ML20137Q317

Requests Permission to Proceed W/Plans to Demolish Facility Biological Shield,Bury Concrete Rubble at Local Landfill & Survey Floor/Ground Area Where Shielding Structure Stands, Pending State of CA Approval

ML20137Q317
Person / Time
Site:	05000187
Issue date:	09/04/1985
From:	Beveniste J NORTHROP CORP.
To:	Bernard H Office of Nuclear Reactor Regulation
References
301-85-JB-145, NUDOCS 8509200117
Download: ML20137Q317 (2)

Text

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1 301-85-JB-145 NORTHROP 4 September 1985 Director NRR c/o Standardization and ,_g ,7 Special Projects Branch ~ o' '

Washingten, D.C. 20555

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Office of Nuclear Reactor Regulations Attn: Mr. Bal Bernard Gentlemen:

The Northrop Corporation is nearing completion of its task to decommission the Triga Reactor Facility. To date over 100 tons of activated concrete have been removed from the interior surfaces of the reactor's biological shield and shipped as low specific activity, radioactive material to the burial site at Hanford, Washington. From the analytical data en seven concrete samples tested by EAL Corporation, Richmond, California, the amount of low level, activated concrete still remaining in the biological shield has been calculated to be approximately 28 metric tons, with about 1.1 millicuries of beta activity and 0.13 millicuries of gam::a activity. The primary emitters contributing to this activity have been identified as Fe55, Co60 and Eu152 - all of which have reasonably short half lives. The remainder of the concrete shield, estimated at 817 metric tons, is, from all indications, neither activated nor contaminated above background levels. We are currently requesting approval from the State of California to dispose of the entire 845 tons of concrete shielding by burial in soil in consonance with the provisions of Section 30288, Title 17, California Radiation Control Regulations. When this request is granted, we intend to demolish the biological shield, bury the concrete rubble at a local landfill, and survey the floor / ground area where the shielding structure now stands.

Northrop hereby asks the NRC for permission to proceed with these plans when the State of California grants our burial request.

This departure f rom the original Dismantling and Decommissioning plan is being proposed because our measurements show that we will be able to meet the 5 R/hr criterion everywhere in the facility but in the exposure room.

Here the 4r geometry to which the gamma detector is subject yields readings about a factor of 2 to 3 higher than this. We have decided, therefore, that unequivocal demonstration of having met the 5gR/hr criterion will be possible only if we demolish the concrete structure and make our final survey in the cleared facility.

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301-85-JB-145 Page 2

. Northrop respectfully requests permission to proceed with this plan as soon as the State of California approves our petition to bury the concrete rubble at a local waste disposal site.

Sincerely yours,

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. Benveniste, Chairman Corporate Radiation Committee e

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