September-October 2018 NPJ

Nuclear Plant Journal, September-October 2018 NuclearPlantJournal.com 15 New Documents EPRI 1. Identification and Assessment of Low-Value Nondestructive Evaluation Examinations with High Outage Impacts . Product ID: 3002012965. Published May, 2018. In support of the Research Focus Area on Nondestructive Evaluation (NDE) Efficiency, EPRI conducted a survey of its members to identify required NDE examinations currently being performed at nuclear sites that may be suitable for reduction in scope, reduction in frequency, or elimination all-together. Optimization of such examinations may result in inspection cost savings for nuclear utilities without compromising safe and reliable operation of the power plant. Members were polled to provide known examinations that may be considered “low value” with “high outage impacts”. Using a focus group of industry experts, results from this poll were analyzed and prioritized based on key metrics. The details and results of this survey and prioritization are contained within this report. From this effort, the five highest- priority examinations were selected for further evaluation. Examination efficacies from statistics gathered via an operational experience inquiry were combined with technical calculations, where applicable, including probabilistic and deterministic fracture mechanics to create technical bases for the optimization of each examination. For the five highest ranked examinations, the technical bases for the specific examination optimization recommendations will be documented in separate Technical Report documents. The pending report titles follow:  Evaluation of Basis for Periodic Visual Examination of Accessible Areas of Reactor Vessel Interior per Examination Category B-N-1 of ASME Section XI, Division 1. EPRI Product ID: 3002012966.  Technical Basis for Optimization of Inspection Requirements for Class 1 and 2 Non-Reactor Vessel Nozzle Inner Radius. EPRI Product ID: TBD.  Technical Basis for Optimization of Inspection Requirements for Class 1 and 2 Pressure Vessel Nozzle-to- Shell Welds. EPRI Product ID: TBD.  Technical Basis for Optimization of Inspection Requirements for Class 1 and 2 Pressure Vessel Welds. EPRI Product ID: TBD.  Technical Basis for Optimization of the Volumetric Examination Frequency for Class 1 and Class 2 Pressure Retaining Bolting greater than 2” in Diameter. EPRI Product ID: TBD. 2. Estimation of Gamma Flux in Boiling Water Reactor Concrete Biological Shield Walls . Product ID: 3002013052. Published July, 2018. Operation of light water reactors beyond 60 years will require knowledge of aging mechanisms and rates in concrete structures, systems, and components. As concrete structures experience environmental degradation, their physical properties can change, which may ultimately affect their ability to perform their functions in nuclear power plants. An example of such a structure is the concrete biological shield (CBS), which is a large, reinforced concrete structure surrounding the reactor vessel with the primary function of attenuating and ultimately shielding the radiation field emanating from the reactor core. In many reactor designs, the CBS has a secondary function of providing structural support for the reactor vessel and is qualified for operational and accident loading scenarios. Early work by Hilsdorf indicated that neutron and gamma radiation may affect the strength of concrete if high enough fluence or dose is absorbed by concrete. Based on that work, regulatory bodies are establishing neutron fluence and gamma dose thresholds beyond which a change in mechanical properties are possible, requiring further analysis to be performed by utilities pursuing life extension. To this effect, this report describes a methodology to estimate the maximum gamma flux in the CBS using known neutron flux values calculated as part of reactor vessel surveillance programs for boiling water reactor designs. 3. Maintenance Rule Users Group Update, Summer 2018 . Product ID: 3002014269. Published July, 2018. The Maintenance Rule Users Group Update is an on-line newsletter that may be accessed by the following link: h t t p : / /mydoc s . ep r i . com/ doc s / CorporateDocuments/Newsletters/ MRUG/3002014269/3002014269.html The MRUG Update newsletter communicates issues and information important to Maintenance Rule Coordinators and those involved in supporting Maintenance Rule programs. Articles are provided by MRUG members, industry experts, regulators, and EPRI personnel. The MRUG Update is published twice a year and is available to all EPRI-member utilities, not just MRUG members. It encourages communication among all Maintenance Rule personnel. 4. Emerging Technologies Brief: Progress Toward U.S. Commercialization of Small Modular Light Water Reactors . Product ID: 3002014460. Published August, 2018. Based on technology initially developed at Oregon State University, NuScale Power’s small modular reactor (SMR) is an advanced light water reactor design with passive safety features. In 2018, the Oregon-based company has reported significant milestones in its pursuit of design certification by the U.S. Nuclear Regulatory Commission (NRC) and deployment of the nation’s first-of-a- kind (FOAK) commercial SMR. According to EPRI innovation scouting, dozens of startups, established vendors, and research groups are pursuing SMRs and other advanced reactor designs for U.S markets. At present, NuScale is leading the pack in terms of licensing timeline, repeated DOE support for design development and commercialization, and the NRC’s determination that the SMR design does not require a safety-related power supply. The above EPRI documents may be ordered by contacting the Order and Conference Center at (800) 313-3774, Option 2, or email at orders@epri.com .