The isotope program at Pacific Northwest National Laboratory is making a comeback, turning to private industry for contracts rather than the Department of Energy.

Over the past seven months, the program in Richland has attracted almost $1 million in contracts and commitments for work using its hot cells and radiochemists. Scientists believe the program can grow 40 percent annually over the next seven years because the demand for isotopes and isotope research is so great.

"There are so many requests, we cannot possibly supply all," said Darrell Fisher, a medical physicist at the Richland lab.

A radioisotope is a form of a radioactive element. It's the product supporters of restarting Hanford's Fast Flux Test Facility want produced for new medicines.

The lab is looking for ways to turn isotopes available from other sources into reliable supplies for useful products.

"(Demand) is more than medical," Fisher said. "It's for basic research science and industrial need. Then we have a strong national security element."

The lab had a strong program in medical isotope research in the 1990s, developing a way to produce the isotope yttrium 90 from nuclear waste. The Food and Drug Administration since has approved a medicine using yttrium 90 for treating a form of lymphoma with a good success rate and few side effects.

In fiscal year 1998, the DOE gave the Richland lab's program $1.7 million. That year, the lab also sold $1.4 million of yttrium 90.

But since then, DOE has moved to turn isotope work over to private companies, including the production of yttrium 90. By last winter, very little isotope work was being done at the Richland lab.

But already the lab gets calls from programs, particularly at universities, that have isotopes from past research they need to get rid of and researchers and businesses seeking specific isotopes.

Since Sept. 11, 2001, interest has increased in reducing stockpiles of excess radioactive material, such as the cesium left over from a New York project to study the effects of radiation on trees.

"It's a big recycling effort," said Fisher, whose colleagues sometimes call him the junk man. "We view the materials as really valuable."

The terrorist attacks last year also increased demand for isotopes to use for national security.

The Richland lab has been working with SAIC, a San Diego-based research and engineering company, producing a vehicle and cargo inspection system developed for the U.S. Customs Service that uses cesium or cobalt isotopes. It's able to find explosives and weapons hidden in trucks or seaport containers without opening the containers, among other uses.

The lab also has contracts to do proprietary work for medical product manufacturers, in-cluding one working on a treatment for heart disease and another working on a treatment for prostate cancer.

Additional work is being done under a research and development agreement with AlphaMed, a Massachusetts company, that could increase the supply of alpha-emitting isotopes for cancer treatments.

The high energy released by the alpha particles, with their short range and short half-life, can destroy tumor cells with minimal damage to healthy tissue. They show promise for difficult-to-treat cancer that has spread from the main tumor. It can be found and killed with isotopes attached to antibodies that target the cancer cells.

"The supply of alpha emitters is desperate," with some of those available too expensive for practical use, Fisher said. The lab and AlphaMed are working on ways to produce reliable supplies of lower-cost alternatives.

In one project, the lab and AlphaMed are using the United States' supply of the rare isotope uranium 232, which likely came from a classified weapons project. It can be used to produce bismuth 212, an alpha emitter with a half-life of 60 minutes.

Because half of it decays every hour, hospitals would need to produce the isotopes on site just before the patients are treated.

The Richland lab is working with AlphaMed to improve and supply a small generator system developed at the University of Chicago that uses chemical reactions to generate bismuth 212 and remove it from other isotopes in the generator.

Isotopes being produced by the present generator system are allowing medical research to continue, including clinical research on animals before new treatments are tested on patients.