., Qualification of the PHOENIX-PIANC Nuclear Design System for Pressurized Water Reactor Cores, WCAP-11596-P-A (Westinghouse Proprietary), June 1988.
- 4. Liu, Y. S., et. al., ANC: A Westinghouse Advanced Nodal Computer Code, WCAP-10965-P-A (Westinghouse Proprietary), December 1985.
- 5. Morita, T. et. al., Topical Report-Power Distribution Control and Load Following Procedures, WCAP-8385 (Westinghouse Proprietary), September 1974.
- 6. Miller, R. W. et. al., Relaxation of Constant Axial Offset Control - FQ Surveillance Technical Specification, WCAP-10216-P-A, Revision 1, February 1994.
45
WESTINGHOUSE NON-PROPRIETARY CLASS 3 APPENDIX This section provides some additional detail to the cases highlighted in Table 3.3.1. These cases yielded the limiting increase in F ~8, FQ or both. The following figures provide the misaligned peaking factors compared to the reference non-misaligned case, and the percent differences between the 24 and 30 step misalignments. Data in these figures are provided as a function of axial offset, covering the maximum expected HFP range for the Salem units. The data summarized in Table 3.3.1 represents the maximum point from these figures.
46
t
)
WESTINGHOUSE NON-PROPRIETARY CLASS 3 Figure A.1 a,c 47
WESTINGHOUSE NON-PROPRIETARY CLASS 3 J
l Figure A.2 a,c 48
t I
I
- +
WESTINGHOUSE NON-PROPRIETARY CLASS 3 Figure A.3 a,c 49
WESTINGHOUSE NON-PROPRIETARY CLASS 3
- ~
Figure A.4 a,c 50
WESTINGHOUSE NON-PROPRIETARY CLASS 3 Figure A.S a,c 51
WESTINGHOUSE NON-PROPRIETARY CLASS 3 Figure A.6 a,c 52
it. '.
WESTINGHOUSE NON-PROPRIETARY CLASS 3 Figure A.7 a,c 53
~ ----
WESTINGHOUSE NON-PROPRIETARY CLASS 3
- ~
4 t'<
Figure A.8 a,c 54