United States Nuclear Regulatory Commission - Protecting People and the Environment

U.S. Nuclear Regulatory Commission

Lower Limit of Detection (LLD) for Potentially Contaminated Oil

HPPOS-221 PDR-9111220112

Title: Lower Limit of Detection (LLD) for Potentially

Contaminated Oil

See the memorandum from F. J. Congel to D. M. Collins dated

January 30, 1985. For cases in which no release of

radioactive material is authorized, the appropriate lower

limit of detection (LLD) is the "operational state of the

art" value used for laboratory measurements of

environmental samples. This is the LLD value given in the

standard Radiological Effluent Technical Specifications

(RETS) for environmental samples. The health physics

position was written in the context of 10 CFR 20.302, but

it also applies to "new" 10 CFR 20.2002. HPPOS-071 and

HPPOS-072 contain related topics.

Region II requested that licensee guidance be developed for

acceptable surveys of potentially contaminated oils and

referred to IE Circular No. 81-07 (see HPPOS-071) as

espousing the use of operational state-of-the-art

measurements for release of materials. However, IE

Circular No. 81-07 does not establish criteria for

releasing radioactively contaminated materials from

restricted areas for unrestricted use (see HPPOS-072).

The regulations applicable to nuclear power reactor

licensees do not provide for the release of materials that

are known to be radioactively contaminated at any level.

Authorization for disposal of specific radioactively

contaminated materials may be requested as specified in 10

CFR 20.302 [or 10 CFR 20.2002]. The intent of the above IE

circular was to provide guidance on acceptable limits of

detection of portable survey equipment, thus defining "how

hard you have to look" for the case in which no release of

radioactive material is authorized.

When no release of radioactive material is authorized, the

appropriate LLD is the "operational state-of-the-art" value

used for laboratory measurements of environmental samples.

This is the LLD given in the standard RETS for

environmental samples (e.g., 15 pCi/L, or 1.5 x 10-8

micro-Ci/ml for Co-58, Co-60 and Cs-134). 49 FR 36653,

PRM-20-15 states that the measured radioactivity for major

sources of waste oil at BWRs and PWRs are typically 1 x

10-7 to 1 x 10-6 micro-Ci/ml.

For cases in which disposal of radioactively contaminated

oil has been authorized by the NRC pursuant to 10 CFR

20.302 [or 10 CFR 20.2002], the necessary LLD need only be

sufficiently low to ensure that the particular limits are

not exceeded. Therefore, these LLDs may be substantially

above the technical specification environmental LLD if the

NRC authorized release limits correspond to radioactivity

concentrations substantially above these levels. Since the

release limits authorized pursuant to 10 CFR 20.302 [or 10

CFR 20.2002] are established on a case-by-case basis, the

corresponding LLDs necessary to ensure that the release

limits are not exceeded will vary accordingly.

Regulatory references: 10 CFR 20.302, 10 CFR 20.2002

Subject codes: 3.6, 6.8, 7.6, 12.8

Applicability: All

Page Last Reviewed/Updated Thursday, March 29, 2012