United States Nuclear Regulatory Commission - Protecting People and the Environment

U.S. Nuclear Regulatory Commission

Question 451: May the codes "ND" (not detectable), "NR"

(not required), and "NC" (not calculated) be used more

generally in the radiation dose data blocks on the NRC

Forms 4 and 5 than is implied by the instructions on the

forms? The purpose in asking this question is to clarify

the guidance for filling out the forms provided in the

regulatory position and in the instructions on the reverse

side of the NRC Forms 4 and 5. The Form 5 instructions

appear to limit the use of the "NR" and "NC" codes to the

committed effective dose equivalent (CEDE) and the

committed dose equivalent (CDE), "ND" is not referenced in

the Form 5 instructions, and the NRC Form 4 instructions do

not appear to refer to any of these codes. We believe that

the references to the codes in the guidance and

instructions on the forms are as examples for emphasis, and

that the intent of the guidance is that "NR" and "ND" are

appropriate for use, as applicable, in any of the dose

blocks, and are not specifically limited for use by the

manner in which referenced or described in the guidance.

However, we do note that "NC" may only be applicable to the

CDE (e.g., if the CEDE were less than 1 rem).

Answer: Yes. As indicated in the second paragraph of

regulatory position 1.1 of the guide, "NR" should be

entered in the blocks on Forms 4 and 5 to indicate the

areas for which monitoring was not required and "ND" should

be entered on these forms to indicate "where monitoring was

provided but not measurable [detectable]". As indicated in

regulatory position 2.2 of the guide, the use of "NC" is

appropriate only for items 16 and 18 on NRC Forms 4 and 5

for cases in which the CEDE does not exceed 1 rem and there

are no overexposures in any dose category within the

monitoring year. (References: Regulatory Guide 8.7, Rev.

1; 10 CFR 20.2104, 10 CFR 20.2106).

Page Last Reviewed/Updated Thursday, March 29, 2012