Health Physics Questions and Answers - Question 402
Question 402: NRC Form 5 (Item No. 21, "Comments") implies that dose from a "hot particle" should be added to the shallow dose equivalent, maximum extremity (SDE, ME - Block 14). However, I&E Notice 90-48 states that "hot particle exposure will not be added to skin doses from sources other than hot particles."
(a) Should hot particle doses be added to the shallow dose equivalent as implied?
(b) If so, should this dose be subtracted from the applicable dose category with regard to remaining available shallow dose equivalent (skin or extremity) for the year? Based on our understanding of the intent of I&E Notice 90-48, we believe that "hot particle" doses should not be ubtracted from the remaining available shallow dose equivalent (skin or extremity) for the year.
Answer: The intent of the "hot particle" example in the instructions for Item 21 on Form 5 is simply to give one an example of how this space on the form might be used. There is no intention to imply that hot particle doses should be added to other doses.The question of adding hot particle skin poses to other skin doses was addressed in IE Information Notice 90-48, "Enforcement policy for Hot Particle Exposures," and the enforcement policy enclosed with that notice, and in Health Physics Position (HPPOS) 246 (in NUREG / CR-5569). The NRC policy and staff positions in these documents have not been changed by revised Part 20 or the instructions for Form 5 in Regulatory Guide. Answers to the specific questions are as follows:
(a) As indicated in HPPOS-246, licensees may choose whether or not to add a hot particle dose to other skin or extremity doses. However, in either case, the record should be clear as to the amount of the hot particle dose. In determining whether or not an overexposure has occurred, the NRC will consider the hot particle dose alone, without adding it to other doses.
(b) The hot particle dose should not be subtracted from the remaining available shallow dose equivalent (skin or extremity) for the year.
(References: 10 CFR 20.2106, 10 CFR 20.2206, Regulatory Guide 8.7)