ML20128H028
| ML20128H028 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 10/04/1996 |
| From: | WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP. |
| To: | |
| Shared Package | |
| ML20128G993 | List: |
| References | |
| NUDOCS 9610090213 | |
| Download: ML20128H028 (41) | |
Text
_
APPLICABILITY OF WCAP-14181 PRA RESULTS TO VOGTLE i
Table of Contents Section Pace 1
1.0 INTRODUCTION
2 2.0 PLANT COMPARISON 3
2.1 Spent Fuel Pool Characteristics 3
2.2 Boron Dilution initiating Events 5
2.2.1 Reactor Cavity Pneumatic Seal Failure 6
2.2.2 CCW Leak 6
2.2.3 Seismic Event 7
2.2.4 Tornado Event 8
2.2.5 Random Pipe Breaks 8
2.2.6 Demineralizer Valves / Makeup Valves /
9 Letdown Valves Open 2.2.7 Initiating Event Results 12 2.3 Boron Dilution Times and Volumes 12 2.3.1 Consideration of Vogtle Dilution Sources 17
3.0 CONCLUSION
S 18
4.0 REFERENCES
19 1
9610090213 961004 PDR ADOCK 05000424 P
ppg
l
1.0 INTRODUCTION
l In an analysis documented in WCAP-14181, " Evaluation of the Potential for Diluting PWR Spent Fuel Pools" (Reference 1), a generic methodology was applied to identify potential events which could dilute the soluble boron contained in a representative PWR spent fuel pool. The methodology utilized a Probabilistic Risk Assessment (PRA) of a " composite plant" to calculate the frequencies of these dilution events.
The results of that PRA supported the conclusion that the event frequencies are less than the NRC Safety Goal Policy Statement target risk objective of 1.0E-06/ry for the assumed composite plant.
In order to form a valid judgment regarding the applicability of the conclusions of WCAP-14181 to Vogtle, a comparison of the Vogtle-specific spent fuel pool features to those of the
" composite plant" was made. The specific items compared are discussed in Section 2.0 of this report. In addition, Vogtle-specific boron dilution events were examined to determine the time available for the operators to respond to a range of dilution events. These representative events considered nominal conditions at Vogtle and were compared to the best estimate case of Reference 1. Deterministic calculations were then performed to define the critical dilution times and volumes for Vogtle. This data was compared to the analogous data for the composite plant. Finally, the dilution sources present at Vogtle were compared to the critical dilution volume to determine the feasibility of a spent fuel pool dilution event. The specific dilution events evaluated for Vogtle are discussed in Section 2.3.
2 4
l 2.0 PLANT COMPARISON 1
]
To assess the applicability of the generic PRA results to Vogtle, the following plant-specific features and characteristics were evaluated:
l Spent Fuel Pool and Related Systems Dilution Sources Dilution Flow Rates Boration Sources j
j Instrumentation l
Administrative Procedures Piping 4
Loss of Offsite Power impact
{
Boron Dilution Initiating Events Boron Dilution Times and Volumes i
4 i
2.1 SPENT FUEL POOL CHARACTERISTICS i
Table 2-1 provides a comparison of relevant spent fuel pool data for the composite f.
plant and Vogtle.
j i
a i
j 3
d
l 1
TABLE 2-1 SPENT FUEL POOL COMPARISON - VOGTLE vs COMPOSITE PLANT l Plant Feature l WCAP-14181 Composite Plant i Vogtle Pool (each pool-2 total)
{
i Pool Water Volume (gal) 232,000 447,030 (without racks or fuel assemblies) 4' 357,500 w/ racks and assemblies When both pools are connected total water volume is 715,000
)
Typical Pool Boron 2200 2400 i
Concentration (ppm)
Location Fuel Building, Top Floor, Seismic I Fuel Building, Grade elevation, Seismic !
Unborated Water Sources CCW. Demineralized Water, CCW, Demineralized Water, Reactor Makeup Water, Fire Reactor Makeup Water, Fire Protection, SW Protection, Utility Water Borated Water Sources CVCS, RWST RWST, RHT i
Piping near Spent Fuel Pool Reactor Makeup, Fire Protection Fire Protection, Demineralized Demineralized Water, CCW, SW Water, Utility Water, Normal Chilled Water Dilution Flow Rates 100 gpm for Demin Water, 2400 gpm for Fire Protection, Reactor Makeup, Fire Protection 375 gpm for Demin Water 600 gpm for Normal Chilled Water, 500 gpm for CCW, SW 45 gpm for Utility Water Instrumentation 1 Train Level Alarm, No Safety 1 Train Level Alarm, No Safety Related Power Related Power 2 alarms total for the two pools i sump alarm, No Safety Related Power i
Loss of Offsite Power Cannet Use RWST Can use RMWST OR RWST (gravity feed)
Leaks in SFP Heat Exch.
To SFP from CCW To SFP from CCW i
Administrative Controls in effect In effect except 1) Currently sample boron 1/ month. 2) Potential dilution path valves are not tagged as such.
4
2.2 BORON DILUTION INITIATION EVENT Based on a review of Vogtle data (i.e., Licensee Event Reports pertaining to spent fuel pool events), one spent fuel pool boron dilution initiating event, previously undetermined in the generic study, was identified. This event was the diversion of letdown flow to the SFP transfer canal due to an improper valve lineup following SFP makeup from the Recycle Holdup Tanks (RHTs). The justification for disregarding some potential initiating events as discussed in Reference 1 is likewise valid for Vogtle.
Note that for Vogtle, the typical spent fuel pool boron concentration is 2400 ppm. This was assumed to be the starting point in this analysis for a dilution event. Per Reference 2, the minimum soluble baron concentration necessary to preclude loss of an acceptable margin to criticality is 1250 ppm. Thus,1250 ppm was assumed as the endpoint for the analysis of Vogtle dilution events.
Further note that the SFPs are normaily connected and contain a combined volume of approximately 715,000 gallons. This value for SFP volume conservatively disregards the Cask Loading Pit which is located between the pools and is part of the total water volume i
when the pools are connected.
When the pools are separated, the volume of each individual pool is approximately 357,500 gallons.
The pools are typically connected approximately 51 weeks out of the year.
External flood water is not expected to enter the SFP. While the SFP is at approximately grade level (220'), the probable maximum flood is at elevation 165' msl.
Finally, the Vogtle analysis assumed that, for the Seismic and Tornado cases where offsite power is lost, the SFP alarms would be available since their battery back-up power supplies are rated for two hours and the dilution flowrate into the SFP would cause the high level alarm setpoint to be reached in as little as 5 minutes.
5
The following sections (2.2.1 - 2.2.7) further discuss the differences between the composite plant and Vogtle in the treatment of the initiating events for SFP C :to.1.
2.2.1 REACTOR CAVITY PNEUMATIC SEAL FAILURE This WCAP-14181 initiating event is not applicable to Vogtle. Vogtle has a permanent cavity seal ring that is inspected for damage which could affect cavity sealing prior to l
flooding the refueling cavity.
2.2.2 CCW LEAK The initiating event frequency, event tree, and top event descriptions discussed in Reference 1 for the composite plant are applicable to Vogtle. In addition, the WCAP-14181 assumption of a 100 gpm leak rate is valid for Vogtle.
However, calculated allowed operator action times are different for Vogtle. Specifically, the detection (DETECT LATER) and response (OPERATOR RESPONSE) times are much longer for Vogtle due to its larger pool volume. Based on the calculated dilution time for a 100 gpm dilution flowrate for the Vogtle pool volume, over 77 hours8.912037e-4 days <br />0.0214 hours <br />1.273148e-4 weeks <br />2.92985e-5 months <br /> are available for detection and response. This is over four times as long as the detection / response time calculated for the best estimate case of the composite plant. With the assumption of 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> operator rounds, the probability of detection is greater than that for the composite plant. Thus, for this initiating event, Vogtle is bounded by the analysis of the composite plant.
The dilution event frequency for the Vogtle large pool due to a CCW leak is calculated to be 4.61E-10/ry. The dilution event frequency for the Vogtle small pool due to a CCW leak is calculated to be 9.60E-10/ry. Thus, the overall dilution event frequency due to a CCW leak is (4.61E-10/ry) (51/52)+(9.60E-10/ry)(1/52) = 4.71E-10/ry which is less than the 1.5E-08 /ry frequency calculated for the composite plant.
6
l l
l 2.2.3 SEISMIC EVENT l
For a Vogtle seismic event, the safe shutdown earthquake is 0.2g (Reference 3). From NUREG-1488 (Reference 4), the mean frequency of exceedance for a.2g earthquake is approximately 2.95E-04/ry.
Thus, the seismic initiating event frequency for Vogtle is greater than the 2.0E-04/ry seismic.aitiating event frequency assumed for the composite plant.
The maximum flow rate from postulated pipe ruptures in the nonsafety-related systems located in the vicinity of the SFP is assumed to be 3520 gpm for this analysis: 2500 gpm for Fire Water,375 gpm for Demineralized Water,45 gpm for Utility Water, and 600 gpm for Normal Chilled Water (a closed system - during the first 15 minutes of the event, a total of 9000 gallons of water could be added by Normal Chilled Water before the system is effectively drained). If cffsite power is available, a 3520 gpm flow rate for the first 15 minutes and 2920 gpm for the remainder of the event are assumed. These flowrates would take approximately 2.6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> to dilute the large pool to the assumed endpoint dilution of 1250 ppm. If offsite power is not available, the dilution sources are assumed to be: 2500 l
gpm from the Fire Water system,120 gpm from gravity drain of the Demineralized Water, 300 gpm for Normal Chilled Water by gravity drain (total water admitted is 9000 gallons in 30 minutes), and 40 gpm for Utility Water by gravity drain. A total flowrate of 2960 gpm would exist for the first 30 minutes, then 2660 gpm for the remainder of the event. Under these conditions, the dilution endpoint for the large pool would be reached in approximately 2.9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br />.
The dilution event frequency for the Vogtle large pool due to a seismic event is calculated to be 1.26E-07/ry. The dilution event frequency for the Vogtle small pool due to a seismic event is calculated to be 1.33E-07/ry. Thus the overall dilution event frequency due to a seismic evert is (1.26E-07/ry) (51/52) + (1.33E-07/ry) (1/52) = 1.26E-07/ry.
l l
7
2.2.4 TORNADO EVENT The Vogtle initiating event frequency for a tornado of sufficient magnituae to be of interest is 1.0E-07/ry. The tornado is assumed to cause a loss of offsite power and the rupture of the piping in the vicinity of the SFP. The pumps for the demineralized water system, normal chilled water system, and the utility water system would not operate following the loss of offsite power. Therefore, if these pipes were ruptured, these systems would deliver unborated water to the spent fuel pool via gravity drain. The piping that could rupture in the vicinity of the Vogtle spent fuel pool as a result of a tornado which is of the greatest significance is the 2500 gpm fire protection piping. The total flow from these sources to the a
SFP due to a tornado with a loss of offsite power wt. be 2960 gpm for 30 minutes, then 2660 gpm for the remainder of the event. The dilution endpoint of 1250 ppm would be reached in approximately 2.9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br />, a shorter period of time than the calculated 3.6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> for the composite plant.
The dilution event frequency for the Vogtle large pool due to a tornado event is calculated to be 8.52E-11/ry. The dilution event frequency for the Vogtle small pool due to a tornado event is calculated to be 8.99E-11/ry. Thus, the overall dilution event frequency due to a tornado event is (8.52E-11/ry) (51/52) + (8.99E-11/ry) (1/52) = 8.53E-11/ry.
e 2.2.5 RANDOM PIPE BREAKS The following differences from the event considered in the Reference 1 analysis are noted.
For Vogtle, there are 165 pipe sections (10' to a pipe section) in the vicinity of the spent fuel pool. The composite plant considered 50 pipe sections. Using a fault tree methodology, the random pipe break frequency for Vogtle is calculated to be 4.39E-04/ry.
This value is approximately three times the 1.3E-04/ry frequency calculated for the composite plant.
8
The accident sequence modeled for the composite plant includes a split fraction for the probability of a break of safety related piping. Thus, the composite plant model assumed a 500 gpm dilution flow rate from a safety related piping break and a 100 gpm dilution flow rate for a non-safety related piping break. For Vogtle however, there is no safety related piping in the vicinity of the spent fuel pool. As noted in Table 2-1, the dilution flow rates for the fire protection, demineralized water system, normal chilled water, and utility water are 2500,375,600, and 45 gpm, respectively, which results in a total flow significantly greater than that assumed for the composite plant. As a result, with respect to operator detection and response time, calculations performed in Section 2.3 indicate that, considering of the larger pool volume, 3.1 hours1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> are available at Vogtle for the largest single random pipe break compared to 3.6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> for the composite plant.
The remaining top events for the random pipe break event of the composite plant are applicable to Vogtle. Based on the above, the Vogtle random pipe break is bounded by the seismic event considered for the composite plant.
The dilution event frequency for the Vogtle large pcol due to a random pipe break event is calculated to be 1.21E-07/ry. The dilution event frequency for the Vogtle small pool due to a random pipe break event is calculated to be 5.61E-07/ry. Thus the overall dilution event frequency due to a random pipe break event is (1.21E-07/ry) (51/52) + (5.61E-07/ry) (1/52)
= 1.29E-07/ry.
2.2.6 DEMINERAllZER VALVES / MAKEUP VALVES / LETDOWN VALVES OPEN A discussion of spent fuel pool dilution events due to the mispositioning of the subject valves at Vogtle is provided below along with the determination of the associr'ed initiating event frequencies.
I i
Demineralizer Valves Open This event is modeled by failure to close and verify closed one valve (8.29E-04), followed by failure to close two other valves (failure to close the first valve (5.0E-03] and a conditional failure to close the second valve [0.5] from WCAP-14181). The frequency of j
this event is 2.07E-06/ry.
The dilution event frequency for the Vogtle large pool due to a demineralizer valves event l
is calculated to be 6.85E-13/ry. The dilution event frequency for the Vogtle small pool due to a demineralizer valves event is calculated to be 1.03E-11/ry. Thus, the overall dilution event frequency due to a demineralizer valves event is (6.85E-13/ry) (51/52) + (1.03E-11/ry) (1/52) = 8.70E-13/ry.
Misalignment of Valves Interfacing with the Spent Fuel Pool l
Normal makeup of the SFP is via the Reactor Makeup Water Storage Tank (RMWST).
This source is non-borated water. Once the valve is opened for makeup to the SFP, continuous monitoring and verification of closure of the valve are required by procedure.
I This dilution event is modeled by the operator failing to close the makeup valve and a verifier failing to verify the valve closed, or error of omission with verification (8.29E-04) multiplied by the average annual frequency of valve opening (50) which equals 4.15E-02/ry. Thus, the frequency of this event is 4.15E-02/ry. The subsequent Vogtle top events j
are the same as those for the composite plant.
The dilution event frequency for the Vogtle large pool due to a misaligned makeup valves event is calculated to be 6.36E-09/ry. The dilution event frequency for the Vogtle small pool due to a misaligned makeup valves event is calculated to be 4.36E-08/ry. Thus, the overall dilution event frequency due to a misaligned makeup valves event is (6.36E-09/ry)
(51/52) + (4.36E-08/ry) (1/52) = 7.08E-09/ry.
10
An additional potential dilution event considered was a valve interfacing with the spent fuel pool transfer canal and the CVCS letdow stem being left open after makeup has been provided from the RHTs to the SFP for evaporative losses. Vogtle SFP makeup from the RHTs is performed by closing the inlet to the RHT that is to be transferred to the SFP. The flowpath is such that if the CVCS letdown divert valve were to divert after the procedure for transfer was complete (with the errors of not opening the RHT inlet and not closing two valves to the SFP inlet from the Recycle Evaporator feed demineralizers). This could result in a flowrate of up to 120 gpm to the Spent Fuel Pool Transfer Canal. The transfer canal would fill and spill into the SFP.
The dilution event frequency for the Vogtle large pool due to a misaligned makeup valves event is calculated to be 5.49E-10/ry. The dilution event frequency for the Vogtle small pool due to a misaligned makeup valves event is calculated to be 7.54E-10/ry. Thus, the overall dilution event frequency due to a misaligned makeup valves event is (5.49E-10/ry)
(51/52) + (7.54E-10/ry) (1/52) = 5.53E-10/ry.
11
-= - _ - _
i 2.2.7 INITIATING EVENT RESULTS Based on Sections 2.2.1 - 2.2.6, it can be concluded that the total Vogtle spent fuel pool boron dilution event frequency (approximately 2.6E-07) is of the same magnitude as the frequency calculated for the composite plant (3.8E-7) using the generic methodology i
presented in Reference 1.
TABLE 2-2 Comparison of Dilution Event Frequencies EVENT WCAP-14181 VOGTLE CCW LEAK 1.5E-8 4.7E-10 SEISMIC 7.3E-9 1.3E-7 TORNADO 4.1 E-9 8.5E-11 RANDOM PIPE BREAK 2.9E-7 1.3E-7 DEMIN VALVE OPEN 5.6E-8 8.7E-13 MAKEUP VALVE OPEN 1.0E-8 7.1 E-9 LETDOV,N DIVERT 5.5E-10 REAC' OR CAVITY SEAL 3.3E-12 N/A TOTA.
3.8E-7 2.6E-7 2.3 BORON DILUTION TIMES AND VOLUMES For Vogtle, the normal boror :encentration maintained in the spent fuel pool is in the range of 2400 ppm. Based on the Vogtle criticality analysis, the soluble boron concentration necessary to meet criticality requirements (i.e., a k., < 0.95) is 1250 ppm. These were the endpoints considered for the deterministic evaluation of dilution volumes and times and a boron dilution event of 1150 ppm (2400 ppm - 1250 ppm) was evaluated. This amount of 12
dilution is greater than that which results in the 820 ppm considered as the best estimate l
case for the composite plant analysis. The dilution volumes and times for the Vogtle scenarios are calculated based on the following equation:
t
= In (Co / C )V/O (Equation 1)
Where:
i ta = time to dilute Co = the boron concentration of the pool volume at the beginning of the event C
= the boron endpoint concentration O = dilution rate (gallons of water / minute) j V = volume (gallons) of spent fuel pool.
I l
The time to dilute depends on the initial volume of the pool and the postulated rate of I
dilution. At Vogtle there are two 447,030 gallon spent-fuel pools which are normally I
opened to each other. The volume of the combined pools (referred to herein as the "large l
pool") was derived by assuming that 20% of each pool's gross volume is taken up by spent j
fuel racks and spent fuel. Therefore, the large pool volume is (447,030) (.80) (2) = 715,248 or approximately 715,000 gallons. This is a conservative value since the volume of the shared cask loading area would be filled with borated water and an integral part of the combined pools, but was not included in this analysis. When the pools are separated, a i
single (small) pool volume is assumed. This volume is half of the large pool volume, or 357,500 gallons (again allowing for the spent fuel and racks).
Equation 1, above, was used to calculate the dilution times for a range of dilution rates from 3520 gpm to 45 gpm for the spent fuel volumes cited above. Tables 2-3 and 2-4 list the Vogtle dilution times and volume data for a dilution event from 2400 ppm to 1250 ppm boron for both the combined (large) pool and single (small) pool cases for the range of dilution flow rates considered. Table 2-5 lists the calculated dilution times and volume data c
for the composite plant dilution event from 2200 ppm to 1380 ppm.
13
TABLE 2-3 Vogtle Dilution Time & Volume Data for Combined (Large) Pools Dilution Event : 2400 ppm to 1250 ppm J
initial Boron Concentration - 2400 ppm Final Boron Concentration - 1250 ppm SFP Volume - 715,000 gallons Dilution Volume - 466,413 gallons Dilution Rate Time to Dilute (gpm)
(minutes)
(hours) 3520 132.5 2.2 2960 157.6 R3 2660 175.3 2.9 2500 186.6 3.1 600 777 13.0 300 1554 25.9 200 2332 38.8 120 3887 64.8 100 4664 77.7 45 10365 172.7 14
TABLE 2-4 Vogtle Dilution Time & Volume Data for Single (Small) Pool Dilution Event : 2400 ppm to 1250 ppm initial Baron Concentration - 2400 ppm Final Boron Concentration - 1250 ppm SFP Volume - 357, 500 gallons Dilution Volume - 233,206 gallons Dilution Rate Time to Dilute 2
(gpm)
(minutes)
(hours) i 3520 66.3 1.1 i
2960 78.8 1.3 2660 87.7 1.5 2500 93.3 1.6 600 388.7 6.5 300 777.4 12.9 200 1166 19.4 120 1943 32.4 100 2332 38.9 45 5182 86.4 15
'I i
i TABLE 2-5 Composite Plant Dilution Time & Volume Data I
Dilution Event: 2200 ppm to 1380 ppm Initial Boron Concentration - 2200 ppm Final Boron Concentration - 1380 ppm SFP Volume - 400,000 gallons i
l Dilution Rate Time to Dilute (gpm)
(minutes)
(hours) 1500 124 2.1 1000 187 3.1 500 373 6.2 300 622 10.5 j
250 746 12.4 200 933 15.6 s
150 1244 20.7 j
100 1866 31.1 50 3731 62.2 16
I 2.3.1 CONSIDERATION OF DILUTION VOLUMES As can be seen in Tables 2-3 and 2-4, a large volume of diluting water, compared to the composite plant, is necessary at Vogtle for a spent fuel pool boron dilution event to occur.
For a dilution event from the nominal spent fuel pool boron concentration of 2400 ppm to a boron endpoint concentration of 1250 ppm, a dilution volume of nearly 466,000 gallons e
(approximately 65% of the normal pool water inventnry) is required for the large pool.
When the pools are separated, the volume requir:2d for the subject dilution becomes approximately 233,000 gallons (again approximately 65% of the normal pool water inventory).
To assess the potential of a spent fuel pool boron dilution event at Vogtle, the water available to dilute the spent fuel pool was determined and can be compared to the volumes required for dilution. The Vogtle dilution sources are summarized in Table 2-6 below.
TABLE 2-6 Vogtle Dilution Sources Dilution Source Quantity Available Total
]
Water Water (gal)
(gal)
Fire Protection Tank 2 (Shared) 300,000 600,000 Demin Water Tank 1 (Shared) 250,000 250,000 Reactor Makeup Tank 2 (1 each unit) 165,000 330,000 lomponent Cooling Surge Tank 4 (2 each unit) 2,200 8,800 Water Utility Water Tank 1 (Shared) 300,000 300,000 t
17
Although the CCW system and the other tanks have makeup capability from other systems, detection of a dilution event via level alarms and/or visual inspections would be expected long before a dilution to 1250 ppm would occur.
3.0 CONCLUSION
S Based on the above analysis, the spent fuel pool boron dilution event frequency for Vogtle is approximately 2.6E-07, which is the same order of magnitude as the composite plant analyzed in WCAP 14181 and less than the NRC Safety Goal Policy Statement target frequency risk level objective of 1.0E-6/ry. Furthermore, evaluations show that a large volume of water (466,000 gallons for the large pool and 233,000 gallons for the small pool) would be necessary to dilute the spent fuel pool to the minimum soluble boron concentration required to preclude loss of an acceptable margin to criticality at Vogtle (1250 ppm). Since such a large water volume addition is required, the dilution event would be readily detected and terminated by plant personnel.
18 m
i
4.0 REFERENCES
l l
1.
WCAP-14181, " Evaluation of the Potential for Diluting PWR Spent Fuel Pools, July 1995.
l 2.
Vogtle Units 1 and 2 Spent Fuel Rack Criticality Analysis with Credit for Soluble Boron, June,1996 l
3.
Vogtle Updated Final Safety Analysis Report.
4.
NUREG-1488, " Revised Livermore Seismic Hazard Estimates for Sixty-Nine Nuclear Power Plant Sites East of the Rocky Mountains," US Nuclear Regulatory Commission, Final Report, April 1994.
5.
NUREG/CR-1278, " Handbook of Human Reliability Analysis with Emphasis of Nuclear Power Plant Application - Final Report," US Nuclear Regulatory Commission, August 1983.
19
..--....-. - -...~.
l' l
ENCLOSURE 7 i
{
VOGTLE ELECTRIC GENERATING PLANT i
REQUEST TO REVISE TECHNICAL SPECIFICATIONS i
CREDIT FOR BORON AND ENRICHMENT INCREASE FOR FUEL STORAGE l
4 COLR SECTIONS i
l l
The following sections would be inserted into the COLRs for VEGP Units 1 and 2. The COLR section numbers for the current COLR would be new section numbers 2.9 and 2.10. The COLR section numbers for the COLR associated with the ITS may be different but the wording would be the same. A marked up version of the current COLRs for Units 4
1 and 2 are included for information. When the COLR for the ITS is issued, the sections l
for the fuel storage pool will be added as independent sections. Therefore, the page l
numbers and section numbers may differ.
Proposed new sections for the Unit 1 COLR a
2.9 Fuel Storage Pool Boron Concentration (Specification 3.7.17) l 2.9.1 The boron concentration shall be greater than or equal to 1100 ppm.
i 2.10 Fuel Assembly Storage (Specification 3.7.18) 2.10.1 All Cell Storage Storage of 17x17 fuel assemblies in any cell location. Fuel assemblies must have an initial nominal enrichment no greater than 2.0 weight percent U-235 or satisfy a minimum burnup requirement shown in table 2 and figure 10.
2.10.2 3-out-of-4 Checkerboard Storage Storage of 17x17 fuel assemblies in a 3-out-of-4 checkerboard arrangement with empty cells. Fuel assemblies must have an initial nominal enrichment no greater than 2.70 weight percent U-235 or satisfy a minimum burnup requirement shown in table 2 and figure 10. A 3-out-of-4 checkerboard with empty cells means that no more than 3 fuel assemblies can occupy any 2x2 matrix of storage cells. Figure 11 shows two examples of acceptable 3-out-of-4 checkerboard patterns.
\\
E7-1
ENCLOSURE 7 VOGTLE ELECTRIC GENERATING PLANT REQUEST TO REVISE TECHNICAL SPECIFICATIONS CREDIT FOR BORON AND ENRICHMENT INCREASE FOR FUEL STORAGE COLR SECTIONS (continued) 2.10.3 2-out-of-4 Checkerboard Storage Storage of 17x17 fuel assemblies in a 2-out-of-4 checkerboard arrangement with empty cells. Fuel assemblies must have an initial maximum enrichment no greater than 5.0 weight percent U-235. A 2-out-of-4 checkerboard with empty cells means that no 2 fuel assemblies may be stored face adjacent. Fuel assemblies may be stored corner adjacent.
Figure 11 shows the 2-out-of-4 checkerboard pattern.
2.10.4 Checkerboard Storage Interface More than one storage pattern may be utilized in the fuel storage pool at the same time.
At the interfaces between all cell, 3-out-of-4, and/or 2-out-of-4 storage patterns, every 2x2 array of assemblies must meet the storage requirements for the assembly in that 2x2 array with the most restrictive storage requirements. Alternately, a row of empty storage cells may be used to interface between storage patterns.
Proposed new sections for the Unit 2 COLR 2.9 Fuel Storage Pool Boron Concentration (Specification 3.7.17) 2.9.1 The boron concentration shall be greater than or equal to 1250 ppm.
2.10 Fuel Assembly Storage (Specification 3.7.18) 2.10.1 All Cell Storage Storage of 17x17 fuel assemblies in any cell location. Fuel assemblies must have an initial nominal enrichment no greater than 1.82 weight percent U-235 or satisfy a minimum burnup requirement shown in table 2 and figure 10.
2.10.2 3-out-of-4 Checkerboard Storage Storage of 17x17 fuel assemblies in a 3-out-of-4 checkerboard arrangement with empty cells. Fuel assemblies must have an initial nominal enrichment no greater than 2.54 weight percent U-235 or satisfy a minimum burnup requirement shown in table 2 and figure 10. A 3-out-of-4 checkerboard with empty cells means that no more than 3 fuel E7-2
1 ENCLOSURE 7 VOGTLE ELECTRIC GENERATING PLANT REQUEST TO REVISE TECHNICAL SPECIFICATIONS CREDIT FOR BORON AND ENRICHMENT INCREASE FOR FUEL STORAGE COLR SECTIONS (Continued)
I assemblies can occupy any 2x2 matrix of storage cells. Figure 12 shows two examples of acceptable 3-out-of-4 checkerboard patterns.
2.10.3 2-out-of-4 Checkerboard Storage Storage of 17x17 fuel assemblies in a 2-out-of-4 checkerboard arrangement with empty cells. Fuel assemblies must have an initial maximum enrichment no greater than 5.0 weight percent U-235. A 2-out-of-4 checkerboard with empty cells means that no 2 fuel assemblies may be stored face adjacent. Fuel assemblies may be stored corner adjacent.
Figure 13 shows the 2-out-of-4 checkerboard pattern.
2.10.4 3x3 Checkerboard Storage Storage of Westinghouse 17x17 fuel assemblies with nominal enrichments no greater than 4.0 weight percent U-235 (equivalent enrichment with IFBA credit, shown in table 3 and figure 11)in the center of a 3x3 checkerboard shown in figure 13. The surrounding fuel assemblies must have an initial nominal enrichment no greater than 1.48 weight percent l
U-235 or satisfy a minimum burnup requirement shown in table 2 and figure 10.
2.10.5 Checkerboard Storage Interface More than one storage pattern may be utilized in the thel storage pool at the same time.
2.10.5.1 Interfaces Between All Cell,3-out-of-4, and'or 2-out-of-4 Storage Patterns At the interfaces between all cell, 3-out-of-4, and/or 2-out-of-4 storage patterns, every 2x2 array of assemblies must meet the storage requirements for the assembly in that 2x2 array with the most restrictive storage requirements. Alternately, a row of empty storage cells may be used to interface between storage patterns.
i 2.10.5.2 Interfaces Between the 3x3 Storage Patterns and All Other Storage Patterns The interface between the 3x3 storage pattern and all othee storage patterns shall consist of a row of empty storage cells.
E7-3
.m ien J-M-s44.44--.344,
++Aate-
--au MAA 4it aaa
- A 4 e_,r C41.m s2 4 J s.,J.-hoe..ad-we.,4i-Ca,+.A n.v a4i.e a.J a 2
4a..i.ma..:s*4cAa,e a:: sw a w--4
--sAe Ja..m-E-i.w--
. rJ-e 445is-m.---a_24..e.e4-.m_.ua
_s--.a 0
Y i
i I
i e
s 5
e V0GTLE ELECTRIC GENERATING PLANT (VEGP) UNIT 1 CYCLE 7 i
a CORE OPERATING LIMITS REPORT MARCH 1996 4
4
- l
.i k
d l
1 4
4 3
1 1.
COLR for VEGP UNIT 1 CYCLE 7 1.0
.CfdE OPERATING LIMITS REPORT This Core Operating Limits Report (COLR) for VEGP UNIT 1 CYCLE 7 has been prepared in accordance with the requirements of Technical Specification 6.8.1.6.
The Technical Specifications affected by this report are listed below:
3/4.1.1.1 SHUTDOWN MARGIN - MODES 1 and 2 3/4.1.1.2 SHUTDOWN MARGIN - MODES 3, 4 and 5 3/4.1.1.3 Moderator Temperature Coefficient 3/4.1.3.5 Shutdown Rod Insertion Limit 3/4.1.3.6 Control Rod Insertion Limits 3/4.2.1 Axial Flux Difference 3/4.2.2 Heat Flux Hot Channel Factor - F,(Z) 3/4.2.3 NuclearEnthalpyRiseHotChannelFactor-F5 J///, ~1, i1 fedk y Pd & (ucM
.3/ M / ff fb2 Am df sMg i
i Ih PAGE 1 of 34'
a i
COLR for VEGP UNIT 1 CYCLE 7 1
2.0 OPERATING LIMITS
)
?
The cycle-specific parameter limits.for the specifications listed in section 1.0 are presented in the following subsections.
These limits have been developed j
using the NRC-approved methodologies specified in. Technical Specification 6.8.1.6 2.1 SHUTDOWN MARGIN - MODES 1 AND 2 (Specification 3/4.1.1.1)-
2.1.1 The SHUTDOWN MARGIN shall be greater than or equal to 1.3 percent Ak/k.
2.2 SHUTDOWN MARGIN - MODES 3. 4 AND 5 (Specification 3/4.1.1.2) 2.2.1 The SHUTDOWN MARGIN shall be greater than or equal to the limits shown in figures 1 and 2.
2.3 Moderator Temperature Coefficient (Specification 3/4.1.1.3) 2.3.1 The Moderator Temperature Coefficient (MTC) limits are:
The BOL/ARO/HZP - MTC shall be less positive than +0.7 x 10-' Ak/k/*F for power levels up to 70 percent RTP with a linear ramp to O Ak/k/*F at 100 percent RTP.
The EOL/AR0/RTP-MTC shall be less negative than
-5.50 x 10-' Ak/k/*F.*
2.3.2 The MTC Surveillance limit is:
The 300 ppm /AR0/RTP-MTC should be less negative than or i
equal to -4.75 x 10-' ok/k/*F.*
where:
BOL stands for Beginning of Cycle Life AR0 stands for All Rods Out HZP stands for Hot Zero THERMAL POWER EOL stands for End of Cycle Life RTP stands for RATED THERMAL POWER 2.4 Shutdown Rod Insertion Limit (Specification 3/4.1.3.5) 2.4.1 The shutdown rods shall be withdrawn to a position greater than or equal to 225 steps.
2.5 Control Rod Insertion Limits (Specification 3/4.1.3.6) 2.5.1 The control rod banks shall be limited in physical insertion as shown in figure 3.
- Based on full-power T-average of 586.4.
PAGE2ofg
COLR for VEGP UNIT 1 CYCLE 7 i
1 2.6 Axial Flux Difference (Specification 3/4.2.1)
(relaxed axial offset control (RAOC) methodology}
2.6.1 The Axial Flux Difference (AFD) acceptable operation limits are provided in figure 4.
2.7 Heat Flux Hot Channel Factor - F,(Z) (Specification 3/4.2.2)
{F, methodology}
RTP 2.7.1 F,(Z) s
- K(Z) for P > 0.5 P
RTP F,(Z) s
- K(Z) for P s 0.5
0.5 where
P THERMAL POWER
=
RATED THERMAL POWER RTP 2.7.2 F,
2.50 2.7.3 K(Z) is provided in figure 5.
C RTP 2.7.4 F (Z) s F.
- K(Z) for P > 0.5 P
- W(Z)
C RTP F, (Z) s F
- KfZ) for P s 0.5 e
0.5
- W(Z) 2.7.5 W(I) values are provided in figures 6 through 9.
I PAGE 3 of J4'
i COLR for VEGP UNIT 1 CYCLE 7 C
2.7.6 The F (Z) penalty factors are provided in table 1.
2.8 Nuclear Enthalov Rise Hot Channel Factor - Ff,, (Specification 3/4.2.3) 1 RTP 2.8.1 F1 s F.,,
- (1 + PF,,, * (1-P))
1 where:
P THERMAL POWFR
=
l RATED THERMAL POWER RTP 2.8.2a F.,,
1.53 for LOPAR fuel and
=
RTP 2.8.2b F.,,
1.65 for VANTAGE 5 fuel
=
4 j
2.8.3 PF,,
0.3 for LOPAR and VANTAGE 5 fuel
=
l 4
i i
l$
PAGE 4 of)4' i
1 COLR for VEGP UNIT 1 CYCLE 7 TABLE 1 Fj(Z) PENALTY FACTOR Cycle Fl(Z)
Burnup Penalty i
(MWD /MTU)
Factor 360 1.021 1408 1.021 3085 1.024 3295 1.030 3924 1.033 4344 1.031 4973 1.026 5392 1.024 6021 1.023 6650 1.022 7069 1.021 Notes:
l 1.
The Penalty Factor, to be applied to Fl(Z) in accordance with surveillance requirement 4.2.2.2.f, is the maximum factor by which Fj(Z) is expected to increase over a 39 EFPD interval (surveillance interval of 31 EFPD plus the maximum allowable extension not to exceed 25% of the i
surveillance interval per Technical Specification 4.0.2) starting from the burnup at which the Fl(Z) was determined.
2.
Linear interpolation is adequate for intermediate cycle burnups.
3.
For All cycle burnups outside the range of the table, a penalty factor of 1.0200 shall be used.
l$
PAGE 5 of)4'
i COLR FOR VEGP UNIT 1 CYCLE 7 5.00 4.00 ACCEPTABLE
{
OPERATING REGION (2500, 3.1h g 3.00 REQUIRED SHUTDOWN y
MARGIN (1600,2.25) 2 j
2.00 O
UNACCEPTABLE I
s OPERATING "3
(950,1.30)
REGION 1.00 0.00 0
500 1000 1500 2000 2500 l
217M RCS BORON CONCENTRATION (ppm)
FIGURE 1 REQUIRED SHUTDOWN MARGIN FOR MODES 3 AND 4 (MODE 4 WITH AT LEAST ONE REACTOR COOLANT PUMP RUNNING)
If PAGE 6 of)W
t COLR FOR VEGP UNIT 1 CYCLE 7 5.00 (2500,4.90) 4.00 ACCEPTABLE
_g OPERATING y
REGION g 3.00 (1250,2.85)
Z REQUIRED SHUTDOWN MARGIN z
3: 2.00 8
5 UNACCEPTABLE OPERATING j
REGION (460,1.00) 0.00 0
500 1000 1500 2000 2500 21751 RCS BORON CONCENTRATION (ppm)
FIGURE 2 REQUIRED SHUTDOWN MARGIN FOR MODES 4 AND 5 (MODE 4 WITH NO REACTOR COOLANT PUMPS RUNNING) lT PAGE 7 of)4
COLR FOR VEGP UNIT 1 CYCLE 7 (Fully Withdrawn *)
28.0 %,225)
(78.0%, 225)-
/
/
[ BANK B
[
/
/
180 I
160 (100 %,161) t
/
/
1
/
/
{
[ BANK C
[
E
/
/
z 120 g
g 9
A
}
E
/
/
?'
/
/
5
/
/
\\
[
[ BANK D 8
/
/
' /
/
f(0%,46)
[
40
/
20
- f
'/
(30.2%, 0)[
0 20 40 60 80 100 POWER (percent of Rated Thermal Power)
- Fully withdrawn shall be the condition where control rods are at a position within the interval 2225 and s231 steps withdrawn.
NOTE: The Rod Bank Inserton Limits are based on the control bank withdrawal sequence A, B, C, O and a control bank tip-to-tip distance of 115 steps.
FIGURE 3 ROD BANK INSERTION LIMITS VERSUS RATED THERMAL POWER
/ff PAGE 8 of)4
COLR FOR VEGP UNIT 1 CYCLE 7 120
(-20.100)
(+10. ico)
,og UNACCEPTABLE UNACCEPTABLE
/
\\
a 80
/
T if 3
ACCEPTABLE y
60 0
2 1
(-35, 50)
(+26,50)
E 40 53 2
20 0
-50
-40
-30
-20
-10 0
10 20 30 40 50 AXIAL FLUX DIFFERENCE (percent Al)
FIGURE 4 AXII.L FLUX DIFFERENCE LIMITS AS A FUNCTION OF RATED THERMAL POWER FOR RAOC Iff PAGE 9 of/4
COLR FOR VEGP UNIT 1 CYCLE 7 t
1 1
1.20 i
l 1.00 x
O I
0.80 a
<r 0.60 am
$<2 l
8 0.40 F = 2.50 a
FI CORE 5T HEIGHT K(Z)
O.20 0.000 1.000 6.000 1.000 12.000 0.925 0
0 2.0 4.0 6.0 8.0 10.0 12.0 CORE HEIGHT (ft) 2'5i FIGURE 5 K(Z)- NORMALIZED Fo(Z) AS A FUNCTION OF CORE HEIGHT PAGE 10 of
i l
COLR FOR VEGP UNIT 1 CYCLE 7 Axial Elevanon BOL Point (feet)
W(z) 1 12.00 1.0000 1.60 l
2 11J10 1.0000 3
11.60 1.0000 4
11.40 1.0000 5
11.20 1.0000 6
11.00 1.0000 7
10.80 1.0000 8
10.60 1.0000 9
10.40 im 1.5C 10 10.20 1.0000 11 10.00 1.2462 12 9.80 1 2334 13 9.60 1.2269 14 9.40 1.2183 15 9.20 1.2096 16 9.00 1.1 % 7 1.4C 17 8.80 1.1 % 3 g
18 8.60 1.2108 19 8.40 1.2202 A
20 8.20 1.2303 21 8.00 1.2383 A
22 7.80 1.2427 A
23 7.60 1.2448 a
24 7.40 1.2442 1*3C 25 7.20 1.2414 T
26 7.00 1.2366
^N 3
27 6.80 1.2298 g
'g 28 6.60 1.2219 g
a 29 6.40 1.2141 r
L g
g A
30 6.20 1.2050 A
A 31 6.00 1.1950 f
A 32 5.80 1.1835 1.2C
- n am 33 5.60 1.1774 Af 34 5.40 1.1861 35 5.20 1.2007 i
i 36 5.00 1.2148 37 4.80 1.2289 38 4.60 1.2433 39 4.40 1.2564 40 4.20 1.2680
-*10 41 4.00 1.2783 42 3.80 1.2872 43 3.60 1.2944 44 3.40 13001 45 3.20 13072 46 3.00 13163 47 2.80 13280 1.00 48 2.60 13432 0
2 4
6 8
10 12 49 2.40 13620 50 2:20 13829 CORE HEIGHT (feet) 51 2 00 1.4038 52 1.80 1.0000 1
53 1.60 1.0000 54 1.40 1.0000 55 1.20 1.0000 56 1.00 1.0000 57 0.80 1.0000 FIGURE 6
!a 0.60 im 29 0.40 1.0000 RAOC W(Z) AT 150 MWD /MTU h.$
l:$
Top ad by.co:n 15% Excluded per Techrucal Spmhcanon 4.2.2.2 This igure is reierred to by Techrucal Spec;hca*ons 4.2.2.2d, B3/4 ?.2 iV PAGE 11 ofJ4' 21741
COLR FOR VEGP UNIT 1 CYCLE 7 Axial Elevanon MOL.1 i
Point (feet) w(z)
A.60 1
12.00 1.0000 i
2 11.80 1.0000 3
11.60 1.0000 4
11.40 1.0000 5
1120 1.0000 6
11.00 1.0000 7
10.80 1.0000 1
8 10.60 1.0000 1.5C 9
10.e 1.0000 10 1030 1.0000 11 10.00 13323 12 4.80 13115 13 9.60 1.2919 14 9.40 1.2756 15 9.20 1.2534 16 9.00 1.2m 1.40 17 8.80
- 2341 18 8.60 1.2404 19 S.40 1.2434 A
20 8.20 1.2494 21 8.00 1.2534 A
22 7.80 1.2538 3
23 7.40 13f18 A
A 24 7.40 1.2472 i
1.3C 25 7.20 1.2404 d
A 26 7310 1.2318 A
27 6.80 1.2213
-N 28 6.60 1.2097 g
^
29 6.40 1.1985 "A
f g
30 6.20 1.1856 A
[
31 6.00 1.1763 A
A 32 5.80 1.1681 1.2C 33 5.60 1.1652 A
A 34 5 40 1.1769 35 5.20 1.1894 6
36 5.00 1.2014 37 4.80 1.2139 38 4.60 1.2258 39 4.40 1.2366 l
40 4.20 1.2460 1.1C 41 4.00 1.2552 42 3.80 1.2637 43 3.60 1.2708 44 3.40 1.2773 4--
45 3.20 1.2861 46 3.00 1.2930 47 2.80 13020 1.On 48 2.60
.13185 49 2.40 13409 0
2 4
6 8
10 12 50 2.20 13627 CORE HEIGHT (feet) g 2g 53 1.60 1.0000 54 1.40 1.0000 55 1.20 1.0000 56 1.00 1.0000 57 0.80 1.0000 58 0.60 1.0000 59 0.40 1.0000 FIGURE 7 60 0.20 1.0000 61 0.00 1.0000 RAOC W(Z) AT 4000 MWD /MTU Technical Speancanon 4.2.2.2 This fqure is referred to F ~ :t al Speoficatons 4.2.2.2d, B3/t 2.2 IY PAGE 12 of)(
2141
COLR FOR VEGP UNIT 1 CYCLE 7 Anal Elevanon MOL2 Point (feet)
W(z) 1.60 1
12.00 1.0000 2
11.80 1.0000 3
11.60 1.0000 4
11.40 1.0000 5
11.20 1.0000 6
11.00 1.0000 7
10.80 1.0000 1.5C 8
10.60 11000 9
10.40 1.0000 i
10 10.20 1.0000 11 10.00 12506 12 9.80 1.2416 13 9.60 1 2,93 14 9.40 1.2343 15 9.20 1.2239 16 m
1.2129 1*40 -
17 8.80 1.2103 18 8.60 1.2166 19 8.40 11249 20 8.20 1.2354 21 8.00 1.2435 22 7.80 1.2480 23 7.60 1.24 %
1*30 24 7.40 1.2483 A
25 7.20 1.2443 A
26 7.00 1.2379
-N A
27 6.80 1.2292 3
28 6.60 1.2187 b
[
29 6.40 1.2071 a
A A
A 30 6.20 1.1952 A
L 31 6.00 1.1810 1.2C A
32 5.80 1.1699 33 5.60 1.1699 Ag 34 5.40 1.1808 35 5.20 1.1923 36 5.00 12024 37 4.80 1.2113 38 4.60 1.2186 39 4.40 1.2245 1.1C 40 4.20 1.2286 41 4.00 1.2312 42 3.80 1.2318 43 3.60 1.2316 44 3.40 1.2316 45 3.20 1.2333 46 3.00 1.2389 1.00 47 2.80 124%
48 2.60 1.2644 0
2 4
6 8
10 12 49 2.40 1.2775 CORE HEIGHT (feet) jj
}$
52 1.80 1.0000 53 1.60 1.0000 54 1.40 1.0000 55 1.20 1.0000 56 1.00 1.0000 57 0.80 1.0000 FIGURE 8 58 0.60 1.0c00 59 0.40 1.0000 RAOC W(Z) AT 11000 MWD /MTU 60 0.20 1.0000 61 0.00 1.0000 Top and Bottom 15% Excluded per Techrucal speahcanon 4.22.2 This fgure is referred to by Technical Specificanons 4.2.2.2d. B3/4.22 7
l h
PAGE 13 ofjN 21751 l
l
COLR FOR VEGP UNIT 1 CYCLE 7 Axial Elevation EOL Point (feet)
W(z) 1.60 1
12.00 1.0000 2
11.80 1.0000 3
11.60 1.0000 4
11.40 1.0000 5
1120 1.0000 l
6 11.00 1.0000 7
10.80 1.0000 l
1.5C 8
10.60 1.0000 9
10.40 1.0000 10 1020 1.0000 11 10.00 1.2023 12 9 80 1.2005 13 9.60
? 2013 14 9.40 1.2077 15 9.20 1.2133 1.4C 16 9.00 1.2167 17 8.80 1.2193 18 8.60 1.2226 19 8.40 1.2297 20 8.20 1.2464 21 8.00 1.2620 22 7.80 1 2732 23 7.60 12816 1.3C 24 7.40 1.2869 25 7.20 12891
%, A a
26 7.00 1.2986 A
27 6.80 1.2851 6
A.
JN 2 3
28 6.60 12802 3
s c na
=
29 6.40 1.2759 e
i 30 6.20 1.2703 3
31 6.00 12635 k
32 5.80 1.2534 1.2C 33 5.60 1.2450 34 5.40 1.2450 35 5.20 1.2497 36 5.00 1.2541 37 4.80 1.2579 38 4.60 1.2614 39 4.40 1.2623 1*10 40 4.20 1.2616 41 4.00 1.2600 42 3.80 1.2565 43 3.60 1.2509 44 3.40 1.2433 45 3.20 1.2322 46 3.00 1.2325 47 2.80 1.2408 1.00 48 2.60 1.2487 0
2 4
6 8
10 12 49 2.40 1.2595 50 2.20 12708 CORE HEIGHT (feet) g 2.g ja8 53 1.60 1.0000 54 1.40 1.0000 55 1.20 1.0000 E6 1.'JO 1.0000 57 0.80 1.0000 58 0.60 1.0000 FIGURE 9 59 0.40 1.0000 60 0.20 1.0000 RAOC W(Z) AT 19000 MWD /MTU 61 0.00 1.0000 Top and Bottom 15% Enduded per TechnkalSped8 cation 42.2.2 l
This figure is referred to by Technical Spec 6cahons 4.2.2.2d B3/4.2.2 l
. PAGE 14 ofJ4 213 1 l
COLR FOR VOGTLE ELECTRIC GENERATING PLANT - UNIT 1 FUEL STORAGE 2.9 Fuel Storage Pool Boron Concentration (Specification 3.7.17) 2.9.1 The boron concentration shall be greater than or equal to 1100 ppm.
2.10 Fuel Assembly Storage (Specification 3.7.18) 2.10.1 All Cell Storage Storage of 17x17 fuel assemblies in any cell location. Fuel assemblies must have an initial nominal enrichment no greater than 2.0 weight percent U-235 or satisfy a minimum burnup requirement shown in table 2 and figure 10.
2.10.2 3-out-of-4 Checkerboard Storage Storage of 17x17 fuel assemblies in a 3-out-of-4 checkerboard arrangement with empty cells. Fuel assemblies must have an initial nominal enrichment no greater than 2.70 weight percent U-235 or satisfy a minimum burnup requirement shown in table 2 and figure 10. A 3-out-of-4 checkerboard with empty cells means that no more than 3 fuel assemblies can occupy any 2x2 matrix of storage cells. Figure 11 shows two examples of acceptable 3-out-of-4 checkerboard patterns.
2.10.3 2-out-of-4 Checkerboard Storage Storage of 17x17 fuel assemblies in a 2-out-of-4 checkerboard arrangement with empty cells. Fuel assemblies must have an initial maximum enrichment no greater than 5.0 weight percent U-235. A 2-out-of-4 checkerboard with empty cells means that no 2 fuel assemblies may be stored face adjacent. Fuel assemblies may be stored corner adjacent. Figure 11 shows the 2-out-of-4 checkerboard pattern.
2.10 Checkerboard Storage Interface More than one storage pattern may be utilized in the fuel storage pool at the same time. At the interfaces between all cell,3-out-of-4, and/or 2-out-of-4 storage patterns, every 2x2 array of assemblies must meet the storage requirements for the assembly in that 2x2 array with the most restrictive storage requirements.
Alternately, a row of empty storage cells may be used to interface between storage patterns.-
Page 15 of 18
COLR FOR VEGP UNIT 1 FUEL STORAGE TABLE 2. MINIMUM BURNUP REQUIREMENTS FOR VOGTLE UNIT 1 3-out-of-4 Nominal All Cell 2 out-of-4
.erboard Checkerboard Enrichment Burnup Burnup Burnup (w/o 235U)
(MWD /MTU)
(MWD /MTU)
(MWD /MTU) 2.00 0
0 0
2.20 2647 0
0 4
2.40 5185 0
0 2.60 7622 0
0 2.70 8806 0
0 2.80 9967 846 0
3.00 12229 2524 0
3.20 14416 4183 0
3.40 16537 5824 o
3.60 18600 7445 o
3.80 20614 9048 o
4.00 22589 10632 0
4.20 24532 12197 0
4.40 26453 13744 0
4.60 28359 15271 o
4.80 30260 16780 0
5.00 32165 18270 0
l l
NOTE: There is no minimum burnup requirement for the 2-out-of-4 Checkerbo._rd Storage Configuration for enrichments up to and including 5.0 weight percent U-235 (COLR Section 2.10.3).
I PAGE 16 of 18
COLR FOR VEGP UNIT 1 FUEL STORAGE l
35000 4
k l
All Cell Storage
/
30000 3-out-of-4 Checkerboard
/
i
/
l
/
/
b
/
l 25000
/
i
/
3 ACCEPTABLE
/
i a
l 5
/
l E
20000
[
a
)
3 e
l E
/
=
j
'. u.
co b
l l
j 15000
/
e i
a
/
i
/
l
}
/
/
10000
/
/
/
l r
/
5000 UNACCEPTABLE
/
/
/
i
/
'I I O
2.0 2.5 3.0 3.5 4.0
-5 5.0 Initial 235U Enrichment (nominal w/o)
NOTE: There is no minimum burnup requirement for the 2-out-of-4 Checkerboard Storage Configuration for enrichments up to and including 5.0.iei;;ht percent l' 235 (COLR Section 2.10.3).
FIGURE 10 VOGTLE UNIT 1 BURNUP CREDIT REQUIREMENTS PAGE 17 of 18
l COLR FOR VEGP UNIT 1 FUEL STORAGE l
l i
l X E Z Z X E Z Z X
E Z
Z i
X X E Z Z Z Z Z X
Z E
Z Empty Storage Cell Fuel Assembly in Storage Cell i
l Typical Acceptable Patterns for 3-out-of-4 l
Checkerboard Storage i
i i
i i
i t
Z Z
Z Z
Empty Storage Cell Fuel Assembly in Storage Cell 2-out-of-4 Checkerboard Storage i
FIGURE 11 VOGTLE UNIT 1 CHECKERBOARD STORAGE CONFIGURATIONS PAGE 18 of 18
-