May 11, 2011 

Mr. John J. Miller, CHP 

International Isotopes, Inc. 

4137 Commerce Circle 

Idaho Falls, ID 83401 

SUBJECT: REQUEST FOR ADDITIONAL INFORMATION FROM INTERNATIONAL 

ISOTOPES REGARDING ACCIDENT ANALYSIS (TAC L32739) 

Dear Mr. Miller: 

The U.S. Nuclear Regulatory Commission’s (NRC’s) staff completed its initial technical review 

regarding Accident Analysis of your license application for the International Isotopes Fluorine 

Products, Inc., for the Fluorine Extraction Process and Depleted Uranium Deconversion facility, 

which is proposed to be constructed and operated in Lea County, New Mexico. Your 

application was transmitted by letter, dated December 30, 2009. Our review of your application 

has identified that additional information is needed in the Accident Analysis area before the staff 

can reach a final safety decision. 

Please provide the additional information requested in the enclosure within 30 days of the date 

of this letter. 

In accordance with Title 10 of the Code of Federal Regulations 2.390 of the NRC’s “Rules of 

Practice,” a copy of this letter and the enclosure will be available electronically for public 

inspection in the NRC Public Document Room or from the NRC’s Agencywide Documents 

Access and Management System (ADAMS). ADAMS is accessible from the NRC Web site at 

http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room). 
J. Miller 2 

If you have any questions regarding this letter, please contact me at 301-492-3566 or via e-mail 

to Maria.Guardiola@nrc.gov. You may also contact Matthew Bartlett at 301-492-3119 or to 

Matthew.Bartlett@nrc.gov. 

Sincerely, 

/RA/ 

Maria Guardiola, Project Manager 

Conversion, Deconversion and 

 Enrichment Branch 

Division of Fuel Cycle Safety 

 and Safeguards 

Office of Nuclear Material Safety 

 and Safeguards 

Docket No. 40-9086 

Enclosure: 

Request for Additional Information 
J. Miller 2 

If you have any questions regarding this letter, please contact me at 301-492-3566 or via e-mail 

to Maria.Guardiola@nrc.gov. You may also contact Matthew Bartlett at 301-492-3119 or to 

Matthew.Bartlett@nrc.gov. 

Sincerely, 

/RA/ 

Maria Guardiola, Project Manager 

Conversion, Deconversion and 

 Enrichment Branch 

Division of Fuel Cycle Safety 

 and Safeguards 

Office of Nuclear Material Safety 

 and Safeguards 

Docket No. 40-9086 

Enclosure: 

Request for Additional Information 

DISTRIBUTION: 

FCSS r/f GChapman, NMSS 

ML111290244 

OFFICE CDEB CDEB CDEB CDEB 

NAME MGuardiola MBartlett LAllen DMorey 

DATE 05/09/2011 05/09/2011 05/11/2011 05/11/2011 

OFFICIAL RECORD COPY 
Enclosure 

Request for Additional Information for International Isotopes, Inc., 

Accident Analysis 

1) Dispersion volumes inside the buildings do not consider building partitions or take into 

account either space taken up by equipment or the mixing efficiency of airborne releases 

because final building design has not been completed. Justify the use of the entire 

building volumes or assign conservative volume fractions when determining dispersion 

and worker exposure inside the buildings. 

Consideration of these building/room parameters is needed to conservatively evaluate 

potential worker exposures and demonstrate compliance with the performance 

requirements in Title 10 of the Code of Federal Regulations (10 CFR) 70.61. 

2) Because final building ventilation design has not been completed, International Isotopes, 

Inc.,(INIS) estimated outdoor releases from buildings based on a flow through a doorway 

of ~0.1 m/s which does not appear conservative for estimating outdoor exposures to 

workers or the public. Unless an accurate or bounding estimate is available from the 

preliminary design, INIS should initially assume a conservative building ventilation rate 

(the maximum rate discussed in Appendix D of the Environmental Protection Agency’s 

(EPA’s) 550-B-99-009, “Risk Management Program Guidance for Offsite Consequence 

Analysis,” cited by INIS is 10 building air exchanges) when calculating outdoor worker 

and public exposures. Provide justification for the building release rates utilized in the 

accident consequence evaluations. 

Using an accurate or conservative bounding of the building/room ventilation/release rate 

is needed to demonstrate compliance with the performance requirements in 

10 CFR 70.61. 

3) INIS appears to have utilized non-conservative Airborne Release Fraction and 

Respirable Fraction (ARF and RF) values for some accident sequences where the 

method of release appears to be inconsistent with either a powder or liquid spill from 

which the ARF and RF values were referenced. Specifically, INIS appears to consider 

UF6 and UO2F2 under the powder or liquid spill category. The staff finds the values 

utilized by INIS inconsistent with releases of UF6 as discussed in NUREG/CR-6410 

Appendix D, Section D.7. This citation discusses releases of pressurized liquid UF6 and 

conservatively assumes any released UF6 either flashes to vapor or forms solid particles 

which remain airborne. The reaction of UF6 with moisture in the air forms hydrogen 

fluoride and UO2F2. Use of the liquid/powder ARF/RF values for liquid or vapor UF6

result in an underestimate of the source term by several orders of magnitude. Justify the 

use of the ARF/RF values utilized for UF6 releases in the accident consequence 

evaluations. 

Using appropriate ARF/RF values is necessary to demonstrate compliance with the 

performance requirements in 10 CFR 70.61. 

4) INIS states that outdoor releases were assessed for a worker located 100 meters from 

the release point. Describe how this is appropriately conservative given the likelihood of 

individuals accessing outdoor areas near the potential release point. Specific examples 

include cylinder releases in the cylinder storage yard, releases through a doorway of a 

building, etc. 
 2 

Accurately assessing chemical and radiological exposures to potential receptors is 

necessary to demonstrate compliance with the performance requirements in 

10 CFR 70.61. 

5) Describe how IROFS BF-3-14 and BF3-21 (drum enclosure and drum closure 

requirements prior to change-out or moving) are coincident (both applicable at the same 

time) such that they both apply to accident sequence 301.26. This is needed to verify the 

limiting risk for this accident sequence consistent with the performance requirements in 

10 CFR 70.61.