ML19337B431
| ML19337B431 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 09/18/1980 |
| From: | Eltawila F Office of Nuclear Reactor Regulation |
| To: | Butler W Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19337B432 | List: |
| References | |
| NUDOCS 8010020397 | |
| Download: ML19337B431 (5) | |
Text
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NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555
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SE?i31580 MEMORANDUM FOR:
Walter R. Butler, Chief, Containment Systems Branch, DSI FROM:
Farouk Eltawila, Containment Systems Branch, DSI APPLICANT:
Washington Public Power Supply Systems (WPPSS)
SUBJECT:
MEETING WITH WPPSS TO DISCUSS THE SRV DISCHARGE LOAD, UFROVED DEFINITION AND APPLICATION METHOD (Chicago, Illinois, August 5, 1980)
The purpose of the subject meeting was to present the WPPSS-2 plant unique SRV discharge load specification based on observations from available Caorso in-plant SRV test results. Due to time limitations, the staff and its consultants were unable to have detailed discussions with the applicant regarding the pro-posed method. Based on our preliminary review of the proposed method, the staff and its consultants find it is important to r d ew the Caorso data to establish the adequacy of the proposed method.
The staff and its consultants are currently reviewing the Caorso test _ data and the WPPSS-2 proposed method and will forward its questions following completion of the review.
An attendance list and a copy of the meeting handouts are enclosed.
Summarv WPPSS-2 utilizes the General Electric cross quencher device to reduce the hydro-dynamic loads generated due to SRV actuation to relieve the reactor pressure ves-sel (RPV) during certain operation conditions.
After SRV actuation, steam from the RPV forces the water and air initially in the SRV discharge line to be ducted into the suppression pool.
Staam then flows through the quencher holes and condenses in the suppression pool. The WPPSS-2 containment must be able to withstand the pool dynamic loads induced by this p rocess.
The initial load specification for the cross quencher described in DFFR-Rev. 3 was judged by the applicant to be overly conservative. Therefore, the WPPSS-2 applicant undertook a program to establish a realistic and yet conservative load specification for the SRV discharge to be applied for WPPSS-2. The objective of this program is to provide improved SRV discharge load definitions and to develop an improved analytical procedure for structural modeling.
Imcroved SRV Discharge load Definition The improved SRV load definition is based on statistical and engineering evalu-ation of pressure traces that were measured at the Caorso Ptaly) suppression pool boundary during SRV discharge tests. Test data from Tokai-2 pcwer plant (Japan) are used to confirm the load specification derived from Caorso.
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SEP 131980 Walter R. Butler A confidence level of 90% with a non-exceedance probability of 90% has been used to develop the design basis pressure. A factor of 1.2, to account for differences between WPPSS-2 design conditions and Caorso test conditions, is then applied to determine the design maximum pressure amplitude. To account for possible variations in frequency content, the selected time histories are compacted and expanded so that the characteristic frequency cover the range of 4.0 to 12.0 Hz.
The vertical spatial distribution derived from Caorso is confirmed with the Tokai-2 data and with acoustic pool analysis.
The circumferential distribution is similar to the distribution recorrmended in DFFR-Rev. 3.
Having established the load specification for SRV discharge, structural modeling methods, verified by application to Caorso and comparison to Caorso test results, is developed.
Develooment of Improved Structural Analytical Model This model is an axisymmetric water-structure-soil coupled system that uses finite element method of analysis to obtain solution in the frequency domain.
Actual pressure traces from Caorso SRV tests were used as externally applied forces to detmnine the structure response spectrum which in turn compared to actual mearurements from Caorso tests.
If both results are comparable, then the buildirg modeling and analysis pro-cedure is qualified.
If they are not comparable to test measurements, the building modeling and the analysis procedures are revised and the procedure is repeated. The above process is done for several pressure traces to assure that the methodology is adequate for calculating responses of a Mark II con-tainment structure subject to SRV discharge loads.
Conclusion The applicant indicated that the improved SRV discharge load definition is conservative since it is based on subsequent actuation pressures (pressure amplitude is higher than initial actuation) cnd confirmed by in-plant SRV discharge tests at both Caorso and Tokai-2.
In addition, the applicant stated that the stactural modeling is adequate for calculating responses based on comparing the results predicted in the model to actual data fran the Caorso test.
Furthermore, when the improved load is appl 1id to WPPSS-2 (steal containment),
the predicted response is comparable to the Tokai-2 steel containment meas-ured response.
SEP 18 ic80 Walter R. Butler Staff Comment The staff indicated that review of the SRV loads improved definition and appli-cation methodology for Mark II containment should involve, in addition to the Containment Systems, the Structural Engineering Branch (SES) and the Mechanical Engineering Branch (MEB) that were not participating in that meeting.
By copy of this memorandum, the Project Manager should request the SEB and MEB to review the applicant's methodology.
The staff also indicated that our questions will be forwarded to them as soon as the staff completes its review of the method.
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Farouk Eltawila Containment Systems Branch Division of Systens Integration
Enclosure:
As stated cc:
D. Ross L. Rubenstein B. J. Youngblood R. Bosnak F. Schauer J. Kudrick C. Anderson N. Su C.C.Lin(BNL)
M. Lynch 4
Washington Public Pet.er Supply System ces:
Joseph B. Knotts, Jr., Esq.
Detevoise & Liberman 1200 Seventeenth Street, N. W.
Washin;?an, D. C. 20036 Richard Q. Quigley, Esq.
Washington Public Power Supply System P. O. Box 968 Richland, Washington 99352 Nicholas Lewis, Chairman Energy Facility Site Evaluation Council 820 East Fifth Avenue Olympia, Washington 98504 Mr. O. K. Earle Licensing Engineer P. O. Box 968 Richland, Washington 99352 Resident Inspector /WPPSS-2 NPS c/o U.S. Nuclear Regulatory Commission P. O. Box 69 Richland, Washington 99352 Mr. N. O. Strand Managing Director Washington Public Power Supply System P. O. Box 968 3000 George Washington Way Richland, Washington 99352
e WPPSS-2 MEETING August 5,1980 farouk Eltawila NRC/DSI/CS3 C. C. Lin BNL G. Kleinstein BNL C. Anderson NRC/ DST /GIB John R. Lehner BNL Ain A. Sonin MIT/BNL Pio Ianni GE Jim Fitch GE Keener Earle WPPSS Gus Kugler WPPSS Ed Fredenburg WPPSS G. L. Gelhaus WPPSS D. C. Baker Burns & Roe, Inc.
B. Bednosien Burns & Roe, Inc.
M. K. Chakravorty WPPSS A. Y. C. Wong Stone & Webster C. N. Krishnaswamy Sargent & Lundy C. A. Malavrh Stone & Webster F. Ogden NMPC T. Trocki GE W. M. Davis GE A. Bournia NRC/ DOL Jim Black GE R. Muzzy GE G. Rerez-Ramirez CNSN&S/ Mexico
Meeting Notice Distribution Central Files NRR R/F (P-428)
CSB R/F F. Schroeder K. Kniel P. Norian B. Eisenhut ft. Tedesco J. Youngblood
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R. Bosnak F. Schauer
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Ross L. Rubensteta j
W. Butler J. Kudrick F. Eltawila T. Su i
C. Grimes i
C. Anderson M. Fields
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