ML20004C248
| ML20004C248 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 05/28/1981 |
| 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, SQRD-50-328-81, NUDOCS 8106020396 | |
| Download: ML20004C248 (2) | |
Text
y S-400 Chestnut Street Tower II May 28, 1981
^
48b D SQRD-50-328/81-22 e.e/h\\itt.D a a
c wJ u
Mr. James P. O'Reilly, Director
.h
,,*q Q 1 19 8 b
q Office of Inspection and Enforcement d
cap 555 k U.S. Nuclear Regulatory Ccanission
\\# u 5 iSN55# k re f' q's;Ns#ff Region II - Suite 3100 Y.
101 Mariatta Street e
Atlanta, Georgia 30303
~ { oti
Dear Mr. O'Reilly:
SRUOYAH NCCTIAR PIJMP UNIT ? - FIN DEFICIENCY IN ERCW SYSTEM -
SQRD-50-328/81-22
'IRIRD IN1ERIM REPORP
'Ihe subject deficiency was initially reported to NRC-OIE Inspector R. V. Crlenjak on March 4,1981, in acx:ordance with 10 CFR 50.55(e) as NCI SGI S;7P 8107.
Interim reports were subnitted on April 3 and April 27, 1981. Enclosed is car third interim report. We expect to subnit our next i
report by July 15, 1981.
If you have any questions, please get in touch with D. L. Lambert at ETS 857-2581.
Very truly yours, TENNESSEE VALLEY AUIBOUITY L. M. Mills, Manaaer Muclear Regulation and Safety Enclosure cc: Mr. Victer Stello, Diractor (Enclosure)
Office of Inspection and Enforcement U.S. Nuclear Regulatory Ccanission Washington, DC 20555 l
l l
1019 S
//
810eoso 3%
_g-
.r.
ENCTASURE 1
j SEQU3YAH NUCLFAR PIANT UNIT 2 FLON DEFICIENCY IN ERCW SYSTEM SQRD-50-328/81-22 10CFR50.55(e)
'IHIRD INPERIM REPORP Description of Deficiency During the preoperational test of the unit 2 Essential Raw Cooling Water System (ERCN) which simulated the worst operating case, which is unit 1 in -
hot standby condition and unit 2 in a post-IDCA condition, with the loss of (1) offsite power, (2) downstream dam, and (3) train B diesel generators, the flow rate requirements to several wi@ents required for safe shutdown could not be met. Se total system flow rate measured in the' test was-approximately 2500 gpn 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 ancher nonconformance report (SQRD-50-328/81-17).
Interim Progress i
TVA has completed the preoperational flow balance test on the ERCN system.
The initial review of the test data indicates that the system will perform satisfactorily for fuel loading since the required total system flow rate has been reduced from 22,000 gal / min to 17,000 gal / min.
The test data indicated that the following wipents had flow deficiencies during the various tests: Electrical Board Rom Air Conditioner A and B; Main Control Room Air Conditioner A and B; and the Stationary Air Cmpressors A, B, C, and D.
Rese deficiencies were anticipated.
Engineering Change Notice (ECN) L5235 had been issued as a result of previous test deficiencies for these conponents and modifications to the piping are being implemented. Until these modifications are complete, there are limitations on the operating conditions of the plant for a two-unit operation. Unit 2 will not be operated when the ERCN cooling water inlet temperature exceeds a certain tenperature which is presently 750F The following wipents also had flow deficiencies, as indicated by the test data:
(1) Dnergency Gas Treat:6ent Rom Cooler 2A (3.7 gal / min of 5 gal / min); (2) Reactor Building Instrument Room Water Chillers IA (26.4 gal / min of 30 gal / min) and 1B (15 gal / min of 30 gal / min); (3) Penetration Rom Cooler 1B1 (24.6 gal / min of 28 gal / min); (4) Residual Heat Removal Pung Ibm Cooler 2B (11 gal / min of 13 gal / min); (5) Spent Fuel Pit Cooling System and %ermal Barrier Booster Pung Space Cooler 1B (24 gal / min of 26 gal / min); (6) Control Rod Drive Mechanism Cooler 2B (82.3 gal / min of 84 gal / min); and (7) Centrifugal Charging Pung Cooler 1B-B (27.3 gal / min of 40 gal / min). %e deficiencies indicated are marginally acceptable except for items (2) and (7). We floe deficiencies to item (2), the Reactor Building Instrument Room Water Chiller la, and item (7), the Centrifugal Charging Pump Cooler 1B-B, occurred in a simulation of the normal power generation l
mode during normal plant operational conditions. %e flow rate through the Cmponent Cooling Heat Exchanger C during this test was 5,000 gal / min, which is the required flow for the design basis event. Reducing this flow for normal operation will reduce these deficiencies to acceptable levels l.
for fuel loading. During the tests, which simulated conditions of the design basis event, these cur @ents received adequate flow.
TVA is continuing to evaluate the system to determine what nodifications should be inplemented to enhance system performance.
1 lu
--.,__-._.~_~-..-----.~------U