ML19330A316
| ML19330A316 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 06/04/1980 |
| From: | Lundvall A BALTIMORE GAS & ELECTRIC CO. |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| IEB-80-05, IEB-80-5, NUDOCS 8007170111 | |
| Download: ML19330A316 (2) | |
Text
<-
Y%
BALTIMORE GAS AND ELECTRIC COMPANY P. O. BOX 1475 B ALTI M O R E, M ARYLAN D 21203 June 4, 1980 ARTMun E.LUNOVALL.Ja.
/ ICE PRESiOCNT Swe*Le Mr. Boyce H. Grier, Director Region I, Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19h06
Subject:
Calvert Cliffs Nuclear Power Plant Units Nos. 1 and 2, Dockets Nos. 50-317 and 50-318 IE Bulletin 80-05
Dear Mr. Gricr:
IE Bulletin No. 80-05 concerns vacuum protection for tanks that contain low pressure or for holdup tanks that can be aligned to contain primary system vater. The bulletin directed us to review the design of the tanks and associated systems to ensure that adequate measures have been taken to protect against vacuum conditions that could result in tank damage with the potential for release of radioactive material.
We have completed an analysis of all tanks at our facility, and the results fall in the following four categories:
1.
The following tanks have atmospheric vents which have adequate capacity to prevent a vacuum from forming:
a.
Boric Acid Storage Tank b.
Refueling Water Tank c.
RC Waste Receiver Tank d.
RC Waste Monitor Tank e.
Misc. Waste Receiver Tank f.
Misc. Vaste Monitor Tank 2.
The following tanks have been designed to withstand greater than i
a full vacuum:
a.
Volume Control Tank b.
Quench Tank c.
Spent Resin Tank d.
Gaseous Waste Decay Tank 3.
The Waste Gas Surge Tank (WGST) has three means of protection from a vacuum condition in the tank:
8 0 0 717 0 ll!
Q
s Mr. B. H. Gricr Juna h, 1980 a.
A drain trap is installed in the drain line from the tank to RC Waste System degasifiers. This trap vill shut when the tank empties, thereby preventing a vacuum.
b.
The compressors which take a suction on the WGS? shutdown at 1.0 psig suction pressure.
c.
A Pressure Control Valve is installed on the tank to admit nitrogen and maintain a pressure of 0 psig. This valve has the capacity to maintain pressure after one compressor fails and continues operation below 1.0 psig, b.
The RC Drain Tank, which is located inside containment, can withstand a pressure as lov as 6.5h psia. The prassure in the tank is normally greater than atmospheric, even while the tank is being pumped down. The level and pressure of this tank are indicated and alarmed in the Control Room. These facts plus the tank's location (inside containment) make it very unlikely that the tank would be damaged by excessive vacuum or that any outside release would occur even if the tank was damaged. However, as an additional precaution, the setpo'.nt of the Nitrogen supply pressure control valve vill b increased to provide a greater supply of nitrogen to the tank as it is being pumped. This change is scheduled for completion by August. For the reasons discusred above, we feel continued operation, even during the interim period while the nitrogen system setpoint is being modified, is justified.
/-
f, Very rul yours, f
e
/
vM e N
. g_o cc:
J. A. Biddison, Esquire G. F. Trowbridge, Esquire Messrs. E. L. Conner, Jr. - NRC J. W. Brothers - Bechtel Division of Reactor Construction Inspection Office of Inspection and Enforcement Washington, D. C.
20555 L.
j