ML19257B534
| ML19257B534 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 07/26/1979 |
| From: | Rehm T NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO) |
| To: | Helfman S PRESIDENT'S COMMISSION ON THE ACCIDENT AT THREE MILE |
| References | |
| TASK-TF, TASK-TMR NUDOCS 8001160802 | |
| Download: ML19257B534 (2) | |
Text
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July 26, 1979 l_
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d SM ID;IN Mr. Stan Helfman President's Comission on T!!I 2100 M Street,,f' W., Suite 714 Washington, D. C.
Dear Stan:
Attached is the informatior, you requested frora Edson Case, Deputy Director, Office of fluclear Reactor Regulation, y-Sincerely, jf Thomas A. Rehm Assistant to EDO Endosure Background info to 1/10/78 re Loop Seals in Pressurizer Surge Line E.KevinCornell/liRC-Tiil[
William Besaw/ADM bcc:
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Background Information to January 10, 1978 f;ote to RSB -- Loop Seals in Pressurizer Eurge Line The potential ef fect of loop seals (i.e., a manometer effect) in a pressurizer surge lir e on pressurizer level indications was considered by fir. S. Israel (RSB) back in 1977 as a generic technical matter rather than during the review of any specific plants; however, he did recognize that the loop seal configuration appears to be unique to B&W The nature of the concern for the loop seal deals with plant designs.
behavior as a mano$eter where level changes would be associated with differences y in pressure between the primary system and the pressurizer.
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In some transient situations where voids would be formed in the primary This
. system, the pressu{izer may not be the hottest point in the system.
Since the could lead to the manometer effect in the pressurizer.
pressurizer is where the instru:;hion is installed to measure system coolant The level, this situa'i, yon could lead to misleading level information.
y operator relies.on level indication for the control of makeup flow to the plant system.
Operating experience.available at the time that the memorandum was prepared did not reveal any situa n for which the operator could not effect safe plant shutdown; consequently, actions to pursue this matter further at the time were not taken.
This has remained generally true up to i
The experience of the Tlil 2 accident, makes it apparent that greater now.
emphasis in the review must be given to this matter.
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$ Wi k W.ecr ave mm 00 cl 1917 142
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