ML20039C383
| ML20039C383 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 12/21/1981 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| REF-PT21-81 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8112290294 | |
| Download: ML20039C383 (2) | |
Text
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t 400 Chestnut Street Tower II December 21,'198I J>
BLRD-50-438/81-74 BLRD-50-439/81-73 c9 z>
Mr. James P. O'Reilly, Director Office of Inspection and Enforcement l
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U.S. Nuclear Regulatory Commission 7,,, k ' e.,
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p-Region II - Suite 3100 9
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101 Marietta Street Nc Atlanta, Georgia 30303 q
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Dear Mr. O'Reilly:
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s BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - REACTOR COOLANT SYSTEM LOW
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PRESSURE SETPOINT ADJUSTMENTS - BLRD-50-438/81-74, BLRD-50-439/81 FINAL REPORT The subject deficiency was initially reported to NRC-0IE Inspector R.
Butcher on November 19, 1981 in accordance with 10 CFR 50.55(e) as NCR D-3963 Enclosed is our final report. We consider 10 CFR Part 21 applicable to this deficiency.
If you have any questions concerning this matter, please get in touch with R. H. Shell at FTS 858-2688.
Very truly yours, TENNESSEE VALLEY AUTHORITT L. M. Mills, Manager Nuclear Regulation and Safety Enclosure ec:
Mr. Richard C. DeYoung, Director (Enclosure)
Office of Inspection and Enforcement ghN U.S. Nuclear Regulatory Commission Washington, DC 20555 s
cc:
Mr. James McFarland (Enclosure)
I Senior Project Manager Babcock & Wilcor Company P.O.' Box 1260 Lynchburg, Virginia 24505 i:,. ;..,
8112290294 811221 PDR ADOCK 05000439 PDR S
e ENCLOSURE BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 REACTOR COOLANT SYSTEM LOW PRESSURE SETPOINT ADJUSTMENTS BLRD-50-438/81-74, BLRD-50-439/81-73 10 CFR 50.55(e)
FINAL REPORT Description of Deficiency Babcock and Wilcox has determined, as a result of recent small break LOCA analysis work, that the present Engineered Safety Features Actuation System (ESFAS) initiation setpoint of 1600 psig is too low. Their analysis, which assumes a 100 psig instrument string error, shows that certain small breaks could result in a delay in ESFAS actuation and initiation of the High Pressure Injection System as initial depressurization would not decrease the Reactor Coolant System pressure to the 1500 psig necessary to activate the ESFAS.
Safety Implications According to the Sabcock and Wilcox analysis, the 1600 psig setpoint would cause a delay in HPI mitigation sufficient to allow core uncovery and possible fuel damage during certain small break LOCAs which would adversely affect plant safety.
Corrective Action Babco;k and Wilcox has notified TVA, other affected utilities, and the NRC of their intent to revise the setpoint to an initial value of 1700 psig. TVA agrees with Babcock and Wilcox's intent and so advised them.
Babcock and Wilcox will verify and finalize the ESFAS setpoint by late 1982 and will.then revise all affected TVA documentation to reflect the new setpoint. Therefore, TVA considers this issue resolved and closed.
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