ML19329A524
| ML19329A524 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 11/29/1972 |
| From: | Maccary R US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Deyoung R US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 8001060040 | |
| Download: ML19329A524 (3) | |
Text
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NOV 29 W2
/;,A7 R. C. DaToung, Assistant Director for Pressurized Water Reactors Diractorate of Licensing STATUS REPORT ON OCONEB 1, 2 AND 3 - FLOW INDUCED VIBRATION TO REACT INIERNALS AND ACCEPTANCE OF TOPICAL REPORTS BAW-10050 A Plant Name:
i Oconee 1, 2, and 3 Licensing Stage:
OL Docket Nos.:
h 270/287 Responsible Branch and Project Manager:
I"eiR Branch No. 4. I. A. Peltier Review Status:
BAW-10050 & BAW-10037 - Complete BAW-10051 & BAW-10038 - Partial The Mechanical Engineering Branch, Directorate of Licensing, has reviewed four topical reports (BAW-10037, 10038, 10050 and 10051) concerning the ho
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functional vibration failures submitted by Babcock & Wilcox (B&W) i MEB conclusions and co'nents on these topicals are as follows:
The l
1.
BAU-10050 - B&W conducted an investigation on the cause of the preoperational test failure.
The r.etalloprophic examination of the ration was the major failure node. failure surfaces concluded that th Co=ponent redesign was based upon (a) further scparation of structural frequencies from vortex shielding frequencies, and (b) further reduction of the stresses to a level below the caterial endurance limit.
modifications will improve the structural integrity of the reactorW internals.
2.
DAW-10037 - Reactor vecsci flow testing was conducted on a one-sixth scale model to investigate flow distribution, pressure loss and the pattern of flow nixing from the various inlets.
inside the core and vent valve testing were er:phasized.The flow characteristics original and the modified desi na were tested.
Both the C
The tests results chved that the rodified design provides more uniform flow distribution with acceptable pressure loss.
flow rate was slightly h'.gher at certain portions of the coreHowever, ninor modifications in design will be required.
, further l
on the approach used to verify the core flow distribution.We concur with B&W
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R. C. DaToung NbV 2 '! 137, 3.
EAU-10051 - B&W has attempted to justify the reactor interns 1s design modifications in BAW-10051 by computing responses of modified components to flow induced vibration. However, the actual flow forcing functions m1y not be verified until the new preoperational vibration test program for Oconce 1 has been completed. We concur that interns 1s have been redesigned based upon a conservative application of the response and failure data from the Oconee 1 preoperatioral tests. However, due to a lack of valid flow forcing functions and complete response determination, we cannot complete our evaluation of this topical at this tine. The applicant has stated that further efforts, including component testing of instrument guide tubes and incore nozzle assemblies will be performed to provide a better understanding of the vibration behawior. The thermal shield vibration response characteristics will be further defined by further evaluation of the Oconee 1 response and failure data.
4.
BAU-10038 - The prototype preoperational vibration testing program including a subsequent inspection program for reactor internals is described in BAW-10038. The applicant cannot provide valid vibration predictions as required by Safety Guide 20 due to inconclusive dynamic anclysis.
Therefore, we cannot complete our evaluation of this report at this time.
We concur with B&W that the design modifications on the internals have been based on a conservative application of the response and failure data from a
Ocenee 1.
However, due to a lack of concrete analytical evidence to assure structural integrity of reactor internals under the transient loadings, satisfactory completion of the new preoperational vibration testing should be considered as a prerequisite for issuing an operating license.
BAW-10051 and EAW-10333 may be approved when the additional tests and evaluations indicated above are completed to provide the basis for vibration predictions.
When the infornation is received and reviewed Oconee 1 may then be qualified as a valid prototype plant. The information contained in EAW-10050 and EAW-10037 will be acceptable by reference in the Oconee 1, 2. and 3 applications.
We are not prepari.2g Topical Report Evaluations on these topicals since these topicals are prmetically unique to the Oconee app'ication.
R. R. Maccary, Assistant Director for Engineering Directorate of Licensing cc: See Attached omer >
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1972-466-903
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