ML20206C790
| ML20206C790 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood  |
| Issue date: | 04/23/1999 |
| From: | Krich R COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9905030203 | |
| Download: ML20206C790 (13) | |
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Commonwealth rdixm Company 1100 Opus Place Downers Gmve, IL 60515-5701 April 23,1999 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 Byron Station, Units 1 and 2 Facility Operating License Nos. NPF-37 and NPF-66 NRC Docket Nos. STN 50-454 and STN 50-455 Braidwood Station, Units 1 and 2 Facility Operating License Nos. NPF-72 and NPF-77 NRC Docket Nos STN 50-456 and STN 50-457 Subject SupplementalInformation Regarding the Use of the Westinghouse Dynamic Rod Worth Measurement Technique
Reference:
Letter from R. M. Krich (Commonwealth Edison Company) to the NRC, "Use of the Westinghouse Dynamic Rod Worth Measurement Tacitnique," dated February 8,1999 in the referenced letter, Commonwealth Edison (Comed) Company notified the NRC of our intention to perform future low power physics testing (LPPT) at Byron Station and Braidwood Station using the Westinghouse developed Dynamic Rod Worth Measurement (DRWM) technique in accordance with the notification requirements of WCAP-13360-P-A, " Westinghouse Dynamic Rod Worth Measurement Technique,"
Revision 1, dated October 1998, as approved by NRC Safety Evaluation issued by letter dated July 30,1998. In a teleconference between representatives of Comed and the NRC on April 13,1999, the NRC requested clarification of three issues. These three issues pertain to the Rod Cluster Control Assembly (RCCA) bank layout configuration at Byron Station and Braidwood Station, the personnel who will develop the DRWM input constants at Byron Station and Braidwood Station, and the specific j
revision of the methodology that will be used in the DRWM analytical calculations.
Attachment A has been revised to specify that the RCCA bank layouts at Byron Station and Braidwood Station are identical, the DRWM desirpi input constants for Byron Station and Braidwood Station will be developed by tr,e Comed Nuclear Fuel Management Departn9nt, and the DRWM computations will be performed in h,0; accordance with WCAP 13360-P-A, Revision 1, dated October,1998. Attachment A has been annotated with revision bars in the right-hand margin to identify these i
I changes from the information submitted by the referenced letter.
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- April 23,1999
- U. S. Nuclear Regulatory Commission
, Page 2 No sanges were made to Attachment 8, "Critena for a Utility Performing Dynamic Rod Worth Measurement (DRWM) Computations."
As noted in referenced letter, the first applications of Comed's analytical computations to support DRWM in LPPT will occur with the startups of Byron Station, Unit 1 Cycle 10, and
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Braidwood Station, Unit 2 Cycle 8. These startups are projected to occur in April 1999, and May 1999, respectively.
Please address any comments or questions regarding this matter to Mr. Joseph A. Bauer at (630) 663-7287.
Respectfully, R. M.
rich Vice President - Regulatory Services Attachments cc:
Regional Administrator-NRC Region lli NRC Senior Resident inspector - Braidwood Station NRC Senior Resident inspector-Eyron Station 3
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ATTACHMENT A DEMONSTRATION OF THE ABILITY TO PERFORM COMPUTATIONS TO SUPPORT DYNAMIC ROD WORTH MEASUREMENTS
1.0 INTRODUCTION
Westinghouse perfonned the first applications of Dynamic Rod Worth Measurements (DRWM) at Byron Staten, Unit 2 Cycle 8, on May 18,1998, and at Braidwood Station, Unit 1 Cycle 8, on November 13,1998. Through the information provided in this report, Commonwealth Edison (Comed) Company intends to demonstrate that the analytical computatens necessary to support DRWM for future cycles of both Byron and Braidwood Statens can be performed by Comed.
Byron and Braidwood Statens utilize the same Westigghouse NSSS and have similar core design strategies Since there are no significant differences between core loading schemes and the RCCA bank layot s are identical at Byron and Braidwood Stations, the validation of the DRWM l
d methodology, contained herein, applies to both units of each station.
Attachment B contains approved NRC cntena that must be met in order to perform computations to support DRWM. NRC approval to use DRWM in Low Power Physics Testing (LPPT) is based on using the technique outlined in Reference 8 and applying the evaluation criteria set forth in to a letter from N. J. Liparulo (Westinghouse Electric Corporation) to R. C. Jones (NRC) dated December 9,1996. Attachment 1 is also contained in Refereoce 8. This report demonstrates that these entena have been met.
Staten personnel received training on procedures, the use of the Advanced Digital Reactivity Computer (ADRC), and application of the ADRC to perform LPPT using DRWM prior to the test.
Additional training was also received during the initial application of DRWM. Station personnel performing computations to support DRWM were trained by Westinghouse in these computations j
on August 25 through 27,1998. Design personnel also received training on April 21, and 22, and October 26 and 27,1998. This training included the ability to set up input, understand arad interpret output results, understand applications and limitations, and to perform analyses in compliance with the procedures provided by Westinghouse. Additional training was provided to design personnel by Westinghouse on February 17,18,19,1999. The DRWM design input constants for Byron and Braidwood Statens will be developed by the Nuclear Fuei Management Department. Qualificaton requirements to perform all controlled analysis are programmatically govemed by Nuclear Engineenng Procedure, NEP-16-80, Qualification Requirements for Nuclear Fuel Services Personnel involved in Controlled Work or Computer Software Development." Byron and Braidwood Statens have developed and implemented the plant procedures necessary for using the DRWM technique ar.d analyzing the results based on Westir,ghouse procedures.
Cross secton data to support DRWM computations are obtained from the PHOENIX-P lattice physics computer code (Reference 1). The flux solutions for these computations are obtained from Revision 1
ATTACHMENT A DEMONSTRATION OF THE ABILITY TO PERFORM COMPUTATIONS TO SUPPORT 3
DYNAMIC ROD WORTH MEASUREMENTS the ANC computer code (Reference 2). Comed's approval to use the PHOENIX-P/ANC methodology is documented in Reference 3 and described in Reference 4. NRC review and approval of these codes and the procedures by which Comed uses these codes are contained in Reference 5. Application of these codes and procedures, and the Westinghouse DRWM procedure, is controlled by the Comed Quality Assurance Program (Reference 6). This Quality Assurance Program meets the requirements of 10 CFR 50, Appendix B.
2.0 COMPARISON OF RESULTS Table 1 provides the DRWM measured and predicted rod worths based on Westinghouse predicbons for Byron, Unit 2 Cycle 8, LPPT. Table 2 provides the DRWM measured and pred' ted c
rod worths based on Comed's predictions for Byron, Unit 2 Cycle 8, LPPT.
Table 3 compares the predicted rod worths based on Westinghouse and Comed data. Table 4 compares the rod worths measured by the DRWM technique using Westinghouse analytical data to wpport the measured data and Comed's analytical data to support the measured data.
3.0 DISCUSSION OF RESULTS Comparing Westinghouse and Comed's predicted results for Byron, Unit 2 Cycle 8, it can be seen from Table 3 that the maximum percent differenco in the predicted worth of any bank is 0.64 %
occurring in Control Bank A. The maximum pcm difference in the predicted worth of any bank is 2.4 pcm occuning in Control Bank B. The difference in the total predicted rod worth is 0.31 % or 14.3 pcm.
Comparing measured results based on Westinghouse and Comed supporting analytical data for j
Byron, Unit 2 Cycle 8, it can be seen from Table 4 that the maximum percent difference in the l
measured worth of any bank is 0.76% occurring in Shutdown Bank C. The maximum pcm difference in the measured worth of any bank is 4.2 pcm occurring in Control Bank B. The difference in the total measured rod worth is 0.38 % or 17.6 pcm.
A provision for implementing changes in the methods and procedures being used for DRWM are governed by p: :edures NFS-A-01, "NFS Department Procedures," and NFS-ND-900, " Nuclear Design Procedures." In addition, Comed receives technical updates from Westinghouse on a regular basis. Enoridentification and reporting is control!ed under procedure NSP-CC-3021, "Centrol of Computer Software and Services." in addition, any problem encountered performing DRWM calculations would be documented in accordance with the Comed Corrective Action 2
Revision 1 l
l
ATTACHMENT A DEMONSTRATION OF THE ABlu1Y TO PERFORM COMPUTATIONS TO SUPPORT DYNAMIC ROD WORTH MEASUREMENTS Pmgram, NSP-AP-4004, " Corrective Action Program Procedure," and NSP-AP-1004, " Corrective Adion Proi,ioni Process." These procedures are controlled in accordance with the Comed QA Program. The Westinghouse " Request or Problem Resolution" tracking system also provides a means by which Comed can directly inform Westinghouse of any problems or errors discovered while performing the DRWM calculations or procedures.
4.0 CONCLUSION
S Base d on the results in Seebon 2.0 and the discussions of results in Section 3.0, it is concluded that Comed has shown that the review criteria in Attachment B have been met. It is concluded that Comed can perform, in wi acceptable manner, the analytical computations to support DRWM tests for future LPPT. These computations can be performed without any additional limitations or restnctions other than what is given in Reference 8. The first applications of Comed analytical l
computations to support DRWM in LPPT will occur with the startups of Byron, Unit 1 Cycle 10, and -
Braidwood, Unit 2 Cycle 8. These startups are projected to occur in April 1999 and May 1999, respectively.
5.0 REFERENCES
- 1. Nguyen, T. Q. et. al, Qualification of the PHOENIX-P/ANC Nuclear Design System for Pressurized Water Reactor Cores, WCAP-11596-P-A (Propnetary) and WCAP-11597-P-A (Non-proprietary), June 1988
- 2. Liu, Y. S., Meliksetian, A., Rathkopf, J. A., Little, D. C., Nakano, F., Poploski, M. J., ANC-A Westinghouse Advanced Nodal Computer Code, WCAP-10965-P-A (Proprietary) and WCAP-10966-NP (Non-proprietary), December 1985 l
S. Letter from R. M. Pulsifer (NRC) to T. J. Kovach (Commonwealth Edison), March 11, 1991, SER for " Topical Report on Benchmark of PWR Nuclear Design Methods Using PHOENIX-P and ANC Computer Codes" 4.
" Benchmark of PWR Nuclear Design Methods Using the PHOENIX-P and Advanced Nodal Code (ANC)," Commonwealth Edison Company Topical Report, NFSR-0081, July 1990
- 5. Chao, Y. A., Easter, M. E., Hill, D. J., Chapman, D. M., Grobmyer, L. R., Hoerner, J. A.,
Westinghouse Dynamic Rod Worth Measurement Technique, WCAP-13360-P-A, dated January,1996 Revision 1
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l ATTACHMENT A 1
DEMONSTRATION OF THE ABILITY TO PERFORM COMPUTATIONS TO SUPPORT DYNAMIC ROD WORTH MEASUREMENTS l
5.0 REFERENCES
(cont'd)
- 6. Comed Quality Assurance Manual, Revision 66
- 7. Letter from T. H. Essig (U. S. NRC) to N. J. Liparuto (Westinghouse), Westinghouse Dynamic Rod Worth Measurement Technique," dated July 30,1998
- 8. Chao, Y. A., Easter, M. E., Hill, D. J., Chapman, D. M., Grobmyer, L. R., Hoemer, J. A.,
Westinghouse Dynamic Rod Wodh Measurement Technique, WCAP-13360-P-A, Revision 1, dated October,1998 l
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Revision 1
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ATTACHMENT A DEMONSTRATION OF THE ABILITY TO PERFORM COMPUTATIONS TO SUPPORT DYNAMIC ROD WORTH MEASUREMENTS TABLE 1 MEASURED AND PREDICTED ROD WORTHS BASED ON BYRON UNIT 2 CYCLE 8 WESTINGHOUSE PREDICTIONS WORTH (pcm)
DIFFERENCE BANK Measured Predicted
% (M-P/P) pcm CA 353.7 359.9
-1.72
-6.2 CB 558.8 568.9
-1.78
-10.1 CC 682.6 708.3
-3.63
-25.7 CD 696.8 669.9 4.02 26.9 SA 301.7 302.4
-0.23
-0.7 SB 674.3 692.6
-2.64
-18.3 f
SC 461.3 450.0 2.51 11.3 SD 451.2 452.2
-0.22
-1.0 SE 396.9 410.0
-3.20
-13.1 j
TOTAL 4577.3 4614.2
-0.80
-36.9 l
-5 Revision 1 I
ATTACHMENT A DEMONSTRATION OF THE ABILITY TO PERFORM COMPUTATIONS TO SUPPORT DYNAMIC ROD WORTH MEASUREMENTS TABLE 2 MEASURED AND PREDICTED ROD WORTHS BASED ON BYRON UNIT 2 CYCLE 8 COMED PREDICTIONS WORTH (pcm)
DIFFERENCE BANK Measured Predicted
% (M-P/P) pcm CA 355.1 362.2
-1.96
-7.1 CB 563.0 571.3
-1.45
-8.3 CC 684.2 710.0
-3.63
-25.8 CD 696.9 671.5 3.78 25.4 SA 302.5 304.1
-0.53
-1.6 SB 674.9 692.0
-2.47
-17.1 SC 464.8 451.7 2.90 13.1 SD 454.2 454.2 0.00 0.0 SE 399.3 411.5
-2.96
-12.2 TOTAL 4594.9 4628.5
-0.73
-33.6 l
l l
6-Revision 1 L
ATTACHMENT A DEMONSTRATION OF THE ABluTY TO PERFORM COMPUTATIONS TO SUPPORT DYNAMIC ROD WORTH MEASUREMENTS TABLE 3 COMPARISON OF PREDICTED ROD WORTHS BASED ON BYRON UNIT 2 CYCLE 8 WESTINGHOUSE (W) AND COMED (U) DATA PREDICTED ROD WORTH (pcm)
DIFFERENCE BANK Wesanghouse Comed
% (U-W)/W pcm CA 359.9 362.2 0.64 2.3 CB 568.9 571.3 0.42 2.4 CC 708.3 710.0 0.24 1.7 CD G69.9 671.5 0.24 1.6 SA 302.4 304.1 0.56 1.7 SB 692.6 692.0
-0.09
-0.6 SC 450.0 451.7 0.38 1.7 SD 452.2 454.2 0.44 2.0 SE
'10.0 411.5 0.37 1.5 4
TOTAL 4614.2 4628.5 0.31 14.3 7
Revision 1
ATTACHMENT A DEMONSTRATION OF THE ABILITY TO PERFORM COMPUTATIONS TO SUPPORT DYNAMIC ROD WORTH MEASUREMENTS TABLE 4 COMPARISON OF MEASURED ROD WORTHS BASED ON BYRON UNIT 2 CYCLE 8 WESTINGHOUSE (W) AND COMED (U) SUPPORTING ANALYTICAL DATA MEASURED ROD WORTH (pcm)
DIFFERENCE BANK Westinghouse CemEd
% (U -W)IW pcm CA 353.7 355.1 0.40 1.4 CB 558.8 563.0 0.75 4.2 CC 682.6 684.2 0.23 1.6 CD 696.8 696.9 0.01 0.1 SA 301.7 302.5 0.27 0.8 SB 674.3 674.9 0.09 0.6 SC 461.3 464.8 0.76 3.5 SD 451.2 454.2 0.66 3.0 SE 396.9 399.3 0.60 2.4 TOTAL 4577.3 4594.9 0.38 17.6 1
8-Revision 1
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ATTACHMENT B CRITERIA FOR A UTKJTY PERFORMING DYNAMIC ROD WORTH MEASUREMENT (DRWM) COMPUTATIONS
. to a letter from N. J. Liparulo (Westnghouse Electnc Ceipereu) to R. C. Jones (NRC) dated December 9,1996, specifies criteria for a utility to use to demonstrate competencies M oerform DRWM design calculations This letter and attachment have been ince permted into WCAP 13360-P-A, Revision 1, " Westinghouse Dynamic Rod Worth Measurement Technique,"
dated October 1998. Attachment 1, " Criteria for a Utility Performing Dynamic Rod Worth Measurement (DRWM) Computation," sets forth the following criteria.
"In order for a utility to perform their own physics calculatons to support the use of the Dynamic Rod Worth Measurement (DRWM) technique' during the Low Power Physics Testing (LPPT), the following five criteria must be met. Compliance with the following five criteria demonstrates a utsht)fs quahficaten and constitutes inherent NRC approval to use DRWM in their LPPT. To document its quahfication, the utility must send the NRC a notification of compliance with the criteria and the date of the intended first app;;ceGen of the codes to determine the DRWM physics constants for LPPT.
Any voluntary limitations or restrictions of the utility's use of the DRWM methodology must also be addressed in the notificaton The NRC would then, at their option, audit the app;;c. Gen of the utility's DRWM program to ensure ceirp;;&nce.
1)
Criterion 1: Elioibility of Codes for DRWM Comoutations Only lattice physics codes and methods, which have received prior NRC review and approval are eligible to be used in determining the physics constants to be used in DRWM.
The NRC review ensures that the codes being used for the DRWM computations were developed under a qualified QA program and were property benchmarked and verified.
2)
Critenon 2: Apolication of Procedures to DRWM Computatens in a manner consistent with the procedures obtained from Westinghouse, the utility analyses shall be performed in conformance with in-house application procedures which ensure that tha use of the methods is consistent with the Westinghouse approved apphcaten of the DRWM methodology, 3)
Crite, ion 3: Trainina and Qu l;f;ceGon of Utihty Personnel Westinghouse will perform the first application of DRWM for LPPT. This will ensure that DRWM is applicable to the specific plant, provide u*ility personnel with traWng in the DRWM technique and be used to meet Criterion 4 - Comparison Calculations for the L
1 Revision 1 i
c+
ATTACHMENTB CRITERIA FOR A UTILITY PERFORMING DYNAMIC ROD WORTH MEASUREMENT (DRWM) COMPUTATIONS DRWM Technique. The first application of DRWM for LPPT by Westinghouse will be appicable for all of the same plant type at the plant site of sppuceh. If the fuel vendor should change subsequent to the first appimation, a second appimation by Westinghouse is not required.
Utilities shall establish and implement a training program to ensure that each qualified user of the DRWM methodology has a good working knowledge of the codes and methods used for DRWM. This training shall include the ability to set up input decks, understand and interpret output results, understand applications and limitations, and to perform analyses in l
compliance with the procedures provided by Westinghouse.
4)
CrRerion 4: Comparison Calculations for the DRWM Technioue l
l Prior to the first application by a utility using their own methods to perform physics '
calculations in support of DRWM for LPPT, the utility will demonstrate its ability to use the j
methods supplied by Westinghouse by comparing its calculated results with the analyses and results obtained by Westinghouse during the first, or subsequent, appuc.M(s) of l
DRWM at the utility's plant. These comparisor;s must be documented in a report, which is part of the utility's QA records. Any signifc' ant differences between the calculations and the l-comparison data must be discussed in the report. As a minimum, the following parameters l
should be compared to the supplier of the DRWM methodology calculations, and should agree within the given acceptable deviation:
Parameter Acceptable Deviation i
i Calculated Bank Worth 12% or *25 pcm l
Calculated TotalWorth of All Banks 12 %
l Measured Bank Worth Obtained for i2% or125 pcm First Application Measured TotalWorth Obtained for
- 2%
FirstApplication 2-Revision 1 i
ATTACHMENT B CRITERIA FOR A UTILIT(
PERFORMING DYNAMIC ROD WORTH MEASUREMENT (DRWM) COMPUTATIONS 5)-
Criterion 5-Quality Assurance and Chance Control All calculations for DRWM by a utility using the Westinghse methodology which has been approved by the NRC shall be conducted under the control of a quality assuiance program which meets the requirements of 10 CFR 50, Appendix B. The (dility QA program will also include the following:
a)
A provision for implementing changes in the methods and procedures being used for DRWM.
b)
A provision forinforming Westinghouse of any problems or errors discovered while using the DRWM' methods or procedures."
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Westinghouse has a requirement to inform utilities that have taken a Technology Transfer on DRWM of changes to the process as part of the their QA procedures regarding Technology Transfer.
3-Revision 1