[en] On March 26, 1985, the US Nuclear Regulatory Commission issued for public comment a ''Proposed Policy for Regulation of Advanced Nuclear Power Plants'' (50 FR 11884). This report presents and discusses the Commission's final version of that policy as titled and published on July 8, 1986 ''Regulation of Advanced Nuclear Power Plants, Statement of Policy'' (51 FR 24643). It provides an overview of comments received from the public, of the significant changes from the proposed Policy Statement to the final Policy Statement, and of the Commission's response to six questions contained in the proposed Policy Statement. The report also discusses the definition for advanced reactors, the establishment of an Advanced Reactors Group, the staff review approach and information needs, and the utilization of the Policy Statement in relation to other NRC programs, including the policies for safety goals, severe accidents and standardization. In addition, guidance for advanced reactors with respect to operating experience, technology development, foreign information and data, and prototype testing is provided. Finally, a discussion on the use of less prescriptive and nonprescriptive design criteria for advanced reactors, which the Policy Statement encourages, is presented

[en] This report describes the Emissions Audit carried out on a chain-grate stoker boiler burning coal. The boiler rated at 4.6MW(th) was installed at the Senior Foster Wheeler test facility in Wakefield where it had been modified so that it could burn both coal and dRDF. This report is based on test work undertaken as part of a programme to assess the environmental impact of the combustion of a variety of wastes as fuels. Emissions monitoring tests were carried out using coal as the fuel for comparison with the other wastes. Combustion of coal in boilers of this size are regulated by the Clean Air Acts whilst combustion of wastes is regulated by the more recent Environmental Protection Act. (author)

[en] This report describes the Emissions Audit carried out on a chain-grate stoker shell boiler burning dRDF at the Senior Foster Wheeler test facility in Wakefield to provide design data for gas cleaning equipment. Sampling was therefore performed in the absence of any abatement equipment other than a standard cyclonic grit arrestor. The chain-grate stoker boiler was tested at two steam loads: 40% MCR to represent low load and, 80% MCR to represent high steam load. Acid gas concentrations in the flue gas were unacceptable. The dominant gas being HCl at 850-1000mgm^-3 for both tests, was considerably higher than the guideline for new plant of 50mgm^-3. HF was also measured at concentrations in excess of the guidance value. It will be necessary to install acid gas scrubbing equipment before dRDF will be acceptable as a fuel. SO₂ and NO_x were both present in measurable concentrations but under current guidance were no cause for concern. (author)

[en] This draft safety evaluation report (SER) presents the preliminary results of a pre-application design review for the standard modular high-temperature gas-cooled reactor (MHTGR) (Project 672). The MHTGR conceptual design was submitted by the U.S. Department of Energy (DOE) in accordance with the U.S. Nuclear Regulatory Commission(NRC) 'Statement of Policy for the Regulation of Advanced Nuclear Power Plants' (51 FR 24643), which provides for early Commission review and interaction. The standard MHTGR consists of four identical reactor modules, each with a thermal output of 350 MWt, coupled with two steam turbine-generator sets to produce a total plant electrical output of 540 MWe. The reactors are helium cooled and graphite moderated and utilize ceramically coated particle-type nuclear fuel. The design includes passive reactor-shutdown and decay-heat-removal features. The staff and its contractors at the Oak Ridge National Laboratory and the Brookhaven National Laboratory have reviewed this design with emphasis on those unique provisions in the design that accomplish the key safety functions of reactor shutdown, decay-heat removal, and containment of radioactive material. This report presents the NRC staff's technical evaluation of those features in the MHTGR design important to safety, including their proposed research and testing needs. In addition this report presents the criteria proposed by the NRC staff to judge the acceptability of the MHTGR design and, where possible, includes statements on the potential of the MHTGR to meet these criteria. However, it should be recognized that final conclusions in all matters discussed in this report require approval by the Commission. Final determination on the acceptability of the MHTGR standard design is contingent on receipt and evaluation of additional information requested from DOE pertaining to the adequacy of the containment design and on the following: (1) satisfactory resolution of open safety issues identified in this report and possible additional safety issues that may become identified at later stages of review; (2) satisfactory completion of final design and licensing reviews by NRC; (3) conformance with applicable NRC rules, regulations, and other guidelines current at the time of any future licensing action; (4) successful completion of required research and development activities, including design, construction, testing, and operation of a prototype reactor before design certification. (author)

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[en] The differential cross sections for the excitation of the n=2 states of atomic hydrogen by high-energy-resolution electron impact have been measured at scattering angles of 33⁰, 54⁰, 70⁰ and 90 ⁰ over the energy range 11.5 to 12.2 eV, allowing the Feshbach resonances below the n=3 inelastic threshold to be studied. The lowest six of these resonances have been identified as ¹S, ³P, ¹D, ¹P, ³F and ³S/³D respectively, using previous classifications. At higher energies, the ³P, ¹D and ¹S states have been tentatively identified. All measured energies agree well with previous work. (author)

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[en] The G⁰ parity-violation experiment at Jefferson Lab (Newport News, VA) is designed to determine the contribution of strange/anti-strange quark pairs to the intrinsic properties of the proton. In the forward-angle part of the experiment, the asymmetry in the cross section was measured for (rvec e)p elastic scattering by counting the recoil protons corresponding to the two beam-helicity states. Due to the high accuracy required on the asymmetry, the G⁰ experiment was based on a custom experimental setup with its own associated electronics and data acquisition (DAQ) system. Highly specialized time-encoding electronics provided time-of-flight spectra for each detector for each helicity state. More conventional electronics was used for monitoring (mainly FastBus). The time-encoding electronics and the DAQ system have been designed to handle events at a mean rate of 2 MHz per detector with low deadtime and to minimize helicity-correlated systematic errors. In this paper, we outline the general architecture and the main features of the electronics and the DAQ system dedicated to G⁰ forward-angle measurements

[en] The structure functions g1p and g1n have been measured over the range 0.014 < x < 0.9 and 1 < Q2 < 40 GeV2 using deep-inelastic scattering of 48 GeV longitudinally polarized electrons from polarized protons and deuterons. We find that the Q2 dependence of g1p (g1n) at fixed x is very similar to that of the spin-averaged structure function F1p (F1n). From a NLO QCD fit to all available data we find Gamma₁^p Gamma₁ⁿ=0.176 ± 0.003 ± 0.007$ at Q2=5 GeV2, in agreement with the Bjorken sum rule prediction of 0.182 ± 0.005