ML20069B707
| ML20069B707 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 03/08/1983 |
| From: | Counsil W NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES |
| To: | Clark R Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.F.1, TASK-TM B10717, NUDOCS 8303170156 | |
| Download: ML20069B707 (2) | |
Text
e w
General Offices e Seiden street. Berhn, Connecticut NORTHEAST UTILITIES l
sY
'es5aNcow HARTFORD. CONNECTICUT 06141-0270
.am..ri
.oe co"*"
(203) 666-6911 o,
ar wesu acow.s-g k
v asomta6Mf mga.EneaosCowaan March 8,1983 Docket No. 50-336 B10717 Director of Nuclear Reactor Regulation Attn:
Mr. Robert A. Clark, Chief Operating Reactors Branch //3 U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Gentlemen:
Millstone Nuclear Power Station, Unit No. 2 NUREG-0737 Item II.F.I.5, Containment Water Level Monitor The purpose of this letter is to inform you of a minor oversight in the docketed documentation associated with the Millstone Unit No. 2 containment water level monitoring system.
As part of the follow-up of an NRC audit of Three Mile Island (TMI) related backfit projects, a design verification of the containment water level monitoring system was conducted to ensure system compliance with NUREG-0737. Item II.F.1.5 of NUREG-0737 states in pertinent part:
"A continuous indication of containment water level....... shall be provided for PWR's and r.hould cover the range from the bottom of the containment to the elevation equivalent to a 600,000 gallon capacity."
Our design verification has revealed that the Millstone Unit No. 2 wide range containment water level monitor can measure a containment water volume of 565,000 gallons. This range is acceptable because the maximum post-accident containment water volume will not exceed approximately 563,800 gallons based on the following:
Ref ueling Water Storage Tank (RWST) Volume 459,400 gallons (1)
Concentrated Boric Acid Tanks Volume 14,000 gallons (1)
Safety Injection Tanks Volume 36,400 gallons (1)
Reactor Coolant System Volume 54,000 gallons less pressurizer steam space and 563,800 gallons volume remaining in Reactor Vessel (1)
Expansion from initial temperature of 500F to final temperature of 2000F assumed and included in stated volumes.
[
ohhOojj6 OC PDR
~
, 1hus, although the containment water level system will not measure the 600,000 gallon generic value specified in Itern II.F.1.5 of NUREG-0737, the system is capable of measuring in excess of the maximum postulated containment water volume of approximately 563,800 gallons. This volume exceeds that which would be calculated on a best-estimate basis because of the conservatisms incorporated into the volume calculation and the fact that it does not account for shrinkage of the RCS volume (due to a lowering of temperature) af ter mixing in the containment sump. As such, the intent of this TMI Action Plan item remains fulfilled.
Because of the minor nature of this documentation discrepancy, we continue to believe that the appropriate classification for this TMI Action Plan item is
" complete". In accordance with the telephone discussion with your office on Friday, March 4,1983, it is our understanding that this submittal has no impact on the TMI orders expected to be issued shortly.
We will assume that the above understanding is correct unless you advise to the contrary.
Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY
/i 4
~
LFL44.
W. G. Counsil i
Senior Vice President
.- -