Featured Research

from universities, journals, and other organizations

Ecologists Spawn New Use For PIT Tags: Radio Frequency Technology Tracks Mixer Efficiency

Date:
October 6, 2005
Source:
Pacific Northwest National Laboratory
Summary:
Fishing for a way to assess mixing behavior in treatment tanks for radioactive waste, ecologists at Pacific Northwest National Laboratory turned to radio frequency technology previously used to track migrating fish. Thousands of passive integrated transponder (PIT) tags were added to a clay simulant and whipped around in tests of mixer equipment in large test tanks and scaled prototypes. This novel application of the PIT tags provided a means of assessing fluid motion without sampling.

Researchers at PNNL are providing performance data for pulse jet mixer and air sparger designs intended for use in Hanford's Waste Treatment Plant. Using a half-scale tank containing about 10,000 gallons of simulated waste, they monitor the performance of the mixers under a variety of conditions.
Credit: Image courtesy of Pacific Northwest National Laboratory

Related Articles


Butrather than swimming out to sea implanted in young steelhead andsalmon, thousands of passive integrated transponder, or PIT, tags wereadded to a clay simulant and then whipped around in tests of airsparger and pulse jet mixer equipment in large test tanks and scaledprototypes.

This novel application of the PIT tags provided ameans of assessing fluid motion without sampling. Performance resultsfrom the tests led to equipment configurations adopted forimplementation, said Dean Kurath, an engineer with PNNL's radiochemicalengineering group.

The Hanford Waste Treatment Plant, currentlyunder construction at the Department of Energy's Hanford Site inWashington state, will be the world's largest facility for treatinghighly radioactive waste. The Hanford Site stores 53 million gallons ofthe waste from past production of plutonium for the nation's nuclearweapons program in 177 underground tanks.

Waste slurries ofvarious compositions and thicknesses will be mixed in several differenttanks in preparation for immobilizing the radioactive waste in glassthrough a process of vitrification or "glassifying." Mixing thematerials will maintain homogeneity in process vessels, limit solidssettling and stratification, improve heat transfer and mix in variousprocess solutions. Mixing will also provide for the controlled releaseof flammable gases generated by the breakdown of organic materials inthe waste slurries.

Bechtel National Inc., which is designing andbuilding the Waste Treatment Plant for DOE, enlisted PNNL to helpdetermine the best designs and technologies for mixing the mudlikewaste that will be present in some of the approximately 20,000-gallontanks. Technologies under consideration included pulse jet mixers, airspargers and steady jets generated by recirculation pumps.

In onetest of an air sparger, 6,000 PIT tags were added to a tank filled withopaque simulant. Not much bigger than a grain of rice, the PIT tagscontain an integrated circuit and an antenna encapsulated in glass. Thetag is activated when it passes within range of an antenna thatgenerates an electromagnetic signal. The signal alerts the tag totransmit its unique digital code back to the reader.

The sameprinciple is at work in antitheft devices attached to retailmerchandise in department stores and in subcutaneous ID tags for pets.But according to PNNL researcher Rich Brown, this is likely the firsttime PIT tags have been associated with mixing simulated radioactivewaste.

As the sparger went to work mixing waste, the tags weredetected using custom-made antennas housed in four vertical wells ofPVC pipe placed in the tank around the central sparger. Aremote-controlled motorized system moved the antennas up and downwithin the wells to detect passing PIT tags at varying depths in thetank.

The tags have a signal range of 3 to 4 inches. Movement ofthe slurry was determined by identifying individual PIT tags duringmultiple antenna passes. In other tests, the PIT tag antennas wereplaced around the outside of the vessel.

PNNL is a DOE Office ofScience laboratory that solves complex problems in energy, nationalsecurity, the environment and life sciences by advancing theunderstanding of physics, chemistry, biology and computation. PNNLemploys 4,000 staff, has a $700 million annual budget, and has beenmanaged by Ohio-based Battelle since the lab's inception in 1965.


Story Source:

The above story is based on materials provided by Pacific Northwest National Laboratory. Note: Materials may be edited for content and length.


Cite This Page:

Pacific Northwest National Laboratory. "Ecologists Spawn New Use For PIT Tags: Radio Frequency Technology Tracks Mixer Efficiency." ScienceDaily. ScienceDaily, 6 October 2005. <www.sciencedaily.com/releases/2005/10/051006090457.htm>.
Pacific Northwest National Laboratory. (2005, October 6). Ecologists Spawn New Use For PIT Tags: Radio Frequency Technology Tracks Mixer Efficiency. ScienceDaily. Retrieved November 26, 2014 from www.sciencedaily.com/releases/2005/10/051006090457.htm
Pacific Northwest National Laboratory. "Ecologists Spawn New Use For PIT Tags: Radio Frequency Technology Tracks Mixer Efficiency." ScienceDaily. www.sciencedaily.com/releases/2005/10/051006090457.htm (accessed November 26, 2014).

Share This


More From ScienceDaily



More Earth & Climate News

Wednesday, November 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Bolivian Recycling Initiative Turns Plastic Waste Into School Furniture

Bolivian Recycling Initiative Turns Plastic Waste Into School Furniture

Reuters - Innovations Video Online (Nov. 26, 2014) Innovative recycling project in La Paz separates city waste and converts plastic garbage into school furniture made from 'plastiwood'. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
Antarctic Sea Ice Mystery Thickens... Literally

Antarctic Sea Ice Mystery Thickens... Literally

Newsy (Nov. 25, 2014) Antarctic sea ice isn't only expanding, it's thicker than previously thought, and scientists aren't sure exactly why. Video provided by Newsy
Powered by NewsLook.com
3D Map of Antarctic Sea Ice to Shed Light on Climate Change

3D Map of Antarctic Sea Ice to Shed Light on Climate Change

Reuters - Innovations Video Online (Nov. 24, 2014) A multinational group of scientists have released the first ever detailed, high-resolution 3-D maps of Antarctic sea ice. Using an underwater robot equipped with sonar, the researchers mapped the underside of a massive area of sea ice to gauge the impact of climate change. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Car Park Solution for Flexible Green Energy

Car Park Solution for Flexible Green Energy

Reuters - Innovations Video Online (Nov. 24, 2014) A British solar power start-up says that by covering millions of existing car park spaces around the UK with flexible solar panels, the country's power problems could be solved. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins