ML020630027
| ML020630027 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 02/05/2002 |
| From: | Lindquist K Northeast Technology Corp |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| Download: ML020630027 (55) | |
Text
Presentation Material Duke/USNRC Meeting February 5, 2002 White Flint N.
BADGER and RACKLIFE K. Lindquist Northeast Technology Corp.
C1 USNRC Meeting 2/5/02 NETCO
RACKLIFEIBADGER
"* Designed and developed to be used hand in hand.
"* RACKLIFE is used to select Boraflex panels for BADGER testing.
Assures panels with highest service history (gamma dose and time of dose) are tested.
Allows testing over a spectrum of service histories to determine if a threshold exists.
Reduces the number of panels to be tested to a manageable population without compromising confidence level of the BADGER measurements.
"* Comparison of BADGER test results with RACKLIFE projections provides a rationale for "tuning" the RACKLIFE escape coefficient(s).
- Assures accuracy of RACKLIFE projections to the next BADGER test.
Select oanels for testina 2
USNRC Meeting 2/5/02 NETCO
BADGER Boron-10 Areal Density Gage for Evaluating Racks In most racks Boraflex is encapsulated within rack structures. Direct inspection requires destructive techniques.
Rack modules rest on the bottom of a water filled pool forty feet deep.
- Inspection/testing of Boraflex was recognized as a challenging task.
BADGER concept devised based on neutron transmission measurements.
USNRC Meeting 2/5/02 NETCO 3
BADGER Chronology Proof-of-principle testing (1993) conducted in the beam hole laboratory of the Penn State Reactor with mock-up sections of fuel racks:
Single sheets of Boraflex with stainless cladding.
Double sheets of Boraflex with water filled (2000 ppm soluble boron) flux trap.
Proof-of-principle test results were positive and a proto-type BWR BADGER designed and fabricated (1994).
- Clean testing in the Co-60 pool at Penn State - May through August of 1995.
- Plant demo at Peach Bottom 2 April 1996.
PWR BADGER designed and fabricated 1996.
- Clean testing fall of 1996.
PWR demo at McGuire 2 January 1997.
- Crew departs today for second campaign at Peach Bottom 2.
USNRC Meeting 2/5/02 4
NETCO
Oeh ad Areal Denslty Moter Drive Systemn Hook Pool Water Surface BRIDGE r
4.0 1
028.
and DETECTOR F 14.5 SýPE T FUEL STORAGE RACK iii POOL WALL
___E 1
NOTES:
- 1. Drawing Not to Scale
- 2. All Dlmenslons In Feet INFORMATIONAL DRAWING ONLY IVE T-7CO~
DRAWING TITLEI B-10 Areal Densrty Meter Pool Setup Arranqumont CLIENT: Eleotric Power R~aroh lrwtltuts
"""0 92 I'"" 1192-4 Iow.092-1 d aTQ*
M. Harrr, f
CA Cho'end Iy; IWLA IL.
USNRC Meeting 2/5/02 B-10 Areal DenksIty gage POOL WAJ.
I I
ent eerD0Sse A ý
ýf "SOURCE SHEADS l
1 Appre*I I"
!Dm ul o
Jl 5
NETCO
TOP FRAME ASSEMBLY DRWG. # 092-04
-168.0 SOURCE ASSEMBLY DRWG. # 092-09 NOTES:
- 1. ALL DIMENSIONS IN INCHES
.DETECTOR PROBE SHAFT(8 REQUIRED)
DRWG. # 092-06 DETECTOR HOUSING ASSEMBLY DRWG. #/ 092-07 LVI"]CO DRAWING TITLE B3-10 Areal Density Meter CLIENT: Electric Power Research Institute Job No. 092 1Flis No. 092-041 Drawing No. 092-03 Created By:
I Chocked By.
Approved By:
1pg.
of USNRC Meeting 2/5/02 NETCO 6
AL]CC)
DRAWING TITLE BWR BADGER Source/Detector Head Arrangement CLIENT: EPRI Job No. 092 1F6 No. 09 2 -41 DOng° No. 092-4a Rev 2 Crote.d By: M.
Harris Check.d By:
Approved By:
USNRC Meeting 2/5/02 NETCO 7
IP9-
gShaft Attachment Coupling
"_/
(BOTTOM VIEW v_-/ Housing Lead-In Plates NOTES:
ELEVATION VIEW Full Seam Weld
,---1/2R Grind & Polish Attachment Plate Full Seam Weld
- 1. ALL DIMENSIONS IN INCHES
- 2. ALL WELDS-IN CASE OF OVERPENETRATION.
GRIND & POLISH
- 3. ITEMS 3 & 6 -
WELD IN POSITION 0 HORIZONTAL MIDPLANE
- 4. ITEM 3 -
POSITION @ VERTICAL MIDPLANE DRILL HOLES © 0' 17.90,33.70, & 46.50 with respect to DATUM A j-I*,I 'CO DRAWING TITLE : B-ID Areal Density Meter Source Head Assembly CLIENT: Electric Power Research Institute Job No. 092 1 Fil No. 092 -04 Drow4ng No. g009S Rev. 1 Created By:
Cheocked By:
Approved Byy; pg, of USNRC Meeting 2/5/02 3,75]
(D (4 Required)
NETCO 8
I ý Shaft Attachment Coupling I
I II I I II I I 5.75 II 1 1i II 5.75 II UI Ii UI U
II I
I I
I III II I
I I
I II I I 5,75 II 1()11 11l~I 11157 IIU U
U U I II II II II I
II II 5
Housing Guide-In 1
Plates Full Seam Weld ELEVATION VIEW 0 Aluminum Detector Housing Wall (4 Required)
Full Seam Weld I
1 /2R Grind & Polish 5,75 0
o n 0On 0 I
°!no A~
GCoupling Attach Plate
__- )Neutron Shield
'ý(7_')AIumin um
ýýBlock Detector Support (D (4 Required)
BOTTOM VIEW NOTES:
- 1. ALL DIMENSIONS IN INCHES
- 2. Item 2-Machine Aluminum to Fit
- 3. Item 5-In Case of OverPenetration Grind & Polish TITLE BWR BADGER Detector Head Assembly CLIENT: Electric Power Research Institute Job No. 092 1 F1. No. 092 -041 Dr*wing No. 092-07 Creoted y M. Harris Cheked By:
Approved By:
pg.
USNRC Meeting 2/5/02 3,7.
PLAN VIEW 9
NETCO
A23S Data DET-1 z 0 co z
I-LU 0
-J 0:
z DET-2 DET-3 DET-4 0
50 100 150 BORAFLEX PANEL ELEVATION, INCHES Low Dose Panel USNRC Meeting 2/5/02 NETCO 10
E13E Data DET-1 z co 03 co co z
I LU N
n 0 z DET-2 DET-3 DET-4 0
50 100 150 BORAFLEX PANEL ELEVATION, INCHES High Dose Panel with Three Gaps USNRC Meeting 2/5/02 NETCO 11
F12W Data z 0 co co co z
I-0 N
,J 0
z DET-1 DET-2 DET-3 DET-4 0
50 100 150 BORAFLEX PANEL ELEVATION, INCHES High Dose Panel with Thinning and One Gap USNRC Meeting 2/5/02 NETCO 12
F2E Data DET-1 z 0 cO o2 co z
(HO) 3SiOSi(OH) 3 (dimer)
+ H 2 0 Si(OH) 4 + dimer -4 [(OH) 2S10]3 (cyclic trimer)
OH OH OH
'7 S.--0SSi*
/Si 0 si 0
OH I
OH OH d1imer + dimer --4 [(OH) 2SiO] 4 (cyclic teiramer)
(b) Polymers form by maximizing siloxane (Si Si) bonds in ring and 3D structures inside, and by minimizing uncondensed SiOH groups which generally are only found on the outer surface USNRC Meeting 2/5/02 NETCO 22
Silica Mass Balance in Spent Fuel Pools RACK CAVITY POOL VOLUME TOTAL S ECA USNRC Meeting 2/5/02 NETCO 23
Source Term for Reactive Silica in Panel Chambers Si= X(1
- Ri/Req! )
K = K (Temperature, Irradiation)
Reqj : Re, (Temperature, pH)
USNRC Meeting ;:,-.
NETCO 24
101 100 w
10-1 10.1 1 0"s 10 1D0 101 101 1010 GAMMA DOSE [fracl]
Silica Release Rate per Unit Area - Fit versus Data USNRC Meeting 2/5/02 NETCO 25
Kinetics Equations for Pool Silica Reactive Quantity of Total Silica, R dR
= +Z [KRiRRi - KRRiR]
Escape (Re-entry) dt
- KRpR + KPRP
- KRDR + KDRD
- kRcR
- kRM (R-M)
+ kERM Polymerization(Depolymerization)
Deposition(Re-Solution)
Cleanup Makeup (Conc. M)
Evaporation USNRC Meeting 2/5/02 NETCO 26
RACKLIFE Input
"* Pool design data Pool water volume and layout
"* Rack design data Module / cell design data Module layout data Boraflex as-built properties
"* Fuel design and operating history data Initial U-235 enrichment and loading (MTU)
Discharge burnup Reactor shutdown time and date Date, time and location to which fuel assembly moved to rack Date, time and location of subsequent fuel moves for each assembly in the pool End of cycle assembly average power Pool water condition pH Temperature Soluble silica versus time Pool cleanup system design data
"* Escape coefficient USNRC Meeting 2/5/02 NETCO 27
RACKLIFE Output
"* Predicted and measured soluble silica versus time
"* Pool wide distribution of exposure
"* Pool wide distribution of boron carbide loss
"* Module and panel by panel exposure
"* Module and panel by panel boron carbide loss USNRC Meeting 2/5/02 NETCO 28
3
- 0.
- 03.
E z
0 I
z LU D_
z 0 C)
-j U
0 LU CL CO) 2.5 2
1.5 1
0.5 0
Jan 1,1987Jan 1, 1989Jan 1,1991 Jan 1,1993Jan 1, 1995 DATE Measured versus Predicted Pool Silica Levels for BWR-A USNRC Meeting 2/5/02 NETCO 29
40 E
- 0.
I, Z
CLl 0
z 0 0
0
-J 0 00~
-j w
D Ui.
z w C-30 20 10 0
1 1
1 I
I Jan 1,1990 Jan 1,1992 Jan 1, 1994 Jan 1,1996 Jan 1,1998 Jan 1,2000 DATE Measured versus Predicted Pool Silica Levels for PWR-C USNRC Meeting 2/5/02 NETCO 30
c44 oIf
- 0)
Z cm)
'aa A
0 a
Co 0a F
0 L
IL z
.0 O
0 4 ooo x,
CGo
0 I (0
Cd C.,
S 4W 4, a.
rn'0 CS CO 02N Al Ad C
0 0
0 0L al I
A]
C Ad S
Module Distribution of Exposure USNRC Meeting 2/5/02 co%
NETCO 33
Module Distribution of Boron Carbide Loss USNRC Meeting 2/5/02 NETCO 34
20 15 0
10 W
W z 0 0 m 5
0
<2.4E9 2.4-3.0E9
>3.0E9 DOSE RANGE[radsj PWR-B Measured and Predicted Boron Carbide Loss Averaged by Dose USNRC Meeting 2/5/02 NETCO 35
PWR A Region 1 Measured and Predicted Boron Carbide Loss Boron Carbide Loss, %
Panel Dose BADGER Measured RACKLIFE A23S 0.OE+00 0+/-9
-2 D13E 1.1E+10
-27+/-15
-16 C13E 1.2E+10
-17+/-10
-18 C13N 1.2E+10
-27+/-11
-18 E2W 1.2E+10
-10+/-9
-11 F2E 1.2E+10
-15+/-9
-13 H13W 1.9E+10
-23+/-10
-18 G12E 2.OE+10
-25+/-10
-21 F12W 2.OE+10
-20+/-10
-22 E13E 2.4E+10
-22+/-11
-23 E13N 2.6E+10
-33+/-13
-23 F13N 3.OE+10
-29+/-11
-24 E13W 3.3E+10
-31+/-13
-24 F14E 3.4E+10
-26+/--12
-24 F13E 3.4E+10
-26+/-11
-24 USNRC Meeting 2/5/02 NETCO 36
Conclusions RACKLIFE models when used in tandem with BADGER testing provide a reliable means to project future Boraflex performance.
- The approach utilizes a predictive model coupled with measurement technique to monitor the slow deterioration of a plant component.
- The approach is analogous to that used in many PWRs to monitor steam generation tube wastage.
USNRC Meeting 2/5/02 NETCO 37
h/
I 02/05/02 Washington.1 C-F~r2I3 NRC Boraflex Information Meeting February 5, 2002 Washington D.C Ray W. Lambert EPRI
Commercial History
- Introduced in late 1970's
- Dominated market through 1980's
- Cost and ease of fabrication were main advantages
- About 75 pools world wide installed Boraflex C-2Ia 02/05/02 Washington.2
Commercial History (cont'd)
° After a few years in service performance problems began to emerge
- Coupons gave first indications Embrittlement at relatively low doses was noted
- Blackness testing indicated shrinkage and some cracking of the Boraflex r= I ra 02/05/02 Washington.3
Commercial History (cont'd)
- Technical support for product was minimal
° Manufacturer was unwilling and unable to assist
- Vendors claimed no responsibility i' Background material qualification information was minimal and inconsistent
° Technical data was insufficient for utilities to perform root-cause analyses 02/05/02 Washington.4 r=I=2
Utilities requested EPRI's help in 1986
"° Hih priority project started using base budget dollars
"° NETCO selected as primary contractor based on experience with:
- Pool criticality analyses
- Fuel designs and performance
- Materials expertise
" As scope of work expanded, a Boraflex Working Group (BWG) was organized with responsibility to:
- Oversee EPRI's R&D work
- Fund activities
"° The BWG is now approaching its end of life 02/05/02 Washington.5 r-F-- I
EPRI R&D Objectives
° Develop fundamental understanding of Boraflex degradation mechanisms
- Develop techniques to measure and manage degradation
- There was early recognition that there would be no silver bullet 02/05/02 Washington.6 C-r=ral
Utilities were highly motivated to support Boraflex R&D
- Ensure pools maintain adequate safety margins Pools were filling fast and loss of storage could lead to reactor shutdown Dry storage option required long lead time and high cost Pools already had been reracked and a second round was difficult and often exceeded $10M 02/05/02 Washington.7 C-:F=fal
Early priorities for EPRI's R&D
- Understand the fundamental composition of Boraflex Understand the shrinkage mechanism and determine the limits
- Analyze the impact of gap formation and pull back effects
- Perform laboratory tests to determine the impact of variables Radiation dose Pool chemistry and pH
- Temperature
- Variety of Boraflex compositions 02/05/02 Washington.8 rfI2ll
Crash effort resulted in the following conclusions and activities:
- Chemical makeup of Boraflex was defined Radiation effects on the polymer cross linking creates hardening and shrinkage Theoretical model developed that suggested a maximum shrinkage of about 3% at doses of about 1 x 1010R
- Tests were started ASAP Material stability tests at Penn State Irradiation tests at AFRRI Full scale panel tests at Beaver Valley 2 Assembly of data base from blackness testing 02/05/02 Washington.9 C11r l-'l
NRC also became aware of the Boraflex issue in the mid 1980's NRC issued its first Information Notice in September 1987 Status in 1987 Boraflex manufacturer was beginning to exit the business
- Fabricators were not offering technical help
-NRC did not have any Boraflex R&D underway
-EPRI program was up and running 02/05/02 Washington. 10
BWG made a conscience decision to voluntarily share R&D data with the NRC NRC representative attended portions of EPRI workshops
-EPRI information was made available to the NRC
,,I-I2I 02/05/02 Washington.1 I
Open interchange continued on topics such as:
- EPRI test data, current results and future R&D plans
- NRC's areas of concern or data needs
- Information Notices and Generic Letters 02/05/02 Washington. 12 C-rM re I
EPRI shrinkage model had been confirmed by data Recognition that shrinkage and gaps were only one part of the degradation mechanism Long-term environmental effects determined to play a major role in the degradation process
- Gradual dissolution process was modeled for irradiated Boraflex Key variables were identified that included:
- Gamma dose
- Rack design
- Access to pool water (called water escape coefficient)
Temperature of pool 0/Reactor and/or pool water treatment designs 02/05/02 Washir'gton. 13
BORAFLEX SHRINKAGE DATA FULL SIZE PANELS-EPRI/BVPS SURVEILLANCE ASSEMBLY EPRI UPPER RANGE PROJECTION EPRI LOWER RANGE PROJECTION UNRESTRAINED PANEL (L}
SUNRESTRAINED PANEL (W)
RESTRAINED PANEL (L) oRESTRAINED PANEL (
A ADHERED PANEL (L)
ADHERED PANEL (M)
E NOTE BELOW II.
I..
BEO 1N '
- i.
,1l08 i
.101 ii
...1 010 1 i011 GAMMA EXPOSURE, RADS NOTE: THESE ARE THE AVERAGE OF THREE WIDTH MEASUREMENTS. EDGE DISSOLUTION HAS CONTRIBUTED TO THE APPARENT CHANGE IN PANEL WIDTH.
1 0
-1
-2
-3
-4 I
Lu zi 0.
-5
Understanding increased to the point that it was practical to model the Boraflex performance
- BWG authorized a project to build a DOS code for modeling performance (start of RACKLIFE)
- Concept was that code would be a tool to help manage the Boraflex issue
-As code developed, its capability exceeded expectations 02/05/02 Washington. 14
It was concluded that to take full advantage of RACKLIFE that there would need to be a way to take measurements to confirm its efficacy
- Blackness testing was inadequate
- Development of BADGER was begun to directly measure B-10 areal density 02/05/02 Washington. 15
Over $3M has been spent on R&D Utilities have committed major resources to the running of RACKLIFE and oing BADGER measurements An in-depth understanding of Boraflex has been developed that:
- Fermits degradation to be managed
- Maintains adequate safety margins in pools
- Has kept reactors operating
-Allows time for utilities to seek and select long term solutions 02/05/02 Washington. 16 CI=r"1
Other specific EPRI Boraflex products have included:
17 utility workshops Full documentation of Boraflex performance data base
- Completion of a 12 year full scale panel test at Beaver Valley 2
- Participation with W in the original Boron credit project
- Special coupon testing at Millstone Destructive inspection and testing of the Ft. Calhoun Boraflex racks
- Special coupon tests at Palisades
- Testing of zinc as a method to reduce Boraflex solubility
- Partner in the RACKSAVER demonstration Evaluated the performance of Boraflex during seismic events Devising technologies for managing silicon levels in pools
- Supported the METAMIC qualification program 02/05/02 Washington. 17 a-F=ral