RadVision3D – LaSalle Case Study

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 […]

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 […]

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 […]

Neutron Shielding – Borated Polyethylene

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. […]

Bio-Shield Door Shielding

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

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 […]