ML20050B873
| ML20050B873 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 04/01/1982 |
| From: | William Jones OMAHA PUBLIC POWER DISTRICT |
| To: | Clark R Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.B.1, TASK-TM LIC-82-141, TAC-44374, NUDOCS 8204070510 | |
| Download: ML20050B873 (2) | |
Text
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e O Omaha Public Power District 1623 HARNEY 8 OMAHA, NE8RASMA 68102 8 TELEPHONE 536 4000 AREA CODE 402 April 1, 1982 LIC-82-141 Mr. Robert A. Clark, Chief e U. S. Nuclear Regulatory Commission d Office of Nuclear Reactor Regulation g Division of Licensing // R E C g pj "~ m ,
Operating Reactors Branch No. 3 m 4
Washington, D.C. 20555
'7 W () g 7pg
Reference:
Letter from W. C. Jones to D. G. Eisenhut dat f nucyrm$%
u nar M
g November 13, 1981 ,s'
'p (Cyd &~
Dear Mr. Clark:
%e -
Subject:
Natural Circulation Cooldown Procedure in the referenced letter, Omaha Public Power District committed to developing and implementing a Fort Calhoun Station procedure by April 1, 1982 for taking the plant to cold shutdown during a natural circulation mode. This District procedure was also be account for reactor vessel head voids.
The required procedure has been developed. However, it relies upon using the recently installed reactor gas vent system (RGVS) to achieve cooldown. Since the present guidelines in NUREG-0737, Item II.B.1, presently preclude the District from using the RGVS, a delay in im-plementing this procedure is requested. The District proposes to implement the natural circulation cooldown procedure upon Commission approval of the RGVS.
The RGVS is needed to ensure a timely cooldown when the reactor coolant system is in a natural circulation mode. Cooldown in natural circu-lation can be achieved without use of the RGVS, but the procedure would be very time consuming because of the need for lengthy hold points to allow head cooling and time limited by the availability of quality condensate for the steam generators. Using the RGVS cooldown could be achieved in a much shorter time period. Without the RGVS, cooldown could take several days. The reduction in cooldown time is achieved by venting the steam void in the vessel head, thus providing a better heat o% ,s transfer for cooling of the vessel head. The District believes the existing requirement to not cooldown while in natural circulation (i.e., O wait until flow is restored) is preferred to implementing a natural 8204070510 020401 PDR ADOCK 05000285 P PDR
Mr. Robert A. Clark' LIC-82-141 l Page Two l circulation cooldown procedure without use of the RGVS. Accordingly,
! 'pending f urther Commission guidance, the District will wait on imple-mentation of the Fort Calhoun Station natural circulation until Com-
- mission approval of RGVS is received, i
Sincerely, UD o W.C.b{ones Divisi'on Manager Production Operations cc: LeBoeuf, Lamb, Leiby & MacRae 1333 New Hampshire Avenue, N.W.
Washington, D.C. 20036 t
I
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