U.S. Nuclear Regulatory Commission

Technical Assistance Request, Westinghouse Electrical Company, Evaluation of Residual Contamination

HPPOS-292 PDR-9306210248

Title: Technical Assistance Request, Westinghouse

Electrical Company, Evaluation of Residual Contamination

See the memorandum from J. E. Glenn to R. R. Bellamy dated

May 18, 1992. This memo responds to a technical assistance

request from Region I, dated April 14, 1992 (Enclosure 1),

for confirmation of their interpretation of the Branch

Technical Position (BTP) for evaluation of residual

concentrations of processed uranium on the Bloomfield, NJ

site and generic applicability to other remediated

facilities with processed uranium waste. The

interpretation of Region I is correct (Enclosure 2) and is

applicable to other remediated sites. For unenriched

uranium, with no decay products of uranium-234 (U-234)

present, the applicable values in the BTP are those for

depleted uranium.

Westinghouse Electric Company's Bloomfield Lamp Plant is

currently being remediated to remove thorium and processed

uranium waste and contamination resulting from past

operations from the facility. The Branch Technical

Position for Disposal or Onsite Storage of Thorium and

Uranium Wastes from Past Operations (BTP) provides guidance

on acceptable concentration limits for various types of

materials for five disposal options. While the BTP

provides numerical guidance for thorium (natural thorium),

there is no criteria for processed uranium.

The Branch Technical Position (46 FR 52061-52063) describes

five options for disposal of certain uranium or thorium

wastes. For each option, a disposal methodology is

described and a concentration limit for each of four

various kinds of material is tabulated. For Option 1,

these values are as follows: natural thorium (Th-232 plus

Th-228) if all daughters are present and in equilibrium, 10

picocuries per gram (pCi/g); depleted uranium, 35 pCi/g;

enriched uranium, 30 pCi/g; and natural uranium ores (U-238

plus U-234) if all daughters are present and in

equilibrium, 10 pCi/g. For other options, higher

concentrations apply. One problem with the BTP is that

there is no stated disposal option nor concentration limit

for processed uranium; i.e., waste materials containing

uranium, in which the uranium is neither enriched nor

depleted and is not natural uranium ore with all daughters

present and in equilibrium. There is a need for a

concentration limit for disposal of this type of material

in order to evaluate the remediation that has been

performed at this site and other sites contaminated with

material of this kind.

The concentration limits for wastes containing processed

uranium should be the same as that tabulated for depleted

uranium since processed uranium most closely resembles the

radiological characteristics of depleted uranium; i.e.,

U-235 makes up only about 0.7% of natural uranium, and

based on Section II.B of Enclosure 3 to the Branch

Technical Position, the U-235 decay chain is generally

unimportant compared with the U-238 chain. For Disposal

Option 1, the appropriate concentration limit for processed

uranium would thus be 35 pCi/g.

NMSS agrees with that interpretation. The basis is the

contribution of U-238 to the inhalation and ingestion doses

relative to that of U-234. For both natural and depleted

uranium, the U-238 contributes a substantial fraction of

the radioactivity; whereas, for enriched uranium, the

radioactivity is completely dominated by the U-234, with

regard to inhalation and ingestion doses.

Regulatory references: None

Subject codes: 5.8, 9.0

Applicability: All