Tag: On The Source

Vertical Storage Cask Gap Shielding

“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. […]

T-Flex Bottle and Vial Shields

NPO uses its custom part and mold making capabilities to produce form fitting shielding for bottles and vials. Bottles and vials filled with radioactive samples require safe storage and transportation. These shields provide just that and can be made to specific attenuation goals for a variety of different isotopes and bottle sizes. Handles and locking […]

Bellows Shielding

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 […]

Smear Frisker Cave

This small compact solution replaces larger heavier lead brick caves to reduce background when surveying surface smears and other samples.  The standard size (shown below) has 1” (25 mm) of lead on the top and bottom and 3” (76 mm) of lead on the sides and back.  Caves are built to order and can be […]

Conoseals Shielding

This past spring outage season, NPO collaborated with a plant to provide them with custom shielding for their Conoseals during Core Exit Thermocouple replacement activities. Unit 1 and Unit 2 had different Conoseal structures, and the challenge was to model a shielding package that could be used for both elements interchangeably. The shielding package was […]

Core Barrel Shielding

In 2013 NPO designed and built a custom Core Barrel Shield for Palisades Nuclear Plant in Covert, MI.  The shielding was implemented in Palisades’ 23rd refueling outage and was a great success.  The story of the project’s success spread in May 2015 when the Palisades plant was recognized during the Nuclear Energy Institute’s best industry practice […]

MCNP Case Study – Dry Cask Shielding

One year ago we introduced our new ability to simulate complex radiation profiles and thereby design the most effective shielding possible (‘NPO uses MCNP to simulate Dry Cask’, March 2016).  Since then we’ve designed and built more than a few shielding systems using this new ability.  Now the day has finally come where we can […]

T-Flex Pipe and Valve Shields

T-Flex is the most versatile shielding material that NPO has to offer. Its ability to be poured as a liquid and cured as a flexible solid makes it ideal for fitting the maximum amount of shielding around a component while keeping space and weight to a minimum. The most common way this is put into […]

Saint-Alban Steam Generator Shielding

EDF Saint-Alban plant, located in Saint-Maurice-l’Exil, France, collaborated with NPO Europe to address a few opportunities for shielding the steam generators during sludge lancing operations. Saint-Alban wanted to reduce shielding installation and removal time from the benchmark of 5.5 hours, reduce total project dose from 476 mRem (4,760 μSv), and remove the physical clutter of […]

Braidwood Dry Cask Annulus Gap Snakes

Exelon Braidwood Station recently saw very good dose reduction with their dry cask campaigns by utilizing NPO T-Flex® Annulus Gap Shielding. This was designed to fit in the annulus gap between the canister and transfer cask and had a fire blanket covering specified by Braidwood. The annulus gap shielding, in addition to more NPO dry […]