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In south-central Washington, engineers are experimenting with ways to clean out the poisonous, radioactive brew in Hanford's underground storage tanks. One million gallons leaked before the clean up started and are seeping toward the Columbia River. The dregs in those waste tanks also present a test. They're sticky and gooey like peanut butter, or in some cases, hard like crusty fudge. Correspondent Tom Banse reports from Richland that the newest clean up helper is an ingenious robot.LISTEN TO THIS STORY 

Story Script
HOW'S THIS FOR AN ENGINEERING CHALLENGE? FIGURE OUT HOW TO SCRAPE OUT THE NASTY GUNK AT THE BOTTOM OF WASTE STORAGE TANKS AT THE HANFORD NUCLEAR SITE. THIS IS NO JOB FOR A SHOVEL AND MOP BRIGADE SAYS HANFORD GROUP VICE PRESIDENT JOEL EAKER OF THE ENGINEERING FIRM CH2M HILL.

Eaker: "It's a mixture of chemicals from fifty years of production of the Cold War nuclear materials."

EVEN FOR A MACHINE, THESE ARE AMONG THE MOST HOSTILE CONDITIONS YOU COULD IMAGINE.

Eaker: "You know if you went into space, then you'd have some other issues. But on the earth, on the planet, yes, we have a pretty good brew."

WHATEVER CLEAN UP TOOL YOU PICK CAN'T BREAK DOWN BECAUSE YOU CAN'T SEND IN A HUMAN TO GO FIX IT. ADDITIONALLY, THE CHOSEN DEVICE MUST HAVE THE FLEXIBILITY OF A CONTORTIONIST.

Eaker: "Like a bottle analogy, you've got to go through a very small opening and then have it impact a large bottom area of 75 feet in diameter."

JOEL EAKER DESCRIBES THE CHALLENGE WHILE STANDING IN A FULL SIZE MOCK UP OF A HANFORD WASTE STORAGE TANK. NEXT TO HIM, SITTING SQUAT ON THE FLOOR IS A PROMISING ANSWER TO THE ENGINEERING CHALLENGE.

Sound: [crawler tracks running]

THIS IS THE REMOTE CONTROLLED WASTE TANK CRAWLER... A MINIATURE BULLDOZER WITH FOLDING BLADE, SPRAY NOZZLE, AND TANK TREADS THAT RETRACT. UNFOLDED, THE ROBOTIC CRAWLER CAN PUSH OR SQUIRT LETHAL CRUD TOWARD THE TALL STRAW OF A VACUUM HOSE, ALSO BEING TESTED RIGHT NOW.

Sound: [vacuum slurps test mud]

THE ROBOT WAS ORIGINALLY DEVELOPED FOR USE AT OIL REFINERIES AND MINES. TANK CLEANUP PROGRAM DIRECTOR ANDY STEVENS SAYS THE GOVERNMENT IS SAVING A LOT OF MONEY USING OFF THE SHELF TECHNOLOGY. STEVENS EXPECTS THE CRAWLER TO BE A BIG HELP GETTING LETHAL TANK CRUD PUMPED OUT SO THAT IT CAN BE MIXED INTO GLASS OR CONCRETE BLOCKS FOR STABLE LONG TERM STORAGE -- EITHER AT HANFORD OR UNDER A MOUNTAIN IN NEVADA.

Stevens: "We anticipate that some of the tanks will be very difficult to take the 99-plus percent of the waste out, because some of that waste will be pretty hard. It won't easily move around. Thus, the purpose of this crawler is to move that difficult waste."

NINETY-NINE PERCENT WON'T BE GOOD ENOUGH FOR SOME. AT PUBLIC HEARINGS THIS WEEK, REPRESENTATIVES FROM HANFORD WATCHDOG GROUPS INCLUDING TOM CARPENTER OF SEATTLE CALLED FOR EVERY LAST DROP OF LIQUID, GOOEY SLUDGE, AND BAKED ON CRUD TO BE TAKEN AWAY.

Carpenter: "You know that Hanford argues that this is an expensive process and it's made more expensive when you try to go for that last one percent. I guess I would argue that you have a duty to protect the health and safety of future generations of the Northwest. That means, you get all of this waste out."

THE ENERGY DEPARTMENT IS TESTING OTHER TECHNOLOGY TO GET THE LEFTOVERS INCLUDING A COMBINATION OF WATER JETS WITH VACUUM SYSTEM THAT MAKES A MINI TORNADO. THE AGENCY HAS EMBARKED ON ACCELERATED CLEAN UP SCHEDULE THAT CALLS FOR AS MANY AS 40 UNDERGROUND TANKS TO BE EMPTIED AND CLOSED BY 2006. I'M TOM BANSE IN RICHLAND, WASHINGTON.

Related Link:
** Department of Energy - Hanford

A service of the University of Washington | Copyright© 2003 KUOW Puget Sound Public Radio

February 3, 2003

See the article on the Reach Website

Tank cleanup crawler put to the test

Geoff Tyree, CH2M HILL

The remote-controlled tank crawler dives into a tank of simulated waste at Hanford's Cold Test Facility. The crawler will help the tank-farm contractor remove sludge from the single-shell tanks.

The Department of Energy Office of River Protection and CH2M HILL Hanford Group are taking a clue from the petroleum industry in the effort to clean up an estimated 53 million gallons of radioactive and hazardous waste stored in Hartford’s 177 large underground tanks.        

Demonstrations of a new remote-controlled cleanup machine are under way in a simulated waste tank at the Cold Test Facility. Called the tank crawler the machine is a sturdy and agile1,300-pound system that looks like a small bulldozer with treads and a folding blade. With the push of a button hydraulics fold the crawler to lust 27 inches wide, narrow enough to enter an underground Hanford waste tank through a riser. Once inside the tank, the crawler will push the thick sludge to a central pump that will transfer the contents out of the tank.        

The crawler is an adaptation of commercially available technology used extensively in the petroleum and mining industries. A Welsh company, Non Entry Systems, Ltd., which has been making similar machines for the petroleum industry since the mid 1980s, manufactured the crawler. The petroleum industry uses the machines to remove sludge from product tanks. Non Entry Systems’ first machine was one that an operator can ride and maneuver inside the tank. It continues to make this model, but it also makes models like the Hanford version that can be operated remotely from a control panel.  

The relatively inexpensive adaptation for use in the Hanford waste tanks focused primarily on the construction materials and specific features for application in a radioactive environment. Unlike the models used in the petroleum industry, the Hanford crawler parts are mostly stainless steel, which makes it easier to decontaminate.

ORP and CH2M HILL are conducting crawler demonstrations using simulated sludge waste in the large, to-scale simulated waste tank at Hanford ’s Cold Test Facility. The first series of tests is being conducted with simulants, which are similar in particle size and viscosity to radioactive and hazardous sludge waste stored in several Hanford tanks. Preliminary tests on each subsystem have been successfully completed, and integrated system testing is under way.  

“We are working toward accelerating the retrieval of waste from Hanford’s older tanks with innovations such as the tank crawler,” said Jim Thompson, manager of ORP’s Single-Shell Tank Project. “We will put the crawler through the paces and evaluate its potential for real tank cleanup work.”

Working with ORP, CH2M HILL is developing methods for removing solid waste from Hanford’s 149 single-shell tanks. Most of the liquid waste has been moved from these older tanks to 28 newer, safer double-shell tanks.

Methods are being developed to remove the remaining solid waste - more than 31 million gallons by volume — from the single-shell tanks. That waste consists of sludge that looks like fine mud and dries very hard, and saltcake which is somewhat like wet beach sand but can dry to an almost rock-like consistency.

The challenge is to mobilize the sludge and saltcake with enough liquid to move it through pipes to newer tanks, while using as little liquid as possible to reduce the possibility of a tank leak. That’s where the tank crawler comes in.

The crawler must be small enough to fit through a relatively narrow opening on top of the tank, agile enough to maneuver over an uneven waste surface and around obstacles in the tank, and durable enough to withstand the highly radioactive environment and a rigorous decontamination process. Remotely operated, the crawler will be lowered into a tank, where it will push the sludge toward a specially designed vacuum pump. An operator will sit at a bank of monitors in a mobile facility outside the tank farm and use multiple camera views to maneuver the machine. A pump-and spray mechanism on the crawler will help move the waste to the central pump.  

The central pump vacuums up the thick waste, which is expected to contain 30 percent to 80 percent solids, and moves it approximately 50 feet to a holding tank on the surface. During testing, the central pump has been removing about 25 gallons of simulated waste – kaolin clay – per minute.

As the crawler is removed from a tank, it goes through a vigorous decontamination process. First it is hit with a low-pressure spray, then a high-pressure spray to loosen and wash off most of the material. Finally, the crawler enters an ultrasonic decontamination chamber with several banks of ultrasonic generators that create strong vibrations, and a final wash removes the smaller particles of waste.

“The crawler is designed to be sturdy enough to handle the challenging environment of a real Hanford waste tank.” said Joel Eacker,. CH2M HILL Hanford Group vice president of Projects. ‘We think it shows promise for accelerating the removal of waste from several of Hanfords tanks.”

Single-shell tank C-104 is currently scheduled for the first deployment of the crawler;  however ongoing evaluations may support accelerated deployments in other waste tanks.

Mid-Columbia

Friday January 17th  2003

Hanford tests tank cleanup ideas

• Miniature bulldozer, huge vacuum cleaner likely to be used to remove radioactive sludge

• By John Stang   Herald staff writer

Herald/Richard Dickin

         From a remote operating site, project engineer Dave Smet manipulates the controls as he pulls a sludge crawler out of the muck  Thursday at the HAMMER test facility in Richland . The 1,300- pound, $1.2 million crawler will be used to move radioactive sludge inside 60 or more of the 177 underground storage tanks on the Hanford site

Call it the milk shake strategy. Like a kid attacking a really thick shake — sucking mightily on the straw, then poking and prodding the goo — that’s how Hanford expects to get thick radioactive sludge out of 60 or more of its huge underground          tanks.

 On Thursday. CH2M Hill Hanford Group began the first coordinated test of all the pieces of its “tank crawler” waste removal system at a mockup tank. The test is expected to be completed today.

           The system has two basic pieces — a miniature bulldozer teamed with a monster-sized vacuum cleaner. Months of testing and training remain, with the  system expected to begin work in a real underground radioactive waste tank C -104      — late this year or early in 2004. Hanford has 55 million gallons

DOE recently set a goal to remove all liquid and solid wastes from 26 to 40 older single-shell tanks by the end of 2006 and then close those tanks.

That means removing almost all solids and sludges, a task never attempted before.      The tanks are huge, capable of holding 500,000 to 1 .2 million gallons. The problem is that the only way to enter them is through pipes ranging from 4 inches to 42 inches in diameter. Squeezing cameras and equipment through the pipes is a major hurdle.            The Department of Energy and CH2M Hill have proposed three ways to break up and  remove the solids and sludges:

         • Using a powerful upside-down sprinkler to spray and breakup radioactive salt cakes into liquids to be pumped out. DOE and CH2M Hill are experimenting          with this technique in Tank U -

         • Shooting water through big hoses to break up and dissolve solids, then pump them out. Hanford plans to begin trying this in Tanks S-102 and 5-112 late this year.

         • The “milk shake” method, which CH2M hill borrowed from the petroleum industry and began testing Thursday.

A huge vacuum cleaner, with a through one of a tank’s pipes to reach close to the bottom and begins sucking out wastes. Water is periodically squirted through the tube to keep it unclogged. 

The problem is the vacuum can cover only a few square feet of the tank floor, which is 75 feet  in diameter.  

Consequently a 6-foot-long, 1,300-pound  bulldozer is inserted its front end hanging straight down — through the 42-inch pipe to be slowly lowered  by a cable into wastes. In the

As soon as the bulldozer is    the bottom, aided by a small water cannon. The crawler’s job is to push the wastes within the vacuum’s reach.

 CH2M Hill and DOE engi  ‘For engineers, this is a fun job. Driving your little robot around, testing it with different thicknesses of wastes,” said Joel Eacker, CH2M Hill vice president for projects. 

Thursday’s test dealt with 40 cubic feet of mud like clay — two feet deep in a 35-hy-20 concrete tub. By comparison, Tank c-I 04  holds 263,000 gallons of  radioactive sludge, eight to 10

For Dave Smet, the CH2M Hill project engineer operating the bulldozer and vacuum by remote control in a nearby trailer, “it’s an intense activity.”

Thursday, he and other engineers watched their choices of 10 cameras, numerous lights and gauges, called up information on a computer screen and nudged       numerous jovsticks — getting a feel for the system and figuring out how to improve it.

 They listened closely to the crawler’s engine and other equipment noises through a loudspeaker, pricking their ears for sounds something could be wrong. 

Tank cleaning work will be slow. Eacker estimated it will take two to five months to remove all the sludge from one tank. 

Each $1 .2 million tank crawler is expected to last possibly six tanks before it becomes too radioactive for workers to safely maintain it. 

Eacker said CH2M Hill might try operating crawlers simultaneously in several tanks if it’s cost effective.       

         • Reporter ,John Stang can be reached at 509-582-1517 or via e-mail at

Mid-Columbia

Monday Sept 23^rd 2002

  Rick Raymond, director of technology integration for CH2M Hill Hanford Group, looks over a tank crawler the company is testing at Hanford ’s Cold Test Facility. The 6-foot long, 1,300- pound remote-controlled machine costs $1 million and is expected to clean six waste tanks at Hanford before it needs to be replaced.

         Tank crawler on cleanup duty

         • CH2M Hill Hanford Group testing robot bulldozer, vacuum designed to enter,clean radioactive waste tanks         By John Stang   Herald staff writer

Think of it as an atomic-age broom  and dustpan. CH2M Hill Hanford Group is testing a  miniature tank crawler” as a way to get  semi-solid radioactive wastes out of the The company has begun testing a tank  Crawler - a miniature bulldozer teamed  up with a huge quasi-vacuum cleaner at Hanford ’s tank mockup site next to the HAMMER facility.

 CH2M Hill expects to use this system to first clean out a tank – single-shell C- 1 04 in 2005, said Joel Hacker, CH2M Hill Hanford Group’s vice president for projects.

Hanford has 55 million gallons of  highly radioactive wastes in 149 old single-shell tanks and 28 newer and safer double-shell tanks. CH2M Hill has pumped most of the liquid wastes from the single shell to the double-shell tanks to await eventual glassification. It is supposed to finish the job by 2004.

But even after the liquids are pumped out, about 31 million gallons of thick sludges, salt cakes and solid wastes will remain in the bottoms of the single-shell tanks. Hanford is researching ways to remove those final materials so the tanks  can be permanently closed.

 The tank crawler and its sister equipment are one of the methods being developed to remove solids from some tanks.

Actually, most of this technology is borrowed from the oil industry, which  uses it in underground petroleum tanks.

 A vacuum pump will be inserted into a Hanford waste tank through one of its narrow pipes - which are the only avenues through which someone on the surface can put something in an underground waste tank. Then a small bulldozer – the tank crawler – is inserted through another tank pipe opening, hanging by a cable perpendicular to the tank’s bottom. This tank crawler is 6 feet long. 2 feet high, and has a blade that can unfold to expand from 24 inches to 40 inches wide.

The bottom line: The tank crawler has to fit through a narrow vertical pipe, then unfold its blade to become a bulldozer.

The tank crawler has a pump and -spray mechanism to enable it to burrow through peanut butterlike wastes  in order to get to the bottom of the tank, dig itself a hole, set itself right-side-up and begin work. Then the tank crawler just pushes wastes to the vacuum pump, which sucks the materials out of the tank.

One tricky part is that the crawler won’t have any cameras on it. Instead, cameras will have to be inserted through another pipe opening in the tank’s ceiling. That means the crawler’s human operator on the surface must cope with odd angles and perspectives to guide the crawler by remote control.

 “It’s going to take a little bit of art to get our operators trained,” Eacker said.

The combined pump, crawler and auxiliary equipment cost about $2 million. CH2M Hill believes a crawler will last through cleaning maybe six tanks before the radioactivity and wear-and-tear make it unusable.

Consequently CH2M Hill believes that ultimately 10 tank crawlers may have to be built. Its immediate plan is to have one primary crawler and one backup crawler in place

         • Reporter John Stang can be reached

         at 509-582-1517 or via e-mail at

jstang@tri-cityherald.com

In-Tank Vehicle will aid Hanford tank waste cleanup

The Department of Energy’s Office of River Protection in Richland , Wash. , is testing a new robotic tool this month for retrieving highly radioactive tank waste. Resembling a tiny tractor, the In-Tank Vehicle (ITV) weighs 1,500 pounds and is five feet long. A suction pump and nozzle assembly sucks up sludge-like waste and shoots it to a central pump, called an articulating mast assembly, which then pumps the waste out of the tank.

The tool was built by Non Entry Systems Limited, Swansea , Wales . A similar piece of equipment called the Houdini was used to remove tank waste at the Department’s Oak Ridge National Laboratory (ORNL). ORNL provided assistance to Office of River Protection personnel as they evaluated the robotic system for use at Hanford .

The ITV will undergo three months of rigorous testing at the Hanford Site’s Cold Test Facility—a life-sized model of an actual Hanford waste tank. Personnel will push the ITV to its limits to deter­mine operating capabilities and to decide if the tool needs further manufacturer modifications. 

See the article on the Reach website

Hanford tank cleanup crawler demonstrated

Geoff Tyree, CH2M HILL Hanford Group.

 Preliminary demonstrations of a new remote-controlled cleanup machine are under way in the simulated waste tank at the Cold Test Facility. Called the Tank Crawler, the machine is a sturdy and agile 1,300-pound system that looks like a small bulldozer with treads and a folding blade.

 With the push of a button, hydraulics fold the crawler to just 27 inches wide, narrow enough to enter a tank through a 36-inch-wide riser that has been fitted with a protective sleeve. Once inside the tank, the crawler will pump and push its way through thick sludge, moving the waste toward a cen­tral pump that will transfer the contents of the tank.

 Working with the Office of River Pro­tection, CH2M HILL Hanford Group is developing methods for removing solid waste from Hanford ’s single-shell tanks. Most of the liquid waste has been moved from these older tanks to newer, safer double-shell tanks.

 Methods are bejng developed to remove the remaining solid waste – more than 31 million gallons by volume.

That waste consists of sludge that looks fine mud and dries very hard, plus saltcake, which is somewhat like wet beach sand but can dry to an almost rock-like consistency.

 The challenge is to mobilize the sludge and saltcake with enough liquid to move it through pipes to newer-tanks, while us­ing as little liquid as possible to reduce the possibility of a tank leak. That’s where the Tank Crawler comes in.

 The crawler must be small enough to fit through a relatively narrow opening on top of the tank, agile enough to maneu­ver over an uneven waste surface and around obstacles in the tank, and du­rable enough to withstand the highly ra­dioactive environment and a rigorous de­contamination process. Remotely operated, the mobile retrieval system will be lowered into a tank, where the crawler will push the sludge toward a specially designed vacuum pump. A pump and spray mechanism on the crawler will help the in-tank vehicle move through the waste.

In the coming months, the crawler will undergo demonstrations with simulated sludge waste in the large simulated waste tank at Hanford ’s Cold Test Facil­ity. The first test will be conducted with mud that is similar in particle size and viscosity to sludge tank waste.

 We are-working  toward accelerating the retrieval of waste from Hanford tanks with innovations such as the Tank Crawler,” said Joel Eacker, CH2M HILL Hanford Group vice president of Projects. “Using simulated waste in this tank, we will put the crawler through its paces and prepare it for real tank cleanup work.”

 The crawler has already undergone some preliminary factory testing. One included pushing around a 600-pound container of concrete. Another in­cluded wrapping the crawler up in steel tape to simulate its ability to break up the tangles of debris from previous op­erations in a tank, including discarded lengths of metal tape used to measure tank levels.

 Single-shell Tank 0-104 is currently scheduled for the first deployment of thE crawler by 2005. This tank was selected because it has not leaked in the past and it contains the most contaminants of concern for their potential long-term health risks. The crawler is designed to be capable of retrieving sludge waste from as many as 60 single-single-shell tanks.