ML082050462
| ML082050462 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 07/18/2008 |
| From: | Tennessee Valley Authority |
| To: | Division of Operating Reactor Licensing |
| Brown Eva, NRR/DORL, 415-2315 | |
| Shared Package | |
| ML082050419 | List: |
| References | |
| TAC MD5262, TAC MD5263 | |
| Download: ML082050462 (49) | |
Text
TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT Extended Power Uprate Steam Dryers July 18, 2008
Non-Proprietary Version IM Agenda
- Mitigation
- Stress Margin Improvement
- Noise Removal
" Hydrodynamic Damping
- Unit 3
- Schedule 2
Non-Proprietary Version Mitigation Two sources of potential acoustic resonance 218 Hz from blank standpipes in flow stream 109 Hz from SRVs in flow stream Modifications are planned to mitigate resonances
- -Acoustic Vibration Suppressors (AVS) for blank standpipes Acoustic Side Branches (ASB) for SRVs Dryer loading during power ascension will follow pV2 3
Non-Proprietary Version Mitigation - AVS I
- Acoustic Vibration Suppressors Address 218 Hz associated with blind flange standpipes in flow stream Unit 3 strain gage data show elimination of resonance Unit 3 accelerometer data show elimination of resonance 4
Non-Proprietary Version Mitigation - AVS Im CLTP Strain Gage Plant Data Browns Fenyr: MSL A Upper (Channel 1)
Browns Fenyr: MSL A Lower (Channel 5)
N-=
°,
N*
=*
1 0.1 0.01 0.00 1 0.0001 10 0.1 0.01 0.001 0.0001 10-s N=*
e, 50 100 150 200 Frequency (Hz)
Browns Ferry: MSL A Upper (Channel 4)
I 0.1 0.01 0.001 0.0001 10-5 0.1 0.01 0.001 0.0001 i0-5 0
so 100 150 200 Frequency (Hz)
Browns Ferry: MSL A Lower (Channel 8) 250
].
u C-.
N----
0 50 100 150 Frequency (Hz) 200 250 0
50 100 150 Frequency (Hz) 200 250 5
Non-Proprietary Version Mitigation - AVS Im CLTP Strain Browns Ferry: MSL B Lower (Channel 13)
Gage Plant Data N
C-C')
N Cl-o 0
C')
0.1 0.01 0.001 0.0001 10-5 1
0.1 0.01 0.00 1 0.0001 10-5 i.
. i B F.
3 V')
1 0.1 0.01 0.00 1 0.0001 10-5 0 Browns Ferry: MSL B Lower (Channel 15)
T I
I I
I I
I I
I I
II I
I I
I I
I I
,r
~~- -- - --
--N-0 50 100 150 200 Frequency (Hz)
Browns Fenry: MSL B Lower (Channel 14) 250 k-50 100 150 200 Frequency (Hz)
Browns Ferry: MSL B Lower (Channel 16) 250 CL
-n 1
0.1 0.01 0.001 0.0001 10-5
__B FN3
- -- --- -- -- -I -- ---- --- --I - -- -- -- -- -- -- -- -
0 50 100 150 Frequency (Hz) 200 250 0
50 100 150 Frequency (Hz) 200 250 6
Non-Proprietary Version Mitigation - AVS Im I
CLTP Strain Gage Plant Data Browns Ferry: MSL C Lower (Chamlel 24)
N N
C-r 1
0.1 0.01 0.001 0.000 1 10.5 1
0,I 0.1 0.01 0.001 0.0001 I0-5 I
i i -- -----i 0
50 100 150 200 Frequency (Hz)
Browns Fenyr: MSL D Lower (Channel 30) m 50 50 0
50 100 150 Frequency (Hz) 200 2:
7
Non-Proprietary Version Mitigation - AVS Unit 3 CLTP Accelerometer Plant Data 3-PCV 1-4 Y Vibration Trend Comparison (Before and After AVS) 10Before AVS After AVS 0.5 0 40
.4.
0.3 5 0.35...
S0.25 --------------------------
S0.2
-L-t--
L-I 0.1 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 Steam Flow (mlblhr) 8
Non-Proprietary Version Mitigation - AVS IM Unit 3 CLTP Accelerometer Plant Data PCV 1-4Y Spectrum Before (Blue) and After (Red) AVS for MSL A Flow = 3.4 mlb/hr 0.2 0.15 0
0.1 0.05 0
0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Hertz 9
Non-Proprietary Version Mitigation - ASB Acoustic Side Branches All 9 SRVs in flow stream Installation to preclude SRV resonance at increased power levels 0 - 109 Hz o Onset at 102% CLTP o Peak at 195% CLTP o Determined by 1/5 SMT ASB same as QC o 24" long - 100.5 Hz first mode o Eliminates SRV resonance o No additional frequencies created 1/8 SMT for Unit 2 was performed to demonstrate ASB effectiveness SRV frequency eliminated - no new frequency created o BFN 1/8 scale test results
" QC in plant results 10
Non-Proprietary Version Mitigation - ASB Im 1/8 SMT Results at CLTP BFN2: CLTP, MSL D Upper
'N 0Z Nq
'-I 0.01 0.001 0.0001 10.5 106 10-7 0
50 100 150 200 Frequency (Hz) 250 11
Non-Proprietary Version Mitigation -ASB Im 1/8 SMVT Results at EPU BFN2: EPU, MSL D Upper N
N Iz 0.01 0.001 0.0001 10-5 10.6 10.
7 0
50 100 150 200 Frequency (Hz) 250 12
Non-Proprietary Version Mitigation - ASB N
1/8 SMT Results at SRV BFN2 Resonance Frequency BFN2 N
N 0*z LN
=
N*
Cu 0
3 10.5 2.5 10.
5 2 10.5 1.5 10.5 1 10.5 5 10° 0
0.0 3 10.5 2.5 10.5 2 10' 1.5 10s5 1 10.5 510 0
0.0 A Upper: without ASBs A Upper: with ASBs
°-
- 0. 0 0
N N
0 7
Illlllllllllllllllllllll 0.08 0.09 0.1 Mach Number BFN2 0.11 0.12 3 10s 2.5 10s 2 10 1.5 105 1 10 "S 5 10.6 0
0.0 3 10s 2.5 10-5 2 10.5 1.5 10.5 1 10s 5 10.6
. I S B Upper: without ASBs S
B Upper: with ASBs s,-
dP; 0.08--
0.09--
0.1--0.11----
S.
iI 06 7
0.08 0.09 0.1 0.11 0.1."
Mach Number BFN2 k.
A Lower: without ASBs A Lower: with ASBs
- ,.o i
im l
S N
N 0
S B Lower: without ASBs........................-.....
S B Lower: with ASBs S
t us S
E0 7
0.08 U-0.09 0.1 0.11 0.12 0.07 0.0 Mach Number Mach Numbers: 0.087 (CLTP) & 0.1 (EPU)
SRVs in MSL flow stream: A=3, B=2, C=1, D=3
)8 0.09 0.1 Mach Number 0.11 0.12 13
Non-Proprietary Version Mitigation - ASB Im 1/8 SMT Results at SRV Resonance Frequency BFN')
BFN2 BFN2 Nt NI
-o 0) z 3 10-5 2.5 10-5 2105 1.5 10 1 10-5 5 10 00.07 3 105 2.5 10-5 2 10.
5 1.5 10-5 1 10-5 106 0
0.07 m
C Upper: without ASBs C Upper: with ASBs t...
40 0
see:
O S
N N
0z 0.08 0.09 0.1 Mach Number BFN2 0.11 0.12 3 10-5 2.5 10 5 2 105 1.5 10.5 1 10.5 5 10.6 0
0.0 3 10-5 2.5 10' 2 10-5 1.5 10s 1 10-5 5 106 n
7 DUpper: without ASBs D Upper: with ASBs 6
0 o-.......-
0@0 0.9 01 0.08 0.09 0.1 Mach Number BFN2 0.11 0.12 C Lower: without ASBs C Lower:with ASBs N
N
- D Lower: without ASBs D lower: with ASBs AI.
1 i,
0.08 0.09 0.1 0.11 0.12 0.07 0.08 Mach Number Mach Numbers: 0.087 (CLTP) & 0.1 (EPU)
SRVs in MSL flow stream: A=3, B=2, C=1, D=3 0.09 0.1 Mach Number 0.11 0.12 14
Non-Proprietary Version Mitigation - ASB Quad Cities Experience 02RI8 kcelerorneter Trends Target Rock Inlet Flange - X 04 0-35 0.3 0-25 o
0-2 o 0.15 0.1 0.05 0
0 500 1000 1500 2000 2500 Core Thermal Power, MWt 3000 15
Non-Proprietary Version Mitigation - ASB Im Quad Cities Experience Quad Cities Unit 2 Strain Gage Spectra Main Steam Une "A Upper Location 2 500E-01 2.OOOE-01 2
& 1.500E-01 C.
- 1MOOE-O1 51000E-02 O.OOOE+O0 0
20 40 60 80 100 120 140 160 180 200 Frequency, Hz 16
Non-Proprietary Version Stress Margin Improvement IM
- Presented margin discussion during April 17 meeting Common understanding of margin expectation o SR-a > 2.0 at EPU; SR-a > 2.7 at CLTP for BFN Review of limiting locations (SR-a < 2.7)
Grouped locations by "families" o Tie bar; steam dam; hood support; drain channels Dryer modifications Sub-structure models 17
Non-Proprietary Version Stress Margin Improvement
" Mitigation of potential acoustic resonances AVSs &ASBs
- Dryer modifications identified Tie bar families Steam dam families
- Sub-structure modeling incorporated Hood support families Drain channel families Stress margin improved to > 2.7 at CLTP conditions Unit 1 SR-a = 2.91 Unit 2 SR-a = 2.81 18
Non-Proprietary Version JRAJ Stress Margin Improvement Unit 1 Limiting Locations at CLTP Location Node SR-P SR-a
% Freq Shift
- 1. Submerged Drain Channel/Skirt 98860 3.1 2.91 7.5
- 2. Remaining tie bar (outer hood)/tie bar base 132385 4.47 3.23 0
- 3. Mid Bottom Perf. Plate Exit/Mid Top Perf. Plate Exit/Tie Bar 106852 6.89 3.24 7.5
- 4. Outer Hood/Hood Mod/Mod Base/Channel Cap 111407 7
3.29 7.5
- 5. Top Cover Middle Hood/Outer Closure Plate/Middle Hood 90897 2.41 3.34 10
- 6. Submerged Drain Channel/Skirt 98156 4.24 3.34 10
- 7. Middle Cover Plate/Hood Support/Inner Hood 104843 2.55 3.44 7.5 19
Non-Proprietary Version Margin Improvement iM Stress Unit 1 Limiting Locations SR-a (weld) 4.9 47 4.5 4,3 4.1 3.9 3,7 3.5 3.3 3.1 2.9 20
Non-Proprietary Version Margin Improvement Stress Unit 1 Limiting Locations 21
Non-Proprietary Version Margin Improvement Stress Unit 1 Limiting Locations jZ SR-a (weld) 4.9 4.7 4.5 4.3 4.1 3.9 3.7 3.5 3.3 3.1 2.9 22
Non-Proprietary Version Stress Margin Improvement Unit 2 Limiting Locations IM Location Node SR-P SR-a
% Freq Shift
- 1. Outer Side PanelNane Bank ThinNane Bank Thick/Outer End 102701 5.27 2.81 7.5 Wall - with ASBs installed
- 2. Outer End Wall Ext/Outer End Wall - with ASBs installed 103411 5.48 3.02 7.5
- 3. Middle Cover Plate/Hood Support/Middle Hood 97294 4.04 2.82 5
- 4. Dam Plate/New Gusset 101769 6.14 2.83 2.5
- 5. Outer Hood/Outer End Wall 103405 5.47 2.84 7.5
- 6. Outer Hood/Gusset Pad Thin/Top Cover Outer Hood 108730 2.58 2.89-
-5
- 7. Top Cover Middle Hood/Outer Closure Plate/Middle Hood 97204 3.17 2.92 10
- 8. Submerged Drain Channel/Skirt 110570 2.53 2.95 10
- 9. Outer Hood/Top Cover Outer Hood 108710 6.44 2.95
-5
- 10. Top Cover Middle Hood/Middle Hood/Shell Tie Bar 107158 3.05 2.96
-5
- 11. Submerged Drain Channel/Skirt 104115 5.2 3
10 23
Non-Proprietary Version Margin Improvement Stress Unit 2 Limiting Locations z
SR-rn (weld) 4 3.9 3.8 3.7 3.6 3.5 3.4 3.3 3.2 3.1
-3 2.9 2.8 2.7 2.6 2.5 24
Non-Proprietary Version Stress Margin Improvement Unit 2 Limiting Locations SR-a (weld) 9 4
3,9 3.8 3.7 3.6 3.5 3.4 3.3 3.2 3.1 3
2.9 2.8 2.7 2.6 2.5 25
Non-Proprietary Version Margin Improvement Stress Unit 2 Limiting Locations x
SR-a (weld) 4 3.9 3.8 3.7 3.8 3.5 3.4 3.3 3.2 3.1 3
2.9 2.81 2.7 2.6 2.5 26
Non-Proprietary Version Stress Margin Improvement
[ju Dryer Modifications
" New tie bar designs
- Steam dam gussets with pads
- Reinforcement of the outer hood cover (Unit 2 only) 27
Non-Proprietary Version Stress Margin Improvement JRAJ Dryer Modifications Units I & 2 Flared & tapered tie bar Unit 2 Flared & tapered tie bar with hood lock outer vane bank discharge 4 1ý 28
Non-Proprietary Version Stress Margin Improvement RW Dryer Modifications Unit 1 Steam dam gussets Unit 2 Steam dam gussets and reinforcement of the outer hood cover Steam Darn Steam Darn Vane Bank Cover-Existing End Gussets.
29
Non-Proprietary Version Stress Margin Improvement Sub-Structure Modeling Sub-Structure modeling applied to more accurately capture local geometry and weld configuration Applied To:
Drain channel to skirt joint at bottom of channel Middle cover plate/hood support/inner hood joint 30
Non-Proprietary Version Margin Improvement Stress Sub-Structure Modeling 4-Step Process
- 1. Develop a shell sub-model with appropriate boundary conditions to recreate the stresses from the CDI model
- 2.
Develop a much more detailed solid model with the same boundary conditions to more accurately represent joint configurations and stress variations
- 3.
Use the results of the solid model analysis to linearize stresses along various paths through the welds
- 4.
Determine the stress correction factor between the shell model and the solid model 31
Non-Proprietary Version Stress Margin Improvement Sub-Structure Modeling
- Linearization process produces stresses consistent with the ASME Code approach for calculation of membrane (Prn) membrane + bending (Pm + Pb) stresses
- The CDI results are modified by the stress correction factors between the shell model and the solid model 0.58 for the drain channel to skirt joint 0.79 for the middle cover plate/hood support/inner hood joint
- 1.8 weld factor is retained 32
Non-Proprietary Version Stress Margin Improvement im Sub-Structure Modeling - Stiffener Shell model Solid model 1..J3 218.
! 71*.1.3-t F~rry 'St~ri o
=
33
Non-Proprietary Version Stress Margin Improvement Sub-Structure Modeling - Drain Channel Shell model Solid model 34
Non-Proprietary Version IRAI Stress Margin Improvement Sub-Structure Modeling - Drain Channel Stress Paths MN 3,-
6 w\\
P12 2,-
7 8
7 1
7 35
Non-Proprietary Version Noise Removal Significant signal magnitude at zero or low flow Translates into fictitious dryer load Noise floor data taken at low steam flow Unit 1 data at 9%
Unit 2 data at 19%
Small steam flow needed for pressure regulation Unit 2 data lowest available Average noise at each frequency subtracted Limited to 3dB (factor of 2) signal reduction P(f) = Po(f)*max 0.51 -*
-f-*
36
Non-Proprietary Version Noise Removal im
- Low flow noise floor represents non-flow signal component Noise = component of measurement not related to flow Po+P 1Q+P 2Q2 Noise floor bounds Po term MSL A Lower, 61.502 Hz CL E
C
.mL_
0 0) 0 0*
U-2n3 W)
M) 0)
a_
180 160 140 120 100 80 60 40 0
Data Quadrati 20
-20 0
20 40 60 Power [ % ]
80 100 120 37
Non-Proprietary Version IM Noise Removal PSD Comparisons BFN1: MSL AUpper 0.1 N
0.01 0.001 0.0001 10-5 0
50 100 150 200 Frequency (Hz) 250 38
Non-Proprietary Version Noise Removal PSD Comparisons BFN2: MSL A Upper 0.1 0.01 CLTP N
19% Power 0.001 0.0001 10-6 0
50 100 150 200 250 Frequency (Hz) 39
Non-Proprietary Version IM Noise Removal Unit 1 Monopole - MSL A 0.001 0.0001 N
Iý CO 0L 10i 10-i0o7' S0-8 0
50 100 150 200 250 Frequency [ Hz ]
40
Non-Proprietary Version M
Noise Removal Unit 1 Dipole - MSL A 0.01 0.001 0.0001 N
Iý w.'
CL 0-5 o
10-10o7 10-0 10 20 30 40 50 60 70 Frequency [ Hz ]
41
Non-Proprietary Version Noise Removal CL E
C 0
A 0
T)
U) 0L 180 160 140 120 100 80 60 40 20 0
MSL A Lower, 61.502 Hz T
I oDataR Qudai F!
Unit 1 Quadr 703 (D
600 40(
CS 00 "a
400 0
LL 20 0
MSL B Upper, 12.732 Hz 0
j Datal 0
- Q artcFit 2
0 i 20 4
0 s
-20 0
20 40 60 80 100 120 3tic Fit
/
I__
-20 0
20 40 60 Power [%]"
80 100 120 120 Power [%]
MSL B Lower, 107 Hz T
1 L
Data 00 0
U.
0.
100 -
80 O:
60 k 0O 40 -
20
-20 0
20 40 60 80 100 120 Power [%]
42
Non-Proprietary Version Noise Removal Unit 1 Quadratic Fit 55 MSL C Upper, 167.40 Hz T
MSL D Upper, 46.549 Hz 160 01 E
0.*0 0
8 En 50 0
Data Quadratic Filt 0
45 C0 E
C 0
0LL En 120 k-140 k 0o oData I -
Quadati FIR 100 k 80 40 V 60 F 35 0
40 1 I
I 30
-20 20 0
20 40 60 Power [%1 80 100 120
-20 0
20 40 60 80 100 120 MSL C Lower, 34.351 Hz T
-I Power [%]
MSL D Lower at 226.1 Hz I
~
_T 500 100 0
0 C
0) 4J) 0 0
Li-T Mn 400 F 0
Data Q
uadraticFt
-0; 300 k
'a
(.
00 8
0 CS 0LL U.
En 80 k 60 k S.....I..
_0 0u d a i 0i 0...
200 40 F 10oo 20 0
-20 0
20 40 60 Power [%]
80 0
-20 100 120 0
20 40 60 80 100 120 Power [%]
43
Non-Proprietary Version Noise Removal 11VA1 Unit 1 Limiting Nodes Noise Removal Location Node SR-a SR-a (Noise (Noise Removed)
Retained)
- 1. Submerged Drain Channel/Skirt 98860 2.91 2.29
- 2. Remaining tie bar (outer hood)/tie bar base 132385 3.23 2.06
- 3. Mid Bottom Perf. Plate Exit/Mid Top Perf. Plate Exit/Tie Bar 106852 3.24 2.53
- 4. Outer Hood/Hood Mod/Mod Base/Channel Cap 111407 3.29 2.74
- 5. Top Cover Middle Hood/Outer Closure Plate/Middle Hood 90897 3.34 2.50
- 6. Submerged Drain Channel/Skirt 98156 3.34 2.69
- 7. Middle Cover Plate/Hood Support/Inner Hood 104843 3.44 2.54 44
Non-Proprietary Version
((
45 45
Non-Proprietary Version II 46
Non-Proprietary Version Unit 3 Original plan to perform Unit 3 stress analysis at CLTP in June 08 Installed 64 main steam line strain gages during Spring refueling outage All but 10 strain gages failed during primary system heatup Remaining operable strain gages are not sufficient to perform stress analysis on Unit 3
- Repair of strain gages at next planned outage of sufficient duration May be Spring 2010 EPU outage Preparations being made for earlier opportunity 47
Non-Proprietary Version Unit 3 TVA seeking approval of all three Units for EPU prior to completing Unit 3 stress analysis
° Unit 1 and 2 analysis experience provides confidence that Unit 3 analysis will be successful Unit 2 and Unit 3 steam dryers are of same design Units 1, 2, and 3 steam systems are similar Available Unit 3 strain gage data indicates load will be similar to Unit 1 o 10 locations on Unit 3 compared with Unit 1 o No new peaks identified o Spectrum and magnitude of signals comparable to Unit 1 License Condition to take data and perform stress analysis Same methods and assumptions as Units 1 and 2 NRC approval prior to exceeding CLTP 48
Non-Proprietary Version Schedule IM Item Date NRC issue RAI-18 (AREVA Fuels) 7/21/2008 NRC issue RAI on Steam Dryers 7/2008 TVA response to RAI on Steam Dryers 8/2008 TVA response to RAI-1 8 (AREVA Fuels) 9/16/2008 ACRS Subcommittee meeting 11/19-20/2008 ACRS meeting 12/4-6/2008 NRC issue EPU Amendment for Units 1, 2, and 3 1/2009 Unit 1 implement EPU 1/2009 Unit 2 implement EPU Spring 2009 Unit 3 Spring 2010
- Repair strain gages
" Perform stress analysis
" NRC approval of stress analysis
- Implement EPU 49