Oconee Heat Exchanger Skid Shielding

April 16, 2024

IMG_1385IMG_1391HX Skid Shielding Survey Results

Browns Ferry 360-Inspection Platform

March 15, 2024


Radiography Shielding

February 20, 2024

Radiography is a non-destructive testing (NDT) technique that uses a radioactive source to detect flaws or defects in the internal structures, typically pipes. This testing process requires an “exclusion zone” to keep workers safe, and the use of shielding shrinks that exclusion zone and improves safety and efficiency. NPO T-Flex Bismuth blankets are large and […]

Custom Fit Meter Shielding

March 6, 2023

Some shielding applications require a precise fit in order to shield effectively. The meter of this instrument was a streaming source for the workers operating it. To fit the area, NPO used drawings of the steel housing and designed T-Flex Tungsten shielding that fit snuggly around the meter. 3D printed molds were used to create […]

Vogtle Reactor Head Shielding

January 9, 2023

In 2021, Vogtle reached out to NPO to help develop a new shielding package for around the reactor head. Their current system consisted of two rings: one under the head, and one around the outside of the head. Each of these shield rings used 1’ x 6’ (305 mm x 1829 mm) 60 lb (27.2 […]

Oconee Reactor Head T-Flex Shielding

June 30, 2022

Reactor head shielding is an essential part of every refuel outage. Oconee Nuclear Station sought to upgrade the shielding used at the bottom of the reactor head, opting to use lead-free T-Flex Bismuth blankets. Specifically designed for the application, these blankets T-Flex blankets were covered in blue PVC with Oconee specified printing that clearly indicated […]

Brunswick Permanent Valve Shield Box

June 29, 2022

Magnetic T-Flex tiles attached to steel frame and secured with cable ties Brunswick Nuclear Station had a valve that was causing a room to be a locked high radiation area. They wished to implement a permanent shielding package in order to down post the room. The valve was set to be removed during an upcoming […]

Primary Sample Panel Shielding

September 10, 2021

South Texas Project had long used lead wool blankets to shield their Primary Sample Panel, an area of the site within Chemistry that sees a lot of traffic. These lead wool blankets were affixed to the Primary Sample Panel via independent high strength magnets that attached to the grommets. With the blankets turned on their […]

Pressurizer Spray Line Shielding

June 9, 2021

  South Texas Project required new shielding for a section of the pressurizer spray line. Though the area looks small, the total shield weight was around 850 lb (386 kg). This was due to the 6.5″ (165 mm) diameter of the pipe and the 1.5″ (38 mm) thick shielding pieces. But despite the size and […]

Heat Exchanger Shielding – Permanent Installation

March 29, 2021

As part of a long-term dose reduction plan, Ameren Callaway sought to install permanent shielding around one of their regen heat exchangers. The intention was to replace the dozens of lead wool blankets used as temporary shielding, and more importantly, eliminate the time and dose costs associated with installing and uninstalling the temporary shielding package. Working […]

T-Flex Blankets

February 10, 2021

How many lead wool blankets does your site deploy every outage? Despite best efforts, do your lead blankets look sloppy while draped over pipes and hot spots or seem mashed and bent around corners and tight spaces? How long have they been there?  How are they handling the use and abuse? Lead wool blankets, while […]

Permanent Pipe Shielding for Davis-Besse

November 17, 2020

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 […]

Magnetic ARGOS Booth Shielding

September 3, 2020

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 Engineering Services

July 9, 2020

NPO offers a number of engineering services to validate the integrity and performance of our shielding. We are the industry experts when it comes to aiding nuclear power plants design new and unique shielding and pride ourselves on our technical expertise. We want to act as part of your team to not only ensure the […]

Shielded Filter Casks

April 29, 2020

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 […]

Boiler Plate Shields

April 28, 2020

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 […]

Dry Cask Shielding Package

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

November 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″ (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 […]

Vertical Storage Cask Gap Shielding

November 7, 2019

“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. […]

Reactor Head Flange Shielding

May 3, 2019

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 […]

T-Flex Bottle and Vial Shields

November 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

May 31, 2018

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 […]

Bellows Shielding

March 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 […]

Smear Frisker Cave

October 24, 2017

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 […]

Lead Panels and Water Shields

August 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

June 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

April 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

March 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

February 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

December 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

November 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

August 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

July 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 (2.44 m x 1.52 m) shield wall constructed by attaching T-Flex panels to a […]

Saint-Alban Steam Generator Shielding

June 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 (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 […]

Bio-Shield Door Shielding

May 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

March 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 (2.74 m). NPO is currently under contract to provide shield […]

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–60. Simple Velcro straps are used […]

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 […]