ML20137M029

Requests Approval to Dispose of Approx 1,000 Metric Tons of Concrete Biological Shielding from Facility.Proposed Disposal Will Be by Burial in Soil at Local Landfill

ML20137M029
Person / Time
Site:	05000187
Issue date:	11/20/1985
From:	Benveniste J NORTHROP CORP.
To:	Bernard H Office of Nuclear Reactor Regulation
Shared Package
ML20137M034	List: ML20137M029 ML20137M040
References
301-85-JB-170, NUDOCS 8512030585
Download: ML20137M029 (2)

Text

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l 301-85 .5B-1 0 NORTHROP November 20,1985 Director, NRR c/o Standardization and Special Projects Branch Washington, DC 20555 Attention: Office of Nuclear Reactor Regulations Mr. IIal Bernard

Subject:

Northrop Triga Reactor Gentlemen:

Pursuant to 10 CFR 20.302, the Northrop Corporation hereby requests approval from the NRC to dispose of approximately 1000 metric tons of concrete biological shielding from the Northrop Triga Reactor, License Number R-90. Proposed disposal is to be by burial in soil at a local landfill.

Analyses by an independent analytical laboratory and extensive calculations (see Attachment A) indicate that only about 22 metric tons of this concrete exhibit any levels of induced activity in excess of background levels. This induced activity totals no more than 0.55 millicuries, the major contributors of which are:

Fe 55 286uci for 22 metric tons Co 60 55 " " " "

Eu 152 194 " " " " "

Eu 154 15 " " " " "

Total 550uci " " " "

Please note that these radionuclides all have relatively short half-lives, and that they are fixed in the concrete. Under normal circumstances, neither leaching nor concrete decomposition would occur until several half-lives have elapsed, thus reducing the amount of any of these radionuclides entering the soil and eventually presenting a hazard to humans.

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i By comparison, the natural background activity in 22 metric tons of concrete is I about 0.64 millicuries, while the entire 1000 metric tons of concrete contain approximately 29.2 millicuries of naturally occurring radionuclides, including:

K 40 374uci for 22 metric tons 17.0 mci in 1000 metric tons Ra226 114 " " " " "

5.2 " " " " "

Th228) 154 7.0 Th232) " " " " " " " "

Total 642uci 29.2 mci The half-lives of these nuclides, ranging upwards to 20 billion years, indicate the natural radionuclides will remain long after the induced radioactivity has decayed away.

The proposed landfill is the Puente IIllls site, in La Puente, California, Pertinent information on the site is enclosed as Attachment D.

Because of the extremely low specific activity of the concrete, no special handling

~ or transportation requirements are deemed to be required, nor are any special procedures necessary to minimize the risks of unexpected or hazardous exposure to workers or the general public. Disposal of this concrete at a local landfill, we believe, presents no more hazard to personnel than disposing of a like amount of ordinary concrete rubble in a similar manner.

Sincerely yours,

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7. Benveniste, Chairman Corporate Radiation Committec

ii sq NORTHROP TRIGA REACTOR CONCRETE DISPOSITION REPORT NOVEMBER 1985 O

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