depotoo
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- Sep 9, 2012
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More info from the tri city herald-
Hanford waste tunnel collapses, no airborne radiation detected
Emergency work starts to fill hole in Hanford radioactive waste tunnel
And-
The tunnel where the breach was discovered Tuesday is the oldest of the two.
It is 360 feet long and was built using primarily creosoted timbers arranged side by side. The Department of Energy said concrete also was used.
Then it was covered with about eight feet of soil. It’s 22 feet high and 19 feet wide, according to Heart of America Northwest, a Seattle-based Hanford watchdog group.
Between June 1960 and January 1965, eight rail cars loaded with radioactive waste were pushed into the tunnel.
A second, stronger waste tunnel was built in 1964 with internal steel I-beams attached to reinforced concrete arches. It has a steel liner.
The second tunnel is 1,700 feet long and holds 28 rail cars of equipment, although it was built for 40.
The last rail car apparently was pushed inside in the early 1990s.
Between 1995 and 1997, water-filled doors of both tunnels and the outer PUREX railroad tunnel door were sealed, according to the CRESP report. Water can serve as a shield against radiation.
Last year a new legal deadline was set, requiring DOE to decide what process it would use to assess the integrity of the tunnels by September of this year.
The cleanup of the tunnels is part of central Hanford work that is required to be finished by 2042.
Those deadlines were among Tri-Party Agreement deadlines for central Hanford revised in 2016, as work had fallen behind schedule there because efforts and budget were focused on cleaning up contamination nearer the Columbia River.
Read more here: Roof failure was at a one-of-a-kind Hanford tunnel system
Hanford waste tunnel collapses, no airborne radiation detected
Emergency work starts to fill hole in Hanford radioactive waste tunnel
And-
The tunnel where the breach was discovered Tuesday is the oldest of the two.
It is 360 feet long and was built using primarily creosoted timbers arranged side by side. The Department of Energy said concrete also was used.
Then it was covered with about eight feet of soil. It’s 22 feet high and 19 feet wide, according to Heart of America Northwest, a Seattle-based Hanford watchdog group.
Between June 1960 and January 1965, eight rail cars loaded with radioactive waste were pushed into the tunnel.
A second, stronger waste tunnel was built in 1964 with internal steel I-beams attached to reinforced concrete arches. It has a steel liner.
The second tunnel is 1,700 feet long and holds 28 rail cars of equipment, although it was built for 40.
The last rail car apparently was pushed inside in the early 1990s.
Between 1995 and 1997, water-filled doors of both tunnels and the outer PUREX railroad tunnel door were sealed, according to the CRESP report. Water can serve as a shield against radiation.
Last year a new legal deadline was set, requiring DOE to decide what process it would use to assess the integrity of the tunnels by September of this year.
The cleanup of the tunnels is part of central Hanford work that is required to be finished by 2042.
Those deadlines were among Tri-Party Agreement deadlines for central Hanford revised in 2016, as work had fallen behind schedule there because efforts and budget were focused on cleaning up contamination nearer the Columbia River.
Read more here: Roof failure was at a one-of-a-kind Hanford tunnel system