Hanford.Gov
About Us
ISS Reactors

Reactors in Interim Safe Storage At-A-Glance
Six of the nine production reactors at the Hanford Site have transitioned to the Long-Term Stewardship (LTS) Program, now that the interim remedial objectives have been achieved:

All six (6) reactors have been placed into placed into interim safe storage (ISS) in accordance with a Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) removal action.  The LTS program is now responsible for managing these reactors and the ongoing surveillance and maintenance activities.
 

History of the Reactors

Between 1943 and 1963, nine graphite moderated plutonium production reactors were constructed along the Columbia River as part of the Manhattan Project to support the production of weapons-grade plutonium. In the early 1960s, all nine reactors were operating. The first reactors to end operations were the 105-F and 105-H, which ceased operations in 1965. The last reactor, the105-N Reactor, shut down in 1987. The reactors were then deactivated and decommissioned and the auxiliary buildings were demolished, in accordance with a CERCLA removal action. 

A safe storage enclosure was constructed around six of the reactors (the six reactors listed above) with sturdy, steel roofing and siding to prevent deterioration and release of contamination. This process resulted in an ISS condition for all six reactors supporting an environmentally secure and cost-effective approach to safeguarding human health and the environment until permanent decommissioning and final closure of the reactors.

Of the other three other production reactors, the 105-B Reactor the world’s first, full-scale nuclear reactor has been designated a National Historic Landmark. The 105-K East and 105-K West Reactors  are currently undergoing decommissioning and are also being placed into ISS.  Upon completion of the remedial actions in the 100 K area and the K East and K West Reactors, it is anticipated that they will be transitioned into the LTS program.

Transition to the LTS Program

All six reactors that have been placed into ISS have been transitioned into the LTS Program with the 105-F Reactor being the first one transitioned to the LTS Program.  The land surrounding the reactors (with the exception of 100F Area ) has not yet been transitioned to the LTS Program due to ongoing remediation. The rest of the surrounding land will be transitioned to the LTS Program once the CERCLA remedial objectives have been achieved.

 

Reactor

Description

105-C

C Reactor -- Construction began in 1951 and it operated until 1969.  It was the sixth reactor constructed and the first to be fully decommissioned and placed in ISS under a CERCLA removal action on the Hanford Site. The implementation of ISS began in August 1996 and was completed in September 1998.

 Operated

Deactivated

ISS Completed

105-C

1952-1969

1971

1998

 

105-D

D Reactor -- Construction began in 1943 and it operated until 1967.  It was the second reactor constructed and was one of the longest serving facilities with 22 years of service. It was the fourth reactor to undergo decommissioning and demolition. The implementation of ISS began at the 105-D Reactor in January 2000 and was completed in September 2004.

 Operated

Deactivated

ISS Completed

105-D

1944-1967

1967

2004

 

105-DR

DR Reactor -- Construction began in 1947 as a potential replacement reactor to 105-D due to the numerous problems encountered in the operation of 105-D. It operated until 1964.  It was the fifth reactor constructed and operated for the shortest amount of time, only 14 years. It was second reactor to undergo decommissioning and demolition. The implementation of ISS began in January 1998 and was completed in September 2002.

 Operated

Deactivated

ISS Completed

105-DR

1950-1964

1964

2002

 

 

105-F

F Reactor -- Construction began in 1943 and it was the third of Hanford’s three original reactors constructed.  It is the one located farthest downstream and the one closest to the City of Richland.   It operated until 1965 and was the third reactor to undergo decommissioning and demolition.  The implementation of ISS began in January 1998 and was completed in September 2003. In October 2014, the regularly scheduled internal surveillance  was completed and nothing of significance was found.

 Operated

Deactivated

ISS Completed

105-F

1945-1965

1965

2003

 

105-H

H Reactor -- Construction began in 1948.  It was the fourth reactor constructed and the first after World War II. It operated for 15 years until 1965.  It was the fifth reactor to undergo decommissioning and demolition.  The implementation of ISS began in April 2000 and was completed in October 2005.

 Operated

Deactivated

ISS Completed

105-H

1949-1965

1965

2005

 

105-N

N Reactor -- Construction began in 1959.  It was the last reactor constructed and was constructed as a dual purpose reactor, also producing electricity. N Reactor was the longest running reactor with over 24 years of service.  It was the sixth reactor to undergo decommissioning and demolition. The ISS at this reactor is different from the other ISS projects because of the reactor design and the attached 109-N Heat Exchanger Building. The implementation of ISS began in January 2007 and was completed in September 2012.

 Operated

Deactivated

ISS Completed

105-N

1963-1987

1998

2012

Surveillance and Maintenance
Surveillance and Maintenance (S&M) activities are performed in accordance to the Hanford Federal Facility Agreement and Consent Order (commonly referred to as the Hanford Tri-Party Agreement) and CECLCA Post remediation requirements to ensure the ISS’s are maintained in a safe, environmentally secure, and cost-effective manner. These activities are performed (up to 75 years) until final disposition.

The LTS Program performs these S&M activities to ensure the reactors in ISS are maintained in a safe, environmentally secure, and cost-effective manner. These activities are required to be performed until permanent decommissioning and final closure.

  • Periodic external inspections - S&M activities consist of periodic inspections to evaluate the structural integrity of each of the safe storage enclosures and to ensure confinement of the remaining hazardous materials for which they were designed to protect.  These activities include annual inspections of the exterior of the safe storage enclosures (e.g., roofing, siding, flashing) and maintenance as necessary to address any issues identified.
  • Regular internal surveillances – surveillances are performed regularly on the accessible internal areas of the ISS reactors (currently required to be performed at five-year intervals) to verify facility status and to ensure their continued protectiveness. 
  • Remote monitoring - remote monitoring of the ambient air temperatures inside the safe storage enclosures at various elevations is currently conducted on a monthly basis. Also, flood detection sensors were installed at the sub-grade level in the safe storage enclosures to detect the buildup of water and are monitored on a monthly basis.
  • Radiological monitoring - annual radiological monitoring around the outside of the safe storage enclosures to meet the monitoring requirement in 10 CFR 835, “Occupational Radiation Protection.”
  • The LTS Program is also responsible for managing the final hazard categorization designated for each of the six safe storage enclosures in accordance with DOE-STD-1027-92, Change Notice 1, Hazard Categorization and Accident Analysis Techniques for Compliance with DOE Order 5480.23, Nuclear Safety Analysis Reports.

 

 

Last Updated 07/02/2018 8:22 AM