ML20081K299
| ML20081K299 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 03/23/1995 |
| From: | Tuckman M DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9503290052 | |
| Download: ML20081K299 (40) | |
Text
'
p.
~ ~ Duke 1%ugt Cornpany (704)373 4011 422 South Church Street Charlotte, NC28242 0001 DUKEPOWER March 23,1995.
U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington. D.C. 20555
Subject:
McGuire Nuclear Station, Units 1& 2 Docket Nos. 50-369 and 370, respectively Response to Request for Additional Information Proposed Fuel Enrichment Increase Gentlemen:
Enclosed, for your review, is Duke Power Company's response to your Request for Additional Information (RAI) dated January 4,1995. The RAI concerns proposed amendments to technical specifications, dated June 13,1994 for McGuire and Sept.19, 1994 for Catawba. The proposed amendments increase the allowable enrichment limit for fuel stored in our spent fuel pools. Responses to the questions applicable to McGuire Nuclear Station are enclosed in Attachment I.
Accompanying changes to the specifications and technical justification are also enclosed in 1. These changes include: 1) changing the surveillance requirement for boron in the SFP's from once per 31 days to once per 7 days in consistency with STS (Specification 3/4.9.12),2) removing the option to use alternate storage configurations in the SFP and replacing it with footnotes to allow specific analysis on alternate fuel types (Specification 3/4.9.13 (c)),3) adding information contained in the BASES to the footnotes to Figures 3.9-1 to 3.9-3 of Specification 3/4.9.13, and 4) changing the bases to discuss the option to use specific analyses on alternate fuel. Please replace the corresponding pages of the original submittal with these revised pages, as appropriate.
Additional changes to the amendment package are also enclosed in Attachment III. These changes modify the No Significant Hazards Analysis and Environmental Impact Statement for the amendment request based on conversations with your office and additional reviews by our staff. These changes provide additional justification for the amendment request.
9503290052 950323 0
PDR ADOCK 05000369 eO P
PDR q
g nam m mm..
q
,l 1
We appreciate your detailed review of our proposal and hope these responses are sufficient to satisfy your concerns. If you have additional questions or need additional information, please contact Ms. Judy Twiggs at 704-382-8897.
l Sincerely, r
b-(b M.S. Tuckman Senior Vice President Nuclear Generation jgt/ attachments U.S. NRC xc:
S.D. Ebeneter, Regional Administrator U.S. Nuclear Regulatory Commission - Region II 101 Marietta Street, NW - Suite 2900 Atlanta, Georgia 30323 Victor Nerses, Project Manager Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop 14H25, OWFN Washington, D.C. 20555 R.E. Martin, Project Manager Office of Nuclear Reactor Regulation 4
U.S. Nuclear Regulatory Commission Mail Stop 14H25, OWFN Washington, D.C. 20555 i
G.F. Maxwell Senior Resident Inspector McGuie Nuclear Station Dayne Brown, Chief State of North Carolina Division of Radiation Protection P.O. Box 27687 Raleigh, N.C. 27611-7687
1
]
M.S. Tuckman, being duly sworn, states that he is Senior Vice President of Duke Power Company; that he is authorized on the part of said Company to sign and file with the Nuclear Regulatory Commission this information conceming revisions to the McGuire Nuclear Station Facility Operating Licenses, NPF-9 and NPF-17. He further acknowledges that all the statements and matter set forth herein are true and correct to the best of his knowledge, b\\
~
M.S. Tuckman, Senior Vice President Subscribed and sworn to before me this 22 day of /NAAC#,1995.
Ydh 2 /N Notab Pjblic 1
My Commission Expires:
$M Z2, /996 I
ATTACHMENT 1
- RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION MCGUIRE PROPOSED FUEL ENRICHMENT INCREASE Q4) De NRC staff believes that the 31 day frequency for verifying spent fuel pool boron concentration stated in proposed SR 4.9.12 is too long, especially during-fuel storage operations. We note that a comparable SR for ensuring subcriticality in the.
reactor during MODE 6 in the improved Westinghouse Standard TS is 7 days and that this is discussed in the BASES for those TS..We request that DPC provide further justification for the proposed SFP surveillance frequency. Any associated changes to the BASES should also be proposed including a discussion of the limiting.
SFP accident analysis A4) We concur that the surveihance requirement for verifying the Spent Fuel Pool (SFP) boron concentration in the Westinghouse STS is 7 days. The current surveillance requirement (SR 4.9.12a) is 31 days. Since McGuire is the only Duke Power facility currently requiring a spent fuel storage related TS, the current SR was used as the-basis for the proposed SR 4.9.12.
The purpose of soluble boron in the SFP is to provide adequate criticality safety margin in the unlikely event of an accident which increases the reactivity of the pool.
Since the only postulated accidents of this outcome involve the movement of fuel assemblies, the SFP boron surveillance is linked with fuel movement in the SFP.
Given that the minimum SFP boron concentration limits are currently 2175 ppm, and expected to increase even further, and that only about 500 ppm is needed to maintain l
k-eff below 0.95 in the event of an accident of this nature, it seems unlikely that a H
boron dilution of more than 1500 ppm in 31 days over such a large volume of water could go undetected. However, section 16.9-7 of the McGuire FSAR requires that the SFP boron concentration be verified every 7 days. Therefore, although the applicability for section 16.9-7 of the FSAR and SR 4.9.12 differ, the surveillance interval in TS 4.9.12 will be changed from 31 days to 7 days to be consistent with the commitment in section 16.9-7 of the FSAR. As part of this change, we also intend to change the applicability for TS 4.9.12 to be consistent with STS. His change allows taking credit for performing a spent fuel pool verification by not i
requiring the SFP boron concentration surveillance, provided no fuel assembly movement has occurred since the last SFP verification.
Included in this package are the necessary revisions to TS 3/4.9.12 in Attachment I and page 8-7 in Attachment IV of our original submittal.
Q7) We do not agree with proposed TS 3.9.13.(a.3 and 3.9.13b.4), which would allow
. i V
t fuel storage configurations other than those myiewed by the NRC, and request that it be deleted.
A7). We understand your concem for not wanting to allow fuel storage configurations other than those reviewed by your staff. The intent of this specification is to allow.
- for specific criticality analyses for special situations without requiring additional TS changes. An example of this would be storage of fuel assembly designs not analyzed as part of this_ license amendment request, as a result of new fuel designs.'or shipments of fuel from another facility. Another, more likely, example would be -
storage of individual fuel pins as a result of fuel assembly reconstitution.. The.
current TS 3.9.12b.2 (approved March 24,1987) is the basis for this proposed TS.
He specification was implemented at McGuire to accommodate storage of Oconee spent fuel shipped to McGuire for storage.
In response to your concern, we have revised TS 3.9-13. - The changes include adding. additional discussion in the BASES to reflect the intended use 'of this i
provision, adding a statement to Tables 3.9-1 through 3.9-5 indicating that specific analyses may be performed to qualify fuel assemblies for storage, and deleting.
proposed TS 3.9.13a.3 and 3.9.13b.4. ' Included in this package are replacement pages for TS 3.9.13, TS Tables 3.9-1 through 3.9-5 and the BASES for TS 3/4.9.12 and 3/4.9.13 of Attachment I and pages 8-8,8-10 through 8-14, and 8-20 through 8-22 of Attachment IV.
Two additional minor modifications have been made to TS Tables 3.9-1 through-3.9-5. The labels for enrichment have been changed from ' Initial Enrichment' to
' Initial Nominal Enrichment'. This change is in response to Q8 for Catawba, and is being applied to McGuire for further clarification and consistency. The 'use of-nominal enrichments is discussed in the BASES for TS 3/4.9.12 and 3/4.9_.13. The other change to the - TS Tables is the addition of ' ACCEPTABLE' and
' UNACCEPTABLE' labels in the plots of enrichment versus burnup. This change was included in the original Catawba submittal for added clarification at the request of the station personnel.
r Q9) He Duke Power submittal.for the McGuire proposed TS changes for fuel enrichment and storage, dated June 13,1994, states that the BWFC Mark BW fuel design is the most reactive of the three fuel types which exist at McGuire. The Duke Power submittal for Catawba, dated September 19, 1994, states that the Westinghouse OFA design is the most reactive fuel of all fuel types stored at any Duke Power facility. Please discuss this apparent discrepancy.
A9) he most reactive fuel assembly design is dependent on the particular conditions.
Due to its wetter lattice, the OFA design is more reactive than the MkBW design for most moderated conditions at beginning of life (BOL). This includes the spent fuel pools and the new fuel vaults with one exception. The MkBW design is more y
+
7-p yny
+p y...i--
M
- c. -
-a reactive under optimum moderation conditions in the McGuire new fuel vaults, due to subtle differences in the geometry. Also, due to its harder spectrum, the MkBW '
design becomes more reactive than the OFA design with ~ depletion due to its increased plutonium production. The burnup at which the MkBW fuel becomes more reactive than the OFA increases with increasing enrichment.
All the analyses for the McGuire submittal used the MkBW design exclusively.
.While the OFA design is more reactive for most BOL conditions, no fresh OFA' -
assemblies are being used at McGuire. Furthermore, the inventory of all OFA assemblics was examined to ensure that all OFA assemblies are less reactive than MkBW assemblies of the same enrichment and burnup by verifying that sufficient burnup exists on theses OFA assemblies. Therefore, the use of only the MkBW design for McGuire is justified. If a fuel assembly design other than the MkBW design is to be used at McGuire in the future, an analysis will be performed to verify that this design is bounded by previous analyses, or a new TS amendment package will be submitted to define new burnup versus enrichment limits.
For Catawba, the spent fuel pool analysis explicitly modeled the BWFC MkBW fuel design, and the Westinghouse standard (STD) and OFA designs. The most reactive of these three designs, for a given burnup and enrichment, was used to set the final TS limit. The Oconee fuel designs were compared to the above designs to verify that the Oconee fuel is less reactive at BOL conditions. However, this comparison did not consider two future Oconee fuel designs which are more reactive than all current designs at BOL. Therefore, the option of storing Oconee fuel at Catawba is rescinded and will be handled on a case by case basis,if needed.
The new fuel vault analysis for Catawba used the OFA design exclusively, which is the most reactive design for this storage configuration for both the fully flooded and optimum moderation conditions.
In conclusion, the statements conceming the most reactive fuel designs in the McGuire and Catawba submittals are accurate. These statements are in the context of new fuel vault calculations. The MkBW fuel design is the most reactive of the three fuel types which exist at McGuire, since no fresh OFA assemblies are stored, or planned for storage at McGuire. For the Catawba new fuel vault, the OFA design is the most reactive fuel of all fuel types currently stored at any Duke Fower facility, excluding future Oconee fuel designs which are planned. Finally, although the MkBW fuel design is more reactive than the OFA design for burned fuel, the criticality analysis explicitly modeled all 17x17 designs for the Catawba spent fuel pool.
L l
i.
l l
L l
ATTACHMENT 2 REVISED PAGES I
This attachment includes the revisions to Attachments I and IV of the McGuire Proposed Technical Specification Changes originally submitted on June 13,1994 i
t 0
i 4'
4 I
i n
-s
w
ATTACHMENT I PROPOSED TECHNICAL SPECIFICATION CHANGES i
This section contains the proposed modifications to the MNS Technical Specifications.
In general, these c'unges increase the initial fuel enrichment limit and establish several restricted loading patterns, and associated burnup criteria, for both regions of the McGuire Spent Fuel Pools. These changes are necessary to improve core reload designs and increase operational flexibility, while at the same time maintaining acceptable criticality safety margin. In addition, several administrative changes have been included in order to provide clarity to the Specifications and bring them more in line with STS format. A description of each of the changes being requested is given below.
The accompanying FSAR changes will be incorporated at the next annual revision foliowing approval of this submittal. These changes are identified and discussed in Section Vill of Attachment IV.
- 1. The Technical Specification index is being changed to incorporate the changes being made to Specifications 3/4.9.12, add Specification 3/4.9.13 and also the accompanying Tables 3.91 to 3.9-5, and Figures 3.9-1 to 3.9-3. This change is purely administrative in nature.
- 2. Specification 3/4.9.12, Spent Fuel Pool (SFP) Storage is being deleted and is being replaced with Specifications 3/4.9.12, Spent Fuel Pool Boron Concentration, and 3/4.9.15, Spent Fuel Assembly Storage. The Specification is being changed to separ 4 UP boron concentration limits from fuel storage requirements, as well as to estab.m ena LCO for SFP boron concentration. These changes are being made in order to accornmodate the more complex SFP storage requirements and provide clarity to these Specifications. The changes also provide more consistency with STS format.
- a. Spent Fuel Pool Boron Concentration Limit in Specification 3/4.9.12 is being changed to allow this lirnit to be established in the COLR. This change is being requested to eliminate the potential for a dilution event by establishing this limit in the COLR. Limits for all other potential sources of borated water to the SFP are also established in the COLR. It also provides consistency with other operational, cycle specific limits. This change will significantly increase operational flexibility while at the same time ensuring acceptable criticality safety margin is maintained. It is also provides more consistency with STS format.
- b. Tne action statement in Specification 3.9.12 (a) is being changed to better reflect appropriate actions necessary if the SFP Boron Concentration is out of limit. This change is administrative however, it better enseres acceptable criticality safety margin is maintained.
- c. The surveillance requirement 4.9.12 is being changed to require verification of Spent Fuel Pool Boron Concentration once per 7 days vs. once per 31 days. This change is being made to provide more consistency with STS and better ensures sufficient boron is available during fuel movement, when it is necessary.
Revision 1
- d. Specification 3/4.9.13, accompanying Tables 3.9-1 to 3.9-5, and Figures 3.9-1 to 3.9-3, are being added to establish several restricted loading pattems (with appropriate interface restrictions) for spent fuel storage and associated burnup criteria. The proposed changes are necessary to increase the efficiency of fuel storage while at the same time ensuring that acceptable criticality safety margin is maintained. The format of these changes is also more in line with STS format. The technical basis for these changes and the associated criticality analysis are described in detailin Attachment IV.
- e. The action statement in Specification 3.9.13 (a) is being changed to more accurately describe appropriate actions if a fuel assembly is misplaced. This change is administrative however, it better ensures that appropriate corrective actions are taken.
n
- f. Surveillance requirement 4.9.13 is being changed to reflect the new fuel storage requirements and provide clarity to this surveillance requirement.
- 3. The BASES for Sections 3/4.9.12 and 3/4.9.13 of the Technical Specifications has been changed to reflect the changes made in the corresponding Specifications and to more fully explain the basis for each LCO, Action Statement and Surveillance Requirement covered by these Specifications. Paragraph 2 of the BASES explains the provisions to use specific analysis for fuel types not previously analyzed. These provisions are necessary for appropriate fuel management. Paragraph 3 of the BASES i
has also been changed to explain the acceptability of using less reactive fuel components or non-fuel components in designated fuel assembly locations and non-fuel components in empty celllocations, as this would ensure the reactivity limits are met while increasing operational flexibility. In addition, the last paragraph specifies the limit for maximum fuel enrichment,4.75 weight %, as the basis for all fuel storage requirements imposed by Technical Specification 3/4.9.13 and to describe appropriate methods for interpolating the data provided in Tables 3.9-1 to 3.9-5. The proposed modifications to the BASES Section are also more cons? tent with those in STS.
- 4. Technical Specification 5.6, Fuel Storage, has been chh iged to reflect appropriate limits, as determined by criticality analysis for fuel storage. in addition, the Specification has been changed to remove extraneous information on rack design and relocate the specification of enrichment limits. These changes allow increased operational flexibility, while maintaining acceptable criticality safety margin, and bring these Specifications in line with STS format.
- a. Specification 5.6.1 has been changed to allow for use of keff s 0.98 under optimum moderation conditions in the rack design criteria for new fuel storage racks. Actual calculations have shown that keff s 0.95, under all storage conditions however, this change allows increased flexibility when performing criticality analyses and is consistent with the criteria currently specified in ANSI-ANS57.3,1983 and STS.
- b. Specification 5.6.1 has also been changed to eliminate information on rack design.
This information is currently discussed in the FSAR and is considered in the criticality analyses.
l Revision 1
l P
- c. Specification 5.6.3 has been changed to eliminate reference to the fuel enrichment limit. This limit has been specified in the BASES for Technical Specification 3.9.13. This change establishes a more appropriate basis for fuel storage rack design, i.e. criticality and maintains consistency with changes to Specification 3.3.1, established in Amendments 137 and 119 for Units 1 and 2, respectively. These changes are also more consistent with STS format.
k Revision 1
i REFUELING OPERATIONS 3/4.9.12 SPENT FUEL POOL BORON CONCENTRATION ~
LIMITING CONDITION FOR OPERATION
- 3.9.12 The boron concentration in the spent fuel pool shall be within the limit specified
)
in the COLR.
l l
l APPLICABILITY:
During storage of fuelin the spent fuel pool.
ACTION:
i
- a. Immediately suspend movement of fuel assemblies in the spent fuel pool and initiate action to restore the spent fuel pool boron concentration to within its limit.
- b. The provisions of Specification 3.0.3 are not applicable.
SURVEILLANCE REQUIREMENTS:
i i
4.9.12 Verify at least once per 7 days that the spent fuel pool boron concentration is within its limit.
i
?
Revision 1
3/4.9.13 SPENT FUEL ASSEMBLY STORAGE LIMITING CONDITION FOR OPERATION 3.9.13 Storage of new or irradiated fuel is limited to the configurations described in this specification.
- a. New or irradiated fuel may be stored in Region 1 of the Spent Fuel Pool in accordance with these limits:
- 1) Unrestricted storage of fuel meeting the criteria of Table 3.9-1; or
- 2) Restricted storage in accordance with Figure 3.9-1, of fuel which does not meet the criteria of Table 3.91.
- b. New or irradiated fuel which has decayed at least 16 days may be stored in Region 2 of the Spent Fuel Pool in accordance with these limits:
~
- 1) Unrestricted storage of fuel meeting the criteria of Table 3.9-3; or
- 2) Restricted storage in accordance with Figure 3.9-2, of fuel which meets the criteria of Table 3.9-4; or
- 3) Checkerboard storage in accordance with Figure 3.9-3 of fuel which does n21 meet the criteria of Table 3.9-4.
APPLICABILITY:
During storage of fuel in the spent fuel pool.
ACTION:
- a. Immediately initiate action to move the noncomplying fuel assembly to the correct location.
- b. The provisions of Specification 3.0.3 are not applicable.
Revision 1
i Table 3.9-1 Minimum Qualifvina Burnuo Versus initial Enrichment for Unrestricted Reaion 1 Storaae initial Nominal Enrichment Assembly Burnup (Weiaht% U-235)
(GWD/MTU) 4.19 (or less) 0 4.20 0.04 4.50 1.92 4.75 3.40 5-S4 b6 3
T ACCEPTABLE y
For Unrestricted Storage c5 2 2
UNACCEPTABLE 3
For Unrestricted Storage 4
0 4.00 4.25.
4.50 4.75 initial Nominal Enrichment (Weight % U-235)
Fuel which differs from those designs used to determine the requirements of Table 3.9-1 may be qualified for Unrestricted Region 1 storage by means of an analysis using NRC approved methodology to assure that k, is less than or equal to 0.95.
Likewise, previously unanalyzed fuel up to 4.75 weight % U-235 may be qualified for
);
Restricted Region 1 storage by means of an analysis using NRC approved methodology to assure that k, is less than or equal to 0.95.
l Revision 1
Table 3.9-2 Minimum Qualifying Burnuo Versus initial Enrichment for Region 1 Filler Assemblies Initial Nominal Enrichment Assembly Burnup (Weicht% U-235)
(GWD/MTU) 2.92 (or less) 0 3.00 1.57 3.50 13.30 4.00 18.32 i
4.50 23.36 4.75 25.84 30 -
y 25 -
4 ACCEPTABLE g 20 -
For Use As Filler Assembly.
$15 1
c5
@ 10 UNACCEPTABLE 5
For Use As Filler Assembly
$5 0
2.5 3
3.5 4
4.5 4.75 initial Nominal Enrichment (Weight % U-235)
Fuel which differs from those designs used to determine the requirements of Table 3.9-2 may be qualified for use as a Region 1 Filler Assembly by means of an analysis using NRC approved methodology to assure that k,is less than or equal to 0.95.
Revision 1
Table 3.9 3 Minimum Qualifying Burnuo Versus initial Enrichment for Unrestricted Region 2 Storaos initial Nominal Enrichment Assembly Burnup (Weloht% U-235)
(GWD/MTU) 2.00 (or less) 10.54 2.50 17.96 3.00 24.64 3.50 30.86 4.00 36.75 4.50 42.38 4.75 45.10 60 -
p 50 ACCEPTABLE For Unrestricted Storage
/
a 30 UNACCEPTABLE ft 20 -
5 For Unrestricted Storage M 10 O
2 2.5 3
3.5 4
4.5 4.75 Initial Nominal Enrichment (Weight % U-235)
Fuel which differs from those designs used to determine the requirements of Table 3.9-3 may be qualified for Unrestricted Region 2 storage by means of an analysis using NRC approved methodology to assure that k,is less than or equal to 0.95.
Revision 1
-)
Table 3.9-4 Minimum Qualifvina Burnuo Versus Initial Enrichment for Restricted Reaion 2 Storaas with Fillers Initial Nominal Enrichment Assembly Burnup (Weicht% U-235)
(GWD/MTU) 2.00 (or less) 4.22 2.50 10.75 3.00 16.80 3.50 22.41 4.00 27.92 4.50 33.14 4.75 35.65 1
60 -
y 50 ACCEPTABLE 40 -
S For Restricted Storage h 30 -
cB
@ 20 -
5 UNACCEPTABLE M 10 For Restricted Storage 0
2 2.5 3
3.5 4
4.5 4.75 Initial Nominal Enrichment (Weight % U-235)
Fuel which differs from those designs used to determine the requirements of Table 3.9-4 may be qualified for Restricted Region 2 Storage by means of an analysis using NRC approved methodology to assure that k, is less than or equal to 0.95.
j l
I Revision 1
4 Table 3.9 5 Minimum Onnlifvina Burrum Verann Initial Enrichment for Reaion 2 Filler Annamblies initial Nominal Enrichment
. Assembly Burnup (Welaht% U-235)
(GWD/MTU) -
2.00 (orless) 18.03 2.50 26.71' 3.00 33.79 3.50 40.56 4.00 46.83 4.50 52.86 4.75 55.78 60 -
ACCEPTABLE
^ 50 For Use As Filler Assembly b
N 40 n.
p 30 -
S UNACCEPTABLE f 20 ~
For Use As Filler Assembly 84 10 -
0 2
2.5 3
3.5 4
4.5 4.75 initial Nominal Enrichment (Weight % U-235)
Fuel which differs from those designs used to determine the requirements of Table 3.9-5 may be qualified for use as a Region 2 Filler Assembly by means of an analysis using NRC approved methodology to assure that k, is less than or equal to 0.95.
l i
Revision 1 L:
Fiaure 3.9-1 Reauired 3 out of 4 Loadina Pattern
)
for Restricted Reaion 1 StoIaQR l
lpD N?diij,.j:
' Oh:4
> * "f g
1 RESTRICTED RESTRICTED RESTRICTED RESTRICTED FUEL FUEL FUEL FUEL
'n,'. R
'J, fg
%Qfgjiff pg>, MfL,
<q V,, gg;^id$1 RESTRICTED FILLER RESTRICTED FILLER FUEL LOCATION FUEL LOCATION
, & qG.
_'q:
~
6'
!!j m f ; c' W :p < ^
- RESTRICTED RESTRICTED RESTRICTED RESTRICTED FUEL FUEL FUEL FUEL f
$N%. '
, jg,' fjg
_Q
,y s
< jes >
ggg>
HESTRICTED FILLER RESTRICTED FILLER l
FUEL LOCAVON FUEL LOCADON
,'m ME :,
Restricted Fuel:
Fuel which does agt meet the minimum burnup requirements of Table 3.9-1. (Fuel which does meet the requirements of Table 3.9-1, or non-fuel components, or an empty location may be placed in restricted fuel locations as needed)_
Filler Location:
Either fuel which meets the minimum bumup requirements of Table 3.9-2, or an empty cell.
Boundary Condition:
Any row bounded by a Region 1 Unrestricted Storage Area shall contain a combination of restricted fuel assemblies and filler locations arranged such that no restricted fuel assemblies are adjacent to each other.
Example: In the figure above, row 1 or column 1 can Dat be adjacent to a Region 1 Unrestricted Storage Area, but row 4 or column 4 can be.
Revision 1
l Fioure 3.9-2 Reauired 2 out of 4 Loadino Pattern for Restricted Reofon 2 Storaos Q
fM DN RESTRICTED FILLER RESTRICTED FILLER FUEL LOCATION FUEL LOCATION
'4ss d$t"ist' W *Y$$
FILLER RESTRICTED FILLER RESTRICTED LOCATION FUEL LOCATION FUEL
~,,,)
.; f ~'.'
g
- %9 ns-
' ag >
l RESTRICTED FILLER RESTRICTED FILLER l
FUEL LOCATION FUEL LOCATION r
m
' t - ni &
s m;
ni ny ny ;gn FILLER RESTRICTED FILLER RESTRICTED LOCATION FUEL LOCATION FUEL
, ?%!?in + yfit M.f Restricted Fuel:
Fuel which meets the minimum burnup requirements of Table 3.9-4, or non-fuel components, or an empty location.
Filter Location:
Either fuel which meets the minimum bumup requirements of Table 3.9-5, or an empty cell.
Boundary Condition:
No restrictions c,.
oundary assemblies.
1 Revision 1
I 1
Fiaure 3.9-3 Reauired 2 out of 4 Londina Pattern for Checkerboard Realon 2 Storaae M@$MN$l MN@$Ehkl CHECKER 80ARE EMPTY CHECKER 80ARE EMPTY FUEL CELL FUEL CELL
> l, N:ll
-l NMb$%ijkhib
^
b8$IEMiNMI I$$kk$f$$$l EMPTY OHECKERBOARE EMPTY OHECKER80ARE CELL FUEL CELL FUEL
- n$hhhhh%sh l'$Gl
- 'Dl 3MM$igden s)' i 3 ' J 'j OHECKERBOARE EMPTY CHECKERBOARE EMPTY FUEL CELL FUEL CELL N s'%y(fi "l' $i", ' {)
i si((khki@f$
.h$h$$5$$N$j EMPTY OHECKERBOAnd EMPTY
- HECKER80ARE CELL FUEL CELL FUEL
$$$hidy
$]$IEN$$pa Checkerboard Fuel: Fuel which does not meet the minimum burnup requirements of Table 3.9-4. (Fuel which does meet the requirements of Table 3.9-4, or non-fuel components, or an empty location may be placed in restricted fuel locations as needed)
Boundary Condition:
At least two oppor.ite sides shall be bounded by either an empty row of cells, or a spent fuel pool wall.
I t
Revision 1
+-..nm-,
+..
x e
s ;
n.
i-x.
-+--~w.-
-.o
. no
_s L
4
' BASES 3/4.9.12 and 3/4.9.13 SPENT FUEL POOL BORON CONCENTRATION and SPENT i
c FUEL ASSEMBLY STORAGE i
The requirements for spent fuel pool boron concentration specified in Specification 3.9.12 ensure that a minimum boron concentration is maintained in the pool. The requirements for spent fuel assembly storage specified in Specification 3.9.13 ensure l
that the pool remains suberitical. The water in the spent fuel storage pool normally contains soluble boron, which results in large subcriticality margins under actual j
operating conditions. However, the NRC guidelines based upon the accident condition l
in which all soluble poison is assumed to have been lost, specify that the limiting k,n f o
0.95 be evaluated in the absence of soluble boron. Hence the design of the spent fuel storage racks is based on the use of unborated water, which maintains each region in a subcritical condition during normal operation with the spent fuel pool fully loaded. The double contingency principle discussed in ANSI N-16.1-1975 and the April 1978 NRC letter (Ref. 4) allows credit for soluble boron under other abnormal or accident conditions, since only a single accident need be considered at one time. For example, the most severe accident scenario is associated with the movement of fuel from Region 1 to Region 2, and accidental mistoading of a fuel assembly in Region 1 or Region 2.
l This could increase the reactivity of the spent fuel pool. To mitigate these postulated criticality related accidents, boron is dissolved in the pool water.
Tables 3.9-1 through 3.9-5 allow for specific criticality analyses for fuel which does not meet the requirements for storage defined in these tables. These analyses would require using NRC approved methodology to ensure that k,n s 0.95 with a 95 percent
- i probability at a 95 percent confidence level as described in Section 9.1 of the FSAR.
This option is intended to be used for fuel not included in previous criticality analyses.
Fuel storage is still limited to the configurations defined in-TS 3.9-13. The use of specific analyses for qualification of previously unanalyzed fuel includes, but is not limited to, fuel assembly designs not previously analyzed which may be as a result of new fuel designs or fuel shipments from another facility. Another more likely, and expected use of this specific analysis provision would be to analyze movement and storage of individual fuel pins as a result of reconstitution activities.
In verifying the design criteria of k,n s 0.95, the criticality analysis assumed the most conservative conditions, i.e. fuel of the maximum permissible reactivity for a given configuration.
Since the data presented in Specification 3.9.13.a and 3.9.13.b represents the maximum reactivity requirements for acceptable storage, substitutions of i
less reactive components would also meet the k n s 0.95 criteria. Hence, any non-fuel component may be placed in a designated empty cell location. Likewise, an empty cell, or a non-fuel component may be substituted for any designated fuel assembly location.
These, or other substitutions which will decrease the reactivity of a particular storage cell will only decrease the overall reactivity of the spent fuel storage pool.
If both restricted and unrestricted storage is used in Region 1, an additional criteria has been imposed to ensure that the boundary row between these two configurations would i
not locally increase the reactivity above the required limit. Likewise if checkerboard storage is used in Region 2, an additional restriction has been imposed on the Revision 1 i
~ - -,. - - -... -
p
'~
n..
boundaries of the checkerboard storage region to ensure that the reactivity would not increase above the required limit. No other restrictions on region interfaces are necessary.
For storage in Region 2 requiring loading pattern restrictions, (per Specifications 3.9.13.b.2 or 3.9.13.b.3) fuel may be stored in either the " cell".or "non-cell" locations.
" Cell" locations are the areas inside the fabricated storage cells and "non-cell" locations are the storage locations created by arranging the fabricated storage cells in 'a checkerboard configuration. Hence the "non-cell" locations are the areas defined by the outside walls of the 4 adjacent " cell" locations.
The action statement applicable to fuel storage in the spent fuel pool requires that action must be taken to preclude the occurrence of an accident or to mitigate the consequences of an accident in progress.
This is most efficiently achieved by immediately suspending the movement of fuel assemblies. Prior to the resumption of fuel movement, the requirements of the LCOs must be met. This requires restoring the soluble boron concentration and the correct fuel storage configuration to _within the corresponding limits. This does not preclude movement of a fuel assembly to a safe position.
The surveillance requirements ensure that the requirements of the two LCOs are satisfied, namely boron concentration and fuel placement. The boron concentration in the spent fuel pool is verified to be greater than or equal to the minimum limit. The fuel assemblies are verified 'o meet the suberiticality requirement by meeting either the initial enrichment and burnup requirements of Table 3.9-1 through 3.9-5, or by using NRC approved methodology to ensure that k.n s 0.95. By meeting either of these requirements, the analyzed accidents are fully addressed.
The fuel storage requirements and restrictions discussed here and applied in section 3.9.13 are based on a maximum allowable fuel enrichment of 4.75 weight % U-235.
The enrichments listed in Tables 3.9-1-through 3.9-5 are nominal enrichments and include uncertainties to account for the tolerance on the as built enrichment. Hence the as built enrichments may exceed the enrichments listed in the tables by up to 0.05 weight % U-235. Qualifying burnups for enrichments not listed in the tables may be linearly interpolated between the enrichments provided. This is because the reactivity of an assembly varies linearly for small ranges of enrichment.
REFERENCES
- 1. " Regulatory Guide 1.13: Spent Fuel Storage Facility Design Basis", U.S. Nuclear Regulatory Commission, Office of Standards Development, Revision 1, December 1976.
2 Design Objectives for Light Water Reactor Spent Fuel Storage Facilities at Nuclear Power Stations", American Nuclear Society, ANSI N210-1976/ANS-57.2, April 1976.
- 3. FSAR, Section 9.1.
- 4. Double contingency principle of ANSI N16.1-1975, as specified in the April 14,1978 NRC letter (Section 1.2) and implied in the proposed revision to Regulatory Guide 1.13 (Section 1.4, Appendix A).
i Revision i 1
I INTRODUCTION This submittal represents Duke Power Company's formal request for approval of a license amendment which establishes several restricted loading patterns and associated bumup criteria for placement of new and irradiated fuel into both regions of the McGuire spent fuel storage pools. Analysis performed in support of this submittal demonstrates that the use of one or more of these configurations for storing fuel with initial enrichments of up to 4.75 weight %
(nominal) U-235 will maintain sufficient criticality safety margins. This amendment will allow for maximum utilization of the fuel storage racks and will provide additional flexibility in the area of reactor core analysis and design.
Also included as part of this submittalis a detailed description of the analytical methodology used to generate the various burnup criteria discussed above. This methodology was specifically developed for spent fuel burnup credit applications and is based on the CASMO and SIMULATE computer codes. Since it has not been previously used by Duke Power Company, formal approval of this methodology is also being sought with this application.
In addition, this submittal is similar to the Seabrook Station Unit 1 Amendment No. 6, which was approved by the NRC August 27,1991. Specifically, both the Seabrook amendment and this amendment request use the CASMO and SIMULATE computer codes for fuel storage burnup credit analysis, establish multiple fuel types with corresponding loading pattern restrictions and allow high reactivity fuel which is unacceptable for storage in an infinite array to be stored with empty locations or with appropriately qualified low reactivity fuel.
II 11ACKGROUND INFORMATION The two unit McGuire Nuclear Station became fully operational in 1983. At that time the plant had a total spent fuel storage capacity of 1000 fuel assemblies utilizing a 15" center-to-center spacing between individual fuel assemblies in two independent spent fuel pools. The McGuire Nuclear Station was initially licensed with a maximum allowable fuel enrichment of 4.0 weight % U-235 with an absolute tolerance of.05 weight %. Since each reactor core design is individually licensed this limit is specifically applicable to the new fuel storage vaults and the spent fuel storage pools.
In 1985 and 1987, the unit 2 and unit I spent fuel storage pools were respectively reracked with eight free standing modules of storage cells totaling 1463 per pool. The majority of the storage cells are closely spaced to accommodate less reactive burned assemblies whereas the remaining cells are intended for the higher reactivity of new or partially bumed fuel. This 2 region concept resulted in a considerable increase in the fuel storage capacity allowing for 10 or more years of additional discharge capability for each reactor unit. The burnup requirements for the burned fuel region (region 2) of the storage racks were defined by a single burnup versus enrichment curve. This curve is currently represented as table 3.9-1 in Technical Specification # 3/4.9.12. No increase in the maximum allowable enrichment was necessary or requested as part of the licensing approval for this rerack project.
In the 7 years since completing the rerack effort, the McGuire Station has permanently discharged a significant inventory of unqualified fuel assemblies which are currently stored with the required checkerboard storage configuration in the region 2 area of the spent fuel pool. Additionally, plans are underway to utilize future reload batches which incorporate fuel assemblies with enrichments in excess of the current 4.0 weight % limit. The continued generation of unqualified assemblies and the pending increase in fuel enrichments together repn sent the basis for this submittal.
1-1
r Proposed Requirements:
Technical Specification
Reference:
3/4.9 Refuelino Onerations UNITS 1 and 2 REFUELING OPERATIONS 3/4.9.12 SPENT FUEL POOL BORON CONCENTRATION LIMITING CONDITION FOR OPERATION 3.9.12 The boron concentration in the spent fuel pool shall be within the limit specified in the COLR.
APPLICABILITY:
When fuel assemblies are stored in the spent fuel pool and a fuel storage pool I
verification has not been performed since the last movement of fuel assemblies in the fuel storage pool.
ACTION:
I
- a. Immediately suspend movement of fuel assemblies in the spent fuel pool and initiate action to restore the spent fuel pool boron concentration to within its limit.
1
- b. The provisions of Specification 3.0.3 are not applicable.
SURVEILLANCE REQUIREMENTS:
4.9.12 Verify at least once per 7 days that the spent fuel pool boron concentration is within its limit.
8-7 Revision 1
I Proposed Requirements: (Con't) 3/4.9.13 SPENT FUEL ASSEMBLY STORAGE l
LIMITING CONDITION FOR OPERATION 3.9.13 Storage of new or irradiated fuel is limited to the configurations described in this specification.
. a. New or irradiated fuel may be stored in Region 1 of the Spent Fuel Pool in accordance with these limits:
- 1) Unrestricted storage of fuel meeting the criteria of Table 3.9-1; or
- 2) Restricted storage in accordance with Figure 3.9-1, of fuel which does no1 meet the criteria of Table 3.9-1.
- b. New or irradiated fuel which has decayed at least 16 days may be stored in Region 2 of the Spent Fuel Poolin accordance with these limits:
t
- 1) Unrestricted storage of fuel meeting the criteria of Table 3.9-3; or
- 2) Restricted storage in accordance with Figure 3.9-2, of fuel which meets the criteria of Table 3.9-4; or
- 3) Checkerboard storage in accordance with Figure 3.9-3 of fuel which does ani meet the criteria of Table 3.94.
APPLICABILITY:
During storage of fuelin the spent fuel pool.
ACTION:
- a. Immediately initiate action to move the noncomplying fuel assembly to the correct location.
- b. The provisions of Specification 3.0.3 are not applicable.
i 8-8 Revision 1
n.
-I wi Propnaed Requirements: (Con't)
Table 3.9-1 Minimum Qualifvina Burnuo Versus initial Enrichment for Unrestricted Realon 1 Stornae initial Nominal Enrichment Assembly Burnup 4
(Weloht% U-235)
(GWD/MTU) 4,19 (orless) 0 4.20 0.04 4.50 1.92 4.75 3.40 4
6
).
5-
$4 R.
8 3
~
ACCEPTABLE T
For Unrestricted Storage c5 2 2
i E
UNACCEPTABLE E
For Unrestricted Storage 0
4.00 4.25 4.50 4.75 l
Initial Nominal Enrichment (Weight % U-235) 1 Fuel which ditters from those designs used to determine the requirements of Table 3.91 may be qualified for Unrestricted Region i storage by means of an analysis j
using NRC approved methodology to assure that k, is less than or equal to 0.95.
4 Likewise, previously unanalyzed fuel up to 4.75 weight % U-235 may be qualified for Restricted Region-1 storage by means of an analysis using NRC approved methodology to assure that k, is less than or equal to 0.95.
'8-10 Revision 1 i
I
... ~.
_. _ _. ~..
Proposed Renuirements: (Con't) i Table 3.9-2 Minimum Qualifvina Burnuo Versus initial Enrichment for Realon 1 Filler Annemblies s
d Initial Nominal Enrichment -
Assembly Burnup (Weicht% U-235)
(GWD/MTU) 2.92 (orless) 0-3.00 1.57 3.50 13.30' l
4.00 18.32 4.50 23.36 4.75 25.84 i
30 -
25 -
N ACCEPTABLE g 20 -
For Use As Filler Assembly 15 -
m UNACCEPTABLE R 10 For Use As Filler Assembly k
5-0 2.5 3
3.5 4
4.5 4.75 Initial Nominal Enrichment (Weight % U-235)
Fuel which differs from those designs used to determine the requirements of Table 3.9-2 may be qualified for use as a Region 1 Filler Assembly by means of an analysis using NRC approved methodology to assure that k, is less than or equal to 0.95.
1 i
8 - 11 Revision I l
(.
'~
Proposed Reauirements: (Con't)
Table 3.9-3 Minimum Qualifvina Burnuo Versus initial Enrichment for Unrestricted Realon 2 Storaae initial Nominal Enrichment Assembly Burnup (Welaht% U-235)
(GWD/MTU) 2.00 (or less) 10.54 2.50 17.96 3.00 24.64 3.50 30.86 4.00 36.75 4.50 42.38 4.75 45.10 60 --
l y 50 ACCEPTABLE i
E For Unrestricted Storage 3@ 40 E 30 g
E R 20 UNACCEPTABLE 5
For Unrestricted Storage
$ 10 0
2 2.5 3
3.5 4
4.5 4.75 Initial Nominal Enrichment (Weight % U-235)
Fuel which differs from those designs used to determine the requirements of Table 3.9-3 may be qualified for Unrestricted Region 2 storage by means of an analysis using NRC approved methodology to assure that k,is less than or equal to 0.95.
8 - 12 Revision 1
p Proposed Requirements: (Con't)
- Table 3.9-4 Minimum Qualifyino Burnun Versus initini Enrichment for Restricted Reaion 2 Storaos with Fillers Initial Nominal Enrichment Assembly Burnup (Weloht% U-235)
(GWD/MTU) 2.00 (orless) 4.22 2.50 10.75 3.00 16.80 3.50 22.41 4.00 27.92 4.50 33.14 4.75 35.65 60 -
y 50 -
40 -
ACCEPTABLE For Restricted Storage v
$ 30 -
N R 20 -
5 UNACCEPTABLE M 10 For Restricted Storage 0
2 2.5 3
3.5 4
4.5 4.75 Initial Nominal Enrichment (Weight % U-235)
Fuel which differs from those designs used to determine the requirements of Table 3.9-4 may be qualified for Restricted Region 2 Storage by means of an analysis using NRC approved methodology to assure that k,is less than or equal to 0.95.
8 - 13 Revision 1
b i
l Propnaed Requirements: (Con't)
Table 3.9-5 1
Minimum Qualifyino Burnuo Versus Initial Enrichment for Recion 2 Filler Assemblies Initial Nominal Enrichment Assembly Burnup (Weicht% U-235)
(GWD/MTU) 2.00 (orless) 18.03 2.50 26.71 3.00 33.79 3.50 40.56 4.00 46.83 4.50 52.86 4.75 55.78 60 ACCEPTABLE
^ 50 For Use As Filler Assembly b
@ 40 s
h 30 -
S UNACCEPTABLE
@ 20 -
For Use As Filler Assembly 5
M 10 -
0 2
2.5 3
3.5 4
4.5 -4.75 Initial Nominal Enrichment (Weight % U-235)
Fuel which differs from those designs used to determine the requirements of Table 3.9-5 may be qualified for use as a Region 2 Filler Assembly by means of an analysis using NRC approved methodology to assure that k,is less than or equal to 0.95.
8 - 14 Revision 1
I Pronosed Reauirements- (Con't)
Figure 3.9-1 Reauired 3 out of 4 Loadina Pattern for Restricted Reaion 1 Storage NM
~
v& -
MsE q s
RESTRICTED RESTRICTED RESTRICTED RESTRICTED FUEL FUEL FUEL FUEL App $4 S ' Mis @ >
m 0" l '
3R ME
% /~
WWena RESTRICTED FILLER RESTRICTED FILLER FUEL LOCATION FUEL LOCATION
>%% e4
' nw ;#s.
We N MEL g 4 M*j;
< gg4yrJ39 RESTRICTED RESTRICTED RESTRICTED RESTRICTED FUEL FUEL FUEL FUEL M'
s a $ +*,
. 80 y
m
_ <a RESTRICTED FILLER RESTRICTED FILLER FUEL LOCAT!ON FUEL LOCATION
> W Mb
, jg3 t
s Restricted Fuel:
Fuel which does nal meet the minimum burnuD requirements of Table 3.91. (Fuel which does meet the re guirements of Table 3.9-1, or non-fuel components, or an empty location may be placed in restricted fuel locations as needed)
Filler Location:
Either fuel which meets the minimum burnup requirements of Table 3.9-2, or an empty cell.
Boundary Condition:
Any row bounded by a Region 1 Unrestricted Storage Area shall contain a combination of restricted fuel assemblies and filler locations arranged such that no restricted fuel assemblies are adjacent to each other.
Example: In the figure above, row 1 or column 1 can Dol be adjacent to a Region 1 Unrestricted Storage Area, but row 4 or column 4 can be.
8 - 15 Revision 1
i Pronosed Reonirements: (Con't)
Fia_ ure 3.9-2 Recuired 2 out of 4 Loadina Pattern for Restricted Reaion 2 Storaae NM, W
, en s
RESTRICTED FILLER RESTRICTED FILLER FUEL LOCATION FUEL LOCATION
%gg,
m wad @A f@hd@##'
- e MJ ':
FILLER RESTRICTED FlLLER RESTRICTED LOCATION FUEL LOCATION FUEL
. p! ';'; ' i,
@!jf M$[s]g.
gg wt
- qapsig,
IRESTRICTED FILLER RESTRICTED FILLER FUEL LOCATION FUEL LOCATION i
.$N NNNl m
a.
i l
^ $2 2 $i$
0%5k 's FILLER RESTRICTED FILLER RESTRICTED LOCATION FUEL LOCATION FUEL
!$%RN M 7 EN 4 j9 i
Restricted Fuel:
Fuel which meets the minimum burnup requirements of Table l
3.9-4, or non-fuel components, or an empty location.
Filler Location:
Either fuel which meets the minimum burnup requirements of Table 3.9-5, or an empty cell.
Boundary Condition:
No restrictions on boundary assemblies.
8 -16 Revision I
I p
I
\\-
Proposed Requirements: (Con't)
Fioure 3.9-3 Raoulred 2 out of 4 Loadino Pattern for Checkerboard Region 2 Storage N5fINMS$N@Nl Ef@$$M3 OHECKERBOARE EMPTY CHECKERBOARC EMPTY FUEL CELL FUEL CELL y#ih@QQW
&ffj?@$$
l E%IMi@$NNl
$$$M@$$
EMPTY OHECKERBOARC EMPTY OHECKERBOARE CELL FUEL CELL FUEL M80rlsA${l
@@MEIE@!l l$ 4 %
[MsMr:
OHECKERBOARE' EMPTY CHECKERBOARE EMPTY FUEL CELL FUEL CELL 6%Qll%
' * ^hlnl?
Ef60@sd9$l l$#N$$$$$$$l EMPTY OHECKERBOARE EMPTY OHECKERBOARE CELL FUEL CELL FUEL
$M35 w#e A%ify$$M^;
Checkerboard Fuel: Fuel which does not meet the minimum bumup requirements of Table 3.9-4. (Fuel which does meet the requirements of Table 3.9-4, or non-fuel components, or an empty location may be placed in checkerboard fuellocations as needed)
Boundary Condition:
At least two opposite sides shall be bounded by either an empty row of cells, or a spent fuel pool wall.
8-17 Revision 1
F 1
- \\
Proposed Requirements:
Technical Specification
Reference:
3/4.9 Refueling Onerations UNITS 1 and 2 BASES j
~
3/4.9.12 and 3/4.9.13 SPENT FUEL POOL BORON CONCENTRATION and SPENT FUEL ASSEMBLY STORAGE The. requirements for spent fuel pool boron concentration specified in Specification 3.9.12 ensure that a minimum boron concentration is maintained in the pool. The requirements for spent fuel assembly storage specified in Specification 3.9.13 ensure that the pool remains suberitical. The water in the spent fuel storage pool normally contains soluble boron, which results in large suberiticality margins under actual operating conditions. However, the NRC guidelines based upon the accident condition in which all soluble poison is assumed to have been lost, specify that the limiting IQ of 0.95 be evaluated in the absence of soluble boron. Hence the design of the spent fuel storage racks is based on the use of unborated water, which maintains each region in a suberitical condition during normal operation with the spent fuel pool fully loaded. The 4
double contingency principle discussed in ANSI N-16.1-1975 and the April 1978 NRC letter (Ref. 4) allows credit for soluble boron under other abnormal or accident conditions, since only a single accident need be considered at one time. For example, the most severe accident scenario is associated with the movement of fuel from Region 1 to Region 2, and accidental misloading of a fuel assembly in Region 1 or Region 2.
This could increase the reactivity of the spent fuel pool. To mitigate these postulated criticality related accidents, boron is dissolved in the pool water.
t Tables 3.9-1 through 3.9-5 allow for specific criticality analyses for fuel which does not meet the requirements for storage defined.In these tables. These analyses would f
require using NRC approved methodology to ensure that k,n s 0.95 with a 95 percent probability at a 95 percent confidence level as described in Section 9.1 of the FSAR.
This option is intended to be used for fuel not included in previous criticality analyses.
Fuel storage is still limited to the configurations defined in TS 3.9-13. The use of specific analyses for qualification of previously unanalyzed fuel includes, but is not limited to, fuel assembly designs not previously analyzed which may be as a result of new fuel designs or fuel shipments from another facility. Another more likely, and expected use of this specific analysis provision would be to analyze movement and i
storage of individual fuel pins as a result of reconstitution activities, j
in verifying the design criteria of k n s 0.95, the criticality analysis assumed the most e
conservative conditions, i.e. fuel of the maximum permissible reactivity for a given configuration.
Since the data presented in Specification 3.9.13.a-and 3.9.13.b represents the maximum reactivity requirements for acceptable storage, substitutions of less reactive components would also meet the k,y s 0.95 criteria. Hence, any non-fuel component may be placed in a designated empty cell location. Likewise, an empty cell, j
l or a non-fuel component may be substituted for any designated fuel assembly location.
8 -20 Revision 1
./
0 Pronosed Requirements: (Con't)
These, or other substitutions which will decrease the reactivity of a particular storage cell will only decrease the overall reactivity of the spent fuel storage pool.
i if both restricted and unrestricted storage is used in Region 1, an additional criteria has been imposed to ensure that the boundary row between these two configurations would not locally increase the reactivity above the required limit. Likewise if checkerboard storage _ is used in Region 2, an additional restriction has been imposed on the boundaries of the checkerboard storage region to ensure that the reactivity would not increase above the required limit. No other restrictions on region interfaces are necessary.
For storage in Region 2 requiring loading pattern restrictions, (per Specifications 3.9.13.b.2 or 3.9.13.b.3) fuel may be stored in either the " cell
- or "non-cell" locations.
" Cell" locations are the areas inside the fabricated storage cells and "non-cell" locations are De storage locations created by arranging the fabricated storage cells in a checkerboard configuration.. Hence the "non-cell" locations are the areas defined by the outside walls of the 4 adjacent " cell" locations.
a The action statement applicable to fuel storage in the spent fuel pool requires that action must be taken to preclude the occurrence of an accident or to mitigate the t
consequences of an accident in progress.
This is most efficiently achieved by immediately suspending the movement of fuel assemblies. Prior to tha resumption of fuel movement, the requirements of the LCOs must be met. This requires restoring the soluble boron concentration and the correct fuel storage configuration to within the corresponding limits. This does not preclude movement of a fuel assembly to a safe position.
k The surveillance requirements ensure that the requirements of the two LCOs are satisfied, namely boron concentration and fuel placement. The boron concentration in the spent fuel pool is verified to be greater than or equal to the minimum limit. The fuel assemblies are verified to meet the suberiticality requirement by meeting either the initial enrichment and burnup requirements of Table 3.9-1 through 3.9-5, or by using NRC approved methodology to ensure that kg s 0.95. By meeting either of these requirements, the analyzed accidents are fully addressed.
The fuel storage requirements and restrictions discussed here and applied in section 3.9.13 are based on a maximum allowable fuel enrichment of 4.75 weight % U-235.
The enrichments listed in Tables 3.9-1 through 3.9-5 are nominal enrichments and include uncertainties to account for the tolerance on the as built enrichment. Hence the as built enrichments may exceed the enrichments listed in the tables by up to 0.05 weight % U-235. Qualifying burnups for enrichments not listed in the tables may be linearly interpolated between the enrichments provided. This is because the reactivity of an assembly varies linearly for small ranges of enrichment.
l 3 21 Revision 1
Proposed Requirements: (Con't)
REFERENCES
- 1. ' Regulatory Guide 1.13: Spent Fuel Storage Facility Design Basis", U.S. Nuclear Regulatory Commission, Office of Standards Development, Revision 1, December 1976.
2 ' Design Objectives for Light Water Reactor Spent Fuel Storage Facilities at Nuclear Power Stations", American Nuclear Society, ANSI N210-1976/ANS-57.2, April 1976.
- 3. FSAR, Section 9.1.
- 4. Double contingency principle of ANSI N16.1-1975, as specified in the April 14,1978 NRC letter (Section 1.2) and implied in the proposed revision to Regulatory Guide 1.13 (Section 1.4, Appendix A).
L I
8 - 22 Revision 1 a.
ATTACHMENT 3
- MODIFICATIONS TO NO SIGNIFICANT HAZARDS ANALYSIS
.AND ENVIRONMENTAL IMPACT ANALYSIS MCGUIRE NUCLEAR STATION 4
1
' l i
1 i
e
+
a
)
.1 ATTACHMENT II NO SIGNIFICANTHAZARDS ANALYSIS Duke Power Company has reviewed the proposed changes utilizing the criteria specified in 10CFR50.92 and has determined that the proposed changes do not involve a Significant Hazards Consideration pursuant thereto, for the reasons discussed below.
- 1. The proposed changes do not involve a significant increase in the probability or consequences of an accident previously evaluated.
There is no increase in the probability or consequences of an accident in the new fuel vault since the only credible accidents for this area are criticality accidents and it has been shown that calculated, worst case Kerr for this area is s 0.95 for fully flooded conditions and Kerr s 0.98 under optimum moderation conditions. This is in accordance with current licensing criteria. Likewise, there is no increase in the probability or consequences of an accident in the Spent Fuel Pool since, for criticality accidents, analyses have shown that Kerts 0.95 under all conditions is being maintained.
There is also no increase in the probability or consequences of a fuel drop accident in the Spent Fuel Storage Pool. Since the mass of an assembly will not be affected by the increase in fuel enrichment, the probability of an accident is not increased, and since the fission product inventory of individual fuel assemblies will not change significantly as a result of increased enrichment, the consequences cf a fuel rupture accident remain unchanged.
The likelihood of other accidents, previously evaluated and described in Section 9.1.2 of the FS AR, is also not affected by the proposed changes. In fact, it could be postulated that since the increase in fuel enrichment will allow for extended fuel cycles, there will be a decrease in fuel movement and the probability of an accident may likewise be decreased.
- 2. The proposed changes do not create the possibility of a new or different kind of accident from any accident previously evaluated.
The proposed changes do not create the possibility of a new or different kind of accident since fuel handling accidents (fuel drop and misplacement) are not new or different kmds of accidents. Fuel handling accidents are already discussed in the FSAR for fuel with enrichments up to 4.0 weight %. As described in Section VI.9 of Attachment IV, additional aralyses have been performed for fuel with enrichment up to 5.00 weight %.
J Worst case mistoading accidents associated with the new loading patterns were evaluated.
It was shown that the negative reactivity provided by soluble boron maintains k rt s 0.95 e
under all conditions.
)
Revision 1
- 3. The proposed changes do not involve a significant reduction in the margin of safety.
The proposed change does not involve a significant reduction in the margin of safety since, a kegs 0.95 is being maintained for fully flooded conditions and a keff 50.98 under
. optimum moderation canditions. The specification of kert s 0.98, for optimum moderation conditions in the new fuel vault, is an addition to the existing specification regnirements of k g_s 0.95 for fully flooded conditions. Although previous analyses have e
been performed to demonstrate that this requiirment could be met, there was no licensing requirement to do so. Addition of this specification brings the specification more in line with current STS requirements and, in fact, may increase the margin of safety since, compliance with this requirement was not previously required.
a
[
Revision 1
~.
+
9 A'ITACHMENT III ENVIRONMENTAL IMPACT ANALYSIS Pursuant to 10CFR51.22 (b), an evaluation of the proposed amendments has been performed to determine whether or not it meets the criteria for categorical exclusion set forth in 10CFR51.22 (c)9 of the regulations. The proposed amendment does involve changes in the use of facility _ components located within the restricted area as defined in 10CFR20, and changes some surveillance requirements however, the proposed amendment does not involve; 1) a significant hazards consideration,2) a significant change in the types or significant increase in the amounts of any effluents that may be released offsite, or 3) a significant increase in individual or cumulative occupational radiation exposure.
In drawing this conclusion, Duke Power Company has reviewed the published Notice of Environmental Assessment and Finding of No Significant Impact for Extended Burnup Fuel Use in Commercial LWR's in the Federal Register (53 FR 6040), dated February 29, 1988. We have determined that the notice is applicable to the::e changes for McGuire Nuclear Station, Units 1 & 2, and it's fuel. In the above cited notice, the staff concluded that the environmental impacts summarized in Table S-4 of 10CFR51.52 for the transportation of fuel up to 4.0 weight percent enriched Uranium-235 and a bumup level of 33,000 MWT/MTU are conservative and bound the corresponding impacts for transportation of fuel with a bumup level up to 60,000 MWD /MTU and enrichments up to 5.0 weight percent. In addition, we have reviewed the Staff's environmental assessment for the Shearon Harris Nuclear Power Plant for enrichment and extended fuel burnup increases pursuant to 10CFR51.21,51.32, and 51.35 and a finding of no significant impact as published in the Federal Register (53 FR 30355) on August 11,1988. We have determined this is equally applicable to these changes, as well.
In summary, we believe this amendment request meets the criteria set forth in i
10CFR51.22 (c) 9 of the regulations for categorical exclusion from an environmental impact statement.
i l
Revision I s
m
+=