[en] This report summarizes the histories of 17 Zircaloy-clad spent fuel assemblies used in dry storage tests and demonstrations at the Engine Maintenance and Disassembly (EMAD) and Climax facilities at the Nevada Test Site (NTS). The 18th assembly was shipped to the Battelle Columbus Laboratory (BCL) and remained there for extensive characterization and as a source of specimens for whole-rod and rod-segment dry storage tests. The report traces the history of the assemblies after discharge from the Turkey Point Unit 3 pressurized-water reactor (1975 and 1977) through shipment (first arrival at EMAD in December 1978), dry storage tests and demonstrations, and shipment by truck cask from EMAD to the Idaho National Engineering Laboratory (INEL) in May/June 1986. The principal objectives of this report are to assess and document the integrity of the fuel during the extensive dry storage activities at NTS and BCL, and to briefly summarize the dry storage technologies and procedures demonstrated in this program. The dry storage tests and demonstrations involved the following concepts and facilities: (1) surface drywells (EMAD); (2) deep drywells (425 m underground in the Climax granite formation); (3) concrete silo (EMAD); (4) air-cooled vault (EMAD); (5) electrically-heated module for fuel assembly thermal calibration and testing (EMAD/FAITM). 20 refs., 43 figs., 9 tabs

[en] Existing and potential design problems associated with the helium-cooled blanket assemblies of experimental, demonstration and hybrid reactor designs considered in the Magnetic Fusion Energy (MFE) Program were assessed. It was observed that a balanced program of design, analysis and experimentation would be required to develop, verify and qualify these designs and those of related hardware and equipment. To respond to the potential experimental requirements of the first-generation reactors (the EPRs and possibly the hybrid concept), the need for a helium test facility was identified. It was determined that this facility should have the capacity for recirculating 100,000 kg/hr of helium at 70 atm and 600⁰C and should have 3 MW of electrical power available for simulating neutron heating. No radioactive material or processes should be used to facilitate ''hands-on'' experimentation and development. The general types of testing anticipated in this facility would include: (1) thermal and coolant flow performance of the blanket and other components in the primary cooling circuit; (2) structural adequacy of the blanket and first wall including vibration considerations; (3) capability for accommodating safety/off-normal conditions. Existing facilities worldwide were surveyed. It was determined that a number of facilities exist in foreign nations for performing the anticipated experiments. However, no large helium gas flow loop exists within the USA. Consequently, it is recommended that a helium thermal-hydraulic blanket test facility be planned and build on a schedule that will meet the unique design development and verification needs of the fusion program. This report provides the rationale and preliminary scoping of the operational characteristics and requirements for such a facility

[en] The results of Production Tests N-611 and N-614 (PTN-611 and PTN-614), Emergency Cooling/Fog Spray Supply Characterization Tests are reported. These production tests consisted of 21 individual tests designed to characterize the diesel-driven pumps and piping sections in the emergency core cooling system (ECCS), the fog spray systems, and the effluent disposal systems. Production Test N-614 included demineralized water and filtered water tank drawdowns and emergency raw water tank fillups to calibrate flow measurement devices in the RWS-2 and the ECCS, and tests to establish the performance of the high-lift fog spray diesel-driven pumps. It also demonstrated operation of the low-lift diesel-driven pumps with the river flow at the minimum release rate allowed by the operating license for Priest Rapids Dam. The tank drawdown data was also used to determine loss coefficients in piping between the demineralized water storage tank and the high-lift diesel-driven pumps. Other tests provided information on the division of the low lift flow between the silo and the RWS-2, and on the performance of the low-lift diesel-driven pumps. 13 figs., 7 tabs

[en] The emergency diesel generators in a nuclear power plant have an important safety function-supplying emergency electrical power to maintain cooling and other vital functions. The research reviewed in this article addresses the safety implications of aging of these emergency diesel generators and the influence of aging on their reliability. Historical operational information was assembled on component and system failures and their causes. One significant research result is that the fast-starting and fast-loading test procedure mandated by Regulatory Guide 1.108 and the standard Technical Specifications has contributed to wear and degradation. Other equally important aging and degradation factors for the diesel generators are identified and reviewed. A new approach developed represents a more balanced aging management program that includes (1) slow-start testing during which operating parameters are monitored, (2) analysis of data trends, (3) training, and (4) maintenance. This approach should improve safety by identifying aging degradation that leads to future diesel generator failures. Timely maintenance could then prevent actual failures

[en] The Pacific Northwest Laboratory has compiled and reviewed base line data on the effectiveness of Engineered Safety Feature (ESF) systems in the retention of fission products and particulate material resulting from a nuclear reactor accident. This work is part of an NRC project to provide the best estimates of the consequences of severe reactor accidents. The resulting report describes the ESF systems (containment spray, secondary containment filter, containment recirculating filter, pressure suppression pool, ice condenser, and main steam line isolation valve leakage control systems). Also described are the anticipated atmospheres in which the ESFs must operate, the experimental studies of ESF system effectiveness, and the models currently available for assessing the performance of the various ESF systems. The information gaps identified as a result of this review have resulted in recommendations for additional work in the areas of: (1) performance data and models of containment chiller/coolers; (2) continued development and experimental verification of the ice condenser model; (3) continued development of the pressure suppression pool model; and (4) continued investigations of the behavior of filtration devices

[en] Recent NRC sponsored aging research work on nuclear service diesel generators has resulted in a recommendation that an improved engine management program should be adopted for aging mitigation and reliability improvement. The center of attention should be to ensure diesel-generator operational readiness. This report emphasizes a ''healthy engine concept'' and recommends parameters to be monitored to determine engine condition. The proposed program and approach recommended in this report represent balanced management where diesel generator testing, inspections, monitoring, trending, training, and maintenance all have appropriate importance. Fast-starting and fast-loading test of nuclear service diesels causes very rapid wear of certain engine components. This report documents this aging and wear mechanism and recommends ways to largely eliminate this unique aging stressor. Current periodic intrusive maintenance and engine overhaul practice have been found to be less favorable for safety assurance than engine overhauls based on monitoring and trending results or on a need to correct specific engine defects. This report recommends that the periodic overhaul requirements be re-evaluated. Diesel generator research on aging and wear is sponsored by the US Nuclear Regulatory Commission (NRC), Office of Nuclear Regulatory Research. The research reported in this report was conducted by Pacific Northwest Laboratory (PNL), which is operated for the Department of Energy by Battelle Memorial Institute. 23 refs., 3 figs., 8 tabs

No abstract available