ML13350A639

Public Comments on DG-8051

ML13350A639
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Issue date:	05/31/2014
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RG-8.022 DG-8051
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Staff Responses to Public Comments on Draft Regulatory Guide DG-8051 (Proposed Revision 2 of Regulatory Guide 8.22)

(Public comments have been edited for clarity)

Draft Regulatory Guide 8.22, "Bioassay at Uranium Mills," (Agencywide Documents Access and Management System (ADAMS) Accession No. ML110960333), was published for public comment in the Federal Register on March 13, 2012 as DG-8051 (77 FR 14837). The U.S. Nuclear Regulatory Commission (NRC) received and analyzed multiple comment submissions. The comments and the NRC staffs responses are presented in the following tables grouped by the person or organization that submitted the comments:

Mr. Gary Chase Tel: (307) 473-1397 E-mail: gbchase@sdwinc.com ADAMS Accession No. ML12089A216 No. Comment or Basis Recommendation NRC Resolution 1 Comment on You may want to consider an upper bound limit for a urinalysis sampling The NRC agreed with the comment; bioassay frequency in time frame, <90 hours, for uranium mill workers under the following ammonium diuranate (ADU) has section C.3 conditions: a) Calcining to 1,200 °F in a multiple hearth dryer using a been included in Section B, feed of ammonium diuranate (NH4)2U207 (i.e., ADU). Background as well as in Section C.3.c. Special Bioassay sampling requirement is now 90 hours0.00104 days <br />0.025 hours <br />1.488095e-4 weeks <br />3.4245e-5 months <br />.

2 General input Mill operating personnel were routinely rotated to each operating The comment was informative, but position, grinding and leach, CCD, solvent extraction, and precipitation no changes to the regulatory guide and drying. That way, no one was placed at one operating position (RG) were warranted.

continually and all were trained at each position. Barreling was normally conducted on dayshift.

3 General input All in-vivo counting was conducted once annually for selected mill The comment was informative, but personnel with everyone counted during their first year of employment. no changes to the RG were Every count period included the mill person with the highest exposure warranted.

potential (no credit was taken for respirator use) during the preceding year. The average annual counting data were all below the minimum detection limit.

4 General input Respirators were not worn for routine mill operation. Airborne uranium The comment was informative, but sampling was crossed checked with NRC personnel on their inspections no changes to the RG were of the mill and the results were considered acceptable by the NRC. warranted.

5 General input There was an extremely low rate of turnover at this mill. The data reflect The comment was informative, but 1

a learning curve for the operators and the effect of engineering controls. no changes to the RG were There was no turnover in the radiation safety department, no change in warranted.

mill analytical procedures or contract laboratory used for urinalysis data during this time frame.

6 Comments on Table Had a 15 µg/liter lower limit of detection in-vitro uranium urinalysis been The NRC agreed with the comment; A-1 used after a >90 hour time off sampling time frame, most of these data this revision of RG 8.22 is not would not have been observed (i.e., there are 24/7 rotating shifts that have including the 15 µg/liter lower limit 4 days, >192 hours, off). If the barreling operation is under control the of detection in-vitro uranium amount of soluble uranium in the air could be missed entirely. urinalysis. Instead is referencing the American National Standards Institute/Health Physics Society (ANSI/HPS) N13.30-2011, Performance Criteria for Radiobioassay which recommends detection methodology, for uranium and urine sample detection capability, which is acceptable to NRC.

Mr. Steven Brown, CHP and Douglas Chambers, Ph.D.

SENES Consultants Limited Tel: 303-941-1056 E-mail: sbrown@senes.ca ADAMS Accession No. ML12132A047 No. Comment or Text of comment Resolution Basis 1 Comments on Frequency - reference to minimum monthly bioassay sampling: In light of the The NRC agreed with the comment; Section C.3.a solubility study data (dissolution in lung fluid simulants) for modern UR products Section C.4.a has been revised to (changed to presented in Attachment 1, a monthly frequency may be inadequate to identify indicate that monthly frequency is C.4.a) intakes of materials with dissolution /elimination half times of a few days or less. only acceptable for Class Y The NRC should consider minimum urinalysis specimen collection frequencies materials based in Table 1.

aligned with weekly shift schedules for workers in the yellowcake areas of mill.

2 Comments on Frequency: The NRC should recognize here that although NUREG-0874 does The NRC agreed with the comment; Section C.3.b represent appropriate and the most current guidance for the dosimetric model this revision of RG 8.22 is aligned 2

(changed to basis of 10 CFR 20, both are based on ICRP 30 dosimetry models of over 30 with Title 10 of the Code of Federal C.4.b) years ago. The more recent lung and uranium dosimetry models of the ICRP, Regulations (10 CFR) Part 20, e.g., ICRP 66, 68 and 71 should at least be recognized here. Standards for Protection against Radiation. As suggested, the latest International Commission on Radiological Protection (ICRP) recommendations associated with uranium bioassay have been cited in this document. It should be noted that some of the recommendations issued by ICRP do not correspond to the requirements specified in the NRCs regulations. In such cases, the NRCs requirements take precedence.

3 Comments on Table 1: As indicated under General Comments above, the uranium products The NRC agreed with the comment; Section C, Table being produced by most UR facilities in the US today are not represented in this although UO3 and UO4 and uranium 1 table, e.g., UO4 and hydrates of UO4 and UO3. hydrates, as well as ADU are uranyl peroxides (UO4 nH2O) and were not represented in Table 1, they are discussed in detail in Section B Background of the guide. Also, the solubility issues are covered in Section C.3.c and C.5.c.

4 Comments on Table 1 and discussions that follow regards to D, W and Y solubility The NRC agreed with the comment; Section C, Table classification system: Similar to comment above, it should be recognized that the the equivalency of the ICRP-26 1 F, M and S solubility types defined in ICRP 68 and 71 are generally considered lung solubility classifications equivalent to ICRP 30 D, W and Y solubility classes, respectively. D/W/Y to that of ICRP-60 F/M/S has been applied in Table 1.

5 Comments on Reference to 1 µg/liter action level: Based on conversations with commercial The NRC disagreed with the Section C.4.e radiochemical laboratories, it is doubtful that detection limits <about 5 µg/L are comment; the NRC staff has revised attainable with any statistical confidence. The 1 g/liter value is also discussed in Section C.7, Quality Control, to Section 8, Quality Control for urinalysis, but appears to be intended in that provide an endorsement of section to define a blank control. Nonetheless, it is doubtful that this can be ANSI/HPS N13.30-2011 guidance analytically demonstrated with statistical confidence. where the 5 µg/L sensitivity is attainable as noted in Table 3 of the 3

standard, indicating that the minimum testing level for indirect radiobioassay performance testing, for uranium is required at 1 µg in mass.

6 Commented in Reference to NUREG/CR-2268: The short lived compound discussed therein is The NRC agreed with the comment; Section C.4.e uranium hexafluoride which is not relevant to uranium recovery facilities. uranyl peroxides is now included in However, see discussion under General Comments above and Attachment 1 as this guide based on the technical related to the uranyl peroxides typically being produced at modern uranium bases in NRPB-W22 Industrial recovery facilities. Uranium Compounds: Exposure Limits, Assessment of Intake and Toxicity after Inhalation (2003), as referenced in the guide (Ref. 13).

7 Comments on Section 7.c.: Prevention of Specimen Contamination, requirement that urine The NRC disagreed with the Section C.6.c volume collected should be adequate for four analyses: (a) the licensee has little comment; a) the urine volume can (changed to control over the urine volume provided by the worker. (b) If multiple analyses are be controlled and it is proportional C.7.a.(2)) required from the same specimen, minimum detection limits are impacted. to the water consumed in the body, (Particularly in consideration of the 1 µg/liter requirement. Under these and b) the original section C.7.c has requirements, it may be problematic to see the 15 µg/liter MQC defined in been deleted and has been replaced Section C.7.a and the 15 µg/liter action level in Appendix A. Furthermore, the 1 by Section C.7, Quality Control,

µg/liter action level of Section 5.e vs. the 15 µg/liter MQC described in this referencing Section 4.0 of section is confusing and appears to be conflicting. ANSI/HPS N 13.30-2011, Performance Criteria for Radiobioassay.

Mr. Oscar Paulson, Kennecott Uranium Company Tel: 307-328-1476 ADAMS Accession No. ML12135A180 No. Comment or Basis Text of comment Resolution 1 Clarifications on Workers Requiring Bioassay: A clear and concise definition of The NRC agreed with the comment, Section C.2. workers requiring bioassay should be incorporated in the glossary. but a clear and concise definition of Licensees should have no doubt as to who must be bioassayed at their workers requiring bioassay to be sites. It is clear, based on how the draft guidance is written for incorporated in the glossary is not example, that any worker that must don a respirator must be necessary. Current proposed document bioassayed following completion of work; however, the other in Sections C.1, C.2, and C.3 clearly 4

requirements are not that clear. The document states that, "...workers state who has to undergo a bioassay.

who handle and work with uranium substances, or are sufficiently The NRC staff also agreed with the close to the process so that intake is possible" must be bioassayed. comment about exempted bioassay The document does not discuss worker exposure time. Workers conditions for those with very limited spending a very limited time with uranium substances are at very low time exposure and those low-risk risk of intake, and thus, bioassaying of them should not be required. visitors who use respirators. Licensees An example would be a worker who spends an hour or less per week may be able to request such an in proximity to uranium processing. In addition, infrequent visitors to exemption under 10 CFR 20.2301, a uranium recovery operation may be, for a very short time (minutes), Applications for Exemptions, subject sufficiently close to the process so that Intake is possible, if they are to NRC approval.

touring the grinding, leaching or counter-current decantation areas of a conventional mill. There should be no requirement that such infrequent visitors be bioassayed.

2 Clarifications on Post Operational and Termination Bioassays: The guide should The NRC agreed with the comment; Section C.1.d recognize that it is not always possible to collect a final bioassay Section C.3.d of the guide states that sample from a worker upon termination of work involving exposure to licensees should develop a contingency uranium. In some cases, workers have failed to report to work and plan to avoid or eliminate the failure to subsequently have been impossible to locate or contact making it collect the last sample. This means an impossible to obtain a final post-operational bioassay. This is additional effort to collect a especially true in the case of contract workers. Contract employees termination sample before the worker work for the contractor and the licensee may be unable to obtain a leaves the facility.

post-operational bioassay of a contract worker who fails to report for work and cannot be found. This contingency should be recognized in the document.

3 Comments for The draft guide states: Bioassay specimens should be collected and The NRC agreed with the comment; bioassays following evaluated after a respiratory protection device is used to reduce intake the guidance on respiratory uses shall use of respiratory of radionuclides. In some cases, respiratory protection must be be consisted with requirements in 10 protection devices donned for a very short period of time (often less than fifteen (15) CFR Part 20, Subpart H Respiratory minutes) to take a reading or perform some minor tasks in an area Protection and Controls to Restrict designated for respirator use. This very short duration exposure with Internal Exposure in Restricted Areas, its low associated risk, does not warrant a special bioassay. This is requirements. In Section C.3.e a especially true for facilities on standby where very brief respirator use discussion on Respiratory Protection is required on an infrequent basis. In any event if a worker were Bioassay, is added for further required to don a respirator, even infrequently and for brief periods of clarification. All respiratory time, that worker would still be subject to bioassaying on a monthly discussions have been consolidated in basis. The Regulatory Guide should be revised to recognize such the Section B Discussion under 5

infrequent short periods of respirator use. Background. Licensees may be able to request an exemption under 10 CFR 20.2301, for low-risk workers or visitors, subject to NRC approval.

4 All ISR (i.e., in-situ recovery) samples appear to exhibit solubility The NRC agreed with the comment; characteristics that meet the definition of absorption Type F as defined the proposed document indicates that in ICRP 71. That is "generally equivalent" to solubility Class D from ADU are uranyl peroxides (UO4 nH2O) the older ICRP 26/30. and are classified as soluble chemicals, i.e., they cant belong to a Class-Y materials bioassay program.

Mr. Josh Leftwich CAMECO Resource Tel. 307-316-7600; ADAMS Accession No. ML12136A119 No. Comment or Basis Text of comment Resolution 1 Clarifications on Dryer Operators use respirators on a daily basis The requirement for The NRC agreed with the comment; Section C.2d: special bioassay collection after respirator use should be limited to the guidance on respiratory uses shall Changed to C.2.c. non-routine activities not covered by C.2.d.(1) or C.2.d.(2). Consistent be consistent with 10 CFR Part 20, The original Section with C.2.d.(1), for routine Dryer Operations, bioassay should be based Subpart H requirements. Also, C.2.e has been upon air sampling results and/or residual contamination that may be Sections C.3.d and C.3.e have been consolidated in found inside of the respirator. the collection of a daily bioassay after deleted. The information is now Section B. routine respirator use pursuant to C.2.e. is redundant with C.2.d.(1). reflected in C.3.d.(1) and C.3.d.(2).

For this reason, CAMECO suggests C.2.e. be modified to address non-routine activities not covered under C.2.d.(1) or (2).

2 Clarifications on the It is not possible to implement a 36-hour delay to avoid uranium that is The NRC agreed with the comment; original Section C.2 eliminated without uptake in kidney tissues. Does C.3.c. apply to the entire Sections C.1, C.2and C.3 and C.3. They are C.2.e.? The language is unclear. Modifying 2.e to address non- have been revised for better now in Sections C.2 routine activities would eliminate this problem. clarification. Does C.4.c. (formerly and C.4, respectively. C.3.c.) apply to C.3.e. (formerly C.2.e.) The answer is yes: It indicates that bioassay frequency and the type of bioassay are often closely related. The 36-hour time-frame is for dosimetry information only; it does not require implementing and the reference has 6

been removed.

3 General comments This would be a significant burden on the dryer operators who wear a The comment was informative, but no respirator every day. Providing a bioassay daily would result in an changes to the RG were warranted.

approximate $ 18,250 ($25 per sample @365 days a year) increase in cost for bioassay analysis for two dryer operators.

Mr. Andrew Mauer Nuclear Energy Institute (NEI):

Tel. 202-739-8018 E-mail: anm@nei.org; ADAMS Accession No. ML12136A452 No. Comment or Basis Text of comment Resolution 1 Comments on Section Section 1: Conditions Under Which Bioassay Is Necessary This The NRC agreed with the comment; C.1 that has been section states that, All workers who handle and work with uranium this statement has been deleted or consolidated in substances, or are sufficiently close to the process so that intake is reconstructed. The current Section C.1 Section C.2. possible (e.g., within a few meters and in the same room as the worker Participation provides clarification handling the material), should participate in the bioassay programs stating that 10 CFR 20.1502(a) and (b) described below. This statement places further restriction on the are the primary conditions for initiating necessity of internal exposure monitoring. 10 CFR 20.1502(b) a bioassay measurement.

requires monitoring if a radiation worker is likely to exceed the applicable annual limit on intake or committed effective dose equivalents. The statement within the regulatory guide removes the evaluation of the likelihood of intake and states that workers with only a possibility of exposure should be monitored, regardless of the magnitude of the intake, and should be reconsidered within the context of the regulations.

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2 Comments on Section Section 2: Types of Bioassay That Should Be Performed Part e of this The NRC agreed with the comment; C.2 section states, Following use of respiratory protection devices. the original Section C.3., has been Bioassay specimens should be collected and evaluated after a reconstructed. In the proposed respiratory protection device is used to reduce intake of document, the Respirator Protection radionuclides. As stated elsewhere in the regulatory guide, bioassay Bioassay has been addressed in Section programs are confirmatory in nature. Collection of bioassay samples C.3.e.

following the use of respiratory protection in no way reduces the intake of radionuclides. Furthermore, at some facilities, respiratory protection is donned on a near daily basis by many workers. Sampling at this frequency would negate the necessity for routine and special bioassay sampling in addition to resulting in an unsustainable quantity of bioassay sample analysis being performed. This increase in sampling does little to benefit the safety of the worker as history has demonstrated that an adequate routine sampling program remains sufficient to determine the occupational radiation exposure.

3 Clarification of Section 4: Action-Levels and Corresponding Actions Part e of this The NRC agreed with the comment; Section C.4.e. section state, When short-lived components are anticipated in the proposed document excludes the urinalysis. Licensees should use the recommendation in NUREG/CR- two-action-levels method stated in 2268 (Ref. 8) to use two-action-levels: at 1 g/L Monday morning NUREG/CR-2268.

urinary excretion rate and an exposure associated urinary output of 100 g/L during the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after the exposure. This is the only mention of a Monday morning urinary excretion rate. There is no further description that defines this type of sampling protocol. Due to the dependence of the urinary excretion rate of soluble uranium on the time following the intake, it is unclear what type of action level is desired.

4 Clarification Section 8: Quality Control: Section C.8, now Section C.7. The The NRC agreed with the comment; section describes a recommended quality control program. Part a Section C.7 Quality Control, has states, The uranium urinalyses sensitivity and detection shall be been revised referencing ANSI/HPS N-achieved at a minimum quantifiable concentration (MQC) of less than 13.30-2011 guidance where the 5 µg/L 15g/L. Although a specific value is defined for an MQC, no sensitivity is attainable as noted in references or definitions are provided for the calculation of this value. Table 3 of the standard, indicating that the minimum testing level for indirect radiobioassay performance testing, for uranium is required at 1µg in mass.

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5 Clarification for the Table A-1 and A-2 refer to a quarterly limit of intake. Current The NRC agreed with the comment; Appendix A regulations are defined in reference to an annual limit on intake (ALI). the quarterly limit of intake is not a It is recognized that this may be in reference to historic regulation. limit. It means 1/4 numerical value of However, if a quarterly limit is intended, definition and reference to the ALI, which is 5 rem, as stated in 10 this limit is necessary. CFR 20.1201. In addition, the word quarterly limit has been removed from Tables A-1 and A-2.

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