ML20005A293
| ML20005A293 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 04/27/1981 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, SQRD-50-328-81, NUDOCS 8106300164 | |
| Download: ML20005A293 (2) | |
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,O 400 Chestnut Stmet Tower II April 27, 1981 SQRD-50-328/81-22 Mr.
a P. O'Reilly, Director Office f Inspection and Enforcement U.S. Nuo Regulatory Commission Region II Suite 3100 101 Mariett treet Atlanta, Geor 30303 Dear Mr. O'Reilly SEQUOYAH NUCLEAR PLANT UNIT 2 - FLOW DEFICIENCY IN ERCW SYSTEM -
SQRD-50-328/81 SECOND I!TTERIM REPORT The subject deficiency was initially reported to NRC-OIE Inspector R. V. Crienjak on March 4, 1981, in accordance with 10 CFR 50.55(e) as NCR SQN SWP 8107. A first interia report was submitted on April 3, 1981.
Enclosed is our second interia report. The submittal date of this report Ws rgreed to by R. V. Celenjak during a telephone conversation on April 14, 1981. We expect to submit our next report by May 27, 1981.
If you have any questions, please get in touch with D. L. Lambert at FTS 857-2581.
Very truly yours, TENNESSEE VALLEY AUTEURITY L. M. Mills, Manager Nuclear Regulation and Safety Enclosure j
00: Mr. Victor Stello, Director (Enclosure)V Office of Inspection and Enforceaant U.S. Nuclear Regulatory Commission Washington, DC 20555 4
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8"wcq P00R ORIGINAL
7 ENCLOSURE SEQUOYAH NUCLEAR PLANT UNIT 2 FLOW DEFICIENCY IN ERCW SYSTEM SQRD-50-328/81-22 10 CFR 50.55(e)
SECOND INTERIM REPORT Description of Deficiency During the preoperational test of the unit 2 Essential Raw Cooling.
Water System (ERCW) which simulated the worst operating case, which is unit 1 in hot standby condition and unit 2 in a post LOCA condition, with the loss of (1) offsite power, (2) downstream dam, and (3) train B diesel generators, the flow rate requirements to several componenta required for safe shutdown could not be met. The $7tal system flow rate measured in the test was approximately 2,500 spa less than the required design flow rate of 22,000 gpm. A portion of the flow deficiency can be attributed to the excessive pressure drop across the strainers, which have been covered by another nonconformance report (SQRD-50-328/81-17).
Interim Progress TVA has reevaluated the operating requirements of the ERCW system.
Components not required to be ~1n service during the dssign basis event (simulated by the test) have been is'olated, and the flow requirements for so7e essential components, which were partially based on heat loads from nonessential components that do not operate ddring the design basis event, have been reduced. As a result, the flow requirements of the system have been reduced. The preoperational test instruction has been changed to incorporate the revised acceptance criteria and the flow balance testing program has resumed.
Due to the reduction in the flow requirements of the ERCW system, the system should be capable of supporting two-unit operation under conditions of the design basis event. The flow testing, presently in progress, should verify the system adequacy. The results of the testing will be included in our next report.
If the ongoing tests do not.yerify system adequacy, the liRC will be notified before unit 2 fuel loading.
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