Réduction du bruit de fond

octobre 20, 2022

Cette petite solution compacte remplace les briques de plomb plus grandes et plus lourdes pour réduire le bruit de fond lors du comptage des frottis. La cavité blindée est construite sur commande et peut être conçue pour répondre à vos exigences de réduction du bruit de fond. La finition est en acier inoxydable. Les poignées […]

Dry Cask Shielding Package

avril 28, 2020

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 […]

Mobile Shielded B25 Container

novembre 15, 2019

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″ thick steel, which provides dose reduction for the rad waste it is intended to store. There are two sliding doors on top and four access doors […]

T-Flex Bottle and Vial Shields

novembre 12, 2018

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 […]

RadVision3D – LaSalle Case Study

mai 31, 2018

In the scope of one job, LaSalle Generating Station saved 12 Rem 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 locked high […]

Bellows Shielding

mars 13, 2018

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 […]

Lead Panels and Water Shields

août 11, 2017

Sometimes the right shield for the job involves placing a shield as close to the source as possible as with pipe and valves shields, but other times the best solution is to put as much shielding as possible into a wall and create general area shielding for the workers. Lead panel shield walls and water shields […]

Conoseals Shielding

juin 9, 2017

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

avril 11, 2017

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

mars 28, 2017

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

février 3, 2017

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 […]

Neutron Radiation: The Concern, Reason, and Solution

décembre 1, 2016

FULL ARTICLE Executive Summary Nuclear Power Outfitters (NPO) offers a wide range of materials that can be used to attenuate neutron radiation. In contrast to the high density/high atomic weight element materials used for gamma attenuation (lead, bismuth, tungsten), neutron radiation is most effectively shielded using relatively low density materials with high hydrogen content, such […]

Carrying Lead Blankets for Fun

novembre 18, 2016

How many times in your career have you seen someone excited to carry lead blankets?  At “The Combine” hosted by Frontline OCR and the local USMC recruiting office, there were more than you could count.  Frontline OCR’s mission is “To create a race that replicates the demands that our first responders and military personnel experience […]

Neutron Shielding – Borated Polyethylene

août 31, 2016

Borated Polyethylene (BPE) is one of the primary materials NPO uses for shielding Neutron Radiation. Our standard BPE is 5% Boron by weight. The benefit of adding Boron is that capture by B-10 reduces the dose from secondary gamma production. It primarily captures through (n, alpha), and the alphas are easily re-absorbed in the material. […]

Steam Dryer Flood Up Water Shielding

juillet 28, 2016

Tungsten T-Flex® was selected as the best material to shield divers during a Steam Dryer repair.   Approval for use in flood up water required chemical testing for leachables and heavy metals.  The end result was an 8 ft X 5 ft shield wall constructed by attaching T-Flex panels to a metal frame.  Each side of […]

Saint-Alban Steam Generator Shielding

juin 9, 2016

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, and remove the physical clutter of shielding/scaffolding as […]

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 […]

Bio-Shield Door Shielding

mai 24, 2016

Limerick Generating Station was in need of custom shielding for their bio-shield doors. Even though shielding was already installed, there was still a gap that continued to be a source of dose. NPO worked closely with ALARA Specialist, Joe Bruno, at Limerick to design a 4-piece magnetic set of custom lead blankets. Each piece had […]

Lower Dry Cask Barrel Shield

mars 9, 2016

Some NPP’s process Dry Casks in a such a way that the entire cask produces a general area dose concern. To reduce these dose rates NPO developed a shield package that sits on the floor and shields the cask to a height of 9 feet. NPO is currently under contract to provide shield package with […]

New Cono Seals Shielding

NPO’s new Cono Seals shield package exemplifies another unique and ideal application for T – Flex®. The Cono Seals are a significant dose contributor during reactor head disassembly and, most recently, reactor head cavitation peening in PWR’s. NPO used Tungsten T – Flex to achieve a HVL (half value layer) of shielding from Co – […]

NPO uses MCNP to simulate Dry Cask

Dry Cask processing operations present a number of complex radiological challenges. The presence of both neutron and gamma radiation coupled with the varying amounts of shielding already provided by the cask and canister make it difficult to know where to put shielding and what type shielding to use. Additionally, shielding limitations often exist in the […]