TRANSMITTED TO DOE/M. WHITAKER 07/05/95

DEFENSE NUCLEAR FACILITIES SAFETY BOARD

March 14, 1995

MEMORANDUM FOR:               G. W. Cunningham, Technical Director
                                                                               
      
COPIES:                  Board Members

FROM:                         F. Bamdad

SUBJECT:                 Trip Report to Rocky Flats, January 3-6, 1995 -
                         Review of Criticality Safety and Building 707
                         Thermal Stabilization Preparations

1.   Purpose:  The purpose of this trip was to review nuclear criticality and
     safety of Buildings 371 and 771 at the Rocky Flats Environmental
     Technology Site (RFETS), and to review selected activities for
     preparations for startup of Thermal Stabilization in Building 707.  This
     review was performed by F. Bamdad (staff) and T. Quale (outside expert).

2.   Summary:  The staff made the following observations during this trip:

     a.   EG&G Rocky Flats relies heavily on administrative controls for
          implementation of safety issues pertinent to criticality hazards
          of operations.  The "double contingency" criteria are often
          implemented through two or more administrative controls or
          operator actions.  The staff believes that such reliance on
          operator performance for implementation of double contingency does
          not seem to be adequate at RFETS due to past history and
          performance of the operations and could lead to future criticality
          infractions or accidents.

     b.   The first two stages out of four stages of the High Efficiency
          Particulate Air (HEPA) filters for the ventilation system for the
          thermal stabilization area (J-module) have not been
          Dioctylphthalate (DOP) tested as required by current building
          Operational Safety Requirement (OSR).  An Unreviewed Safety
          Question (USQ) had been approved by the Rocky Flats Field Office
          (RFFO) which justified not testing these stages.  The OSR,
          however, was not revised to reflect this change.  The staff
          believes that operations which are not in strict compliance with
          the OSR represent poor conduct of operations and degrade the
          safety culture in the building.  In fact, cognizant personnel in
          the building including the shift manager did not understand the
          basis for not complying with the OSR. 

3.   Background:  The staff reviewed nuclear and criticality safety at RFETS
     during a trip on November 28 through December 2, 1994.  Several issues
     were identified by the staff that indicated lack of an aggressive
     program at RFO and EG&G for implementation of safety issues.  The staff
     recognized the need for further review of the RFETS safety program which
     was partially performed during this trip.

4.   Discussion:

     a.   The staff reviewed several criticality analyses performed by EG&G-
          RF in support of solid and liquid stabilization programs to be
          conducted in Building 707 and Building 771.  The staff believes
          that the EG&G facility safety engineering group is not being as
          conservative in these analyses as is prudent.  For example,

               1.   Procedures for draining tanks which have solutions
                    with unconfirmed plutonium concentrations allow the
                    solution to be drained into three 4-liter bottles for
                    sampling.  A 12-liter volume in a single spherical
                    unit with moderate reflection could possibly pose a
                    criticality concern when the plutonium concentration
                    is 100g/liter.  Highly concentrated solutions do exist
                    in Building 771 and could accidently be drained
                    through valve misalignment.  Limiting the sample
                    volume to 10 liters or requiring physical separation
                    of the bottles could eliminate any criticality concern
                    even with solutions at 500g/liter Pu concentration and
                    fully reflected.
          
               2    EG&G assumes that a nominal Keff of 0.95 is acceptable
                    for analytical results.  The staff believes that the
                    0.95 is too high a criticality coefficient threshold
                    for computer program calculations, considering the
                    uncertainties of these programs and the sensitivity of
                    the results to the analyst's inputs and assumptions.

     b.   In the letter dated February 1, 1994, the Board transmitted a trip
          report to the Department of Energy (DOE) and cited some safety
          concerns with regard to OSR deficiencies and lack of HEPA filter
          surveillance and maintenance at RFETS.  DOE has received and
          recently approved two USQ documents which reduce the safety
          surveillance requirements (DOP testing) for the HEPA filters in
          Buildings 707, 371, 771 and 774.

          Safety documents in support of the resumption of operation in
          Building 707 (including the Safety Analysis Report (SAR)) assume
          that all four stages of the HEPA filters are tested and maintained
          to a specified standard.  Some of these HEPA filters, however,
          have not been tested with the frequency specified in the OSR and,
          therefore, are in violation of their safety requirements.  Rather
          than trying to bring the HEPA filters into compliance with the OSR
          and SAR requirements, RFFO has approved an USQ which proposes
          maintaining only two stages of the HEPA filters in compliance with
          the OSR requirements, instead of all four stages.  This reduction
          in filter stages has resulted in an increase in risk to the public
          by a factor of 20 for explosion from briquetting (no longer
          performed), and by a factor of 6 for fire in glovebox J-60,
          (frequency of 0.02 per year).  RFFO has accepted the increase in
          risk for startup of Thermal Stabilization.  

          RFFO utilized the USQ justification to authorize Thermal
          Stabilization operations to proceed with only two stages of HEPA
          filters meeting the surveillance requirements.   Although the
          technical justification for relaxing the OSR requirements (the USQ
          documents) was prepared and approved by RFFO in September 1994,
          the corresponding OSR was not revised because RFFO safety
          engineers did not think it was necessary.  The staff believe that
          the OSR is one of the key safety documents that the operations
          people should be encouraged to respect and implement.  Operations
          which are not in strict compliance with OSR revision to support
          the building condition (even if the technical justification has
          been approved) is an example of poor conduct of operations and
          degrades the safety culture.  Such degraded safety culture and
          lack of conduct of operations in Building 771 led within the last
          few months to a criticality infraction with potential for
          significant consequences and to an unauthorized valve alignment
          incident.

5.   Future Actions and Followups:  The observations made by the staff during
     this trip and the one on November 28 through December 2, 1994 identify
     some concerns with the safety culture of the RFFO and EG&G Safety
     Engineering groups.  It appears that the safety engineers are more
     willing to support the activities than questioning the safety issues
     related to the activities.  The staff will investigate this finding
     further and review the independent safety oversight organizations during
     a trip scheduled for early February 1995.