Reactor Decommissioning History
Zion Decommissioning Unit-1 and Unit-2
revised as noted below

Currently Active in RV / RVI Work
Recent Updates
as of 8 June 2015

Reactor related effort in progress this week are:

  • Unit-2 reactor vessel is being cut, with some pieces packaged in shipping boxes.
  • Unit-1 reactor pool cavity drained down and being prepared for RV cutting.

RVI-1
Unit-1 was started after Unit-2 and was the last RVI work performed. The segmentation of the Zion reactor vessel internals campaign was announced complete as of December 15, 2014 when the Unit-1 Lower Core Assembly (LCA) was placed into its shipping container. The Reactor Cavity Pool is still full of water awaiting removal of miscellaneous items.

RVI-2
All parts of Zion Unit-2 Reactor Vessel Internals (RVI) are segmented and in liners.

RV-1
The reactor vessel decommissioning / segmentation in Unit 1 will begin as equipment used in Unit-2 becomes available.

RV-2
Currently torch cutting to segment the reactor vessel into smaller pieces to fit into shipping containers.

GTCC (Greater Than Class C)
There are 4 GTCC canisters in the Zion ISFSI. The last placed there 3/6/2015.

Fuel
All fuel is on the Zion ISFSI pad in 61 dry fuel canisters. Loading of the first can was during Christmas 2014, and the last can moved to the ISFSI on January 10, 2015 making this a very impressive campaign.


For more details on Zion Reactor Segmentation, contact us, click here, or visit us on Facebook.

Overview

Zion 1 & 2 (ZNPS) are Westinghouse commercial PWR power reactors. There are located midway between Chicago, Illinois and Milwaukee, Wisconsin on the beach of Lake Michigan. Unit 1 (DPR-39) & Unit 2 (DPR-48) each had a generating capacity of 1085 MWe and design capacity of 3250 MWt. Commercial operations were achieved for Unit-1 on December 1973 and for Unit-2 on September 1974. Final reactor operation for Unit-1 was February 21, 1997 and Unit-2 was September 19, 1996. Both units are currently being decommissioned at the same time. In March 2014, ZionSolutions' John Sauger noted that 2018 is targeted completion for the Zion Decommissioning project.

Both Zion reactor vessel internals (RVI) are segmented. The RPV's (RV's) are planned to be thermal cut starting in 2015 (with some abrasive or diamond wire saw assistance). The (61) dry fuel storage casks and (4) GTCC casks are stored vertically outdoors at the on-site ISFSI using NAC International MAGNASTOR and MAGNATRAN models of TSC (Transportable Storage Canister).

Reactor Decommissioning Specifics

Reactor Vessel Internals Removal
Underwater segmentation is completed by using cold cutting methods (reciprocating saw, rotary saw, milling). There were four primary segmentation tools used. There was one fixed tool (called the VRS) in the shallow end that segmented the upper internals and final size reduced many of the lower internals. Lower internals were initially segmented using three "portable" machines (i.e. the cutting tool was mounted to the piece being cut instead of the piece being mounted on the cutting tool). These machines were named the CHORCE, BMT, and FaST.

Reactor Vessel Removal
The RV will be segmented and packaged in pieces, then shipped to Clive. RV cutting process is to be Oxy-fuel from the outside. RV will be lifted and pieces cut (as was once planned for Humboldt Bay). The original cutting process planned was Wire Saw (AWS), but the Oxy-fuel type of thermal cutting later selected because it will be faster.

The RV Head for Unit 2 was shipped to the EnergySolutions waste facility in Clive as one piece while the Unit-1 was size reduced (hand held torch) before shipping.

Segmentation and Packaging Plan (S&P Plan)
Siempelkamp Nuclear Services (SNS) segmentation plan for the Zion Reactor Vessel and Reactor Vessel Internals.

GTCC Packaging
The Greater than Class C (GTCC) material from the reactor will remain on site with the fuel in the ISFSI. There are four canisters. These are the NAC International MAGNASTOR and MAGNATRAN models of TSC (Transportable Storage Canister). While already in use for fuel storage, Zion is the first application for GTCC packaging for this model TSC.

Key People
John Sauger, Dave Brown, Dan Pryor, Ken Bentley, Ron Richards, Steve Larson (these are reactor related people only).

Contractors (reactor related)
ZionSolutions - EnergySolutions
TLG Services (for D&D cost estimating in 1999).
Bigge Crane (heavy transport out of containment)
Siempelkamp Nuclear Services, Inc. (SNS - formerly MOTA Corporation)
NAC International (Dry storage for GTCC)
WMG
PlantDecommissioning.com (Equipment design, fabrication, staff augmentation)

Comments
The Zion D&D is considered the largest and the first side-by-side decommissioning of two power producing nuclear units.

Related Publications and Documents
ZionSolutions 8-24-2011 Weekly Reader Newsletter with RVI Segmentation overview.
ZionSolutions 9-29-2011 Weekly Reader Newsletter with RVI Segmentation update.
ZionSolutions 11-28-2011 Weekly Reader Newsletter on Cavity Fill Milestone.
July 2014 Power Magazine

References
The NRC's web page as of 8/24/06 & 2/22/10.
INSC web page as of 8/22/05.
Exelon Nuclear Operations Communications Department on 8/25/06.
Commonwealth Edison's PSDAR to the NRC dated February 14, 2000, revision 0.
Conversations with site people Feb 2010 through above date.

For more details on Zion Reactor Segmentation, click here or visit us on Facebook for current pictures and news. Click here to return to the Reactor List.