Daily Rules, Proposed Rules, and Notices of the Federal Government


[Docket No. 50-123; NRC-2009-0139]

Missouri University of Science and TechnologyNuclear Research Reactor; Environmental Assessment and Finding of No Significant Impact

The U.S. Nuclear Regulatory Commission (NRC or the Commission) is considering issuance of a renewed Facility Operating License No. R-79,held by the Missouri University of Science and Technology (the licensee or MST), which would authorize continued operation of the Missouri University of Science and Technology Research Reactor (MSTR), located in Rolla City, Phelps County, Missouri. Therefore, as required by 10 CFR 51.21, the NRC is issuing this Environmental Assessment and Finding of No Significant Impact.

Environmental AssessmentIdentification of the Proposed Action

The proposed action would renew Facility Operating License No. R-79 for a period of twenty years from the date of issuance of the renewed license. The proposed action is in accordance with the licensee's application dated August 20, 2004, as supplemented on November 16, November 27, and December 26, 2007, and January 17, March 6, June 26, September 16, and November 7, 2008. In accordance with 10 CFR 2.109, the existing license remains in effect until the NRC takes final action on the application.

Need for the Proposed Action

The proposed action is needed to allow the continued operation of the MSTR to routinely provide teaching, research, and services to numerous institutions for a period of twenty years.

Environmental Impacts of the Proposed Action

The NRC has completed its safety evaluation of the proposed action to issue a renewed Facility Operating License No. R-79 to allow continued operation of the MSTR for a period of twenty years and concludes there is reasonable assurance that the MSTR will continue to operate safely for the additional period of time. The details of the staff's safety evaluation will be provided with the renewed license that will be issued as part of the letter to the licensee approving its license renewal application.

The MSTR is located in a separated building on the east side of the main campus of the MST. The reactor is housed in a steel frame structure with insulated metal walls. The reactor building footprint is 49 feet x 33 feet (approximately 15 meters x 10 meters). Utilities such as electrical supply, sewage, and water are provided by the main campus systems. There are no nearby industrial, transportation, or military facilities that could pose a threat to the MSTR.

In December 1961, the U.S. Atomic Energy Commission (AEC) issued an operating license to the University of Missouri--Rolla (renamed Missouri University of Science and Technology) for operation of a research reactor on its campus. The MSTR is based on the design of the bulk shielding reactor (BSR) at Oak Ridge National Laboratory, which was a materials testing reactor (MTR). Reactors of this type have common features, such as light-water moderation, natural convection cooling, open pools, and plate-type fuel. This license, R-79, authorized the facility to operate at steady-state power levels up to 10 kW(t). In 1967, the license was amended to allow operation up to its current power level of 200 kW(t). In 1992, the fuel was converted from high-enriched uranium (HEU) to low-enriched uranium (LEU). The low power level of the core allows for sufficient cooling by natural convection. The reactor's experimental facilities include a pneumatic transfer system, in-core irradiation tube, a beam tube, and a thermal column. There are four control rods loaded in any particular core configuration to allow the MSTR to routinely operate with various powers and experiments. The MSTR has no pulse capability. The sum of the absolute values of all experiments is limited to a maximum reactivity of 1.2% Dk/k by technical specification, which is well below the maximum reactivity limit of 1.5% Dk/k established in the safety analysis. The licensee's analysis in Chapter 13 of the safety analysis report (SAR) shows that a stepwise reactivity insertion of 1.5% Dk/k does not adversely affect the health and safety of public and the reactor staff.

The licensee has not requested any changes to the facility design or operating conditions as part of the renewal request. Therefore, the license renewal should not change the environmental impact of facility operation.

I. Radiological Impact

Gaseous effluents are discharged by the reactor ventilation fan at a volumetric flow rate of approximately 140 m3/min (5 x 103ft3/min). Other release pathways exist; however, they are normally secured during reactor operation and have insignificant volumetric flow rates compared to the ventilation fan. The dose rate at the reactor bridge with the reactor operating at 200 kW is less than 5 mrem/hr. Nitrogen-16, argon-41, and direct radiation from the reactor core contribute to this dose rate. Nitrogen-16 has a very short half-life (7.13 sec), and the reactor has a core diffuser system which creates a water circulation pattern designed to suppress nitrogen-16 transported to the surface of the pool and reduce the reactor pool surface dose rate. Because of the short half-life of nitrogen-16 compared to the transit time, exposure to the public is negligible. Analysis of effluent samples has found only argon-41. The licensee measured the dose from normal operations to a person in the unrestricted area. The concentration of argon-41 leaving the reactor roof fan exhaust where argon-41 is released to the general public was measured at 4.24 x 10[?]10microcuries per milliliter (mCi/ml). The calculations very conservatively assume that the reactor operates continuously for a year and that the member of the public stands at the point of maximum exposure continuously for the entire year. Using the conservative assumption above, the measured result was 2 mrem. This is below the 10 CFR Part 20, Appendix B, Table 2, limit of 50 mrem for submersion. The licensee also measured occupational exposure to argon-41 in the reactor bay. Using the worst-case conditions, the conservative measurement of argon-41 concentration in the reactor building from pool release was 1.80 10[?]7mCi/ml, more than a factor of 10 below the regulatory limit of 3.0 x 10[?]6mCi/ml (10 CFR Part 20, Appendix B). These calculations demonstrate that routine airborne effluents released from the MSTR are well within 10 CFR Part 20 criteria for occupational workers and members of the public, and are therefore acceptable to the staff.

Pool water activity is monitored monthly to ensure that no gross pool contamination or fuel cladding rupture has occurred. Liquid effluents are analyzed for radioactive contamination and approved by the MSTR Radiation Safety Office before discharge.

Un-compacted solid low-level radioactive waste consists of gloves, pads, used resins, filters, and various activation products from experiments conducted using the MSTR. This radioactive waste is transferred to the MSTR Dangerous Materials Storage Facility (DMSF) for future shipment to a commercial burial site, in accordance with the requirements of applicable NRC and Department of Transportation regulations, including 10 CFR Part 61, 10 CFR Part 71, and 49 CFR Part 170 through 178.

Facility personnel, staff, and students involved with the operation of the MSTR are assigned dosimeters. Personnel exposures reported to the NRC were within the limits set by 10 CFR 20.1201, and were as low as reasonably achievable (ALARA). Visitors are also monitored with direct reading dosimeters. No visitors receivedany reportable or significant exposure in the past 20 years. No changes in reactor operation that would lead to an increase in occupational doses are expected as a result of license renewal.

The environmental impacts of the fuel cycle and transportation of fuels and wastes are described in Tables S-3 and S-4 of 10 CFR 51.51 and 10 CFR 51.52, respectively. An additional NRC generic environmental assessment (53 FR 30355, dated August 11, 1988, as corrected by 53 FR 32322, dated August 24, 1988) evaluated the applicability of Tables S-3 and S-4 to higher burn-up cycle and concluded that there is no significant change in environmental impact from the parameters evaluated in Tables S-3 and S-4 for fuel cycles with uranium enrichments up to 5 weight percent uranium-235 and burn-ups less than 60,000 MWt days per metric ton of uranium-235 (MWd/MTU). The MSTR uranium enrichment limit and the burn-up limit would stay within the 5 percent and the 60,000 MWd/MTU limits. Therefore, the environmental impacts of the fuel cycle and transportation of fuels and wastes, to and from the site, would not be significant.

II. Non-Radiological Impact

The MSTR core is submerged in an open pool containing 30,000 gallons (113,560 liters) of demineralized light water. The core is cooled by natural convection. Heat from the water pool is dissipated primarily by evaporation into the reactor bay and discharged to the environment by the ventilation system. The auxiliary cooling system with a heat exchanger is also available to reduce the water temperature if needed. Release of thermal effluents from the MSTR will not have a significant effect on the environment. The small amount of waste heat, approximately 200 kW at full power operation, is released to the atmosphere by means of the dry cooler, and therefore will not lead to the creation of fog. Extensive drift will not occur at this heat dissipation rate.

Environmental Effects of Accidents

The maximum hypothetical accident (MHA) scenario is discussed in Chapter 13 of the MSTR SAR. The accident scenario assumes that a capsule, containing fissile material after irradiation in the fuel experiment, breaks and releases all gaseous fission products in the reactor building and uncontrolled environment. In analyzing the MHA, occupational doses resulting from this accident would be 410 mrem (4.10 mSV), which is more than a factor of ten below 10 CFR Part 20 limits of 5000 mrem (50 mSV). Maximum doses for members of the general public were conservatively calculated to be 46 mrem (0.46 mSv), and are below the 10 CFR Part 20 limit of 100 mrem (1 mSv). The analysis shows that the failure of an irradiated fueled experiment will not exceed 10 CFR Part 20 limits. Therefore, it is acceptable to the staff.

National Environmental Policy Act (NEPA) ConsiderationsI. Endangered Species Act (ESA)

The site occupied by the MSTR does not contain any Federally- or State-protected fauna or flora, nor do the MSTR effluents impact the habitats of any such fauna or flora.

II. Costal Zone Management Act (CZMA)

The site occupied by the MSTR is not located within any managed coastal zones, nor do the MSTR effluents impact any managed coastal zones.

III. National Historical Preservation Act (NHPA)

The National Register Information System lists several historical sites located around the Missouri University of Science and Technology, but operation of the MSTR will not impact any historical sites.

IV. Fish and Wildlife Coordination Act (FWCA)

The licensee is not planning any water resource development projects, including any of the modifications relating to impounding a body of water, damming, diverting a stream or river, deepening a channel, irrigation, or altering a body of water for navigation or drainage.

Environmental Impacts of the Alternatives to the Proposed Action

As an alternative to license renewal, the staff considered denial of the proposed action. If the Commission denied the application for license renewal, facility operations would end and decommissioning would be required with no significant impact on the environment. The environmental impacts of license renewal and this alternative action are similar. However, the benefits of teaching, research, and services provided by facility operation would be lost.

Alternative Use of Resources

The proposed action does not involve the use of any different resources or significant quantities of resources beyond those previously considered in the issuance of Amendment No. 9 to Facility Operating License No. R-79 for the Missouri University of Science and Technology Research Reactor dated March 5, 1991, for the HEU to LEU conversion.

Finding of No Significant Impact

On the basis of the environmental assessment, the NRC concludes that the proposed action will not have a significant effect on the quality of the human environment. Accordingly, the NRC has determined not to prepare an environmental impact statement for the proposed action.

Agencies and Persons Consulted

In accordance with its stated policy, on February 14, 2008, the NRC staff consulted with the Missouri State official, Floyd Gilzow, of the State Liaison Office, Department of Natural Resources, regarding the environmental impacts of the proposed action. The State official had no comments.

For further details with respect to the proposed action, see the licensee's letter dated August 30, 2004 (ADAMS Accession No. ML042820116), as supplemented by letters dated November 16, 2007 (ADAMS Accession No. ML073240523), November 27, 2007 (ADAMS Accession No. ML073320467), December 26, 2007 (ADAMS Accession No. ML080070088), January 17, 2008 (ADAMS Accession No. ML080240307), March 6, 2008 (ADAMS Accession No. ML080930439), June 26, 2008 (ADAMS Accession No. ML081820410), September 16, 2008 (ADAMS Accession No. ML 082630565), and November 7, 2008 (ADAMS Accession No. ML083190529), and Documents may be examined, and/or copied for a fee, at the NRC's Public Document Room (PDR), located at One White Flint North, 11555 Rockville Pike (first floor), Rockville, Maryland. Publicly available records will be accessible electronically from the Agencywide Documents Access and Management System (ADAMS) Public Electronic Reading Room on the NRC Web site, Persons who do not have access to ADAMS or who encounter problems in accessing the documents located in ADAMS should contact the NRC PDR Reference staff at 1-800-397-4209, or 301-415-4737, or send an e-mail

For the Nuclear Regulatory Commission.
Kathryn Brock, Chief, Research and Test Reactors Branch A, Division of Policy and Rulemaking, Office of Nuclear Reactor Regulation.