NPO was brought on to provide shielding for Mechanical Penetrations Room No. 1 at Davis-Besse. This room featured a variety of pipe runs with many valves, bends, and reductions throughout as well as many hot spots. Using a combination of drawing information and practical measurements taken on site, NPO provided a shielding package using T-Flex […]
Byron had an issue with an ARGOS Zeus unit in the main exit area of the RCA. Background gamma radiation from a line in the overhead was shining down and causing false alarms on the gamma detectors to the point of making the unit inoperable. Due to the position of the Argos unit it was […]
NPO worked closely with AVANTech in designing a set of three shielded casks that reduced dose from 26,000-30,000 mRem/hr (260,000-300,000 μSv/hr) to less than 60 mRem/hr (600 μSv/hr) on contact. Two casks were utilized with one as a spare. Each shielded cask housed one of their Solids Collection Filter canisters for torus water/sludge filtration at […]
Inside the steam generators of CANDU nuclear power plants, a divider plate separates the hot leg from the cold leg. Dozens of bolts hold this divider plate together, and these bolts trap hot particles that are a major source of radiation during inspections. NPO designed magnetic shielding designed to fit around each bolt. Since it […]
In 2019, Davis-Besse Nuclear Power Station, purchased an array of shielding from NPO for their spent fuel storage campaign. This package included a transfer cask shield bell, canister shield ring, and annulus gap shielding. All of these items contributed to greatly reduced dose rates for both gamma and neutron radiation. Shield bells are a single-pick […]
This mobile shielded container has all the same internal dimensions as a standard B25 container, but with a few added features. All six sides of the container are 0.5″ (13 mm) thick steel, which provides dose reduction for the rad waste it is intended to store. There are two sliding doors on top and four […]
“Discrete exposure savings listed at 41 mrem [410 μSv]. However, the shielding also provided critical radiological configuration control during this high profile first time evolution.” -Timothy Bigler, Point Beach Nuclear Point Beach was set to perform a Vertical Storage Cask inspection and required shielding for the VCC/MSB gap created when the shield ring was removed. […]
TVA Sequoyah needed a way to shield the surrounding area of their reactor head while inspection work was being done. To avoid setting up scaffolding or stand alone lead blanket racks that would take up valuable floor space, NPO designed lead blanket racks that would make use of the stud holes of the reactor head […]
In the scope of one job, LaSalle Generating Station saved 12 Rem (120 mSv) through the use of 3D gamma radiation source mapping and intervention analysis, RadVision3D. The Reactor Water Cleanup valve is an Anchor Darling valve that needed to be breached and have the internals replaced during a refuel outage. It is located in a […]
For BWR plants, shielding the inner bellows is particularly challenging. During refueling operation the concrete shield plugs above the reactor well are removed and replaced by water. This water filled gap becomes a source for both radiation and contamination. NPO designed a specialized system to address the concerns with shielding this area. Some of the […]