GO2-97-219, Application for Amend to License NPF-21,modifying Min Critical Power Ratio Safety Limits by 980515 to Allow Continued Power Operation at WNP-2 Following Restart from R-13 Refueling Outage
| ML17292B130 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 12/04/1997 |
| From: | Bemis P WASHINGTON PUBLIC POWER SUPPLY SYSTEM |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML17292B131 | List: |
| References | |
| GO2-97-219, NUDOCS 9712120362 | |
| Download: ML17292B130 (15) | |
Text
CATEGORY 1 REGUL RY.INFORMATION DISTRIBUT v'YSTEM (RIDS)
P ACCESSION NBR:9712120362 DOC.DATE: 97/12/04 NOTARIZED: YES DOCKET FACIL 50-397 WPPSS Nuclear Project, Unit 2, Washington Public Powe 05000397 AUTH3PAME AUTHOR AFFILIATION BERISI'P.R.
Washington Public Power Supply System RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)
SUBJECT:
Application for amend to license NPF-21,modifying min critical power ratio safety limits by 980515-to allow continued power operation at WNP-2 following restart from R-13 refueling outage.
DISTRIBUTION CODE:
AOOID COPIES RECEIVED:LTR ENCL SIZE: 7 + Il0 l
TITLE: OR Submittal:
General Distribution NOTES:
E RECIPIENT ID CODE/NAME PD4-2 LA POSLUSNY,C COPIES LTTR ENCL 1
1 1
1 RECIPIENT ID CODE/NAME PD4-2 PD COPIES LTTR ENCL 1
1 INTERNAL: ACRS NRR/DE/ECGB/A NRR/DRCH/HICB NRR/DSSA/SPLB NUDOCS-ABSTRACT 1
1 1
1 1
1 1
1 1
1 LE CE ER 1
NRR/DSSA'/SCSB NRR/DSSA/SRXB OGC/HDS3 1
1 1
1 1
0 1
1 1
0 EXTERNAL: NOAC 1
1 NRC PDR 1
1 D
E N
NOTE TO ALL "RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE WASTE. TO HAVE YOUR NAME OR ORGANIZATION REMOVED FROM DISTRIBUTION LISTS OR REDUCE THE NUMBER OF COPIES RECEIVED BY YOU OR YOUR ORGANIZATION, CONTACT THE DOCUMENT CONTROL DESK (DCD)
ON EXTENSION 415-2083 TOTAL NUMBER OF COPIES REQUIRED:
LTTR 15 ENCL 13
WASHINGTON PUBLIC POWER SUPPLY SYSTEM
,P.O. Box 968
~ Richland, Washington 99352-0968 December 4, 1997 G02-97-219 Docket No. 50-397 U.S. Nuclear Regulatory Commission,.
Document Control Desk Washington, D.C. 20555 Gentlemen:
Subject:
WNP-2 OPERATING LICENSE NPF-21 REQUEST FOR AMENDMENT MINIMUMCRITICALPOWER RATIOSAFETY LIMITS
References:
- 1) ~ Critical Power Correlation Uncertainty for Limited Data Sets, ANF-,." '~
1125(P), Supplement 1, Appendix D, Siemens Power Corporation - Nuclear" Division, Submitted on April 18, 1997
- 2) ~ Critical Power Correlation, ANF-1125(P)(A) with Supplements 1 and 2, Advanced Nuclear Fuels Corporation, April 1990 3)
Letter KVW:97:115 dated May 20, 1997, KV Walters (Siemens) to RA Vopalensky (Supply System), Revised MCPR Safety Limits for WNP-2 Cycle 11 4)
Letter KVW:97:077 dated April 8, 1997, KV Walters (Siemens) to RA Vopalensky (Supply System), "A%% Additive Constant Uncertainties for the SPC 9x9-9X Fuel Design" 5)
Letter HDC:97:033 dated April 18, 1997, HD Curet (Siemens) to US NRC Document Control Desk, "Interim Use ofIncreased ANFB Additive Constant Uncertainty" 97i2i20362 97i204 PDR ADOCK 05000997 P
I 'OO63 llllllllllllllllllllllllllllllllllllllll
l
~y ~ep
~ ':~'
~
0 I
... REQUEST FOR NT MRIMCMCRITICAL WRR IIATICSARITT LMITS Page 2 6)
Letter dated July 3, 1997, TG Colburn (NRC) to JV Parrish (Supply System),
"Issuance of Amendment for the Washington Public Power Supply System Nuclear Project No. 2 (TACNo. M98746) (Amendment No. 15 1)"
7)
Letter dated November 5, 1997, ABBWP-97-104, Rev. 1, R Matheny (ABB) to RAVopalensky (Supply System), "WNP-2 Cycle 14 Safety LimitMinimum Critical Power Ratio for SVEA-96 Fuel Based on Reference Core" In accordance with the Code of Federal Regulations, Title 10, Parts 50.59, 50.90, and 2.101, the Supply System hereby submits a request for amendment of the WNP-2 Operating License.
Specifically; the Supply System is requesting modification of the minimum critical power ratio safety limits by May 15, 1998.
Approval of the proposed change is necessary to allow continued power operation at WNP-2 followingrestart &om the R-13 refueling outage.
The proposed change would extend application of the current Cycle 13 Technical Specifications for Siemens Power Corporation (SPC) A'ILIUM-9Xfuel into Cycle 14.
The current ATRIUM-9X minimum critical power ratio (MCPR) in Section 2.1.1.2 of 1.13 for two loop operation and 1.14 for single loop operation (Reference 3) would be applied in Cycle 14 as well. This fuel is co-resident with Asea Brown Boveri (ABB)fuel at WNP-2. The ABB fuel MCPR safety limitfor two loop operation (1.07) is unchanged.
The ABB fuel MCPR safety limitfor single loop operation is increased from 1.08 to 1.09 (Reference 7) for Cycle 14.
SPC notified the Supply System (Reference 4) and other users ofthe A'IRIUM-9fuel design that a change was necessary in the previously approved method used by SPC to determine the additive constant uncertainty (Reference 2).
This change affects the MCPR safety limits for the ATRIUM-9 fuel used at WNP-2 (Reference 3).
The proposed amendment requests NRC approval for the continued use of the same interim safety limits for the ATIUUM-9 fuel in Cycle 14 that were previously established (Reference 5) and approved (Reference 6) for Cycle 13.
Continued use ofthe interim values is being requested because the revised methodology submitted by SPC (Reference
- 1) has not been approved by the NRC.
Following NRC approval of the SPC method, another license amendment is anticipated to revise the interim MCPR safety limits.
Additional information has been attached to this letter to complete the Supply System's amendment request.
Attachment 1 provides a detailed description of the proposed changes.
summarizes the proposed changes and provides marked up pages of the Technical Specifications. describes an evaluation ofthe proposed changes in accordance with 10CFR50.92(c) and concludes they do not result in a significant hazards consideration. provides the
, Environmental Assessment Applicability Review and notes that the proposed change meets the eligibility criteria for a categorical exclusion as,set forth in 10CFR51.22(c)(9).
Therefore, in accordance with 10CFR51.22(b),
an environmental assessment of the change is not required.
Attachment 5 submits the typed Technical Specification pages as they would be revised by this amendment.
This request for an amendment has been reviewed and approved by the WNP-2 Plant Operations Committee and the Supply System Corporate Nuclear Safety Review Board.
In accordance with 10CFR50.91, the state ofWashington has been provided a copy ofthis letter.
~
N eJ o~
P ~ C (Jg>
a>
5
=l 5
ll
,. REQUEST FOR illBlhHMCRITICA Page 3 T
WER RATIO SAFETY LIMITS Should you have any questions or desire additional information regarding this matter, please contact me 'or P. J. Inserra at (509) 377-4147.
Respectfully, Vice President, Nuclear Operations MailDrop PE23 Attachments:
1.
Description ofthe Proposed Change 2.
Marked up Technical Specification Pages 3.
Evaluation ofSignificant Hazards Considerations 4.
Environmental Assessment ApplicabilityReview 5.
Revised Technical Specification Pages EW Merschofr-NRC RIV KEPerkins, Jr. - NRC MV,Walnut Creek Field Office TG Colburn - NRR C Poslusny, Jr. - NRR NRC Sr. Resident Inspector - 927N DI.Williams - BPA/399 CR Wallis - EFSEC PD Robinson - Winston &Strawn
h il
\\
~ C 4
l! e
STATE OF WASHINGTON) s
~
)
COUNTY OF BENTON
)
Subject:
Request for Amendment Minimum ri ical Power R ti Safet Limi I, G. O. SMITH, being duly sworn, subscribe to and say that I am the Acting, Vice President, Nuclear Operations for the WASHINGTONPUBLIC POWER SUPPLY SYSTEM, the applicant herein; that I have the full authority to execute this oath; that I have reviewed the foregoing; and that to the best of my knowledge, information, and belief the statements made in itare true.
DATE J
, 1997 G. O. Smith Acting, Vice President, Nuclear Operations On this date personally appeared before me G.O. Smith, to me known to be the individual who executed the foregoing instrument, and acknowledged that he signed the same as his free act and deed for the uses and purposes herein mentioned.
GIVENunder my hand and seal this ~eef day of 1997 Notary Public m and f r the STATE OF WASHINGTON Residing at My Commission Expires
4 iglllllllltggl.,
4l
'qg V
44 Q p g~,*"
IIill.
i0 lillllliiliii
.. REQUEST FOR MENT.
SRRRIIM CIIITICAL WRR RATIO SASRTY LOOTS, Page 1 of 3 Description ofthe Proposed Changes 1.
Summary ofthe Proposed Changes The current licensing analysis projects Cycle 14 willbe comprised of 124 &esh ABB assemblies, 112 once-burned ABB assemblies, 104 twice-burned ABB assemblies, and 424 ofthe at least thrice-burned SPC ATRIUM-9Xassemblies. The NRC approved methodology (i.e., COLR Reference 11: CENPD-300-P-A) assumes that the safety limitMCPR (SLMCPR) for the non-ABB resident fuel is unchanged Rom the last cycle forwhich itwas evaluated by its, supplier. The ATRIUM-9Xfuel was last evaluated by SPC in Cycle 11. Accordingly, a new ATRIUM-9XSLMCPR for Cycle 11 has been determined by SPC (Reference 3) using the, changes to the additive constant uncertainty discussed below.
The SPC determined SLMCPR was applied by ABB to Cycle 14 and willbe applied to future cycles that
'se the ATRIUM-9Xfuel.
Alicense amendment is being requested to:
~
continue the use ofthe existing SPC MCPR safety limits (Technical Specifications Section 2.1.1.2) in Cycle 14 that were previously approved for Cycle 13; and
~
to change the ABBMCPR safety limitfor single loop operation from 1.08 for Cycle 13 to 1.09 for Cycle 14.
ABB has calculated single loop SLMCPR results that are about 0.006 greater for Cycle 14 than they were for Cycle 13 (Reference 7).
The higher Cycle 14 results are due to an assembly radial power distribution used for the Cycle 14 calculations which places a slightly greater number of assemblies close to the peak assembly power than for the Cycle 13 calculations.
The increase in ABB single loop MCPR safety limitis attributed to a slightly more conservative assembly power distribution used in the Cycle 14 calculations following ABB standard methodology.
While the Cycle 13 result is also conservative, the increase in Cycle 14 is intended to accommodate small cycle to cycle variability.
Continued use ofthe MCPR safety limitincrease on ATRIUM-9Xfuel during Cycle 14 is due to a new additive constant uncertainty calculated and conservatively applied by SPC to the ATRIUM-9Xfuel.
This new ATRIUM-9Xadditive constant uncertainty is necessmy because SPC has determined that the original data base (82 points) used to determine the ATRIUM-9Xadditive constant uncertainty should be expanded to include a wider range of test conditions (Reference 4). In response to this need for additional data points, SPC compiled a larger set ofdata for the recalculation ofthe additive constant uncertainty.
Data sets &om fuel designs which, like ATRIUM-9X,have full length rods, 9x9 design, and inner water channels were included in the statistical analysis to provide a data pool of527 points at diferent pressures and Qows.
The revised methodology for treating the uncertainties has been submitted to the NRC for approval (Reference 1).
Until the new SPC methodology is approved by the NRC (Reference 1), an interim approach willbe used that provides additional conservatism in the calculation ofthe MCPR safety limit consistent with Reference 5. Reference 5 established a conservative additive constant uncertainty using the di6erence calculated between the additive constant uncertainties for the ATRIUM-9Bbefore and after the data set was expanded Rom 125 to 527 points. This difference was then conservatively doubled and added
~
~
.. REQUEST FOR MENT.
MRIMIIMCRITICA WERIIATIOEAEETTLMITE Attacbment 1, Page 2 of 3 to the original additive constant uncertainty (based on the 125 point data set) to establish a new interim value.
This interim value can be applied to the ATRIUM-9Xfuel because the expanded data set covers both the ATRIUM-9Band ATRIUM-9Xfuel designs.
This conservative interim additive constant uncertainty was then used by SPC in conjunction with their original NRC approved methodology (Reference 2) to determine the appropriate MCPR safety limit for the ATRIUM-9Xfuel in WNP-2 Cycle 11 (the ATRIUM-9Xdesign was the lead fuel in that cycle). Accordingly, the interim MCPR safety limits for the ATRIUM-9Xfuel have been determined by SPC to be 1.13 fortwo loop operation and 1.14 for single loop operation, (Reference 3).
The Supply System believes that this conservative approach for calculating the interim MCPR safety limitwillcontinue to ensure design basis fuel protection while Reference
- 1. is under NRC stafF review.
Using NRC'approved methodology, ABB applied these interim values as the basis for the Cycle 14 safety limitfor the co-resident ATRIUM-9X.
After NRC approval. ofReference 1, another license amendment is anticipated to change gower) the, ATRIUM-9XMCPR safety limitto a value supported by, the new NRC approved methodology (based on the revised data base).
2.
Detailed Description ofthe Proposed Safety LimitChanges A)
Siemens Power Corporation (SPC)
Just as in Cycle 13, WNP-2 willuse Siemens Power Corporation (SPC) ATRIUM-9Xfuel assemblies in Cycle 14 operation.
SPC has determined that the need existed to increase the size ofthe data base for determining the additive constant uncertainty for SPC's ATRIUM-9Xfuel designs with an internal water channel (Reference 4).
SPC calculated a new additive constant uncertainty (ACU) for the ATRIUM-.9Xfuel by including additional experimental data fiom critical power tests for other fuel designs which share many ofthe same design features as the ATRIUM-9Xdesign.
The information was selected to address the full operating range ofthe fuel. Reference 1 details the statistical analysis performed on the data.
SPC increased its ATRIUM-9Xand ATRIUM-9Bcritical power test data base &om 82 and 125 data points, respectively, to 527 data points that cover a much wider range of pressures, mass cruxes and axial power shapes.
The Experimental Critical Power Ratio (ECPR) and the standard deviation ofthe ECPR for each of the 527 data points were statistically examined by an Analysis of Variance.
The results ofthe Analysis ofVariance for each ofthe pressures are a mean ECPR, a standard deviation of ECPR, degrees of&eedom, and equivalent sample size (Reference 1).
The overall uncertainty for CPR is statistically calculated using the standard deviation of the pooled data and the variance between the means associated with the axial power shapes.
An upper 95/o confidence limit standard deviation is calculated based on Chi-Square for the calculated degrees of fi'eedom. The overall standard deviation in ECPR is converted to an ACU. The conversion is derived
&om the ratios ofthe ANFB correlation standard deviation to the additive constant standard deviation for the ATRIUM-9Xdata.
This calculation is explained in detail in Reference 1 and summarized below:
0'
~
r ii r.y, 4$
rr>>C
,. REQUEST FOR MENT
~
RRRMIMCRITICA WARIAATICSASRTT CMITS, Page 3 of 3 Overall Standard Deviation = 0.0388 (Reference 1)
ECPR to ACURatio = 1.99 (Reference 1)
ACUfor ATRIUM-9X(data set of527 points) = 0.0388
- 1.99 = 0.0195 For additional conservatism, this calculated additive constant uncertainty is not directly applied to the MCPR safety limitcalculation. Rather, a conservative additive constant uncertainty is used to calculate a new ATRIUM-9XMCPR safety limitforWNP-2 Cycle 11.
Utilizing the ATRIUM-9B design as the basis, the difference is calculated between the additive constant"uncertainties after and prior to the data=set being expanded to include 527 points.
This difference is then conservatively doubled.
The doubled difference in the additive constant uncertainties is then adde'd tothe additive constant uncertainty prior to the expansion ofthe'data set (based on 125 data points). This calculation is summarized below:
Additive Constant Uncertainty for ATIGUM-9B(data set of 125 points) = 0.010 Additive Constant Uncertainty for ATRIUM-9B(data set of527 points) = 0.0195 Calculation ofthe interim Additive Constant Uncertainty forthe ATRIUM-9B=
(0.010+ 2(0.0195-0.010)) = 0.029 The resulting conservative additive constant uncertainty of0.029 for ATRIUM-9Bwas then applied to the ATRIUM-9Xfuel and was used to calculate the interim MCPR safety limits of 1.13 (two loop operation) and 1.14 (single loop operation) for ATRIUM-9Xfuel for WNP-2 Cycle 11 (Reference 3).
Using NRC approved ABB methodology, these MCPR safety limitvalues apply for future cycles for the ATRlUM-9Xfuel.
AfterNRC approval ofReference 1, an additional license amendment is anticipated to change gower) the MCPR safety limit for the ATRIUM-9Xfuel based on the application of the newly approved methodology.
B)
Asea Brown Boveri (ABB)
ABB has completed an evaluation of the cycle dependent SVEA-96 Safety Limit Minimum Critical Power Ratio (SLMCPR) forWNP-2 Cycle 14 (Reference 7). The Cycle 14 SLMCPR of 1.07 for two loop operation remains unchanged from Cycle 13.
The SLMCPR for single loop operation has been determined to be 1.09 for Cycle 14.
The calculated single loop SLMCPR results are about 0.006 greater for Cycle 14 than they were for Cycle 13. The higher Cycle 14 results are due to an assembly radial power distribution used for the Cycle 14 calculations which places a slightly greater number of assemblies close to the peak assembly power than for the Cycle 13 calculations.
The increase in single loop MCPR safety limitis attributed to a slightly more conservative assembly power distribution used in the Cycle 14 calculations followingABB standard methodology.
While the Cycle 13 result is also conservative, the increase in Cycle 14 is intended to accommodate small cycle to cycle variability.
0 ~
)J '4.'
I
,N' E 'I