ML20085M635
| ML20085M635 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 12/17/1973 |
| From: | Eric Thomas TENNESSEE VALLEY AUTHORITY |
| To: | Oleary J US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML20085M634 | List: |
| References | |
| AO-BFAO-7343W, NUDOCS 8311090113 | |
| Download: ML20085M635 (2) | |
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Mr. John F. O' Leary, Director
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Dear Mr. O' Leary:
TEllHESSEE VALLEY AUTHORITY - EROWNS FERRY HUCLEAR PIl.HT UNIT 1 -
DOCKET N0. 50-259 - FACILITY OPERATING IICENSE DPR VIBRATIOUS IN TORUS AUD TORUS-RING HEADER Please refer to my letter dated November 28, 1973, enclosing abnormal occurrence report EFAO-7343W. Enclosed is an interim report to inform you of the testing and ccrrective work performed to data to alleviate the vibration prcblem in the torus and torus-ring header on Browns Ferry nuclear Plant unit 1.
Very truly yours, TEUNESSEE VALLEY AUTHORITY M
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E. F. Thomas Director of Power Production Enclosure CC(Enclosure):
Mr. Norman C. Moseley, Director Region II Regu]Atory Operations Office, USAEC 230 Peachtree Street, NW.
Atlanta, Cecrgia 30303
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B311090113 740114 b
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PDR ADOCK 05000259 8
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- i BROWNS FERRY NUCLEAR PIAf;T tmIT 1 VIBRATION IN TORUS AND TORUS-RING IEADER INTERIM REPORT
Reference:
Letter from E. F. Thccas to John F. O' Leary, AEC, Director of the Directorate of Licensing, Office of Regulation, Washington, DC,
" Tennessee Valley Authority - Brcuns Ferry Nuclear Plant Unit 1 -
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Docket No. 50-259 - Facility Operating License DPR Abnormal Occurrence Report BFAO-7343W," with enclosure, dated November 28, 1973.
The referenced abnorm 1 occurrence report described vibration in the torus and torus-ring header upon opening relief valves in unit 1.
The follcwing is a surrary 4
of the testing and corrective work performed to date to alleviate this situaticn.
1.
The space between the torus support saddle feet and support pads, discovere$
during testing en November 18, 1973, and noted in the abnormal occurrence report, were shimmed before November 27 with temporary shims to reduce vibration.
2.
On November 27 and 30, relief valves (4 and 19) were opened one at a time to confirm that the chims had reduced vibration.
Special instrumentation was used to measure terus and tcrus-ring header deflection. Although some improvement was noted, the torus and torus-ring header movements were still 1
larger than desired.
3.
In an attempt to reduce torus-ring header movement, the torus-ring header support was tedified to prevent vertical movement of the header relative tc 4
the support. This ecdification was completed before December 3 and special instrumentation including strain gages were installed.
4.
On Decc.mber 3 and again on December 8 relief valves (4,19, and 31) were operated one at a time. The purpose of these tests was to evaluate the effect-of the torus-ring header support modification and to provide additional data in preparation for possible further corrective action. The torus-ring header movement was found to be acceptable particular.ly in the area where the terus support saddle feet and the support pads were in contact with the base plates and were supporting load.
5.
During the scheduled outage now under way, each torus support saddle will be jacked, permnently shimmed,and loaded to ensure adequate load distribution.
6.
Following the scheduled outage, the strain gages and special instrumentation
- will be reinrtalled en tte torus and torus-ring header._ The relief valves will be operated to confirm acceptability of the modification and demonstrate.
an acceptably low level of torus and torus-ring header vibration. A final report will be submitted after testing.
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