ML060170269: Difference between revisions

From kanterella
Jump to navigation Jump to search
(Created page by program invented by StriderTol)
 
(StriderTol Bot change)
 
(3 intermediate revisions by the same user not shown)
Line 2: Line 2:
| number = ML060170269
| number = ML060170269
| issue date = 12/13/2005
| issue date = 12/13/2005
| title = BWROG Non-proprietary Slides. GE Presentation Regarding Decay Ratio Adder Removal for BWROG Stability Solution Options I-D and Ii
| title = BWROG Non-proprietary Slides. GE Presentation Regarding Decay Ratio Adder Removal for BWROG Stability Solution Options I-D and II
| author name =  
| author name =  
| author affiliation = General Electric Co
| author affiliation = General Electric Co
Line 9: Line 9:
| docket = 05000341, PROJ0691
| docket = 05000341, PROJ0691
| license number = NPF-043
| license number = NPF-043
| contact person = Honcharik M C, NRR/DPR/PSPB, 301-415-177
| contact person = Honcharik M, NRR/DPR/PSPB, 301-415-177
| case reference number = BWROG-05032, TAC MC8714
| case reference number = BWROG-05032, TAC MC8714
| package number = ML060240100
| package number = ML060240100
Line 19: Line 19:


=Text=
=Text=
{{#Wiki_filter:BWROG-05032 Enclosure 2 GE Presentation Regarding Decay Ratio Adder Removal for BWROG Stability Solution Options I-D and II Redacted and Non-Proprietary Information Decay Ratio Adder Removal Option I-D/Il Exclusion Region Licensing Methodology Presentation to NRC-Closed Session December 13, 2005 imagination at work 1/DR Adder Removal NRC Presentation
{{#Wiki_filter:BWROG-05032 Enclosure 2 GE Presentation Regarding Decay Ratio Adder Removal for BWROG Stability Solution Options I-D and II Redacted and Non-Proprietary Information
/12/13/2005 Agenda* Purpose* Background
* Proposal* Recent Instability Events* Justification to Remove 0.15 DR Adder* Demonstration Analysis-* Summary of ODYSY LTR Changes* Conclusion imagination at work 2/DR Adder Removal NRC Presentation I 12/13/2005 Pu rpose* Provide justification for removal of 0.15 core decay ratio adder from Options l-D and 11 exclusion region licensing methodology
* Provide description of proposed changes relative to approved ODYSY LTR imagination at work 3/DR Adder Removal NRC Presentation
/12/13/2005


===Background===
Decay Ratio Adder Removal Option I-D/Il Exclusion Region Licensing Methodology Presentation to NRC - Closed Session December 13, 2005 imagination at work                                               1/
* BWROG Stability Long-Term Solutions (LTS)defined in NEDO-3 1960-Enhanced Option I-A (EIA)-Option l-D-Option 11-Option Ill* LTS must meet GDC-12-Prevent oscillations from occurring, or-Detect & suppress oscillations, or-Both prevent and detect & suppress imagination at work 4/DR Adder Removal NRC Presentation I 12/13/2005  
DR Adder Removal NRC Presentation /
12/13/2005


===Background===
Agenda
* EIA-Prevention solution applicable to all plants-Oscillation prevention provided by analytically determined exclusion, restricted regions protected by automatic scram, rod block (respectively)
* Purpose
-ODYSY approved for region generation and validation in NEDC-32339P Supplement 1* Option Ill-Detect & suppress solution applicable to all plants-Oscillations automatically detected & suppressed by new plant hardware imagination at work 5/DR Adder Removal NRC Presentation/
* Background
12/13/2005  
* Proposal
* Recent Instability Events
* Justification to Remove 0.15 DR Adder
* Demonstration Analysis-
* Summary of ODYSY LTR Changes
* Conclusion imagination at work                                               2/
DR Adder Removal NRC Presentation I 12/13/2005


===Background===
Pu rpose
* Option l-D-Prevention and detect & suppress solution-Applicable to plants with small cores where only core-wide mode oscillations are possible-Existing flow-biased APRM flux scram detects and suppresses core-wide mode oscillations
* Provide justification for removal of 0.15 core decay ratio adder from Options l-D and 11 exclusion region licensing methodology
-Oscillation prevention provided by analytically determined, administratively controlled exclusion region-Buffer region defined outside of exclusion region-Stability monitor required imagination at work 6/DR Adder Removal NRC Presentation  
* Provide description of proposed changes relative to approved ODYSY LTR imagination at work                                                   3/
/12/13/2005  
DR Adder Removal NRC Presentation /
12/13/2005


===Background===
===
* Option I-D Stability Monitor-Stability monitor must be operational to enter Buffer Region-Calculated decay ratios must be below specified stability criterion to operate in Buffer Region-If decay ratios above criterion, immediate exit from Buffer Region required-If inadvertent entry into Buffer Region and stability monitor not operational, immediate exit required-Plants do not normally operate in Buffer Region imagination at work 7/DR Adder Removal NRC Presentation  
Background===
/12/13/2005  
* BWROG Stability Long-Term Solutions (LTS) defined in NEDO-3 1960
  -    Enhanced Option I-A (EIA)
  -  Option l-D
  -    Option 11
  -   Option Ill
* LTS must meet GDC-12
  - Prevent oscillations from occurring, or
  - Detect & suppress oscillations, or
  - Both prevent and detect & suppress imagination at work                                                       4/
DR Adder Removal NRC Presentation I 12/13/2005


===Background===
===
* Option 11-Prevention and detect & suppress solution-Applicable to BWR/2 plants-Existing quadrant based flow-biased APRM flux scram detects and suppresses both core-wide and regional mode oscillations
Background===
-Oscillation prevention provided by analytically determined, administratively controlled exclusion region imagination at work 8/DR Adder Removal NRC Presentation 12/13/2005  
* EIA
  - Prevention solution applicable to all plants
  - Oscillation prevention provided by analytically determined exclusion, restricted regions protected by automatic scram, rod block (respectively)
  - ODYSY approved for region generation and validation in NEDC-32339P Supplement 1
* Option Ill
  - Detect & suppress solution applicable to all plants
  - Oscillations automatically detected & suppressed by new plant hardware imagination at work                                                         5/
DR Adder Removal NRC Presentation/
12/13/2005


===Background===
===
Background===
* Option l-D
  - Prevention and detect & suppress solution
  - Applicable to plants with small cores where only core-wide mode oscillations are possible
  - Existing flow-biased APRM flux scram detects and suppresses core-wide mode oscillations
  - Oscillation prevention provided by analytically determined, administratively controlled exclusion region
  - Buffer region defined outside of exclusion region
  - Stability monitor required imagination at work                                                        6/
DR Adder Removal NRC Presentation /
12/13/2005
 
===
Background===
* Option I-D Stability Monitor
  - Stability monitor must be operational to enter Buffer Region
  - Calculated decay ratios must be below specified stability criterion to operate in Buffer Region
  - If decay ratios above criterion, immediate exit from Buffer Region required
  - If inadvertent entry into Buffer Region and stability monitor not operational, immediate exit required
  - Plants do not normally operate in Buffer Region imagination at work                                                            7/
DR Adder Removal NRC Presentation /
12/13/2005
 
===
Background===
* Option 11
  - Prevention and detect & suppress solution
  - Applicable to BWR/2 plants
  - Existing quadrant based flow-biased APRM flux scram detects and suppresses both core-wide and regional mode oscillations
  - Oscillation prevention provided by analytically determined, administratively controlled exclusion region imagination at work                                                          8/
DR Adder Removal NRC Presentation 12/13/2005
 
===
Background===
* Original (FABLE) exclusion region licensing methodology approved in NEDO-31960
* Original (FABLE) exclusion region licensing methodology approved in NEDO-31960
* ODYSY exclusion region licensing methodology for Options I-D/Il approved in NEDC-32992P
* ODYSY exclusion region licensing methodology for Options I-D/Il approved in NEDC-32992P
* ODYSY methodology includes 0.15 core decay ratio (DR) adder-0.15 is added to the calculated ODYSY core DR to yield a "procedure" core DR-Procedure core DR is compared to 0.80 stability criterion to determine exclusion region boundary-0.15 adder effectively makes stability criterion 0.65 imagination at work 9/DR Adder Removal NRC Presentation  
* ODYSY methodology includes 0.15 core decay ratio (DR) adder
/12/13/2005 Background  
  - 0.15 is added to the calculated ODYSY core DR to yield a "procedure" core DR
-Stability Criteria Map Core Decay Ratio 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Channel Decav Ratio 0.8 0.9 1.0 ()imaginationat work 10/DR Adder Removal NRC Presentation  
  - Procedure core DR is compared to 0.80 stability criterion to determine exclusion region boundary
/12/13/2005  
  - 0.15 adder effectively makes stability criterion 0.65 imagination at work                                                         9/
DR Adder Removal NRC Presentation /
12/13/2005
 
Background                       - Stability Criteria Map 1.0 0.9 0.8 0.7 Core      0.6 Decay Ratio    0.5 0.4 0.3 0.2 0.1 0.0 0.0 0.1 0.2 0.3   0.4 0.5 0.6   0.7 0.8 0.9 1.0 Channel Decav Ratio
()imaginationat work                                                                                10/
DR Adder Removal NRC Presentation /
12/13/2005
 
===
Background===
* ((
* ODYSY LTR did not take credit for methodology improvement to expedite licensing approval imagination at work                                              11/
DR Adder Removal NRC Presentation /
12/13/2005
 
===
Background===
* ODYSY methodology improvements include:
    -rr
                                            ))
imagination at work                                          12 /
DR Adder Removal NRC Presentation /
12/13/2005
 
Proposal
* Option I-D/Il exclusion regions becoming larger due to high energy core designs
  - Affects plant operation
* 0.15 Adder adds unnecessary conservatism to exclusion region methodology for Option I-D/Il
  - Demonstrated by recent instability event analyses and operational experience
* BWROG proposes to remove 0.15 Adder to yield more acceptable regions and avoid unnecessary operational challenge
  - Requires NRC review and approval imagination at work                                                    13/
DR Adder Removal NRC Presentation /
12/13/2005
 
Increasing Exclusion Region Size for representative plant (with 0.15 DR Adder) 100 90                              Cycle 23 80 I-70 0
a.
60 1i 50 40 30 20 10 0
0          10  20 30 40 50      60    70 80      90          100 Core Flow (%)
imagination at work                                                              14/
DR Adder Removal NRC Presentation /
12/13/2005 cv3
 
Recent Instability Events Exclusion and Buffer regions calculated for two plants with recent instability events
* Nine Mile Point 2 - July 24, 2003
  - Recirc pumps downshift and FCV runback
  - Flow reduction: 94% to 28%, power: 100% to 35%
  - FW temperature equilibration raised power to 45%
  - Slow growing oscillations developed
* Perry - December 23, 2004
  -    Recirc pumps downshift
  -    Flow reduction: 99% to 33%, power: 100% to 44%
  -    FW temperature equilibration raised power to 55%
  -  Slow growing oscillations developed C imagination at work                                                      15 /
DR Adder Removal NRC Presentation /
12/13/2005
 
((
                                                          .i imagination at work                                16/
DR Adder Removal NRC Presentation /
12/13/2005
 
[I 17 /
I' imagination at work DR Adder Removal NRC Presentation /
12/13/2005
 
                                                        ))
I imagination at work                                18 /
DR Adder Removal NRC Presentation /
12/13/2005
 
((
                                                        ))
imagination at work                                19/
DR Adder Removal NRC Presentation I 12/13/2005
 
Recent Instability Events
* Exclusion regions calculated with 0.80 DR Criterion (no adder) provide significant margin to power/flow conditions where instability events occurred
* Buffer region adds significant additional margin
* Exclusion regions calculated with 0.65 DR Criterion (0.15 adder) contain excessive margin 0.15 DR Adder excessively conservative for Option I-D/Il exclusion region application imagination at work                                                          20/
DR Adder Removal NRC Presentation /
12/13/2005
 
Justification to Remove 0.15 DR Adder
* For Options l-D and 11, SLMCPR protection provided by flow-biased APRM flux trip
  - Detect and suppress solution element provides direct SLMCPR protection
  - Conservative plant-specific analysis performed each cycle to demonstrate margin to SLMCPR (described in NEDO-32465) imagination at work                                                      21/
DR Adder Removal NRC Presentation /
12/13/2005
 
Justification to Remove 0.15 DR Adder
* Exclusion Region provides additional measure of protection (i.e., defense-in-depth)
  - Prevention solution element provides additional, indirect SLMCPR protection
  - Standard approved ODYSY uncertainty (20%)
applied to evaluation is appropriate and sufficient
  - Events near boundary not anticipated, not significant and unlikely to approach SLMCPR
  - Region generated based on limiting analysis conditions (Haling depletion, longest cycle exposure analyzed, limiting cycle exposure used)
  - Different (larger) exclusion region generated for reduced feedwater temperature operation imagination at work                                                        22/
DR Adder Removal NRC Presentation /
12/13/2005
 
Justification to Remove 0.15 DR Adder
* Exclusion Region conservatism demonstrated by comparison to actual events
* Buffer Region further reduces likelihood of instability for Option I-D plants
* Stability monitor required and operating at all Option l-D plants for additional protection
* Flow-biased APRM flux trip has been lowered for both Option 11plants and several Option l-D plants to offer timely scram in case THI oscillations develop imagination at work                                                23 /
DR Adder Removal NRC Presentation 12/13/2005
 
Justification to Remove 0.15 DR Adder
* ODYSY is best-estimate stability code
    -    ((
    - Significant theoretical improvement over FABLE
* ODYSY used in conservative procedure to produce reasonably limiting exclusion region
    - Protects against reasonably limiting events 0.15 DR Adder excessively conservative for ODYSY exclusion region procedure I  imagination at work                                                            24/
DR Adder Removal NRC Presentation /
12/13/2005
 
Proposed ODYSY Procedure 1 rr 0
2.
0 0
a  imagination at work                                25 /
DR Adder Removal NRC Presentation /
12/13/2005
 
Proposed ODYSY Procedure
: 3. [
4.
0 0
5.
6.
I    imagination at work                                26/
DR Adder Removal NRC Presentation /
12/13/2005
 
Proposed ODYSY Procedure
*E[
27/
imagination at work  DR Adder Removal NRC Presentation I 12/13/2005
 
Demonstration Analysis
* Exclusion regions generated for two new plants and three plants from original ODYSY LTR
  - New: Plant 1, Plant 2
  - Original: Plant 3, Plant 4, Plant 5
* Regions generated with and without DR adder
  - Core DR criterion: 0.80, 0.65
* Regions generated for reduced feedwater temperature for Plant 1
  - Nominal, -30F,-60F
(  imagination at work                                                  28/
DR Adder Removal NRC Presentation 12/13/2005
 
Demonstration Analysis Plant          BWR  Core Core Loading    Cycle    Inlet Type  Size by Fuel Type  Length  Orifice          Original (MWd/ST) Diameter        Licensed (in)            Power 1            4  548  1Ox10 - 100%  12,930  2.22              100.0 2              3  580  10x10 - 81%    13,150  2.21              106.1 9x9- 19%
3            4  560  10x10 - 34%    13,868  2.09              104.1 9x9 - 64%
8x8 - 2%
4            4  368    8x8 - 100%  10,775  2.09              104.1 5            4  368    9x9 - 30%    10,425  2.22              100.0 8x8 - 70%
I imagination at work                                                                    29/
DR Adder Removal NRC Presentation /
1211312005
 
Plant 1 Demonstration Exclusion regions with and without 0.15 DR Adder 100 90 80 I
0  70 CL 0~
60 E
Is  50 40 30 20 10 0
0        10 20 30 40 50      60    70 80    90        100 Core Flow (%)
imagination at work                                                                30/
DR Adder Removal NRC Presentation /
12/13/2005 c 1 4
 
Plant 1 Demonstration
((
imagination at work                                31 /
DR Adder Removal NRC Presentation /
12/13/2005
 
Plant 1 Demonstration Er imagination at work                                32 /
DR Adder Removal NRC Presentation /
12/13/2005
 
Plant 2 Demonstration Exclusion regions with and without 0.15 DR Adder 100-90  -
DR-O 65 80 DR=0.80
          ~70 p~60 o50 40 30 20 10 0    10 20 30 40      50      60    70 80    90        100 Core Flow (%)
imagination at work                                                                      33,/
DR Adder Removal NRC Presentation /
12/13/2005 CIS5
 
Plant 3 Demonstration Exclusion regions with and without 0.15 DR Adder 100                                            A 90 -
80 70 60 10
      *0 50 40 30 20 10 0
0      10 20 30 40 50      60        70 80        90          100 Rated Core Flow (%)
imagination at work                                                                     34 /
DR Adder Removal NRC Presentation /
12/13/2005 C\@
 
Plant 4 Demonstration Exclusion regions with and without 0.15 DR Adder 100.
90 80 70                    DR=0.65 DR=0.80 o    60              D M    50 40 30 20 10 0    10 20    30    40  50      60      70 80      90        100 Rated Core Flow (%)
( EGO imagination at work                                                                            35/
DR Adder Removal NRC Presentation /
12/13/2005 Crl
 
Plant 5 Demonstration Exclusion regions with and without 0.15 DR Adder 100-90- -
80 -                DR=0.65 70 0:
60 50 40 30 20 10 0
0  10 20 30 40  50      60      70  80    90        100 Rated Core Flow (%)
1  imagination at work                                                                    36/
DR Adder Removal NRC Presentation /
12113/2005 Co
 
Demonstration Analysis Conclusions
* Analysis performed for plants of different size, varying exclusion region sizes, 8x8 - lOx1O fuel
* [I imaginationatwork                                                  37 /
DR Adder Removal NRC Presentation /
12/13/2005


===Background===
Summary of ODYSY LTR Changes
* [[* ODYSY LTR did not take credit for methodology improvement to expedite licensing approval imagination at work 11/DR Adder Removal NRC Presentation  
* Removal of 0.15 Core DR Adder
/12/13/2005  
* Removal of comparison to FABLE
    - Outdated and unnecessary to include
* Explicit treatment of feedwater temperature
    - Separate region generated for reduced FW temp
* Addition of recent instability event analysis
* Addition of two new plants (with new fuel/core designs) to demonstration analysis
*E((
imagination at work                                                   38/
DR Adder Removal NRC Presentation /
12/13/2005


===Background===
Conclusions
* ODYSY methodology improvements include:-rr]]imagination at work 12 /DR Adder Removal NRC Presentation
/12/13/2005 Proposal* Option I-D/Il exclusion regions becoming larger due to high energy core designs-Affects plant operation* 0.15 Adder adds unnecessary conservatism to exclusion region methodology for Option I-D/Il-Demonstrated by recent instability event analyses and operational experience
* BWROG proposes to remove 0.15 Adder to yield more acceptable regions and avoid unnecessary operational challenge-Requires NRC review and approval imagination at work 13/DR Adder Removal NRC Presentation
/12/13/2005 Increasing Exclusion Region Size for representative plant (with 0.15 DR Adder)100 90 Cycle 23 I-0 a.1i 80 70 60 50 40 30 20 10 0 0 10 20 30 40 50 60 70 80 90 Core Flow (%)imagination at work DR Adder 100 14/Removal NRC Presentation
/12/13/2005 cv3 Recent Instability Events Exclusion and Buffer regions calculated for two plants with recent instability events* Nine Mile Point 2 -July 24, 2003-Recirc pumps downshift and FCV runback-Flow reduction:
94% to 28%, power: 100% to 35%-FW temperature equilibration raised power to 45%-Slow growing oscillations developed* Perry -December 23, 2004-Recirc pumps downshift-Flow reduction:
99% to 33%, power:-FW temperature equilibration raised-Slow growing oscillations developed C imagination at work 100% to 44%power to 55%15 /DR Adder Removal NRC Presentation
/12/13/2005
[[imagination at work.i 16/DR Adder Removal NRC Presentation
/12/13/2005
[I imagination at work I'17 /DR Adder Removal NRC Presentation
/12/13/2005 I imagination at work]]18 /DR Adder Removal NRC Presentation
/12/13/2005
[[imagination at work]]19/DR Adder Removal NRC Presentation I 12/13/2005 Recent Instability Events* Exclusion regions calculated with 0.80 DR Criterion (no adder) provide significant margin to power/flow conditions where instability events occurred* Buffer region adds significant additional margin* Exclusion regions calculated with 0.65 DR Criterion (0.15 adder) contain excessive margin 0.15 DR Adder excessively conservative for Option I-D/Il exclusion region application imagination at work 20/DR Adder Removal NRC Presentation
/12/13/2005 Justification to Remove 0.15 DR Adder* For Options l-D and 11, SLMCPR protection provided by flow-biased APRM flux trip-Detect and suppress solution element provides direct SLMCPR protection
-Conservative plant-specific analysis performed each cycle to demonstrate margin to SLMCPR (described in NEDO-32465) imagination at work 21/DR Adder Removal NRC Presentation
/12/13/2005 Justification to Remove 0.15 DR Adder* Exclusion Region provides additional measure of protection (i.e., defense-in-depth)
-Prevention solution element provides additional, indirect SLMCPR protection
-Standard approved ODYSY uncertainty (20%)applied to evaluation is appropriate and sufficient
-Events near boundary not anticipated, not significant and unlikely to approach SLMCPR-Region generated based on limiting analysis conditions (Haling depletion, longest cycle exposure analyzed, limiting cycle exposure used)-Different (larger) exclusion region generated for reduced feedwater temperature operation imagination at work 22/DR Adder Removal NRC Presentation
/12/13/2005 Justification to Remove 0.15 DR Adder* Exclusion Region conservatism demonstrated by comparison to actual events* Buffer Region further reduces likelihood of instability for Option I-D plants* Stability monitor required and operating at all Option l-D plants for additional protection
* Flow-biased APRM flux trip has been lowered for both Option 11 plants and several Option l-D plants to offer timely scram in case THI oscillations develop imagination at work 23 /DR Adder Removal NRC Presentation 12/13/2005 Justification to Remove 0.15 DR Adder* ODYSY is best-estimate stability code-[[-Significant theoretical improvement over FABLE* ODYSY used in conservative procedure to produce reasonably limiting exclusion region-Protects against reasonably limiting events 0.15 DR Adder excessively conservative for ODYSY exclusion region procedure I imagination at work 24/DR Adder Removal NRC Presentation
/12/13/2005 Proposed ODYSY Procedure 1 rr 0 2.0 0 a imagination at work 25 /DR Adder Removal NRC Presentation
/12/13/2005 Proposed ODYSY Procedure 3. [4.0 0 5.6.I imagination at work 26/DR Adder Removal NRC Presentation
/12/13/2005 Proposed ODYSY Procedure*E[imagination at work 27/DR Adder Removal NRC Presentation I 12/13/2005 Demonstration Analysis* Exclusion regions generated for two new plants and three plants from original ODYSY LTR-New: Plant 1, Plant 2-Original:
Plant 3, Plant 4, Plant 5* Regions generated with and without DR adder-Core DR criterion:
0.80, 0.65* Regions generated for reduced feedwater temperature for Plant 1-Nominal, -30F,-60F ( imagination at work 28/DR Adder Removal NRC Presentation 12/13/2005 Demonstration Analysis Plant BWR Core Core Loading Cycle Inlet Type Size by Fuel Type Length Orifice Original (MWd/ST) Diameter Licensed (in) Power 1 4 548 1Ox10 -100% 12,930 2.22 100.0 2 3 580 10x10 -81% 13,150 2.21 106.1 9x9- 19%3 4 560 10x10 -34% 13,868 2.09 104.1 9x9 -64%8x8 -2%4 4 368 8x8 -100% 10,775 2.09 104.1 5 4 368 9x9 -30% 10,425 2.22 100.0 8x8 -70%I imagination at work 29/DR Adder Removal NRC Presentation
/1211312005 Plant 1 Demonstration Exclusion regions with and without 0.15 DR Adder 100 90 I 0 0~CL E Is 80 70 60 50 40 30 20 10 0 0 10 20 30 40 50 60 70 80 Core Flow (%)90 100 imagination at work 30/DR Adder Removal NRC Presentation
/12/13/2005 c 1 4 Plant 1 Demonstration
[[imagination at work 31 /DR Adder Removal NRC Presentation
/12/13/2005 Plant 1 Demonstration Er imagination at work 32 /DR Adder Removal NRC Presentation
/12/13/2005 Plant 2 Demonstration Exclusion regions with and without 0.15 DR Adder 100-90 -DR-O 65 80 DR=0.80~70 p~60 o50 40 30 20 10-0 imagination at work 10 20 30 40 50 60 70 80 90 100 Core Flow (%)33,/DR Adder Removal N RC Presentation
/12/13/2005 CIS5 Plant 3 Demonstration Exclusion regions with and without 0.15 DR Adder 100 A 90 -80 10*0 70 60 50 40 30 20 10 0 0 imagination at work 10 20 30 40 50 60 70 80 Rated Core Flow (%)90 100 34 /DR Adder Removal NRC Presentation
/12/13/2005 C\@
Plant 4 Demonstration Exclusion regions with and without 0.15 DR Adder 100.90 80 70 DR=0.65 DR=0.80 o 60 D M 50 40 30 20 10 0 10 20 30 40 50 60 70 80 90 100 Rated Core Flow (%)( EGO imagination at work 35/DR Adder Removal NRC Presentation
/12/13/2005 Crl Plant 5 Demonstration Exclusion regions with and without 0.15 DR Adder 100 -80 -DR=0.65 0: 70 60 50 40 30 20 10 0 0 1 imagination at work 10 20 30 40 50 60 70 Rated Core Flow (%)80 90 100 36/DR Adder Removal NRC Presentation
/12113/2005 Co Demonstration Analysis Conclusions
* Analysis performed for plants of different size, varying exclusion region sizes, 8x8 -lOx1O fuel* [I imaginationatwork 37 /DR Adder Removal NRC Presentation
/12/13/2005
-Summary of ODYSY LTR Changes* Removal of 0.15 Core DR Adder* Removal of comparison to FABLE-Outdated and unnecessary to include* Explicit treatment of feedwater temperature
-Separate region generated for reduced FW temp* Addition of recent instability event analysis* Addition of two new plants (with new fuel/core designs) to demonstration analysis*E[[imagination at work 38/DR Adder Removal NRC Presentation
/12/13/2005 Conclusions
* 0.15 Core DR Adder introduces unnecessary conservatism that may affect operations and should be removed from Option I-D/Il exclusion region methodology
* 0.15 Core DR Adder introduces unnecessary conservatism that may affect operations and should be removed from Option I-D/Il exclusion region methodology
* New, standalone ODYSY LTR (NEDC-33213P) will be submitted for NRC review-Basis no longer includes comparison to FABLE-Title will reflect ODYSY application for Option I-D/I1 imagination atwork 39/DR Adder Removal NRC Presentation I 12/13/2005 NRC Feedback* Questions?
* New, standalone ODYSY LTR (NEDC-33213P) will be submitted for NRC review
* Comments?a ~ imagination at work 40/DR Adder Removal NRC Presentation  
  - Basis no longer includes comparison to FABLE
/12/13/2005}}
  - Title will reflect ODYSY application for Option I-D/I1 imagination atwork                                                         39/
DR Adder Removal NRC Presentation I 12/13/2005
 
NRC Feedback
* Questions?
* Comments?
a ~imagination at work                               40/
DR Adder Removal NRC Presentation /
12/13/2005}}

Latest revision as of 09:47, 23 March 2020

BWROG Non-proprietary Slides. GE Presentation Regarding Decay Ratio Adder Removal for BWROG Stability Solution Options I-D and II
ML060170269
Person / Time
Site: Fermi, Boiling Water Reactor Owners Group  DTE Energy icon.png
Issue date: 12/13/2005
From:
General Electric Co
To:
Office of Nuclear Reactor Regulation
Honcharik M, NRR/DPR/PSPB, 301-415-177
Shared Package
ML060240100 List:
References
BWROG-05032, TAC MC8714
Download: ML060170269 (41)
v • d • e


Text

BWROG-05032 Enclosure 2 GE Presentation Regarding Decay Ratio Adder Removal for BWROG Stability Solution Options I-D and II Redacted and Non-Proprietary Information

Decay Ratio Adder Removal Option I-D/Il Exclusion Region Licensing Methodology Presentation to NRC - Closed Session December 13, 2005 imagination at work 1/

DR Adder Removal NRC Presentation /

12/13/2005

Agenda

  • Purpose
  • Background
  • Proposal
  • Recent Instability Events
  • Justification to Remove 0.15 DR Adder
  • Demonstration Analysis-
  • Summary of ODYSY LTR Changes
  • Conclusion imagination at work 2/

DR Adder Removal NRC Presentation I 12/13/2005

Pu rpose

  • Provide justification for removal of 0.15 core decay ratio adder from Options l-D and 11 exclusion region licensing methodology
  • Provide description of proposed changes relative to approved ODYSY LTR imagination at work 3/

DR Adder Removal NRC Presentation /

12/13/2005

=

Background===

  • BWROG Stability Long-Term Solutions (LTS) defined in NEDO-3 1960

- Enhanced Option I-A (EIA)

- Option l-D

- Option 11

- Option Ill

- Prevent oscillations from occurring, or

- Detect & suppress oscillations, or

- Both prevent and detect & suppress imagination at work 4/

DR Adder Removal NRC Presentation I 12/13/2005

=

Background===

  • EIA

- Prevention solution applicable to all plants

- Oscillation prevention provided by analytically determined exclusion, restricted regions protected by automatic scram, rod block (respectively)

- ODYSY approved for region generation and validation in NEDC-32339P Supplement 1

  • Option Ill

- Detect & suppress solution applicable to all plants

- Oscillations automatically detected & suppressed by new plant hardware imagination at work 5/

DR Adder Removal NRC Presentation/

12/13/2005

=

Background===

  • Option l-D

- Prevention and detect & suppress solution

- Applicable to plants with small cores where only core-wide mode oscillations are possible

- Existing flow-biased APRM flux scram detects and suppresses core-wide mode oscillations

- Oscillation prevention provided by analytically determined, administratively controlled exclusion region

- Buffer region defined outside of exclusion region

- Stability monitor required imagination at work 6/

DR Adder Removal NRC Presentation /

12/13/2005

=

Background===

  • Option I-D Stability Monitor

- Stability monitor must be operational to enter Buffer Region

- Calculated decay ratios must be below specified stability criterion to operate in Buffer Region

- If decay ratios above criterion, immediate exit from Buffer Region required

- If inadvertent entry into Buffer Region and stability monitor not operational, immediate exit required

- Plants do not normally operate in Buffer Region imagination at work 7/

DR Adder Removal NRC Presentation /

12/13/2005

=

Background===

  • Option 11

- Prevention and detect & suppress solution

- Applicable to BWR/2 plants

- Existing quadrant based flow-biased APRM flux scram detects and suppresses both core-wide and regional mode oscillations

- Oscillation prevention provided by analytically determined, administratively controlled exclusion region imagination at work 8/

DR Adder Removal NRC Presentation 12/13/2005

=

Background===

  • Original (FABLE) exclusion region licensing methodology approved in NEDO-31960
  • ODYSY exclusion region licensing methodology for Options I-D/Il approved in NEDC-32992P
  • ODYSY methodology includes 0.15 core decay ratio (DR) adder

- 0.15 is added to the calculated ODYSY core DR to yield a "procedure" core DR

- Procedure core DR is compared to 0.80 stability criterion to determine exclusion region boundary

- 0.15 adder effectively makes stability criterion 0.65 imagination at work 9/

DR Adder Removal NRC Presentation /

12/13/2005

Background - Stability Criteria Map 1.0 0.9 0.8 0.7 Core 0.6 Decay Ratio 0.5 0.4 0.3 0.2 0.1 0.0 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Channel Decav Ratio

()imaginationat work 10/

DR Adder Removal NRC Presentation /

12/13/2005

=

Background===

  • ((
  • ODYSY LTR did not take credit for methodology improvement to expedite licensing approval imagination at work 11/

DR Adder Removal NRC Presentation /

12/13/2005

=

Background===

  • ODYSY methodology improvements include:

-rr

))

imagination at work 12 /

DR Adder Removal NRC Presentation /

12/13/2005

Proposal

  • Option I-D/Il exclusion regions becoming larger due to high energy core designs

- Affects plant operation

  • 0.15 Adder adds unnecessary conservatism to exclusion region methodology for Option I-D/Il

- Demonstrated by recent instability event analyses and operational experience

  • BWROG proposes to remove 0.15 Adder to yield more acceptable regions and avoid unnecessary operational challenge

- Requires NRC review and approval imagination at work 13/

DR Adder Removal NRC Presentation /

12/13/2005

Increasing Exclusion Region Size for representative plant (with 0.15 DR Adder) 100 90 Cycle 23 80 I-70 0

a.

60 1i 50 40 30 20 10 0

0 10 20 30 40 50 60 70 80 90 100 Core Flow (%)

imagination at work 14/

DR Adder Removal NRC Presentation /

12/13/2005 cv3

Recent Instability Events Exclusion and Buffer regions calculated for two plants with recent instability events

  • Nine Mile Point 2 - July 24, 2003

- Recirc pumps downshift and FCV runback

- Flow reduction: 94% to 28%, power: 100% to 35%

- FW temperature equilibration raised power to 45%

- Slow growing oscillations developed

  • Perry - December 23, 2004

- Recirc pumps downshift

- Flow reduction: 99% to 33%, power: 100% to 44%

- FW temperature equilibration raised power to 55%

- Slow growing oscillations developed C imagination at work 15 /

DR Adder Removal NRC Presentation /

12/13/2005

((

.i imagination at work 16/

DR Adder Removal NRC Presentation /

12/13/2005

[I 17 /

I' imagination at work DR Adder Removal NRC Presentation /

12/13/2005

))

I imagination at work 18 /

DR Adder Removal NRC Presentation /

12/13/2005

((

))

imagination at work 19/

DR Adder Removal NRC Presentation I 12/13/2005

Recent Instability Events

  • Exclusion regions calculated with 0.80 DR Criterion (no adder) provide significant margin to power/flow conditions where instability events occurred
  • Buffer region adds significant additional margin
  • Exclusion regions calculated with 0.65 DR Criterion (0.15 adder) contain excessive margin 0.15 DR Adder excessively conservative for Option I-D/Il exclusion region application imagination at work 20/

DR Adder Removal NRC Presentation /

12/13/2005

Justification to Remove 0.15 DR Adder

  • For Options l-D and 11, SLMCPR protection provided by flow-biased APRM flux trip

- Detect and suppress solution element provides direct SLMCPR protection

- Conservative plant-specific analysis performed each cycle to demonstrate margin to SLMCPR (described in NEDO-32465) imagination at work 21/

DR Adder Removal NRC Presentation /

12/13/2005

Justification to Remove 0.15 DR Adder

  • Exclusion Region provides additional measure of protection (i.e., defense-in-depth)

- Prevention solution element provides additional, indirect SLMCPR protection

- Standard approved ODYSY uncertainty (20%)

applied to evaluation is appropriate and sufficient

- Events near boundary not anticipated, not significant and unlikely to approach SLMCPR

- Region generated based on limiting analysis conditions (Haling depletion, longest cycle exposure analyzed, limiting cycle exposure used)

- Different (larger) exclusion region generated for reduced feedwater temperature operation imagination at work 22/

DR Adder Removal NRC Presentation /

12/13/2005

Justification to Remove 0.15 DR Adder

  • Exclusion Region conservatism demonstrated by comparison to actual events
  • Buffer Region further reduces likelihood of instability for Option I-D plants
  • Stability monitor required and operating at all Option l-D plants for additional protection
  • Flow-biased APRM flux trip has been lowered for both Option 11plants and several Option l-D plants to offer timely scram in case THI oscillations develop imagination at work 23 /

DR Adder Removal NRC Presentation 12/13/2005

Justification to Remove 0.15 DR Adder

  • ODYSY is best-estimate stability code

- ((

- Significant theoretical improvement over FABLE

  • ODYSY used in conservative procedure to produce reasonably limiting exclusion region

- Protects against reasonably limiting events 0.15 DR Adder excessively conservative for ODYSY exclusion region procedure I imagination at work 24/

DR Adder Removal NRC Presentation /

12/13/2005

Proposed ODYSY Procedure 1 rr 0

2.

0 0

a imagination at work 25 /

DR Adder Removal NRC Presentation /

12/13/2005

Proposed ODYSY Procedure

3. [

4.

0 0

5.

6.

I imagination at work 26/

DR Adder Removal NRC Presentation /

12/13/2005

Proposed ODYSY Procedure

  • E[

27/

imagination at work DR Adder Removal NRC Presentation I 12/13/2005

Demonstration Analysis

  • Exclusion regions generated for two new plants and three plants from original ODYSY LTR

- New: Plant 1, Plant 2

- Original: Plant 3, Plant 4, Plant 5

  • Regions generated with and without DR adder

- Core DR criterion: 0.80, 0.65

  • Regions generated for reduced feedwater temperature for Plant 1

- Nominal, -30F,-60F

( imagination at work 28/

DR Adder Removal NRC Presentation 12/13/2005

Demonstration Analysis Plant BWR Core Core Loading Cycle Inlet Type Size by Fuel Type Length Orifice Original (MWd/ST) Diameter Licensed (in) Power 1 4 548 1Ox10 - 100% 12,930 2.22 100.0 2 3 580 10x10 - 81% 13,150 2.21 106.1 9x9- 19%

3 4 560 10x10 - 34% 13,868 2.09 104.1 9x9 - 64%

8x8 - 2%

4 4 368 8x8 - 100% 10,775 2.09 104.1 5 4 368 9x9 - 30% 10,425 2.22 100.0 8x8 - 70%

I imagination at work 29/

DR Adder Removal NRC Presentation /

1211312005

Plant 1 Demonstration Exclusion regions with and without 0.15 DR Adder 100 90 80 I

0 70 CL 0~

60 E

Is 50 40 30 20 10 0

0 10 20 30 40 50 60 70 80 90 100 Core Flow (%)

imagination at work 30/

DR Adder Removal NRC Presentation /

12/13/2005 c 1 4

Plant 1 Demonstration

((

imagination at work 31 /

DR Adder Removal NRC Presentation /

12/13/2005

Plant 1 Demonstration Er imagination at work 32 /

DR Adder Removal NRC Presentation /

12/13/2005

Plant 2 Demonstration Exclusion regions with and without 0.15 DR Adder 100-90 -

DR-O 65 80 DR=0.80

~70 p~60 o50 40 30 20 10 0 10 20 30 40 50 60 70 80 90 100 Core Flow (%)

imagination at work 33,/

DR Adder Removal NRC Presentation /

12/13/2005 CIS5

Plant 3 Demonstration Exclusion regions with and without 0.15 DR Adder 100 A 90 -

80 70 60 10

  • 0 50 40 30 20 10 0

0 10 20 30 40 50 60 70 80 90 100 Rated Core Flow (%)

imagination at work 34 /

DR Adder Removal NRC Presentation /

12/13/2005 C\@

Plant 4 Demonstration Exclusion regions with and without 0.15 DR Adder 100.

90 80 70 DR=0.65 DR=0.80 o 60 D M 50 40 30 20 10 0 10 20 30 40 50 60 70 80 90 100 Rated Core Flow (%)

( EGO imagination at work 35/

DR Adder Removal NRC Presentation /

12/13/2005 Crl

Plant 5 Demonstration Exclusion regions with and without 0.15 DR Adder 100-90- -

80 - DR=0.65 70 0:

60 50 40 30 20 10 0

0 10 20 30 40 50 60 70 80 90 100 Rated Core Flow (%)

1 imagination at work 36/

DR Adder Removal NRC Presentation /

12113/2005 Co

Demonstration Analysis Conclusions

  • Analysis performed for plants of different size, varying exclusion region sizes, 8x8 - lOx1O fuel
  • [I imaginationatwork 37 /

DR Adder Removal NRC Presentation /

12/13/2005

Summary of ODYSY LTR Changes

  • Removal of 0.15 Core DR Adder
  • Removal of comparison to FABLE

- Outdated and unnecessary to include

- Separate region generated for reduced FW temp

  • Addition of recent instability event analysis
  • Addition of two new plants (with new fuel/core designs) to demonstration analysis
  • E((

imagination at work 38/

DR Adder Removal NRC Presentation /

12/13/2005

Conclusions

  • 0.15 Core DR Adder introduces unnecessary conservatism that may affect operations and should be removed from Option I-D/Il exclusion region methodology
  • New, standalone ODYSY LTR (NEDC-33213P) will be submitted for NRC review

- Basis no longer includes comparison to FABLE

- Title will reflect ODYSY application for Option I-D/I1 imagination atwork 39/

DR Adder Removal NRC Presentation I 12/13/2005

NRC Feedback

  • Questions?
  • Comments?

a ~imagination at work 40/

DR Adder Removal NRC Presentation /

12/13/2005

Retrieved from "https://kanterella.com/w/index.php?title=ML060170269&oldid=2666940"