Radioactive Trees at the
Berkeley's Lawrence Hall of Science


Lab cuts down Eucalyptus amid protest
Lawrence Hall of ScienceLBNL chop down and chip a grove of trees contaminated with tritium. The amount of contamination is at issue.

Jon Mays, Berkeley Daily Planet
July 17, 2001

Wood chips from a cut-down grove of Eucalyptus trees contaminated with radioactive Tritium is alarming a group of concerned residents near the Lawrence Berkeley National Laboratory. They say the lab should and UC Berkeley should undergo a full environmental impact review before the three yearlong project is continued in the Berkeley hills.

"If we don't know the levels of tritium then it is inappropriate for the lab to cut down the trees in such a cavalier way," said L A Wood, who lives less than a mile away from the lab and the Lawrence Hall of Science.

Lab and UC Berkeley officials, however, emphasize that cutting the trees is perfectly safe. "The trees in question are very very far away from the tritium. To have any damage you'd have to eat 3,000 pounds of chips. You'd have to eat an awful lot of chips," said Paul Lavely, director of the UC Berkeley office of radiation safety.

Last week, workers began cutting down trees and feeding them into a chipper next to the Hall of Science. Lavely added that there was little dust since the trees were wet. Concerns over fire safety prompted the
clearing, according to lab spokesperson Ron Kolb.

lhsBut Wood believes that the lab is fast tracking the project to get rid of evidence that they were feeding contaminants into the air.

In a letter to Gene Bemardi, co-chair of the Committee to Minimize Toxic Waste, from Richard Nolan, director of the Berkeley site office for the U.S. Department of Energy, Nolan wrote that he did not expect any tree removal until at least December 2001. "I was quite shocked that they were being cut," Bernardi said.

But Kolb moving the project faster was to the lab's benefit because the fire season is currently in full swing. He said the lab tested 171 trees in the area in 1998 and 1999 and said the amount of tritium discovered was negligible. The tritium got into the trees from a labeling facility established in 1982. In the facility, staff "label" drugs and other material by replacing hydrogen atoms with tritium atoms. Because tritium is radioactive, it helps researchers detect a drug's presence in the body.

In 1998, the lab said annual dose from the facility to a person living next to the Lab was .27 millirem - far below what the average person encounters in daily living. However, a 1996 study conducted by Dr. Leticia Menchaca, indicated that some trees as far away as 150 meters from the labeling facility had extremely high levels of tritium.

Kolb said that none of the trees being cut down are close to those levels. Instead,-he reemphasized that the cut trees have very levels and pose no health hazard. "We are confident that those levels should have no concern," he said.

LHSBut Wood isn't buying it. "Last Thursday, there were kids playing 20-30 feet away from the downed trees. There is a tremendous amount of controversy as to how hot the trees are," he said. "The whole process has been controversial but there has been no review. They simply do not want to open the door because the door is Pandora's box."


From: Paul Lavely Thursday, July 12, 2001
To: Al-Hadithy, Nabil Subject: Concern for LHS Importance: High

You asked if we have done an evaluation of any risks that the tree cutting/chipping may present for occupants of LHS? The answer is no, nothing formal, but informally (no documentation) we have. We looked at the concentration of tritium in the trees on the UCB side of the fence and found that the amount of tritium decreases very rapidly with distance from the stack. The tree work that is going on is not near the "high level" trees.

Next we looked at the Franke estimate of the amount of tritium in the entire grove being about 1 curie in above ground sources (trees, duff, grasses, etc.) Based on that, if ALL the tritium in the entire grove were re-released it would represent a dose to LHS of about 0.002 mrem. Even if I assume that Franke is low by a factor of ten a release of 10 curies would have a dose of about 0.0ˆnrem. LBNL had calculated the dose from duff and the need to consume 60 lbs to get to the 10 mrem dose (this was presented to the task force).

This dose (tritium in the grove) has already been derived and assigned once - when the tritium was first released and should not be counted again UNLESS the calendar year total would exceed 10 mrem. I looked at the issue of vectors and routes of exposure. This work is not generating significant amounts of dust. What is being generated is small chips of still wet tree material. Virtually all the materials is deposited locally and does not carry with the wind as does the airborne tritium released from the stack.

There is no model for tritium containing dust being adsorbed through the skin, by ingestion, or by inhalation. However, a conservative assumption is that it can be no worse than inhalation and that risk has already been calculated.

To get to the LHS staff or visitors inside the building the material would have to enter the ventilation system and be distributed. We sample this air and will be pulling that sample at the end of July and should have the lab's analysis by the end of August.


To: CEAC Members City of Berkeley Community Environmental Advisory Commission
From: David McGraw, Director of Environmental Health & Safety Division, LBNL
May 11, 2000

Dear Commission Members:

Thank you for the opportunity to present our wildland fuel reduction program at the May CEAC meeting. In conjunction with the Hills Emergency Forum, we have strongly supported vegetation management efforts and have significantly reduced the fuel load at the Laboratory. The City of Berkeley's Fire Commission has recognized the Berkeley Lab's program as a model for other agencies in the East Bay. In response to questions raised at the Commission meeting regarding the fuel reduction program, I would like to provide the following information.

First, a question was asked about sending felled trees offsite for processing of wood into pulp (pulping). Since the program began in 1995, each year trees have been sent to pulping facilities in Korea or Japan. This is the standard practice with Eucalyptus thinning and removal projects in the Bay Area. With respect to trees at the Berkeley Laboratory, we have received approval from the Department of Energy, that trees may be released if their tritium levels are not detectable or otherwise indistinguishable from background level of tritium. This determination is currently based on a Decision Rule that was developed at Berkeley Lab (attached). Typically, the Decision Rule's threshold for releases has been approximately 0.5 pCi/gram for tissue free water tritium (TFWT) and approximately. 5 pCi/gram for organically bound tritium (OBT). In the future, Berkeley Lab is planning to send additional trees offsite if tritium levels are below the release threshold determined by the Decision Rule.

Second, a question was asked regarding the distribution or disposal of wood chips. Berkeley Lab chips branches and other small woody material and distributes it onsite for mulch purposes. No material has been sent off site for chipping, and all chips have been used on the Laboratory site. Berkeley Lab intends to continue to use all chips on site.

Third, a question was asked about a container located at the service yard off Centennial Drive. This container is used by the Lab's ground keeping staff to store lawn clippings, leaves that have been raked, weeds pulled from garden beds and similar trimmings from their regular landscaping duties. No material has been collected from the area near the stack; therefore, no material from this area has been placed in "green waste" containers. This material is collected for recycling by Richmond Sanitary.

Fourth, a question was asked about the number of trees that have been felled near the stack. In 1999, facilities maintenance requirements resulted in the cutting of four small diameter Eucalyptus sprouts in this area. Three were felled when their branches came close to the stack. One was felled during the construction of a maintenance stairway. All four were left in the area. This is a standard practice when very few small-diameter sprouts are felled.

Also, please be aware that Berkeley Lab has submitted an application to DOE, which proposes an increase in the threshold for offsite tree removal to 3,000 pCi/gram (combined TFWF and OBT). Dose assessments performed using very conservative assumptions have shown that these releases will result in extremely small potential impacts of less than 1 mrem/year to an offsite individual. This proposal is consistent with the national standard: ANSI/HPS N13.12 - 1999, Surface and Volume. Radioactivity Standards for Clearance. Until DOE approves this application, the release threshold will continue to be based on the Berkeley Lab Decision Rule.

I hope that this information helps you to understand this aspect of Berkeley Lab's vegetation management. I will be happy to have DOE and Laboratory representatives return to a future meeting of the City of Berkeley Community Environmental Advisory Commission to answer any additional questions you may have.

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