ML20028B542

Informs of Method for Leak Testing non-TRIGA (Patr) Fuel Elements.Fuel Pellets Will Be Loaded Into Separate Aluminum Tubes & Sealed by Arc Welding to Form Fuel Tube. Record Will Verify Integrity

ML20028B542
Person / Time
Site:	Pennsylvania State University
Issue date:	11/30/1982
From:	Levine S PENNSYLVANIA STATE UNIV., UNIVERSITY PARK, PA
To:	Rozier Carter Office of Nuclear Reactor Regulation
References
NUDOCS 8212030010
Download: ML20028B542 (3)

Text

T H E P ENNSYLVANI A S T ATE U NIVERSITY UNIVERSITY PARK, PENNSYLVANIA 16802 College of Engineering Area code 814 Brea/cale Nuclear Reactor 865-6351 30 Nov aber 1982 Robert E. Carter Project Manager Standardization and Special Projects Branch Division of Licensing Nuclear Regulatory Commission Washington, D.C. 20555 Subj ect: Leak Test Method for Non-TRIGA (PATR) Fuel Elements Docket No.: 50-5 NRC License: R-2

Dear Bob,

In regard to our conversation at the November Washington ANS meeting, it was decided that I should inform you in detail on the method to be used to leak test the non-TRICA (PATR) fuel elements. In Dr. R. G. Cunningham's letter of October 18, 1982 to your branch chief , Cecil Thomas, the NRC was provided with a description of the PATR fuel elements. Referring to this description, the UO2 fuel pellets are to be loaded into separate aluminum tubes and scaled by arc welding to form a fuel tube. These tubes will then be leak tested using a leak testing chamber which has been i designed and constructed to leak-test specimens up to 1-1/2 inches in diameter and up to 30 inches long. Several fuel tubes will be inserted in this device.

( The test procedure for this device consists of passing the test l specimens through a ball valve to the inside of the chamber. (See Figure 1).

l The chamber is then evacuated for about an hour to remove the air from the j chamber. The test chamber is then pressurized with helium at %175 psig, for a minimum of six hours. This, in turn, will pressurize the specimen under test, filling it with helium gas through any leaks that exist in it.

Once the test specimen is pressurized for at least six hours, it is removed from the test chamber and, without delay, immersed in a suitable liquid (isopropyl alcohol or ethylene glycol) and observed for bubbles.

Isopropyl alcohol or ethylene glycol should be used for immersion of the specimen to eliminate the possibility of being misled by bubbles formed in other liquids which originate from dissolved air in the liquid. O30 8212030010 821130 PDR ADOCK 05000005 p PDR

Pegn 2 Previous experience with this type of leak system .has -shown that the method will easily identify water leaks in the tubes. The method of assembling the fuel tubes to construct a PATR fuel element should not introduce new leaks. This is because the attachment area of the tubes to the aluminum fittings that hold them in place will be distant from the welds on the tubes. Nevertheless,'the first few PATR fuel elements constructed will be leak tested again to verify their integrity.

Records will be kept as a means of quality control to assure all PATR fuel elements are leak tight.

If you have further questions, please let me know.

4 Sincerely yours, M

, S. H. Levine, Director I

Breazeale Nuclear Reactor

~ Professor of Nuclear Engineering SHL/r cc: E. H. Klevans I. B. McMaster W. F. Witzig i.

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