ML20070Q105
| ML20070Q105 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 01/17/1983 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8301260435 | |
| Download: ML20070Q105 (2) | |
Text
K TENNESSEE VALLEY AUTHORITY CH ATTANOOGA. TENNESSEE 37401 q
400 Chestnut Street Tower II
=
January 17, 1983
~]
BLRD-50-438/82-51 C
BLRD-50-439/82-46 w
C:
U.S. Nuclear Regulatory Commission Region II Attn:
Mr. James P. O'Reilly, Regional Administrator 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303
Dear Mr. O'Reilly:
BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - DEFICIENCY IN UNDERVOLTAGE PROTECTION DURING AN ACCIDENT - BLRD-50-438/82-51, BLRD-50-439/82 l THIRD INTERIM REPORT The subject deficiency was initially reported to NRC-0IE Inspector R. V. Crlenjak on July 27, 1982 in accordance with 10 CFR 50.55(e) as NCR BLN EEB 8205. This was followed by our interim reports dated August 25 and November 19, 1982. Enclosed la our third interim report. We expect to submit our next report by September 19, 1983 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 AUTHORITY l
L. M. Mills, $anager Nuclear Licensing l
Enclosure cc:
Mr. Richard C. DeYoung, Director (Enclosure)
Office of Inspection and Enforcement i
U.S. Nuclear Regulatory Commission l
Washington, D.C.
20555 8301260435 830117 PDRADOCK05000g oppy S
An Equal Opportumty Employer g {A
ENCLOSURE s
BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 DEFICIENCY IN UNDERVOLTAGE PROTECTION DURING AN ACCIDENT NCR BLN EEB 8205
- ~ ~ ' -
BLRD-50-438/82-51, BLRD-50-439/82-46 10 CFR 50.55(e)
THIRD INTERIM REPORT Description of Deficiency During a design review, it was determined that the present design of the additional level of under-or overvoltage protection does not fully comply.
with the requirements as stated in Bellefonte Final Safety Analysis Report Question 430 38 and the guidelines in NRC branch technical position PSB-1.
Misinterpretation of these requirements by TVA caused the original design not to consider a degraded voltage concurrent with an accident. Because of this misinterpretation, the time delay selected to initiate separation of the Class IE distribution system from the degraded offsite power system will not permit connection to the alternate or emergency power systems soon enough to ensure adequate voltages for the required safety-related motors.
Interim Progress TVA has revised its design criteria for the standby ao auxiliary power system (N4-RPD775A) in order to incorporate the design modifications necessary to satisfy the NRC branch technical position on degraded voltage protection. TVA has issued Engineering Change Notice 1559 to accomplish the design changes. The analysis to determine the voltage and time-delay setpoints is continuing.
V,
g, -.
A-.
-, 4, 41
,,