DEFENSE NUCLEAR FACILITIES SAFETY BOARD

April 28, l994

MEMORANDUM FOR:G. W. Cunningham, Technical Director

COPIES:        Board Members

FROM:          Dermot M.  Winters

SUBJECT:       Review of Idaho Chemical Processing Plant High Level Waste
               Tank Farm Activities - March 29, 1994

1. Purpose:  This report documents a DNFSB staff review conducted on March 29,
   1994, of activities being conducted at the Idaho Chemical Processing Plant
   (ICPP) high level waste tank farm.

2. Summary:  The high level waste tank farm upgrade project at the ICPP is
   intended to bring transfer systems, including underground piping and
   ventilation lines associated with the high level waste tanks, into
   compliance with standards for high hazard underground storage tanks.  During
   the early March monitoring of corrective actions resulting from a December
   1993 radiation exposure incident, the staff became concerned that the
   upgrade project was being initiated without proper design and readiness
   reviews of the activities planned for this major radiological work effort. 
   The staff was also concerned about the approach to construction as then
   formulated by DOE and Westinghouse (WINCO).  Subsequently, during a follow-
   up visit on March 29 the staff reviewed the overall system analyses for the
   tank farm, the details of the upgrade project including its safety bases,
   and some of the associated analyses.  The staff also toured the tank farms
   and observed limited work in-progress.  Based on this review, the DNFSB
   staff believes the systems engineering analysis approach taken by DOE and
   WINCO is reasonable and represents an improvement in the overall methodology
   towards determining what and when activities need to be undertaken, and what
   fundamental requirements need to be specified.  The balance of the March 29
   review focused on the upgrade efforts.  As a result of their review efforts
   conducted during mid to late March, WINCO and DOE made significant changes
   and improvements in the construction approach and methods.

3. Background:  At the Idaho Chemical Processing Plant (ICPP), DOE is having
   Westinghouse Idaho Nuclear Company complete several upgrades to the high
   level waste tank farms.  The main purpose of this work is to bring transfer
   systems, including underground piping and ventilation lines associated with
   the high level waste tanks, into compliance with legal (Resource
   Conservation and Recovery Act) and technical standards for high hazard
   underground storage tanks.  

   Field work for the upgrades was scheduled to begin in early March 1994.  The
   work entails excavating several large areas around valve boxes and along
   buried piping runs to inspect and replace tile-encased lines, installing a
   new large valve box and associated piping, replacing essentially all
   transfer valves with an improved ball valve design, replacing the pressure
   and vacuum relief line interconnected to all waste tanks, and removing or
   capping old contaminated lines where encountered.  

   The DNFSB staff has been following the response of DOE and WINCO to an
   occurrence last year (ID-WINC-WASTEMNGT-1993-0014/Initial Notification
   12/12/93) involving workers who were contaminated during maintenance
   activities in one of the ICPP tank farm's valve boxes.  The staff has been
   monitoring the corrective actions resulting from this incident as part of an
   ongoing topical area review on radiation protection.  During a review of
   these issues in early March 1994, the staff also observed a review activity
   related to the upgrade project work.  The staff became concerned that the
   upgrade project was being undertaken without proper design and readiness
   reviews of the activities planned for this major radiological work effort. 
   This issue is closely tied to the corrective actions from the occurrence. 
   The lessons learned and corrective actions identified as a result of
   analysis of the occurrence have been incorporated in conduct of construction
   requirements for this project.

4. Discussion/Observations:  The DNFSB staff reviewed the overall system
   analyses for the tank farm and the details of the upgrade project including
   its safety bases and some of the associated analyses.  Also, the staff
   toured the tank farms and observed limited work in-progress.  Key items are
   noted as follows:

   a. Tank Farm Systems Analyses:  To provide an overall perspective of the
      tank farm and the relationship of the upgrade work being performed,
      WINCO presented the results of their ICPP tank farm systems analyses. 
      WINCO used a systems engineering based approach which followed some of
      the early steps of a typical systems engineering process:  problem
      definition (needs analysis), functional requirements definition,
      alternatives assessment, system definition, and evaluation and
      optimization.  The latter three steps typically are part of the
      conceptual design phase of an overall systems engineering life cycle. 
      The analyses have been documented in WINCO-1192, "ICPP Tank Farm Systems
      Analysis," dated January 1994.  

      The systems analyses included the effect of regulatory requirements that
      are associated with the upgrade effort and the consent order milestones
      to cease use of certain tank types starting in 1999 with capacity only
      in one to two tanks available for use as of 2013.  The analyses assumed
      that the current consent order upgrade requirements would be met to
      allow continued use of all of the existing tanks through 1999 according
      to the current cease use schedule.  They also evaluated whether there
      was a need for new waste tank capacity at ICPP as a result of potential
      future waste processing activities.  This effort resulted in the
      following major recommendations by the systems engineering team:
      
         1.  Install and operate a high level liquid waste evaporator by
             1997-1998.
 
         2.  Minimize liquid waste generation within operational safety and
             environmental constraints.

         3.  By 2008 start operation of a waste immobilization facility
             (potentially a vitrification plant or other technology for
             treating wastes for long-term storage).

         4.  Operate the new waste calciner as needed to eliminate the need
             for new tank farm capacity.

         5.  Maximize the sodium and potassium concentration in the calcine
             to  minimize  the amount of waste to be immobilized.

         6.  Avoid using Bin Set 7 for calcine storage, if possible, to
             reduce calcine retrieval activities and decommissioning costs.

         7.  Use waste tank WM-190 for liquid waste storage and one of the
             pillar and panel vault tanks as a spare.

         8.  Renegotiate the consent order and amended court orders to revise
             cease use dates for tanks and specific requirements on certain
             tanks which would eliminate the need for new tanks or extended
             calciner operations.

      The DNFSB staff believes the systems engineering analysis approach taken
      by DOE and WINCO to be reasonable and represents an improvement in the
      overall methodology towards determining what and when activities need to
      be undertaken, and what fundamental requirements need to be used.  Based
      on staff reviews of the systems approach efforts at other sites, the
      DNFSB staff believes the WINCO analysis could be used as an initial
      benchmark by others in conducting similar analyses to determine what the
      appropriate option(s) might be at their sites.  While WINCO's "system"
      used in this analysis encompassed the ICPP tank farm, some related
      facilities, and interfaces between the tank farms and these facilities,
      WINCO senior management noted that further analyses would be pursued
      that would broaden the system to include the entire ICPP and consider
      its ultimate end-state.  

   b. Tank Farm Upgrade Project:  The balance of the staff review focused on
      the upgrade efforts.  WINCO provided a historical review of the project
      and the detailed scope of the current efforts.  Also, the current plan
      for conducting the excavations was reviewed.  It was apparent that WINCO
      and DOE-ID had taken a second look at the initial approach of drilling
      large diameter holes for pilings to support bracing beams.  WINCO
      identified several concerns that had been raised by the internal
      readiness review group including accident conditions that would arise. 
      One such concern noted was that due to the uncertainties in locating
      buried piping, during drilling one of the large borings, the auger could
      grab hold of a small piping line that might be attached to a waste tank. 
      This could result in a loss of tank integrity. 

      As a result of the review efforts conducted during mid to late March by
      WINCO and DOE, significant changes in the approach were made from the
      methods that the staff reviewed in early March.  The major change will
      be that instead of the large borings, the earth fill around the valve
      boxes and buried lines will be removed in "phases" using an open cut
      slope approach.  Each phase will remove a layer about five feet in
      depth.  After a layer is removed further geotechnical surveys will be
      performed to provide better subsurface information concerning the
      location of buried systems.  The area to be excavated has been increased
      to provide for the sloped excavation technique, and to minimize the use
      of pilings and associated drilling.  The excavation by layers will use
      mechanical equipment and where needed hand excavation.  WINCO indicated
      that during excavation work monitoring for radiation fields and
      contaminated areas of soil would be nearly continuous.   

      The layer removal approach would be continued to about 20-25 feet in
      depth.  WINCO indicated that most of critical buried systems would have
      been located by the time this depth is reached.  At this depth, WINCO
      expects to be able to drill smaller diameter borings, and use pilings
      and bracing beams for the additional 10-15 feet of depth required to
      begin building the new valve box.  

   c. Tank Farm Tour:  After the WINCO briefings, the DNFSB staff toured the
      tank farm where work was in progress using the new excavation approach. 
      Radiological containment techniques that were employed appeared to be
      fairly well engineered.  Work activities are being tightly controlled
      through "plan of the day" meetings held each morning with those specific
      individuals who will perform the planned work on that day.

      Radiation work permits are issued only for one day and are specific to
      the activities being performed that day.  Several of them are issued
      with only specific individuals allowed to perform the particular work. 
      While the staff toured the farm area not much excavating was occurring. 
      There was some activity in a few radiological containment huts set up
      over valve boxes.  The design of these huts appeared to be well thought
      out.  They included ample windows for observing work, and enclosed
      "foyers" used as buffer areas for staging tools and equipment, and for
      removing soil and old equipment.   

5. Future Actions:  The staff will continue to observe work practices and
   planning activities as the project progresses.  Specific follow-up reviews
   related to monitor work activities in the areas of conduct of operations,
   radiological protection and work control are planned for April, May, and
   June, 1994.  The DNFSB staff anticipates monthly reviews of this effort as
   a minimum.  The staff plans to follow-up on the systems engineering efforts. 
   Based on current DOE-ID plans, it is anticipated that the DNFSB systems
   engineering follow-up review will occur in September.