ML20058P597

Documents Understanding of Activities Associated W/Leakage of Water from Pulstar Reactor Coolant Sys,Based on Discussions W/Ej Mcalpine of NRC on 931123

ML20058P597
Person / Time
Site:	North Carolina State University
Issue date:	11/24/1993
From:	Stohr J Office of Nuclear Reactor Regulation
To:	Perez P North Carolina State University, RALEIGH, NC
References
NUDOCS 9312270195
Download: ML20058P597 (3)

Text

- DECgqKORDO?Y NOV 2 4 B33 Docket No. 50-297 License No. R-120 North Carolina State University ATTN: Mr. Pedro B. Perez Associate Director Department of Nuclear Engineering P. O. Box 7909 Raleigh, NC 27695-7909 Gentlemen:

SUBJECT:

WATER LEAKAGE FROM REACTOR COOLANT SYSTEM This correspondence documents our understanding of your activities associated with the leakage of water from your PULSTAR reactor coolant system. Based on your discussions with Mr. E. J. McAlpine of this office on November 23, 1993, we understand that you believe there is a relatively small leak from the reactor coolant system. This apparent leak only became detectable through careful analysis of the amount of water needed to maintain the reactor pool water level during the past seven weeks. Based upon your internal procedures, you ceased operation of the reactor when the leak rate from the system reached one gallon per hour. Following shutdown of your reactor operations, you notified the Radiation Protection Council, the campus Radiation Safety Office, the Dean of the College of Engineering, and the campus Information Office. .

While the systems and procedures you have in place are sufficient to respond to the current situation, these conditions warrant the increased vigilance you have demonstrated. We understand that you propose to take the following actions:

(1) Maintain the reactor in a shutdo,in condition until the Radiation Protection Council, with input from the Reactor Safeguards Advisory Group, has met and agreed to a course of action that you will develop to identify potential leak paths and possible corrective actions.

(2) Isolate the reactor pool from the piping leading to the N-16 Holdup Tank which may be the source of the leak, and increase the frequency of pool water sampling and analyses to once per week.

(3) Operate the reactor in the natural convection mode in accordance with your Technical Specifications only if it can be shown that isolating the reactor pool reduces the water loss rate from the pool to levels consistent with normal evaporation rates seen in the past.

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9312270195 931124 / pp PDR ADDCK 05000297 P PDR

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NOV 2 41993-North Carolina State University 2 (4) If it is determined that there is a leak associated with the N-16 Hold-up Tank loop, formulate a plan to excavate the soil from around the piping leading to the N-16 Holdup Tank to expose flanges which you suspect to be the source of the leak. These will be examined and repaired, as necessary, by either replacing the gaskets between the flanges in that system or by removing the flanges and welding the piping.

(5) Perform tests to verify that the repairs have acceptably controlled the leakage.

As discussed, situations like this are of concern to the NRC because water containing radioactive materials can potentially migrate from a restricted area, your reactor pool, to an unrestricted area, the surrounding environment.

In this case, however, we understand that your data on pool water analyses indicate that any pool water leakage would meet the criteria specified in 10 CFR Part 20 for release to unrestricted areas. We commend your conservative actions to shutdown the reactor, look for the potential leak, and initiate cleanup activities.

Your prompt notification of the NRC in this situation was proper and demonstrates your sensitivity to the situation. You should continue to inform the NRC of such issues and promptly notify the NRC if the situation with the leak changes substantially. We appreciate your cooperation in this matter.

If you have any questions, please contact me, i Sincerely, J. Philip Stohr, Dirbctor Division of Radiation Safety and Safeguards cc: Dr. D. Dudziak, Head Nuclear Engineering Department North Carolina State University P. O. Box 7909 Raleigh, NC 27695-7909 Dr. William Vernetson Director of Nuclear Facilities Department of Nuclear Engineering l Sciences l University of Florida 202 Nuclear Sciences Center  ;

Gainesville, FL 32611 j (cc cont'd - see page 2)

I

r- 140V 2 41993 4

North Carolina State University 3 (cc cont'd)

Dr. Ratib A. Karam, Director Neely Nuclear Research Center Georgia Institute of Technology 900 Atlantic Drive, NW Atlanta, GA 30332 l Dr. R. U. Mulder, Director Reactor Facility University of Virginia Charlottesville, VA 22901 Dayne H. Brown, Director Division of Radiation Protection .

Department of Environment, '

Health, and Natural Resources P. O. Box 27687 Raleigh, NC 27611-7687 I l

bcc: A. Adams, NRR  :

J. Caldwell, NRR l C. Bassett, RII )

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