ML20214C719

Discusses Amount of Induced Activity Remaining in Concrete Biological Shield for facility.Twenty-two Metric Tons of Activated Concrete,Containing 0.55 Mci Neutron Induced Activity,Remain on Site,Per Nov 1985 Rept

ML20214C719
Person / Time
Site:	05000187
Issue date:	02/05/1986
From:	Benveniste J NORTHROP CORP.
To:	Garcia E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
301-86-JB-14, NUDOCS 8602210248
Download: ML20214C719 (2)

Text

-

301-86-JB-14 g DECEIVED NRC NORTHROP S m 12 m il: og February 5,1986 REGl0H V qp NRC Region V 1450 Maria Lane Suite #210 Walnut Creek, CA 94596 Attention: Mr. Emilio Garcia

Subject:

Northrop TRIGA Reactor

Dear Mr. Garcia:

During the last six months, the disposition of the concrete biological shield for the Northrop Triga Reactor has been a major concern in our decommissioning program.

As explained in previous correspondence, concrete samples have been analyzed and calculations performed to determine the amount of induced activity still remaining in the shield after the removal, packaging and shipping of approximately 110 metric tons of low level radioactive concrete to the burial site in Hanford, Washington.

Last September, early estimates made in letters to the Nuc! car Regulatory Com-mission and the State of California indicated about 28 metric tons of slightly acti-vated concrete, containing about 1.2 millicuries, remained on site. During October and November, further refinements in the calculations resulted in lower estimates of 22 metric tons of activated concrete containing about 0.55 millicuries.

These latter values were published in the "Northrop Triga Reactor Concrete Dis-position Report", dated November,1985, and mentioned in Federal, State and County correspondence during December 1985.

It is Northrop% firm conviction that the information in this concrete disposition report is valid and the calculations as accurate as is reasonably possible.

8602210248 860205 PDR ADOCK 05000187 W PDR w nmconm,nar, . un ten o mn and Te , a ce o~

Of 48 Pa v 3?t h P uk . PP os Ventas Pe' +mt V Caldorria 00274 6

• Te eor e e (213) J / / 43li t o

l In summary:

1. Approximately 110 metric tons of activated concrete were buried at the IIanford site as low specific activity, radioactive waste;

2. About 22 metric tons (of the 1000 metric tons still remaining on-site) contain about 0.55 millicuries of neutron induced activity;

3. Northrop is presently awaiting formal responses from the NRC and the State to our requests for approval to bury all of the 1000 metric tons of concrete in a local landfill as non-radioactive waste.

Should you have further questions, please feel free to contact the undersigned.

Sincerely yours, f

,/ L-w~.v T

' KBenveniste, Chairman Corporate Radiation Committec 4