Affirmation Session Public Meeting on “Integration of Mitigating Strategies for Beyond-Design-Basis External Events and the Re-evaluaton of Flooding Hazards

The Commission is being asked to act on a final rule that amends Parts 50 and 52 of Title 10 of the Code of Federal Regulations. The final rule establishes regulatory requirements for nuclear power reactor applicants and licensees to mitigate beyond-design-basis events. The NRC is making generically applicable the requirements in NRC orders for mitigation of beyond-design-basis events and for reliable spent fuel pool instrumentation. This rule also addresses a number of petitions for rulemaking submitted to the NRC following the March 2011 Fukushima Dai-ichi event. This rule is applicable to power reactor licensees and power reactor license applicants. The Commission has voted to approve the publication and implementation of this final rule subject to the changes noted in the attachment

Safety Evaluation Report Related to the Renewal of the Operating License for the TRIGA Training and Research Reactor at the University of Utah

This Safety Evaluation Report for the application filed by the University of Utah (UU) for a renewal of operating license R-126 to continue to operate a training and research reactor facility has been prepared by the Office of Nuclear Reactor Regulation of the U.S. Nuclear Regulatory Commission. The facility is owned and operated by the University of Utah and is located on its campus in Salt Lake City, Salt Lake County, Utah. The staff concludes that this training reactor facility can continue to be operated by UU without endangering the health and safety of the public

A strategy for minimizing common mode human error in executing critical functions and tasks

Human error in execution of critical functions and tasks can be costly. The Three Mile Island and the Chernobyl Accidents are examples of results from human error in the nuclear industry. There are similar errors that could no doubt be cited from other industries. This paper discusses a strategy to minimize common mode human error in the execution of critical functions and tasks. The strategy consists of the use of human redundancy, and also diversity in human cognitive behavior: skill-, rule-, and knowledge-based behavior. The authors contend that the use of diversity in human cognitive behavior is possible, and it minimizes common mode error

High level seismic/vibrational tests at the HDR: An overview

As part of the Phase II testing at the HDR Test Facility in Kahl/Main, FRG, two series of high-level seismic/vibrational experiments were performed. In the first of these (SHAG) a coast-down shaker, mounted on the reactor operating floor and capable of generating 1000 tonnes of force, was used to investigate full-scale structural response, soil-structure interaction (SSI), and piping/equipment response at load levels equivalent to those of a design basis earthquake. The HDR soil/structure system was tested to incipient failure exhibiting highly nonlinear response. In the load transmission from structure to piping/equipment significant response amplifications and shifts to higher frequencies occurred. The performance of various pipe support configurations was evaluated. This latter effort was continued in the second series of tests (SHAM), in which an in-plant piping system was investigated at simulated seismic loads (generated by two servo-hydraulic actuators each capable of generating 40 tonnes of force), that exceeded design levels manifold and resulted in considerable pipe plastification and failure of some supports (snubbers). The evaluation of six different support configurations demonstrated that proper system design (for a given spectrum) rather than number of supports or system stiffness is essential to limiting pipe stresses. Pipe strains at loads exceeding the design level eightfold were still tolerable, indicating that pipe failure even under extreme seismic loads is unlikely inspite of multiple support failures. Conservatively, an excess capacity (margin) of at least four was estimated for the piping system, and the pipe damping was found to be 4%. Comparisons of linear and nonlinear computational results with measurements showed that analytical predictions have wide scatter and do not necessarily yield conservative responses, underpredicting, in particular, peak support forces

Making the most of what we have: Application of extrapolation approaches in radioecological wildlife transfer models

© 2015 The Authors. We will never have data to populate all of the potential radioecological modelling parameters required for wildlife assessments. Therefore, we need robust extrapolation approaches which allow us to make best use of our available knowledge. This paper reviews and, in some cases, develops, tests and validates some of the suggested extrapolation approaches.The concentration ratio (CRproduct-diet or CRwo-diet) is shown to be a generic (trans-species) parameter which should enable the more abundant data for farm animals to be applied to wild species.An allometric model for predicting the biological half-life of radionuclides in vertebrates is further tested and generally shown to perform acceptably. However, to fully exploit allometry we need to understand why some elements do not scale to expected values.For aquatic ecosystems, the relationship between log10(a) (a parameter from the allometric relationship for the organism-water concentration ratio) and log(Kd) presents a potential opportunity to estimate concentration ratios using Kd values.An alternative approach to the CRwo-media model proposed for estimating the transfer of radionuclides to freshwater fish is used to satisfactorily predict activity concentrations in fish of different species from three lakes. We recommend that this approach (REML modelling) be further investigated and developed for other radionuclides and across a wider range of organisms and ecosystems.Ecological stoichiometry shows potential as an extrapolation method in radioecology, either from one element to another or from one species to another.Although some of the approaches considered require further development and testing, we demonstrate the potential to significantly improve predictions of radionuclide transfer to wildlife by making better use of available data

Final Environmental Impact Statement to Construct and Operate a Facility to Receive, Store, and Dispose of 11e.(2) Byproduct Material Near Clive, Utah

A Final Environmental Impact Statement related to the licensing of Envirocare of Utah, Inc.\u27s proposed disposal facility in Tooele County, Utah, (Docket No. 40-8989) for byproduct material as defined in Section 11e.(2) of the Atomic Energy Act, has been prepared by the Office of Nuclear Material Safety and Safeguards. This statement describes and evaluates (1) the purpose of and need for the proposed action, (2) alternatives considered, and (3) environmental consequences of the proposed action. The Nuclear Regulatory Commission has concluded that the proposed action evaluated under the National Environmental Policy Act of 1969 and 10 CFR Part 51, is to permit the applicant to proceed with the project as described in this Statement

Concentrations of Uranium Isotopes in Uranium Millers\u27 and Miners\u27 Tissues

The alpha-emitting isotopes of uranium and thorium were determined in the lungs of 14 former uranium miners and in soft tissues and bones of three miners and two millers. These radionuclides were also determined in soft tissues and bones of seven normal controls. The average concentrations in pCi/kg wet weight in 17 former miners\u27 lungs are as follows: U-238, 75; U-234, 80; Th-230, 79. Concentrations of each nuclide ranged from 2 to 325 pCi/kg. The average ratio of U-238/U-234 ws 0.92, ranging from 0.64 to 1.06. The mean ratio of Th-230/U-234 was 1.04, ranging from 0.33 to 3.54. The near equilibrium between Th-230 and U-238,234 indicates that the rate of elimination of uranium and thorium from lungs is the same in former uranium miners. The concentrations of U-234 and U-238 were highest in lung; however, the concentration of Th-230 in bones was either higher than or comparable to its concentration in lung. The concentration ratios of Th-230/U-234 in bone of uranium miners and millers measured in our laboratory have been compared with results predicted by ICRP-30 metabolic models. These results indicate that the ICRP metabolic models for thorium and uranium were only marginally successful in predicting the ratio of Th-230/U-234 in bones, and that effective release rate of uranium from skeleton may be more rapid than predicted by the ICRP model