ML020590151
| ML020590151 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 02/26/2002 |
| From: | NRC/NRR/DLPM/LPD3 |
| To: | Nuclear Management Co |
| References | |
| Download: ML020590151 (12) | |
Text
SFP Boron Concentration 3.7.15 3.7 PLANT SYSTEMS 3.7.15 Spent Fuel Pool (SFP) Boron Concentration LCO 3.7.15 The SFP boron concentration shall be Ž 1720 ppm.
APPLICABILITY: When fuel assemblies are stored in the Spent Fuel Pool.
ACTIONS
NO T E -----------------------------------------------------------
LCO 3.0.3 is not applicable.
CONDITION REQUIRED ACTION COMPLETION TIME A. SFP boron concentration A.1 Suspend movement of Immediately not within limit, fuel assemblies in the SFP.
AND A.2 Initiate action to restore SFP Immediately boron concentration to within limit.
SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.7.15.1 Verify the SFP boron concentration is within limit. 7 days Palisades Nuclear Plant 3.7.15-1 Amendment No. 4-t-9,207
Spent Fuel Assembly Storage 3.7.16 3.7 PLANT SYSTEMS 3.7.16 Spent Fuel Assembly Storage LCO 3.7.16 The combination of initial enrichment, burnup, and decay time of each fuel assembly stored in Region II shall be within the requirements of Table 3.7.16-1.
APPLICABILITY: Whenever any fuel assembly is stored in Region II of either the spent fuel pool or the north tilt pit.
ACTIONS
NOTE ---------------------------------------------------------
LCO 3.0.3 is not applicable.
CONDITION REQUIRED ACTION COMPLETION TIME A. Requirements of the LCO A. 1 Initiate action to move Immediately not met. the noncomplying fuel assembly from Region 11.
SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SIR 3.7.16.1 Verify by administrative means the combination of Prior to storing the initial enrichment, burnup, and decay time of the fuel assembly in fuel assembly is in accordance with Region 11 Table 3.7.16-1.
3.7.16-1 Amendment No. 4-89, 207 Palisades Nuclear Plant
Spent Fuel Assembly Storage 3.7.16 TABLE 3.7.16-1 (gage 1 of 1)
Spent Fuel Minimum Burnup and Decay Requirements for Storage in Region II of the Spent Fuel Pool and North Tilt Pit Initial Burnup Burnup Burnup Burnup Burnup Enrichment (GWD/MTU) (GWD/MTU) (GWD/MTU) (GWD/MTU) (GWD/MTU)
(Wt%) No Decay 1 Year Decay 3 Year Decay 5 Year Decay 8 Year Decay
_1.14 0 0 0 0 0
-1.14 3.477 3.477 3.477 3.477 3.477 1.20 3.477 3.477 3.477 3.477 3.477 1.40 7.951 7.844 7.464 7.178 6.857 1.60 11.615 11.354 10.768 10.319 9.847 1.80 14.936 14.535 13.767 13.187 12.570 2.00 18.021 17.502 16.561 15.875 15.117 2.20 21.002 20.417 19.313 18.499 17.611 2.40 23.900 23.201 21.953 21.034 20.050 2.60 26.680 25.905 24.497 23.487 22.378 2.80 29.388 28.528 27.006 25.879 24.678 3.00 32.044 31.114 29.457 28.243 26.942 3.20 34.468 33.457 31.698 30.397 29.008 3.40 36.848 35.783 33.920 32.544 31.079 3.60 39.152 38.026 36.059 34.615 33.077 3.80 41.419 40.226 38.163 36.650 35.049 4.00 43.661 42.422 40.257 38.673 37.007 4.20 45.987 44.684 42.415 40.778 39.028 4.40 48.322 46.950 44.588 42.877 41.041 4.60 50.580 49.158 46.690 44.911 43.003 (a) Linear interpolation between two consecutive points will yield acceptable results.
(b) Comparison of nominal assembly average burnup numbers to these in the table is acceptable if measurement uncertainty is
- 10%.
Palisades Nuclear Plant 3.7.16-2 Amendment No. 1-89, 207
Design Features 4.0 4.0 DESIGN FEATURES 4.1 Site Location The Palisades Nuclear Plant is located on property owned by Consumers Energy on the eastern shore of Lake Michigan approximately four and one-half miles south of the southern city limits of South Haven, Michigan. The minimum distance to the boundary of the exclusion area as defined in 10 CFR 100.3 shall be 677 meters.
4.2 Reactor Core 4.2.1 Fuel Assemblies The reactor core shall contain 204 fuel assemblies. Each assembly shall consist of a matrix of zircaloy-4 clad fuel rods with an initial composition of depleted, natural, or slightly enriched uranium dioxide (U0 2) as fuel material. Limited substitutions of zirconium alloy or stainless steel filler rods for fuel rods, in accordance with approved applications of fuel rod configurations, may be used.
Fuel assemblies shall be limited to those fuel designs that have been analyzed with applicable NRC staff approved codes and methods and shown by tests or analyses to comply with all fuel safety design bases. A limited number of lead test assemblies that have not completed representative testing may be placed in nonlimiting core regions. A core plug or plugs may be used to replace one or more fuel assemblies subject to the analysis of the resulting power distribution.
Poison may be placed in the fuel bundles for long-term reactivity control.
4.2.2 Control Rod Assemblies The reactor core shall contain 45 control rods. Four of these control rods may consist of part-length absorbers. The control material shall be silver-indium-cadmium, as approved by the NRC.
4.3 Fuel Storage 4.3.1 Criticality 4.3.1.1 The Region I fuel storage racks (See Figure B 3.7.16-1) are designed and shall be maintained with:
- a. Fuel assemblies having a maximum planar average U-235 enrichment of 4.95 weight percent; Palisades Nuclear Plant 4.0-1 Amendment No. 489 2 0 7
Design Features 4.0 4.0 DESIGN FEATURES 4.3 Fuel Storage 4.3.1 Criticality (continued)
- b. Keff ! 0.95 if fully flooded with unborated water, which includes allowances for uncertainties as described in Section 9.11 of the FSAR.
- c. A nominal 10.25 inch center to center distance between fuel assemblies with the exception of the single Type E rack which has a nominal 11.25 inch center to center distance between fuel assemblies; and
- d. New or irradiated fuel assemblies.
4.3.1.2 The Region II fuel storage racks (See Figure B 3.7.16-1) are designed and shall be maintained with;
- a. Fuel assemblies having maximum planar average U-235 enrichment of 4.60 weight percent;
- b. Keff < 1.0 if fully flooded with unborated water, which includes allowances for uncertainties as described in Section 9.11 of the FSAR.
- c. Ke, - 0.95 if fully flooded with water borated to 850 ppm, which includes allowance for uncertainties as described in Section 9.11 of the FSAR.
- d. A nominal 9.17 inch center to center distance between fuel assemblies; and
- e. New or irradiated fuel assemblies which meet the initial enrichment, burnup, and decay time requirements of Table 3.7.16-1.
4.3.1.3 The new fuel storage racks are designed and shall be maintained with:
- a. Twenty four unirradiated fuel assemblies having a maximum planar average U-235 enrichment of 4.95 weight percent, and stored in accordance with the pattern shown in Figure 4.3-1, or Thirty six unirradiated fuel assemblies having a maximum planar average U-235 enrichment of 4.05 weight percent, and stored in accordance with the pattern shown in Figure 4.3-1;
- b. K !<0.95 when flooded with either full density or low density (optimum moderation) water including allowances for uncertainties as described in Section 9.11 of the FSAR.
4.0-2 Amendment No. 489, 207 Plant Palisades Nuclear Plant 4.0-2 Amendment No. 489, 207
Design Features 4.0 4.0 DESIGN FEATURES 4.3 Fuel Storage 4.3.1 Criticality (continued)
- c. The pitch of the new fuel storage rack lattice being Ž 9.375 inches and every other position in the lattice being permanently occupied by an 8" x 8" structural steel or core plugs, resulting in a nominal 13.26 inch center to center distance between fuel assemblies placed in alternating storage locations.
4.3.2 Drainage The spent fuel storage pool cooling system suction and discharge piping is designed and shall be maintained to prevent inadvertent draining of the pool below elevation 644 ft 5 inches.
4.3.3 Capacity The spent fuel storage pool and north tilt pit are designed and shall be maintained with a storage capacity limited to no more than 892 fuel assemblies.
4.0-3 Amendment No. 489, 207 Plant Nuclear Plant Palisades Nuclear Palisades 4.0-3 Amendment No. 44-9, 207
Design Features 4.0 4.0 DESIGN FEATURES E-OI-1Ol-IO -1Ol-DODO 0 El*[-10 E 0DO E O]O[1 E~l-I0l0r-oI-0r-0 CENTERLINE LEGEND PATTERN REPEATS FD X8STEELBOX BEAM O ASSEMBLY STORAGE LOCATION (ENRICHMENT - 4.95 WT%U-235)
- ASSEMBLY STORAGE LOCATION (ENRICHMENT <- 4.05 WT%U-235)
Note: If any assemblies containing fuel enrichments greater than 4.05% U-235 are stored in the New Fuel Storage Rack, the center row must remain empty.
Figure 4.3-1 (page 1 of 1)
New Fuel Storage Rack Arrangement Palisades Nuclear Plant 4.0-4 Amendment No- 207
SFP Boron Concentration B 3.7.15 B 3.7 PLANT SYSTEMS B 3.7.15 Spent Fuel Pool (SFP) Boron Concentration BASES BACKGROUND As described in LCO 3.7.16, "Fuel Assembly Storage," fuel assemblies are stored in the fuel storage racks in accordance with criteria based on initial enrichment, discharge burnup, and decay time.
The criteria were based on the assumption that 850 ppm of soluble boron was present in the spent fuel pool. The pool is required to be maintained at a boron concentration of Ž 1720 ppm. Criterion 2 of 10 CFR 50.36 (c) (2) requires that criticality control be achieved without credit for soluble boron. However, in 1998 the NRC documented requirements that could be established to maintain criticality below 0.95. This is documented in "Guidance on the Regulatory Requirements for Criticality Analysis of Fuel Storage at Light-Water Reactor Power Plants", Laurence I. Kopp, U.S. Nuclear Regulatory Commission, Office of Nuclear Reactor Regulation, Reactor Systems Branch, February 1998. The precedent of taking credit for soluble boron in spent fuel pool water to provide criticality control has also been established. Soluble boron credit was used in the Westinghouse Spent Fuel Rack Criticality Analysis Methodology described in WCAP-14416-NP-A and that methodology was approved for use by an NRC Safety Evaluation dated October 25, 1996. The criteria discussed above was developed using a method that closely followed the Westinghouse methodology. Additionally the requirements specified by the NRC guidance are in place at Palisades.
APPLICABLE A fuel assembly could be inadvertently loaded into a fuel storage rack SAFETY ANALYSES location not allowed by LCO 3.7.16 (e.g., an insufficiently depleted or insufficiently decayed fuel assembly). Another type of postulated accident is associated with a fuel assembly that is dropped onto the fully loaded fuel pool storage rack. Either incident could have a positive reactivity effect, decreasing the margin to criticality. However, the negative reactivity effect of the soluble boron compensates for the increased reactivity caused by either one of the two postulated accident scenarios.
The concentration of dissolved boron in the SFP satisfies Criterion 2 of 10 CFR 50.36(c)(2).
LCO The specified concentration of dissolved boron in the SFP preserves the assumptions used in the analyses of the potential accident scenarios described above. This concentration of dissolved boron is the minimum required concentration for fuel assembly storage and movement within the SFP.
APPLICABILITY This LCO applies whenever fuel assemblies are stored in the spent fuel pool.
Palisades Nuclear Plant B 3.7.15-1 Amendment No. 4-89, 207
SFP Boron Concentration B 3.7.15 BAS ES ACTIONS The ACTIONS are modified by a Note indicating that LCO 3.0.3 does not apply.
If moving irradiated fuel assemblies while in MODE 5 or 6, LCO 3.0.3 would not specify any action. If moving irradiated fuel assemblies while in MODE 1, 2, 3, or 4, the fuel movement is independent of reactor operation. Therefore, inability to suspend movement of fuel assemblies is not sufficient reason to require a reactor shutdown.
A.1. and A.2 When the concentration of boron in the spent fuel pool is less than required, immediate action must be taken to preclude an accident from happening or to mitigate the consequences of an accident in progress.
This is most efficiently achieved by immediately suspending the movement of fuel assemblies. This does not preclude the movement of fuel assemblies to a safe position. In addition, action must be immediately initiated to restore boron concentration to within limit.
I SURVEILLANCE SR 3.7.15.1 REQUIREMENTS This SR verifies that the concentration of boron in the spent fuel pool is within the required limit. As long as this SR is met, the analyzed incidents are fully addressed. The 7 day Frequency is appropriate because no major replenishment of pool water is expected to take place over a short period of time.
REFERENCES None Palisades Nuclear Plant 8 3.7.15-2 Amendment No. 1-89,207
Fuel Assembly Storage B 3.7.16 B 3.7 PLANT SYSTEMS B 3.7.16 Fuel Assembly Storage BASES BACKGROUND The fuel storage facility is designed to store either new (nonirradiated) nuclear fuel assemblies, or used (irradiated) fuel assemblies in a vertical configuration underwater. The storage pool is sized to store 892 fuel assemblies, which includes storage for failed fuel canisters. The fuel storage racks are grouped into two regions, Region I and Region II per Figure 3.7.16-1. The racks are designed as a Seismic Category I structure able to withstand seismic events.
Region I contains racks in the spent fuel pool having a 10.25 inch center-to center spacing and a single rack in the north tilt pit having an 11.25 inch by 10.69 inch center-to-center spacing. Region II contains racks in both the spent fuel pool and the north tilt pit having a 9.17 inch center-to-center spacing.
Because of the smaller spacing and poison concentration, Region II racks have more limitations for fuel storage than Region I racks. Further information on these limitations can be found in Section 4.0, "Design Features." These limitations (e.g., enrichment, burnup) are sufficient to maintain a k,, of _<0.95 for fuel of original enrichment of up to 4.95% for Region I, and 4.6% for Region II.
APPLICABLE The fuel storage facility was originally designed for SAFETY ANALYSES noncriticality by use of adequate spacing, and "flux trap" construction whereby the fuel assemblies are inserted into neutron absorbing stainless steel cans.
The current criticality calculations also take credit for soluble boron to prevent criticality.
The spent fuel assembly storage meets the requirements specified in "Guidance on the Regulatory Requirements for Criticality Analysis of Fuel Storage at Light-Water Reactor Power Plants", Laurence I. Kopp, U.S. Nuclear Regulatory Commission, Office of Nuclear Reactor Regulation, Reactor Systems Branch, February 1998." This document established the requirements for use of soluble boron to maintain k., below 0.95.
The spent fuel assembly storage satisfies Criterion 2 of 10 CFR 50.36(c)(2).
LCO The restrictions on the placement of fuel assemblies within the spent fuel pool, according to Table 3.7.16-1, in the accompanying LCO, ensures that the ke, of the spent fuel pool will always remain < 0.95 assuming the pool to be flooded with water, borated to 850 ppm. The restrictions are consistent with the criticality safety analysis performed for the spent fuel pool according to Table 3.7.16-1, in the accompanying LCO. Fuel assemblies not meeting the criteria of Table 3.7.16-1 shall be stored in accordance with Specification 4.3.1.1.
APPLICABILITY This LCO applies whenever any fuel assembly is stored in Region II of either the spent fuel pool or the north tilt pit.
B 3.7.16-1 Amendment No. 4-89, 207 Palisades Nuclear Plant
Spent Fuel Assembly Storage B 3.7.16 BASES ACTIONS The ACTIONS are modified by a Note indicating that LCO 3.0.3 does not apply.
If moving irradiated fuel assemblies while in MODE 5 or 6, LCO 3.0.3 would not specify any action. If moving irradiated fuel assemblies while in MODE 1, 2, 3, or 4, the fuel movement is independent of reactor operation. Therefore, in either case, inability to move fuel assemblies is not sufficient reason to require a reactor shutdown.
When the configuration of fuel assemblies stored in Region 11the spent fuel pool is not in accordance with Table 3.7.16-1, immediate action must be taken to make the necessary fuel assembly movement(s) to bring the configuration into compliance with Table 3.7.16-1.
SURVEILLANCE SR 3.7.16.1 REQUIREMENTS This SR verifies by administrative means that the combination of initial enrichment, burnup, and decay time of the fuel assembly is in accordance with Table 3.7.16-1 in the accompanying LCO prior to placing the fuel assembly in a Region II storage location.
REFERENCES None Palisades Nuclear Plant B 3.7.16-2 Amendment No. 489,207
Spent Fuel Assembly Storage B 3.7.16 BASES 465.00' Ref.
176,00' Ref.
MAIN POOL Figure B 3.7.16-1 (page 1 of 1)
Spent Fuel Pool Arrangement Paliade Palisades Nuclear Plant Nulabts .5. 1 .'1Plant O-J / lI IUIII Il" IV IW.
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