ML19312C138: Difference between revisions
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: 6. Law Engineering Testing Company Reports: | : 6. Law Engineering Testing Company Reports: | ||
(a) Jocassee Hydro-Station Seismic Studies Summary Report, dated September 30, 1976 l j | (a) Jocassee Hydro-Station Seismic Studies Summary Report, dated September 30, 1976 l j | ||
(b) Letter Report dated September 30, 1976 regarding possible ' | (b) Letter Report dated September 30, 1976 regarding possible ' | ||
Maximus Acceleration at Oconee Nuclear Station from Jocassee Reservoir Induced Seismicity. | Maximus Acceleration at Oconee Nuclear Station from Jocassee Reservoir Induced Seismicity. | ||
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i 1 | i 1 | ||
i LIST OF TABLES i | i LIST OF TABLES i | ||
i TABLE PAGE | i TABLE PAGE | ||
{ l Summary of HZP Physi:s Test Results. . . 14 4 | { l Summary of HZP Physi:s Test Results. . . 14 4 | ||
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i i 5 | i i 5 | ||
I s | I s | ||
4 | 4 e--e ,. , , n.-- , .- | ||
e--e ,. , , n.-- , .- | |||
: r. . ..e,.m , . - , , - . + , , , , - - . . , . . - , , , , , - , -a-..w- ,, ,,---,,n-- - ~-v e vm~r | : r. . ..e,.m , . - , , - . + , , , , - - . . , . . - , , , , , - , -a-..w- ,, ,,---,,n-- - ~-v e vm~r | ||
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) | ) | ||
3-D equilibrium Xenon was present in the core. Also, there was little or no control rod motion throughout the test. The results of the intercali-bration measurements and corresponding outputs from the fixed incore detector system were: | 3-D equilibrium Xenon was present in the core. Also, there was little or no control rod motion throughout the test. The results of the intercali-bration measurements and corresponding outputs from the fixed incore detector system were: | ||
1 | 1 | ||
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i | i | ||
TABLE 1 - | TABLE 1 - | ||
SUM *1ARY OF IIZP PilYSICS TEST RESULTS . | SUM *1ARY OF IIZP PilYSICS TEST RESULTS . | ||
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: a. I | : a. I | ||
. FIGURE I RELATIVE | . FIGURE I RELATIVE | ||
* GROUP 6 NEASURED EJECTED ROD WORTHS i | * GROUP 6 NEASURED EJECTED ROD WORTHS i | ||
: A ' | : A ' | ||
B | B C 1 I | ||
C 1 I | |||
; D .si .39 E | ; D .si .39 E | ||
.I2 G | .I2 G | ||
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l l l | l l l | ||
l | l | ||
FIGU RE 2 FIXED INCORE DETECTOR SYSTEM A | FIGU RE 2 FIXED INCORE DETECTOR SYSTEM A | ||
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. _ . _ . _ . . .,., .-' ,i - N_1s m ;__ _ _ . - , _ _ | . _ . _ . _ . . .,., .-' ,i - N_1s m ;__ _ _ . - , _ _ | ||
c 5 | c 5 | ||
-I F 9:' 'Y 2 | -I F 9:' 'Y 2 (( | ||
. . . - _ _ _ c. , | . . . - _ _ _ c. , | ||
Ti w - | Ti w - | ||
Line 547: | Line 537: | ||
s.o . . | s.o . . | ||
v | v | ||
.u _ - - _ | .u _ - - _ | ||
e-- | e-- | ||
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m E-g | m E-g | ||
: s. - __ _ _ - . . . _ _ . _ _ . _ , _ | : s. - __ _ _ - . . . _ _ . _ _ . _ , _ | ||
-._.2__._;._c_._ | -._.2__._;._c_._ | ||
_ - :t-=? t .- r- _d | _ - :t-=? t .- r- _d | ||
Line 609: | Line 597: | ||
r-: = | r-: = | ||
*- + s . _ . _-. h_ .x- == - - = =m s ,_ _-. | *- + s . _ . _-. h_ .x- == - - = =m s ,_ _-. | ||
l'*'"-" ) c N- 5- p- _._ _. _. ~ l c.--- | l'*'"-" ) c N- 5- p- _._ _. _. ~ l c.--- | ||
3 (_ : . ._ y y- _ _ . . _. _ . .- - . _ | 3 (_ : . ._ y y- _ _ . . _. _ . .- - . _ | ||
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C *. . !: | C *. . !: | ||
: rw--- ? - - - - -- - | : rw--- ? - - - - -- - | ||
l q ._. | l q ._. | ||
.:----*-----------* _ 4 | .:----*-----------* _ 4 |
Latest revision as of 06:49, 16 March 2020
ML19312C138 | |
Person / Time | |
---|---|
Site: | Oconee ![]() |
Issue date: | 01/31/1978 |
From: | BABCOCK & WILCOX CO. |
To: | |
References | |
BAW-1477, NUDOCS 7912060692 | |
Download: ML19312C138 (50) | |
Text
{{#Wiki_filter:> -.
. E BAWa- 1477 JInu_ry, 1978 -~
OCONEE 1 CYCLE 4 QUADRANT FLUX TILT NOTICE -
' THE ATTACHED FILES ARE OFFICIAL RECORDS OF THE DIVISION OF DOCUMENT CONTROL. THEY HAVE BEEN l
' CHARGED TO YOU FOR A LIMITED TIME PERIOD AND MUST BE RETURNED TO THE RECORDS FACILITY BRANCH 016. PLEASE DO NOT SEND DOCUMENTS CHARGED OUT THROUGH THE MAIL. REMOVAL OF ANY PAGE(S) FROM DOCUMENT FOR REPRODUCTION MUST BE REFERRED TO FILE PERSONNEL. RR".AIDRV PCKE II 20?Y DEADLINE RETURN DATE DOCktt # bo .% 7 C0331 # % 2 7eo ' 2-am ~ = -" 2 :m= RESULtTORY DOCKET Dli RECORDS FACILITY BR ANCH
~
Babcock &Wilcox
.? g 3 g g g g g g g f
* *~'* ., J . r . 1 .Mr. Benard C. Rusche Page 2 October 1, 1976 ,
s
- 6. Law Engineering Testing Company Reports:
(a) Jocassee Hydro-Station Seismic Studies Summary Report, dated September 30, 1976 l j (b) Letter Report dated September 30, 1976 regarding possible ' Maximus Acceleration at Oconee Nuclear Station from Jocassee Reservoir Induced Seismicity. Ve truly yours, s / u . La . William O. Parker, Jr MST:vr Enclosures l l
. I BAW - 1477 January, 1978 l
OCONEE 1 CYCLE.4 QUADRANT FLUX TILT PREPARED BY Supervisory Enginee , Fuel Management & Development Unit
-e > REVIEWED AND APPROVED BY Manager, Fuel Engineering Section ager, Plant Performance Services Section i M Manager, Operating Plant Licensing Unit
[Obhw v Fuel Project Manager, Oconee Units ty l
. e i
TABLE OF CONTENTS PAGE I. Background. . . . . . ...... . ... . . 1 II. Characterization of Cycle 4 Tilt. ... . .. 2 A. Ejected Rod Measurements. . . .... .. 2 B. Out-of-Core Detectors . .. . ..... . 2 C. Fixed Incore System . .. .. ... ... 3 D. Incore Detector Calibration Probe Test. . 4 III. Cycle 4 Tilt Evaluations. .. . . . .. ... 5 A. Evaluation of Potential Causes of the Tilt. . . . . . ... . . ..... .. 5 B. Diagnostic Testing. ..... ... ... 5 C. Technical Specification Considerations. . 7 IV. Effects of Cycle 3 Operation. . .. .. ... 7 V. Generic Tilt Considerations . . . ... . . 10 VI. Summary and Conclusions . . . ...... . 12
I f i e t ~ 1 1 1 4 4 i i 1 i LIST OF TABLES i i TABLE PAGE { l Summary of HZP Physi:s Test Results. . . 14 4
- 2 Sununary of Cycle 4 Quadrant Tilt . .. . 15 a
3 i 3 Potential Causes of Tilt . .. . .. . . 16 4 1 J d 1 i I 4 I I 4 i I i i 5 I s 4 e--e ,. , , n.-- , .-
- r. . ..e,.m , . - , , - . + , , , , - - . . , . . - , , , , , - , -a-..w- ,, ,,---,,n-- - ~-v e vm~r
l LIST OF FIGURES FIGURE PAGE 1 Relative Group 6 Measured Ejected Rod Worths. . . . . . . . 18 2 Fixed Incore Detector System. . . . . . . . .. . . . . . . 19 3 Incore Tilt Measurement at 40%FP. . . . . . .. . . ... . . 20 4 Incore Tilt Measurement at 100%FP . . . . . . . . . . . . . 21 5 Tilt by Level at 40%FP. . .. .. . . . . . . . . . . . . . 22 6 Tilt by Level at 100%FP . . . . . . . .. . . .. . . . . . 23 7 Radial Peaking Factor Comparison at 40%FP, 3.5 KFPD . . . . 24 8 Total Peaking Factor Comparison at 40%FP, 3.5 EFPD. .. . . 25 9 Radial Peaking Factor Comparison at 75%FP,18 EFPD. . .. . 26 10 Total Peaking Factor Comparison at 75%FP, 18 EFPD . . . . . 27 11 Radial Peaking Factor Comparison at 100%FP, 28.4 EFPD . . . 28 12 Total Peaking Factor Comparison at 100%FP, 28.4 EFPD. . . . 29 13 Radial Peaking Factor Comparison at 100%FP, 37.4 EFPD . . . 30 14 Total Peaking Factor Comparison at 100%FP, 37.4 EFPD. . .. 31 15 Radial Peaking Factor Comparison at 100%FP, 46.2 EFPD . . . 32 t 16 Total Peaking Factor Comparison at 100%FP, 46.2 EFPD. . . . 33 17 Radial Peaking Factor Comparison at 100%FP, 56.6 EFFD . . . 34 18 Total Peaking Factor Comparison at 100%FP, 56.6 EFPD. . . . 35 19 Cycle 3 Tilt Versus Burnup. . .. . ... . .. . .. . . . 36 20 Cycle 3 to 4 Fuel Shuffle Map . . . .. . ... . . . . . . 37
-111-
I. BACKGROUND
. Initial criticality for Oconee 1, Cycle 4 was achieved on October 14, 1977.
Routine reload startup physics testing proceeded on schedule until 0550 on October 16 when the hot zero power (HZP) ejected rod worth measured by boron swap was found to be 48% lower than the predicted worth. After a preliminary review of both the measurement and the predicted worth failed to resolve this ejected rod worth disparity, it was decided to measure additional ejected rod worths. The relative ejected rod worth for each of the eight rods in Group 6 was determined by swapping individual rods against control rod Group 5. These measurements, which are reported in Figure 1, showed an unexpected asymmetry in the relative worths of the' four symmetric rods in the outer ring of Group 6. The inner ring of Group 6 showed tue same asymmetrical trend although the magnitude of the asymmetry was very small because the ejected rod worth was small and the rods were close to the center of the core. The distribution of the Group 6 worths indicated a definite quadrant flux tilt, but the magnitude of the tilt could not be quantified at HZP because the HZP flux levels are not sufficient to be measured by the incore detector system. Since all the ejected rod worths were well below the upper limit used in the plant safety analyses, and since all other HZP test results w;ere within accep-tance criteria (see Table 1), the plant was escalated to 15% full power (FP) to further evaluate the quadrant tilt. Initial 15% FP indications from the incore detector system indicated a tilt 1 of approximately +10% in the WX quadrant and a -12% in the diagonally opposite YZ quadrant. After core conditions were partially stabilized at this power level, the tilts were determined to be about 6%. Since these tilt indications were ccusistent with the measured ejected rod worth distribution and since trends from the out-of-core detectors showed similar tilts, it was evident that l l _1_
s a real flux tilt existed in the core. The extensive series of investigations ~ and tests described in Sections II, III and IV were then conducted to further evaluate and characterize the Cycle 4 tilt and to identify any relation to Cycle 3 operation. II. CHARACTERIZATION OF THE CYCLE 4 TILT Evidence of a quadrant flux tilt in Oconee 1, Cycle 4 has been obtained from four essaatially independent sources. The information provided from each source is described below to characterize the tilt. A. Ejected Rod Measurements The asymmetrical results obtained from ejected rod worths measured at symmetric core locations provided the first indication of the Cycle 4 tilt. Each of the eight Group 6 rods were individually removed from and re-inserted into the core by inserting and withdrawing control rod Group 5. The relative worth of each ejected rod is then determined from the Group 5 position change in conjunction with the measured integral worth curve for Group 5. The relative Group 6 worths given in Figure 1 clearly display an asymmetry. The results in Figure 1 indicate a positive flux tilt in the WX quadrant and a negative tilt in the YZ quadrant. B. Out-of-Core Detectors During the initial escalation to 15% power, the out-of-core detectors indicated a tilt trend consistent with data obtained later from the incore detector system. Because the out-of-core detectors are re-calibrated to the plant heat balance, only trends in til* (over the time period between calibrations) are available from these detectors. However, it is sig-nificant that the out-of-core detectors provided an independent qualitative verification of the Oconee 1, Cycle 4 tilt.
C. Fixed Incore Detector System 1 Most of the informa, tion available to characterize the tilt was obtained from the fixed incore detector system. This system is composed of 52 detector strings each containing seven self-powered, fixed rhodium detectors which are evenly spaced axially along the active fuel length. Sixteen detector strings arranged in an inner and outer ring are utilized to monitor the core quadrant symmetry. Figure 2 shows the location of each detector string and defines the inner and outer symmetric rings. - Table 2 provides a summary of the quadrant tilts measured by the incore system since the beginning of Cycle 4. All of the data clearly indicate a positive tilt in the WX quadrant and a corresponding negative tilt in the YZ quadrant. Also, as expected, the tilt decreases as power level and cycle burnup increase. The tile decreases with increasing cycle burnup because the higher relative fuel burnup in the positively tilted quadrant reduces the re-activity worth of the fuel which tends to lower power in that quadrant. Simi-larly, the larger negative reactivity due to thermal-hydraulic feedback effects and the higher Xenon concentrations in the higher power quadrant also tend to decrease the tilt as the power level increases. Figures 3 and 4 provide maps of the tilt measured at each symmetric detector location at 40% FP and 100% FP respectively. The tilt is distrib-uted reasonably uniformly throughout each of the tilted quadrants and all four symmetric strings in the positive (negative) quadrant display a positive (negative) reading. This relatively uniform distribution of the tilt combined with the results of the power distribution comparisons given below indicater that the source of the tilt is probably distributed rather than localized. More specifically, the incore data indicates that the tilt is probably not caused by a localized reactivity effect such as a dropped control rod or broken rodlets. Figures 5 and 6 show the axial distribution of the tilt at 40% FP and 100% FP respectively. The tilt is consistent in that the sign of the tilt at all seven levels is the same. Also, the asymmetry is largest in the middle of the core and becomes smaller'near the core extremities. Fiaures 7 throuah 18 nrovide a comnariann nf measurad and predictad radial and total peaking factors at each detector string location for 40% FP, 75% FP, and 100% FP conditions. The calculations were performed in a core follow mode using the FLAME three dimensional nodal code. Quarter core symmetry was assumed for all the calculations. Even though the tilted nature of the core causes some differences la the comparison, the overall agreement is reasonably good and there are no extremely large deviations. Thus, these peaking factor comparisons show that, other than the power gradient caused by the tilt, the core is performing as expected without any indications of anomalous behavior. Also, as noted previously, since there are no obvious concentrated areas of large power distribution differences, the source of the tilt is probably distributed rather widely. D. Incore Detector Calibration Probe Test on November 30, 1977, intercalibrated rhodium detector probes were inserted into the calibration tube of four inner and four outer symmetric detector strings located in LOC and YZ quadrants. The test probes had been I previously calibrated at the Lynchburg Pool Reactor. Oconee 1 had been operated at 100% FP for several days prior to and during the test so that
)
3-D equilibrium Xenon was present in the core. Also, there was little or no control rod motion throughout the test. The results of the intercali-bration measurements and corresponding outputs from the fixed incore detector system were: 1
Flux Results from Calibration Test WI Quadrant YZ Ouadrant Fixed Incores +2.50% -2.50% Intercalibrated Probes +2.58% -2.58% This test confirmed that there indeed is a quadrant tilt in Oconee 1, Cycle 4 and that the present fixed incore detector system is accurately measuring this tilt. III. CYCLE 4 TILT EVALUATIONS A. Evaluation of Potential Causes of the Tilt A compilation was made of the mechanism that could be causing the quadrant tilt at Oconee 1. Some of the more credible causes from this ex-tensive list are given in Table 3. This Table also provides a brief explanation of how most of the potential causes were either eliminated or classified as highly improbable. The evaluation of each potential cause was based on a combination of the tests described below, computer analyses, review of design and manufacturing records, and characteristics of the observed tilt. A detailed review of all the potential tilt causes and of the data available to evaluate each cause has indicated that the significant l portion of the Cycle 4 tilt is being caused by the presence of a small l i tilt in Cycle 3 which was magnified by the Cycle 4 fuel shuffle scheme. Details on the effects of the Cycle 3 tilt on Cycle 4 are provided in 1 Section IV. B. Diagnostic Testing Several specific diagnostic tests were performed during Cycle 4 to i evaluate potential causes of the tilt before escalation to 75% FP. These I eats and their results are described below. l \ l i
f
- 1. Rod Exercise Test at 15% FP All of the control rods in the low power quadrant were inserted individually into the core to determine if they affected the core power level. If a control rod was uncoupled from its rod drive (which could produce a substantial tilt), movement of the rod drive would have no effect on the core. All rods tested produced an observable change in reactor power, indicating that all the rods were coupled to a drive.
- 2. Removal of All Rods at 40% FP All control rods and axial power shaping rods (APSR's) were with-drawn from the ' core at 40% FP to determine if a rod mispatch (eg. a Group 7 rod patched in Group 8 (APSR's)) was causing the tilt. The tilt was still present with all the rods withdrawn, thus eliminating a rod mispatch as the cause of the tilt.
- 3. Insertion of Control Rod Groups at 30% FP If the tilt was being caused by individual control pins (rodlets) which had broken off in a rodded location, full insertion of the group with the broken rodlets should balance the poison distri-bution in the core. This balancing of the poison should initially cause the tilt to change quadrants (due to the residual asymmetrical Xenon distribution) and eventually create a balanced quadrant l
l power distribution. Extensive testing was performed at 30% FP i from October 23rd through October 25th to determine if broken rodlets we e the cause of the tilt. Every rod group was fully inserted into the core by swapping one group against another. While significant changes in the tilt (+6.5% to +2% and -8% to
~3.5%) were observed ~ as the core flux shape was af fected by various l.
group insertions, tha tilt was not eliminated at any time during
- the test. Therefore, broken rodlets in a control rod location was ruled out as a cause of the tilt.
C. Technical Specification Considerations A detailed review of the~0conee 1, Cycle 4 technical specifications was conducted when it became apparent that a significant tilt existed in the core. All of the available data - ejected rod measurements, incore tilt results, power distribution' comparisons, and the overall results from the normal startup testing program - were evaluated to assess the impact of the tilt on the plant operating limits. Also, additional analyses were performed to further quantify the effect of the tilt on important safety parameters. As a result of these efforts a revised set of technical specifications were developed to conservatively account for the effects of the Oconee'1, Cycle 4 tilt. Under these revised technical specifica-tions, the plant could escalate safely to 100% FP in a rods out mode of operation. These revised technical specifications were approved by the NRC in November, 1977 for the first 100 EFPD of Cycle 4 operation and the plant was escalated to 100% FP. IV. EFFECTS OF CYCLE 3 OPERATION As previously indicated, the Cycle 3 operational history was considered as a possible cause of the Cycle 4 tilt. This section describes the results of the investigation to determine the impact of Cycle 3 operation on the Cycle 4 tilt. An in-depth analysis of Cycle 3 was performed to establish the tilt history of that cycle as accurately as possible. This analysis utilized unprocessed incore detector signals and eliminated failed detector locations to reduce any asymmetry which could have been introduced by online computer signal
substitution routines. Figure 19 shows the results of this analysis plotted as a function of Cycle 3 burnup. These resulta confirmed that there were quadrant tilts present in Cycle 3. The average positive tilt in the WX quadrant throughout the cycle was estimated to be about 1% and the maximum positive WX tilt at any time during the cycle was 1.7%. Also, a noticeable tilt change of between .7% and 1.5% occurred in each quadrant at about 150 EFPD in Cycle 3. These tilts were well within the technical specification limit: and did not constitute any safety or operational problems in Cycle 3; hence, no in-depth analysis was considered necessary at that time. However, subsequent calculations have revealed that although these tilts were essentially insignificant relative to Cycle 3 operation, they could have a significant impact on Cycle 4. The tilt in Cycle 3 would cause the fuel assemblies in the WX quadrant of the core to receive a higher burnup than those in the YZ quadrant. During the re-fueling, fuel assemblies in the WX and YZ quadrants were moved acroso the core (see Figure 20 ) into a region of higher importance, i.e. , towards the center of the core. This shuffle pattern placed more reactive fuel assemblies (due to the lower burnup) in the WX quadrant than in the YZ quadrant, thereby causing a Cycle 4 tilt distribution consistent with that measured. A computer analysis was performed to evaluate the magnitude of tilt which would be induced in Cycle 4 due to an asymmetry carried over from Cycle 3. The FLAME code was utilized to simulate an end of Cycle 3 burnup asymmetry of +2% in the WX quadrant and a -2% in the YZ quadrant. The fuel was then shuffled into the Cycle 4 pattern and a full core analysis was performed at the beginning of Cycle 4 to determine the effects of the burnup asymmetry. The analysis showed that this 22% burnup asymmetry at the end of Cycle 3 would cause the following tilts in Cycle 4: EFPD Power Level WI Tilt YZ Tilt 5 75% +6.50 -6.22 30 100% +4.50 -4.30 This calculation illustrates that the Cycle 4 tilt is very sensitive to the Cycle 3 asymmetry, and that the Cycle 3 tilt history was sufficient to cause most of the Cycle 4 tilt. As a further check, the FLAME code was used to calculate the Group 6 ejected rod worths in Cycle 4 with the burnup effects from a 12% burnup asymmetry at the end of Cycle 3. The ejected rod worths obtained were .29% ap for location N-12 and .56% ao for location D-4. This difference is consistent with the measured relative values of .24% ao for N-12 and .51% do for D-4. A detailed review has been conducted of the Cycle 3 thermal-hydraulic performance information. Core inlet and outlet temperatures as measured with RTD's and loop flows as measured with the Gentille system were normal and relatively constant throughout the cycle. There were no obvious anomalies in the hot let, cold leg, or steam generators. This conclusion is also supported by secondary side instrumentation. In addition, the characteristics of the Cycle 3 tilt were not consistent with the tilt characteristics that were seen in a test ac Oconee III where an inlet temperature difference was induced between the cold legs and the subsequent core power distribution was measured. The incore thermocouple data was analyzed for various times in Cycle 3 to obtain the relative temperature changes as a function of burnup. This analysis did not show any correlation of axit-channel temperature distribution asymmetry with the Cycle 3 tilt. The overall characteristics of Cycle 3 plant operation were reviewed to determine if there was any anomalous behavior which may have related to the Cycle 3 tilt. l There were nine maintenance outages during Cycle 3; one for the removal of , the Surveillance Specimen Tubes, one for turbine repair, two for control rod stator replacement and five for once-through steam generator (OTSG) tube plugging. The outage for the removal of the Surveillance Specimen Tubes occurred before the escalation to 100% FP during the cycle startup. Physics tests (described in Section IIIB) proved the control rod assemblies (CRA's) were i functioning properly at the start of Cycle 4. Therefore, no CRA fingers were lost as a result of rod trips. Two tubes in "A" OTSG and nineteen tubes in "B" OTSG were plugged during Cycle 3. This number of plugged tubes is small relative to the total number of tubes (15,531) in each OTSG and, as shown by the thermal-hydraulic data review, did not measurably chtnge OTSG performance. Iodine activities in the coolant, which indicates the amount of fuel re-leasing activity, were essentially constant throughout the cycle. Gross alpha activity was below detectable levels throughout the cycle, which shows there were no gross fuel failures during the cycle. Activated silver levels in the coolant were low in Cycle 3, consistent with levels seen in previous cycles. This shows the CRA clad integrity was maintained during Cycle 3. Cobalt - 58, Cobalt - 60, and total activated corrosion product levels were examined for Cycle 3, and no anomalies were found. Thus, other than the small tilt, the overall operating data from Cycle 3 do not exhibit any unusual characteristics which might be related to the Cycle 4 tilt. V. GENERIC TILT CONSIDERATIONS Since the discovery of the Oconee 1, Cycle 4 tilt, efforts have been in progress to perform an in-depth eval'ation u of tilt at other B&W plants. The unprocessed signal evaluation technique (described in the Section IV assessment of the Oconee 1, Cycle 3 tilt) was applied to determine as accurattty as possible 4 the tilt in all operating B&W plants. Both, current operating cycles and all previous cycles were reviewed for each. plant. This review showed that of the approximately 20 cycles of operating history at B&W plants, only five cycles had clearly discernible tilts: Oconee 1, Cycles 3 and 4, Oconee 3, Cycle 3, ANO-1, Cycle 2*, and TMI-1, Cycle 3. Except for Oconee 1, Cycle 4, all of these tilts were small (1 to 2% at 100% FP), all are currently well within technical specification limits, and pose no safety or operational concerns. However, in light of the effects that a small tilt at Oconee 1 eventually caused, an extensive program is being pursuea to evaluate all aspects of the current tilt situation and to minimize the impact of these tilts on future cycles. The various aspects of this program are described below. A. Modification of Core Shuffling Design Procedures As observed at Oconee 1, fuel shuffling techniques can have a substantial effect on core tilt changes from cycle to cycle. While normal design shuffling procedures do not in themselves cause any quadrant asymmetries, it is possible for the shuffle scheme to amplify or reduce an asymmetry from one cycle to the next. As previously mentioned, the practice of
" cross-core" shuffling can magnify tilts. Therefore, the " cross-core" shuffling procedure is being eliminated. Moreover, the revised shuffle procedures are being structured to minimize the impact of a previous cycle tilt by distributing the fuel more evenly among the four quadrants. For special cases, such as Oconee 1, Cycle 5, where a known tilt was present in the previous cycle, the shuffle scheme will be custom designed to account l for .the effects of the tilt on core power and burnup distributions. *A symnaetric ejected rod test (similar to the Oconee 1, Cycle 4 test) was I performed at 222 EFPD in Cycle 2. This test indicated no significant rod )
worth asymmetries, i
~ _
B. Symmetric Ejected Rod Testing The measurement of^the ejected rod worth in four symmetric core lo-cations by rod swap has proven to be an indicator of core symmetry. There-fore, this test is being recommended as part of the HZP physics testing program for upcoming startups. This test will provide an early indication of possible core asymmetries and will stimulate special tilt monitoring and evaluation efforts when necessary. C. Increased Level of Tilt Monitoring Tilt has been monitored routinely at each operating plant and by normal core follow efforts at B&W. However, as a result of the recent experience with tilt on Oconee 1, an increased level of tilt surveillance is being incorporated as part of the normal core follow efforts for each plant. The tilt from all operating plants will be closely monitored using the best l available analysis techniques. Any unusual and/or significant tilts ob- l 1 served will be reported to the operating plants. Also, feedback will be l provided to design personnel so that the tilt can be properly accounted for in the design of future cycles. D. Generic Tilt Evaluation Program An intensive program has been initiated to fully evaluate the cause of the measured tilt on a generic basis. A special Tilt Task Force has been convened which will function independently of the effort to license operating plants. The tilts observed at various operating units will be extensively analyzed and correlated to investigate the basic mechanisms which are initiating core asy:mnetries. VI.
SUMMARY
AND CONCLUSIONS l In summary, during Oconee 1, Cycle 4 startup a quadrant tilt was observed which was confirmed by four independent sources. An extensive investigation l l : 1 I l I ._. _
of this tilt has indicated that it was principally caused by an accentuation
, of the previous cycle tilt through. a '? cross-core" shuffling procedure. The technical specifications for Cycle 4 were revised to conservatively account for the observed tilt thus supporting continued safe operation of the plant.
Fuel shuffling design procedure changes have been made which will minimize the Propagation of tilts in the future. New monitoring and test procedures are being implemented for all operating B&W plants to provide additional surveillance and awareness of tilt. With respect to Oconee 1, Cycle 4, new technical specifications are being submitted concurrently with this report to support operation for 100 EFPD to the end of Cycle 4. Detailed analyses have been conducted which verify that Geonee 1 may operate with these new technical specifications without any degradation of the safety of the plant. Finally, a generic program is in progress to investigate the basic mechanisms which cause the small tilts measured at B&W operating cores. l l l l 1 l i
TABLE 1 - SUM *1ARY OF IIZP PilYSICS TEST RESULTS . MEASURED PREDICTED ACCEPTANCE EVALUATION OF ITEMS UNITS VALUE VALUE CRITERION ACCEPTANCE CRITERION
- 1. All Rods Out critical ppm Boron 1334 1328 !100 +6 ppmB Boron Concentration
- 2. Sensible Heat amps 1x10- NA NA --
- 3. NI Overlap decade >2 >l >l --
- 4. Total CR Group %Ak/k 2.998 2.76 110% -7.9% deviation Worth (5-7)
- 5. CRG 7 Worth %Ak/k .865 .76 !15% -12.1%
- 6. CRG 6 Worth %Ak/k .892 .88 !15% - 1.3%
7 7. CRG 5 Worth %Ak/k 1.241 1.12 115% - 9.7% e
- 8. CRG 1-4 Worth %Ak/k NA NA NA --
2
- 9. Ejected Rod (N-12) %Ak/k .39 .58 120% -48.7%
- 10. Diff. Boron Worth %Ak/k 1.067 0.988 10% - 6.5%
100 ppm
- 11. Temp. Coeff. of A. ARO A. .09 A. .06 A. + .15
-4 Reactivity Ak/k F i.4x10 x 10~4 B. ARI B. .70 B. .72 . .019
- 12. Moderator Coeff. A. ARO, Ak/k -4 A. .28 A. .14 1.4x10 A. .14 of reactivity per F x 10-4 & <.5x104 B. ARI B. .51 B. .53 B. .019
*I * - "'8"#*
- 1. % Deviation =
Measured X 100% Deviation = Predicted - Measured (for Items 1,11,12)
- 2. Corrected value for CRG 5 at 0% WD and measurement uncertainty.
TABLE 2
SUMMARY
OF CYCLE 4 TILT _DATE EFPD %FP WX XY YZ ZW 10/17/77 0.0 15 5.66 1.26 -6.94 0.01 10/19/77 0.3 40 3.66 0.73 -5.14 0.76 10/20/77 1.0 40 3.81 0.84 -5.36 0.71 10/23/77 1.6 31 3.33 1.39 -4.99 0.28 10/28/77 3.5 40 2.88 0.69 -4.42 0.84 10/31/77 5.8 75 2.88 0.82 -3.86 0.16 11/01/77 6.4 75 2.87 0.84 -3.82 0.12 11/18/77 17.9 74 2.65 0.61 -3.12 0.14 11/30/77 28.4 99 2.30 0.46 -2.52 -0.23 12/09/77 37.4 100 2.40 0.38 -2.30 -0.48 12/19/77 46.2 100 2.28 0.31 -2.13 -0.46 ! 1/04/78 56.6 100 1.67 .28 -1.80 .40 1/09/78 61.4 100 1.56 .25 -1.64 .34 1 TABLE 3 POTENTIAL CAUSES OF TILT CAUSES EVALUATION I. Control Components
- 1) Control Rod Decoupled Eltninated by rod exercise test at 15% FP
- 2) Control Rod Mispatched Eliminated by removal of all rods at 40%FP Test
- 3) Control Rod Finger or Fingers a. Eliminated for Control Rod Lodged in Fuel Assembly locations by insertion of control rods at 30%FP test
- b. Eliminated partial finger in unrodded assembly because low activated silver in crud
- c. Eliminated for Orifice Rod locations because dimensionally impossible
- d. Full finger in peripheral assembly credible. Incore data does not indicate a localized effect, therefore, low probability.
- 4) Asymmetric APSR Worth Eliminated by removal of all rods at 40%FP test
- 5) Lumped Burnable Poison Cluster Loaded By Mistake Eliminated by check of core loading II. F uel
- 6) Misloaded Fuel Assembly Eliminated by check of video tape of core loading
- 7) Abnormal Enrichment or Poison Check of fuel manufacturing records in Rods, Assembly, or Assemblies revealed no abnormalities
- 8) Asymmetric Fuel Burnup (caused Credible, examination of cycle 3 data by cycle 3 tilt) indicates a tilt existed.
- 9) Mechanical Failure Eliminated. Plant radiochemistry does not indicate gross fuel failures IABLE 3, CONT.
CAUSES EVALUATION III. Core & Internals
- 10) Flow Blockage Data does not support. The ejected rod worth measurements are conducted under isothermal (HZP) temperature conditions. Since the tilt was present under isothermal conditions, flow blockage can be eliminated as a cause.
Loose Parts Monitoring System has indicated no unusual " noise" in the reactor. i l l i
. \
l I
- a. I
. FIGURE I RELATIVE
- GROUP 6 NEASURED EJECTED ROD WORTHS i
- A '
B C 1 I
- D .si .39 E
.I2 G
H w_ .i i ,07 _y ! K l
.09 M
N .34 .24 0 - P l R i 1 2345 6 7 8 9101112131415 These values are useful only relative to each other and do not represent the actual worth of each ejected rod. l l l l
FIGU RE 2 FIXED INCORE DETECTOR SYSTEM A e . . c X . X - D . . . E e AV my e G F x -- . X l H . . . . . l x -- -- . M x
-- ~~ . . X . l N , e g . X X - -
E'S " . P e Z INNER SYMM. RI NG l A . . 9 OUTER ! O SYMM. RING 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 n 1. T ACTIV E T "[4 3/4 " FUEL 4 LENGTH 20 4/7" ^ _ 3 _ _ FIXED RHODIUM 2 X DETECTOR e e BOTTOM OF CORE wh
FIGURE 3 INCORE TILT MEASUREMENT AT 40% FULL POWER z A ' B 3.69 % M C 4,qt 3,q3 D E ,qq 3.i4 F 4.45 .q.oq 4.14 -1.01 1 H w. _y K g ii 4.33 L .51 -5.ss M _ zq
, 3,%
N O -m
.68 To .34 -- 5.6 To P
R 2 1 2345 6 7 8 910III2131415 l l
FIGURE 4 INCORE TILT MEASUREMENT AT l00% FULL POWER 4 8 2.2870 31 7o C ,.n am D
.99 2.29 4.34 -1.97 b l.91 -l.25 H w. _y K .i.iS
- 76 .45 -G33
-I.38 -1.86 N .03 -1.99 P
R _4670
-2.13%
Z I 2345 6 7 8 910II!2131415 l 1 l
FIGURE 5
~
40% FULL DOWER QU A JMNT TIL~~ BY LEV E _ X 2.43 .7 i TOP OF CORE 3.55 1.59 3.77 .22 3.69'(o 4.45 .6 I .76% 3.86 .76 - 3.91 .47 y 2.47 1.28 BOTTOM OF CORE W y
.63 - 3.77 i .04 - 5.18 .64 -4.83 i .687; 1.19 - 6.25 - 5.13 % ! - 5.94 l.31 l .24 - 4.62 l -I1 . - 3.64 Z l Jh.
r GURE 6 00 % rU__ DOWE R QU A J RA \lT ~~ _~~ 3Y _ EVE _ X 2.03 0.I3 TOP OF CORE 2.99 0.59 3.I 3 0.09 2.28% 2.72 - 0.31 .31"lo 2.22 0.28 1.7 i O.84 v O.83 0.32 BOTTOM OF CORE W Y
-0.41 -1.75 -1.8l -1.78 -0.90 -2.32 -46 (o . 0.49 -2.90 -2.13 7o 0.21 -2.71 -0.65 -1.90 0.08 -1.22 Z
l N1s
FIGURE 7 RADI AL PEAKING FACTOR COMPARISION
., AT 40% FP ., 3. 5 EFP D A
B i.* 86
'5 .u C i.
- i. n,4 i.a
- i. o, ur>
- i. i4
.u,a D . i oa i.1s .62 i.io i.i2 . ia E i. a i.26 i.3i i.2.
- i. io i.21 1.11 i.11 F i. i. i.so i.n i.i4 i.os
- i. i4 i.26 i.n i. it i.ia C .B5 152 i.35 1.n i.24 i.o9 Bu i.22 1.24 i.iS i.22 1.09 H us 44 i.ou .e4 i.is .9s
.9'T .a i 1.oq .95 K i.29 i.zi i.zo 1.2% i.it i.o9 L i.iu i.i9 i.i4 . 9, i.ou i.ou i.ia i.co i . o, i.i4 M .42 i.29 i.22. i.ou .9 t i.zz i.22 i.on 93 N .az i.is i.e. .% 1 15 i.09 0 - .ai i.i3 i.oa i.oi H***"#*d .% l.14 1.14 1 15 Calculated P i.iz i.iq R uu .s, 68 .Go l
1 2345 6 7 8 9101112131415 l I l fdeasured Predicted Power Level 40% 40% i j Group 7% WD 71 72 Group 8% WD 31 l 34 l Imbalance % -4.6% 9.3% Su rnup , EFFD 3.5 l 3.5 l 1
FIGURE 8 TOTAL PEAKING FACTOR CONPARISION AT 40 L F P , 3.5 E FPD A B i55 ia*
- 1. 2.1 i.o9 C i.ui i.ss i.u + .*'
i.a i.sa i.ua uo D i.s :- i'4 .82 1.ui 1.84 % E ,.4s i.uI ius i .u, 1.01 i.10 170 i.78 F i.ui i.us i.so i .u, i.48 i.M i .qr, i.sz i.e4 i.cA b po i.48 1.18 1.4 B 1.57 1.4 L i.zi i.no i.,c i.s4 i.no i.34 H .ai i S4 i.to i.44 i.is
.% I.35 i.24 i.49 i.32. 'n K i.r.i i si i64 i.qo i .,o i.too L i.si i.ss i.3<. i.53 i.4 1.fo1 1.M i.5% 1.51 1.G4 M i.24 i.u4 1 55 138 i.25 i.4i i.qo i.7o i .si i.3 t N i.ss i.4, i.44 i.42. i.us i . <.o 0 -
i.iu i.ss i.si i.3i *a==ed i.ai i.a i.ca u.s ca cu2acca P i.4, i.G'1 R .an .ns 9, .eu I 2345 6 7 8 9101112131415 tiea su red Predicted Power Level 40 40 Group 7% WD 71 72 Group 8% WD 31 34 Imbalance % -4.6% 9.3% Burnup, EFPD 35 3.5 l l
FIGURE 9 RADIAL PEAKING FACTOR COMPARISION AT 75% ,18 E F PD A B ioA 5
.68 .Bo C i.i4 i.06 i.is .
i.ii ... i.ii
. ,66 s
1.04 1.l(a .G Za i.68 i.io .46 b i.05 1.15 1.18 g.14 i.ca i.zS i.tb i.ig
}-_ i.ib i. IG i.is i.it i.08 i.ii i.29 t. is i.io 3.51 6fe i.28 i.40 i.i? t.it I.oS .BB i.2% i.t9 t.14 i.2s i.o9 H . <A i.co .94 s. i t .as .ii 49 . 92, i. io .%
K i 26 i.zi i zt i.1% i .7.s i.09 L i.i5 i. ii i.n i.ac. i.ou
- i. ife i. it i. io i.os i.it M .9i 94 i.z1 i.zi i.o, .wt i.ts i.zs i.oe 92 N .ai i.is i.io
.C4l i.is i.04 0 - .ss i.ii i.e. . .wa i.i t i. ii 1. io P i.iz
- i. t fo
.fA 58 Measured ; .7i .G2- Calculated i 2345 6 7 8 910111213I415 Measured Predicted i Power Level 75 75 Group 7:wo , 85 84 Group 8tWD 42 44 Imbalance 0 5% 0.5%
Burnup, EFPD 18.0 18.0 l l l l
FIGURE 10 TOTAL PEAKING FACTOR COMPARISION AT 757o FP.,18 EFPD A , B t 5' t 64 s.es i.e C i.sz ii2.ts, i $2-i.sz na
.a i i.sz D i24 i5 ^
- i. 2. i.43 .ao E i 22 i4s i4s i.43 i .1. i.42 i.4z i.4z F i.ss i.se i.ss i.44 i.zs i.s t i.46 i.s i i.43 i.31 h i.o
- l.4T i. (eO i.s 0 i.4o i.15 {
i.05 i.41 i.48 i.34. i.42. i.ti i H .as i22 i.i4 i ir- i52 ice i
.es s.io i.3o i. iz K i 45 ia i44 i.42. i.42. i.ta L i.ss i.2, is4 i.zi i.zi i.42. i.sz i.si i.so i.sz l % 1.os i.oA 1.4% i. M i.Li i.oS l i .*I Z i.42. i.30 i.io )
N i.os i.ss i.za i.og i.ss i.za O i.es i.za i.2<. i.sv seasurea l i.09 i.31 i.52 t.12. Calculated ; p i.as i.41 l R es 'a
.87 M(o l
i 2345 6 7 8 9101112131415 ' Mea su red Predicted Power Level 75 75 Group 7WD 85 84 Group 8%WD 42 44 imbalance 0.5% 0.5%
- 8urnup, EFPD 18.0 18.0 l
l l
. FIGURE 11 RADI AL PEAKING FACTOR COMPARISION AT 100% FP,28.4 EFPD A ,
B 94 *"
.eA .Bt C i.a i.o? i. n ., i i.u i.os i.u .,2 D i.= ,
i.is 65 i.oS i.oq .48 E i.as i.zz i.z s i.zz i . e. i . 2.i i.zi s.ie F i.is i.z. i.iu i.i4 i.os . i.ii i.z6 i. n i.oq i.u . b 8A i.16 134 1.i1 i.to 1.o?
.ss i.zi i.26 i. it i.zi i.og H ., o i.os .nz i.oa .*s ., s .9a .az i.oe .au K izs i. zz. i.ie i.zi i.zi i.e.
L i. iw i. o i.o2 i.oa i.oe
- i. i, i. n i.oe i.oy i. n M .94 i.zi i zi i.os .m A4 i.11 1 11 1.o'T AL N .az i.is i.oe
.9s i.i4 i.es O .at i.iz i.o2 i.04 m eeurea i .94 i.il i.H 1. i t Calculated l P i. i4 :
- 1. t1 l R ,i .si
.13 .G3 !
l i 2345 6 7 8 9 10 l I 12 13 14 15 Neasured Predicted Power Level , %HFP iOO 100 l Group 7, %WD 82.8 84.0 Group 8, two 34.8 38.0 t i imbalance -2.4% i.8% l Burnup, EFPD 28.4 28.4 l 1
FIGURE 12 TOTAL PEAKING FACTOR COMPARISION AT 100 To FP,28.4 EFPD A " B - iis i o4 i.o3 .98 C i.Za i.st i.si .e3
,. sz i .1,. i.sz .9 o D i za iss ' 9, '
i.so i.au E i.Zs i.4o i.a i.4i
~
i.so i.a i . . .i i i.az F i.30 i.48 i.st i.4a i.zs . i.sz i .4, i.28 i.au i.sz b l.Os 1.44 i.ss i.s4 i38 l 12, i.03 l.4I i.47 1.s3 1.4 i i.2G H .se i.ia i.cs i.2e i.or 89 i.14 i.08 i.28 i.ii K i.4 x- I.m i.ss 1.4 i i.4 i i.z9 L i.s6 i.26 i.u i.2s i.2s i.s4 i.sz i.so i.sz i.si M i.oT i.sg i.as i.2.i i.os i.io i.41 i.4 t i.si s.oe N is i.sz i.28 i., i i.s2. i.19 0 i.os i.u i.25 i. 2.i neaeurea
- i. io i. s2. i.s2 i .2.9 Calculated P i.ss i.34 R .e .u 61 ~
IG I 2345 6 7 8 910111213I415 MEASURED PREDICTED Power Level, %HFP 100 100 Group 7, %VD 82.8 84.0 Group 8, %WD 34.8 38.0 Imbalance -2.4% 1.8% Burnup, EFPD 28.4 28.4 1 FIGURE 13 RADI AL PEA' KING FACTOR COMPARISION AT l00 % FP., 37.4 EFPD i A , B Se $6
.es .e3 C i.i4
- i. i4 .ue '
t.ii i. cQ i. ii 97 D i.oe i . i r. *' t.07 l.o9 . (e6 E i.ov i. u i.ts i.tt I l.c7 i.to i. M t.iB i
- l. M l .Zf. i.i4 t.lt 1.09
- t. t t i.zr. i. i t g.oq t.u !
b .B8 t.25 1.54 i. t 4 1.11 1.07
.89 i.2.0 i.16 1. t L i.10 1 09 l H .u.
i.c i .9z i.os .9<. 1
.I5 As .% t i.oe 97 K i.n i .= i.n i.20 i.2.0 i.oe L i. ie i. n i.o2 i.oy i.ca i.u. i. n i.es i.o2 i.n M 92 .44 i.to i.zo i . o, .m t.20 i.2o i .o'T 9t N 92. i.is i.os R5 t.14 t.08 0 .a4 i.it i. i o i.o2 xe , urea 44 i. i t i. ii i. ii Calculated P i . u.
I. lG R .tt .uz
.,3 53 1 2345 6 7 8 9 10 I I 12 13 14 15 Measured Predicted Power' Level 100% 100%
Group 7, %WD 86 88 Group 8,%w3 36 38 Imbalance, % -1.9% 3.0% Burnup, EFPD 37.4 37.4
- Unavailable string
FIGURE I4 TOTAL PEAKING FACTOR COMPARISION AT 100 70 FP., 37.4 EFPD A , B i i9 i.os i.oS A9 C i.si . i. s i .se 1.34 s.ze 1.34 .a D i.za i.s4 ,
.e i.51 i.4e ' .19 E i.zs i.39 i.42. i.4o
- i.sz i.43 i.43 i.4a F i.ss i.4. i.34 1.4,r i.zs i.s4 i.ae i.so i.4a i.34 b l 0t i.4i 1.ss 133 i.sa i.2.1 i 03 1.43 i.4 e i.ss i.43 i.ze H .sa . :.n i.ov i.u i. ,
.se , . u. i. io i.za i.i4 K i:42 i.ss i.34 i 4s i.45 i.si b lM l% l.SZ g, g2, i . 2.5 l% l54 i.5z g.34 i.34 M i.05 13T i.34 i.zo 1.05 l ii 1.43 1.45 i.s4 1.o t N i.e3 i.31 i .3.
i It i.34 i.5i l 09 1.2*7 i.% i.15 Measured I. II i.34 i.34 i.18 Calculated P i.34 R .es .24
.s .,s i 2345 6 7 8 9101112131415 Measured Predicted . Power Level 100 100 Group 7, two 86 88 Group 8, %WD 36 38 Imbalance -1.9% 3.0%
Burnup, EFP0 37.4 37.4 Unavailable string
~
FIGURE 15 RADIAL PE AKING FACTOR COMPARISION AT 100% FP,46. 2 EFPD A , B 96 S"
.9 o 33 C i.is e s.is .v.
i i.it i.e i. it . D i .o - i. i s u' i.c6 i.oS 69 E i.oe i.Li i.u i.zo i.oe i. is i.12 i . t, F i. ie i.z3 i.lz i. i z. i.e. . i.IL i13 i.09 t.oe 1. tt
.67 i.zt i.30 i. it I.19 t.04 .no i.19 i.23 i.io 3 19 1.09 H ., i i.co .ao i . o<. .9s .44 .94 .90 1.06 9T K i.zo i. i e i.is i.19 i.iq i. on L i.is i. io i.os 1.00 i.ov l.iB i.it l .OG l.ob 1. it b .47 .9s i.tB l.iB i.os ,41 i.is i.is i.ou 94 N .at i. i4 i.02 .se i.is i.o2 0 .92 i. n i.oq i. ca seasurea .95 1. lt 1.12. t. is calculated P i. is i.iB R ,e .st .u .es i 2345 6 7 8 9101112131415 Measured Pred icted Power Level 100 foo !
Group 7 %WD 83 34 Group 8, %WD 34 ;g i ! Imbalance -1.3% -0.8% i Burnup 46.2 46.2 l Unavailable strin9 ' 1 I 4
FIGURE 16 TOTAL PEAKING FACTOR COMPARISION AT 100 To F P., 46.2 EF P D A , B iis i.o4 i.oc. i.oi C i.so = i.so .e i .1, i.zs i .z, .94 D i.zs i.49 ets i.u. i.4o 83 E i.zi i.39 i.se i.
- i.zu i.s3 i.ss i.
- F i.e i.44 i.sz i.as i.2s .
- i. z, i.4o 1.23 i.ao i .2, b i.co i.40 1.48 i.sz t.s7 i.iB
- i. oc. i. u i.4o i.zs 1.ss i.zs H .se i.is i.ou i.za i.es
.9z i.oa i.os i.zz im K i.* i.sz i.ss i.ss i.ss i.zs L i.e i.za i.za i.ie i.zz i.ai i .z, i.zs i.z4 i.z, M i.os . i. e i.sz i. ie i.o2 i.on s.ss i.ss i.24 i.it N i.cz i.z9 i.1s i.oq i.zy i.zs O i.es i.zs i .2 <. - i.zz seeaurea i.07 i .t'T i.17 i.53 Calculated P i.n i.ai R .ss .,4 91 .48 l 2345 6 7 8 910II12131415 Measured Predicted Power Level '
100 100 Group 7, %WD 83 84 Group 8, %WD 34 38 Imoalance -1.3% -0.8% Bu.nup, EFPD 46.2 46.2 Unavailable string
.. FIGURE 17 RADIAL PEAKING FACTOR COMPARISION AT l00% FP,56.6 EFPD A , B
- 85 90 61 l
C i.iz i.oe i.is .w. 1 i.19 1.09 1.19 80 l D i.ou i.ia .as i.oe i.oS .To' i.ob l.li 1.11 i. i9 i.08 1. 6 i. is i. iT : F i.ie i.12 i.iz i.is i.09 . i i4 1.It i.oS .os i.i9
.%1 1.11 i.19 i. I i i.tB l i.o'T .Cl O i.t B i.11 i.08 i.is ' i.oq H .59 i .o i 9o i.on .9s .I5 94 .89 a.05 94 K i.zi i. i e i.ie i.ie i.is i.on L i.e i.ii 1.o<. i . o <. i.ee i.iB l. ion i 04 1.05 i. t9 b .93 Ab i.%O i.iB i.04 .95 i.16 1. i B i.os .9%
N .9 s i.ib i.e. i 0'I i . i 2, i . o'T O .93 i.it i.io i.o, r .sored AG 1. i9 t . iCl .i4 Calculated P i.ia R .is .e4
.'Th .ich 1 2345 6 7 8 9 10 lI 12 13 14 15 Mea su red Predicted Power Level 100 100 Group 7, %WD 80 81 Group 8, %WD 32 34 Imbelance -1.3% 1.3%
Burnup, EFPD 56.6 56.6
.. FIGURE 18 - . TOTAL PEAKING FACTOR COMPARISION AT 100 To FP.,56.6 EFPD .
A , B - i.i' ioz i.o <. i.e i C i.29 i. ia i.so .92 ' i.Si i.17 i.si .93 D i.23 i45 Si i.ze i.4i .e3 E i.ia i.* i.ne i.34 i.ze i. 3, i.n i. 3<, F i.n i.a4 i.sz i.sq i .2, . i.ai i.as i.2s i.4, i.3i G i.oi i.a . i. 4 % i.sz i .3. i .1, i.ou i.3, i.43 i.zn i.32 i.u H .se i.i9 i.or. i.2s i.ov
.91 i. i i i.04 i.23 i.i3 K i.sv i.s4 i.*
i.s, i . 3, 124 L i.3o i.za i.zy i.iy i.23 i.se i.si i.19 i.2s i.si il
' M i.os i.sv i.34 i.is i.e. l
- i. t t i.37 i.s r i.zs i st l.od i.sz I.14 i
! i. it i.so i.14 0 i.os 1.1, i . 2, i.zz xe ,ured
- 1. i i i.si i Si I
i.si Calculated I P i.ss i i.36 R .e, ., s l
- .St .28 1 2345 6 7 8 9101112131415 Measured Predicted Power Level 100 100 Group 7, %WD 80 81 Group 8, %WD 32 34 Imbalance -1.3% 1.3%
Burnup, EFPD 56.6~ 56.6
FIA RE 19 ! _. __ _ = . .. .- _ _ 2- 'P
- i ;- _. -
__ _- m-- _ - 2__ _ - _ = _ _ :_ =_.-__:+.-,*-_
^
_. .V ' gg. : ; ( . - , s .- e -::
*E - . n 'n W- . _ . _ . _ . . .,., .-' ,i - N_1s m ;__ _ _ . - , _ _
c 5
-I F 9:' 'Y 2 (( . . . - _ _ _ c. ,
Ti w - ___ LM'~.E-- - - s.o . . v
.u _ - - _
e--
'"~.g_. g . - E.} - \r f n
t.-
~ .W'i LC.- ?-T' a -- . . =
i--_,_ g g_ f-
. _.-',,. y . _ _ __ _ . . _ _ _ . . - v2- - - '.G" h -
u t-c____.
-K 'Y_2:x=_ n
_=.. _s n H ,,TV' ' _ m_-" '"g y _- b i '_
.-.._L..
V- N " f
; ,i _ ._m. .. _ L J . -.L @ a _. _ $-12. '
6 ._- _ .-w / _A. 'W
;!Njf~5 & N?- ?= . $ '--5w' .~.__$5't. ~~ - w_-
_i.---_'.m= s_.._..--=
', , ,..W t --
Z - c g-- '
,g, _
6 ,/ m _.---.. =.- -g-..---; _ _t_- = _ _ _ _ [_- - - m E-g
- s. - __ _ _ - . . . _ _ . _ _ . _ , _
-._.2__._;._c_._
_ - :t-=? t .- r- _d
- - + ..___ J =
Li Z ', i _.- -
-- _ t - - .:gt?:55 2* f , _ . - i aE -
___o.__. . g--_..- . . . . EM- !- I _1 ._.__- _ " -~ ~ * ~ ~_ ? I" : _p y *p"u-" :: l
* ----- ! ".1".- ~ Z J. : *" * .___I~
7.]s ... ~ . - * - - - *--C- f q
.( % i - - --+
1 1
. : _-l__;.; ;;--..; -;. c:-.; :r d.
t9_--. .
. .- 1 ;g; j' = E %=e .Xis ! 2.: =
T _-Mi'Mi i-h, z 56 :-
, y_=- = -
r-: =
*- + s . _ . _-. h_ .x- == - - = =m s ,_ _-.
l'*'"-" ) c N- 5- p- _._ _. _. ~ l c.--- 3 (_ : . ._ y y- _ _ . . _. _ . .- - . _
.g.= g.:; _ . _ _ =_=
[ m= .= _M e.. ee.e.* m.
.._.t_.. .__ , _ . - g_.w- , ..- . _ _,r-*.7 V '+ - = .- - ~ _ - ~ - . t . ! 7 --t 3._ m __ ; - p_. . . _ . .. --b-. L. .,., ;_, .,,y.__ ,a ,;]. 1
_t-*..__-_--_-.: . n
* " - " " - ~
_.__.-___.r . , , s_.__ _:=b ._ . 8'-"-"'-
< _ _ - =. W ._ _. . . ._ ,__._ _--__ ___ - - _. _- _._. ,__= .__.__,_.____-..n. _ ..
C *. . !:
- rw--- ? - - - - -- -
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- Figure 20 Cycle 3 to 4 Fuel Shuffle Map FUEL TRANSTER E CANAL
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I 6 6 6 6 6 A 48 48 6 6 6 6 6 6 48 N9 06 N-7 8 5 5 48 6 6 48 5 5 48 6 6 g.9 0-12 P-11 u-8 P5 04 u7 j C 5 2 6 6 48 5 48 5 , 5 6 6 d3 5 P 12 u 10 R8 u6 P4 P6 gg) 0 (Itvi) P-10 5 4A 5 48 5 5 48 6 6 48 5 5 4B 09 R9 L4 R-7 07 03 L-2 K5 K.ll L.14 0 13 _E 48 48 5 5 6 6 5 48 48 5 48 5 6 6 5 K9 R 10 0 10 R6 K7 K-3 N-2 N3 F N 13 N 14 K-13 5 5 48 5 48 6 5 5 48 5 48 6 48 5 48 N4 L1 K1 L-5 u2 K4 j 4 14 K 15 L-15 N 12 0-6
,q K-12 L il 4A 5 48 48 6 48 5 4A 5 48 48 48 5 4A - ,_ 6 H3 L-3 H6 H-1 H5 F3 H 11 H 15 H-10 F 13 H-13 H8 H L 13 6 48 5 5 48 5 48 48 5 5 4B $
48 5 6 G4 l F-15 0 12 C8 04 F-l G-1 F5 E2
, K, G-12 E 14 F 11 G 15 5 5 6 6 5 48 5 48 48 6 6 5 5 4B 48 A 10 C6 A6 G7 G3 02 0-3 L, 0 13 0-14 G-13 69 4A 5 48 5 5 48 6 6 48 5 5 48 5 u G.Il F .14 C 13 C9 A9 F8 A7 C7 C-3 F2 G5 j 2 2. 6 6 5 48 5 48 5 5 gg 6 5 6 c3 A8 E6 84 8-6 g,) l N (sn) 8 10 B 12 E 10 l 5 48 5 5 48 6 6 G S 48 5 0 E9 C-12 B 11 E-6 85 C4 E-7
[ 48 48 6 6 6 6 6 6 48 l I 09 C-10 07 6 6 6 6 6 R Z l 10 11 12 13 14 15 4 5 6 7 8 9 1 2 3 l Baten Previous Core Location a i l 1
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