BERKELEY, CA – A team of researchers at the Department of Energy's Lawrence Berkeley National Laboratory has developed an interactive computer program that building managers and owners can use to assess their vulnerability to — and to prepare for — chemical, biological, and radiological (CBR) weapons attacks or accidental toxic releases.

Heating, ventilation, and air conditioning systems are often the first line of defense against airborne chemical, biological, or radiological agents. The Building Vulnerability Assessment and Mitigation Program (BVAMP) helps building managers assesses vulnerability and make improvements.

The Building Vulnerability Assessment and Mitigation Program (BVAMP) can be obtained free through a website established by Berkeley Lab, which provides advice on CBR responses for buildings.

"Protecting buildings against CBR agents is an unfamiliar area for many building managers," says Tracy Thatcher, a scientist in Berkeley Lab's Environmental Energy Technologies Division (EETD) and a principal investigator in this effort. "Building managers already face conflicting demands for increased occupant comfort, building safety, operating efficiency, and cost reduction."

According to Thatcher, the heating, ventilation, and air conditioning system (HVAC) is often the first line of defense in the case of airborne CBR agents. "Preplanning and manipulating the HVAC system can significantly reduce the severity of a release," she says.

CBR threats can include deliberate terrorist attacks resulting in the release of hazardous materials, or accidents such as freight-train derailments and refinery releases.

With funding from the California Energy Commission's Public Interest Energy Research (PIER) program, Thatcher and her team developed the user-friendly, efficient, and field-tested program that can be used to assess vulnerability and get specific recommendations for a given building while minimizing energy penalties sometimes associated with improving HVAC system security.

BVAMP leads the building manager through several sets of questions about the building, focusing on four major topic areas: emergency response plan, building access, HVAC systems, and HVAC controls. It then produces a building vulnerability assessment report that details any areas where the manager could increase the protection of the building and prioritizes recommendations, both in terms of relative cost (high vs. low) and threat level.

Reducing the vulnerability of a facility requires actions in three areas: HVAC system control and operation, building system security, and emergency response planning. BVAMP has recommendations on both indoor and outdoor releases.

In the case of an outdoor CBR release — for example, a refinery accident causing a chemical plume -- Thatcher says, "Modifying the operation of the HVAC system during an emergency can significantly reduce its impact, potentially saving lives and reducing property contamination. Occupants are more likely to survive if they shelter in a building where the HVAC system can be quickly shut down to reduce indoor exposures. Reducing the air exchange rate, or leakiness, of a building can further reduce occupant exposure."

During the indoor release of a CBR agent, says Thatcher, "Building managers need to respond differently. Increasing the outside air supply and eliminating recirculation of return air into the building reduces both the spread of the chemical via the HVAC system and the concentration near the chemical source."

Berkeley Lab researchers participating in this project were Thatcher, Richard Sextro, Emily Wood, and Eve Edelson.

Berkeley Lab is a U.S. Department of Energy national laboratory located in Berkeley, California. It conducts unclassified scientific research and is managed by the University of California. Visit the website at http://www.lbl.gov.

Additional information

• More on safeguarding buildings against chemical and biological attack