High Flux Beam Reactor Facility Description

One of 10 national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory is located in the Town of Brookhaven in Suffolk County on Long Island, approximately 60 miles east of New York City. The BNL site occupies about 5,300 mostly-wooded acres in Suffolk County. Many of the Lab’s facilities are near the center of the site, in a developed portion that covers about 1,700 acres. The High Flux Beam Reactor (HFBR) is located in this central portion of the BNL property. The HFBR complex covers approximately 13 acres.

Background

The mission of the HFBR was to provide a source of neutrons for multidisciplinary scientific research in materials science, chemistry, biology, and physics. The HFBR achieved criticality on October 31, 1965. The reactor was originally designed for operation at a power level of 40 megawatts (MW). In addition to its external beams of neutrons, seven sample irradiation thimbles for neutron activation experiments were provided. In 1982, an equipment upgrade allowed operations at 60 MW. The reactor was shut down in 1989 to analyze the safety impact of a hypothetical loss-of-coolant accident. It was restarted in 1991 at 30 MW. The HFBR was shut down for routine maintenance and refueling in 1996 when a leak was discovered in the spent fuel pool that released tritium-contaminated water into the ground. The reactor remained shut down for three years for safety and environmental reviews. In January 1998, all the spent fuel was removed and shipped off site to allow for the insertion of a stainless steel liner in the spent fuel pool for the restart of the reactor. However in 1999, the DOE decided to permanently shut down the HFBR.

The HFBR Complex

The HFBR complex consists of multiple structures and systems that were necessary to operate and maintain the reactor. The most recognizable features of the complex are the domed reactor confinement building and the distinctive red-and-white stack (at right).

Portions of the complex building structures, systems, and components, some of which are underground, are contaminated with radionuclides and chemicals as a result of previous HFBR and Brookhaven Graphite Research Reactor (BGRR) operations. A number of actions have been taken to remove contaminated structures, hazardous materials, and contaminated equipment and components to prepare for permanent decommissioning. The remaining structures and systems are described below.

The High Flux Beam Reactor complex (in gray) includes Building 704 Fan House; Building 705 Stack; Building 750 Confinement Bldg; Building 751 Cold Neutron Facility; Building 802 Fan House and Tritiated Water Evaporation Facility.
 

 
Building 750, HFBR Confinement Building

Building 750, which houses the HFBR, is a hemispherical dome. It is the superstructure of the confinement building. The structure is constructed of welded steel plates supported by an I-beam framework that rests on a cylindrical base. The inside diameter of the hemisphere at its base is 176 ft. 8 inches. The base is 22 ft. 4 in. high and rests on a bedplate that is bolted to the reinforced concrete foundation ring. The foundation of the confinement building is a 5 ft. thick reinforced concrete mat bearing on the soil beneath the building.

The interior of the confinement building contains the reactor and biological shield and is divided into equipment, experimental, balcony, and operations levels. The operations level contained the control room, instrument and maintenance shops, labs and offices. The equipment level contained the spent fuel pool water purification system, pumps and heat exchangers, cooling systems, and the spent fuel pool. The experimental level (shown at right) was for scientific users. The reactor biological shield which surrounds the reactor occupies the central portion of this level. A large open space surrounding the biological shield housed experimental equipment and there were labs and offices along the perimeter wall. Offices, locker rooms, toilets, and HVAC equipment were located on the balcony. Access to the confinement building is provided by four airlocks: a personnel airlock; a forklift airlock; and two tractor trailer airlocks, one located on the experimental level and one on the equipment level. Most of the HFBR’s systems have been put into a lay-up condition. Only the building heating, ventilation, fire suppression, and cooling (HVAC) systems remain in service.

Reactor and Biological Shield

The reactor core consisted of 28 individual fuel assemblies arranged in a close-packed array. The fuel material was enriched uranium alloyed in aluminum and clad with aluminum in curved plates. Heavy water (D2O) served as the moderator/reflector and primary coolant. The reactor vessel was fabricated from aluminum alloy and contained the active core, reflector, and control rods. The vessel consists of an 82 in. spherical section welded to a 46 in. cylinder. The overall height of the vessel assembly is 24.75 ft. There are nine horizontal beam entry tubes that are integral parts of the vessel’s spherical section. The core region provided space and access for 16 experimental facilities.

The biological shield (diagram below) surrounds both the reactor vessel and the 9 in. thick thermal shield. The biological shield is 8 ft. thick and consists of an inner and outer steel shell filled with high-density concrete which also serves as an essential component of the structural integrity of the confinement building. The thermal shield is a carbon steel shell lined with lead.

There are 16 control rod blades (CRBs, below, right) within the reactor vessel. They are separated into main and auxiliary groups, each containing eight CRBs. The CRBs operated in the reflector region just outside the core. The CRBs are angle-shaped in cross-section and are made of stainless steel, encapsulating europium oxide and dysprosium oxide.

Building 704, Fan House

The fan house was initially constructed to provide primary and secondary cooling air for the BGRR. It encloses the BGRR discharge plenum and also houses the electrical switchgear and the normal and emergency power batteries for the HFBR. This switchgear also provides normal power to Bldgs. 703 and 701 and provides the pathway for the HFBR Bldg. 750 exhaust through underground ductwork and filter banks.

Building 705, Stack

The 100-meter tall stack was initially constructed to provide for elevated exhaust for the BGRR primary and secondary cooling air. Subsequently, additional building exhaust systems were connected to the stack. Currently, exhaust streams from Bldgs. 801 and Bldg. 750, the HFBR confinement building, are still connected to the stack.

Building 802 – Fan House

This structure (at right) houses the fans and equipment that provided the building exhaust flow for Bldgs. 801, 815, and 830. It also housed the equipment for evaporation of low-level tritiated water.

Underground Stack Ventilation Ducts and Lines

The underground stack ventilation ducts are the interconnecting ducts from Bldg. 750 and Bldgs. 801 and 802. Short sections of ducts from Bldgs. 901 and 701 are also included.

Last Modified: May 22, 2009
Please forward all questions about this site to: John Burke

One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. Brookhaven is operated and managed for DOE's Office of Science by Brookhaven Science Associates, a limited-liability company founded by the Research Foundation for the State University of New York on behalf of Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.

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