ML20067A167

Reviews GE Research Reactor Fuel self-protection Assessment - BGS-9-90

ML20067A167
Person / Time
Site:	Vallecitos Nuclear Center
Issue date:	10/02/1990
From:	Schnitzler B EG&G IDAHO, INC.
To:	Carpenter W EG&G IDAHO, INC.
References
NUDOCS 9101240278
Download: ML20067A167 (1)

Text

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• Providing research and development services to the government" INTEROFFICE CORRESPONDENCE ,

Date: October 2, 1990 To: W. R. Carpenter, MS 2409 / , ') ' )

From: B. G. Schnitzler, MS 3515 6,@5

Subject:

REVIEW OF GEllERAL ELECTRIC RESEARCH REACTOR FUEL SELF-PROTECTION ASSESSMENT - BGS-9-90

References:

(a) G. E. Cunningham (GE) letter to T. S. Michaels (NRC) dated March 15, 1990 (b) G. E. Cunningham (GE) letter to T. S. Michaels (NRC) dated-August 31, 1990 (c) B. G. Schnitzler, A Calculational Method for Determining _

Bioloaical Dose Rates from Irradiated Research Reactor Fuel, NUREG-CR-4203, April 1985 The Code of Federal Regulations (10 CFR 73.6) establishes requirements for the physical protection of special nuclear material of moderate and low strategic significance. The level of physical protection at nonpower reactor facilities may be reduced if the special nuclear material has a ,

total external radiation dose in excess of 100 rems per hour at a distance of three feet.

Reference (a) transmitted a self-protection assessment for fuel of the General Electric Nuclear Test Reactor (NTR) at the Vallecitos Nuclear Center in Pleasanton, California. The referenced transmittal indicated a self-protection time in excess of 80 days based on an axial dose point and on the order cf 160 days based on a dose point located at the axial mid-pl ane . The reactor power history mode'lling einployed was conservative from a radiological protection standpoint, but nonconservative for the purposes of dem.istrating fuel self-protection, Reference (b) transmitted a revised self-protection assessment for the llTR fuel. The modelling employed in the revised transmittal is conservative for the purposes of demonstrating fuel self-protection. The gamma dose rate at the axial mid-plane remains above 100 rems per hour for about 29 days.

Comparable results were obtained in an independent calculation using the GE NTR power history from Reference (b) and the INEL fuel self-protection code described in Reference (c). Although the FUELDR code does not contain a GE-flTR geometric model, comparable photon transport can be expected from similar plate type fuel elements.

jr cc: J. M. Ryskamp, MS 3515 g (1 B. G. Schnitzler (2)_ .

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