DEFENSE NUCLEAR FACILITIES SAFETY BOARD
                                                                  
June 30, 1994                       
                                                                  
                              

MEMORANDUM FOR:     G.W. Cunningham, Technical Director           
                                         

COPIES:                  Board Members

FROM:                    Roger Zavadoski

SUBJECT:                 Hanford--PFP Ventilation Systems Trip
                         Report (May 24-26, 1994)

1. Purpose:  This trip report documents the Defense Nuclear
   Facilities Safety  Board's (DNFSB) technical staff (Roger
   Zavadoski), May 24-26, 1994, review of the
   ventilation/filtration system and associated safety envelope
   requirements at the Plutonium Finishing Plant (PFP).

2. Summary:  The DNFSB staff notes the following key observations: 

   a. The installation and use of the ventilation/filtration
      system at PFP corresponds to the 
         authorization basis. 
   b. The site contractor maintains its own calibrated equipment
      and trains its staff. 
   c. The future role and use of the filtration equipment during
      decontamination and  
            decommissioning activities has not, to date, been
thoroughly reviewed.

3. Background:  The PFP is an old facility that was built in 1949. 
   The original design was performed in accordance with the
   applicable contemporaneous criteria; however, today, it does not
   meet current criteria.  Ventilation wise, the original design
   called for a building turnover once every three minutes.  Today,
   the air turn over in the building occurs once every twelve
   minutes, a respectable rate by today's standards.  The
   reliability of the motive force provisions for the redundant
   fans in the ventilation system that derived their power from a
   redundant normal supply was originally enhanced by adding
   redundant steam driven fans.  The steam supply and the emergency
   electrical supply (which does not run the ventilation fans) are
   not designed to withstand seismic events.  In the event of a
   seismic occurrence, the supply fans are shut down in order to
   prevent building pressurization.  The electrically driven
   exhaust fans are then replaced with the steam turbine driven
   exhaust fans.

4. Discussion/Observations:  

   a. The status and configuration of the ventilation/filtration
      system for the PFP were reviewed based on documentation
      presented in (1) the Plutonium Finishing Plant Safety
      Analysis Report (DNFSB Log # 94-3129), (2) the Authorization
      Basis for PFP (DNFSB Log # 94-3130), (3) selected drawings
      of the ventilation systems (DNFSB Log # 94-3125), (4) Safety
      Envelope Features, Appendix C (DNFSB Log # 94-3132), and (5)
      Operational Safety Requirements (OSR) (DNFSB Log # 94-3131).

      The documentation clearly establishes that the role of the
      ventilation/filtration system is to operate continuously
      even during and after accidental conditions by supplying a
      redundant and diverse source of motive supply to the exhaust
      fans.  Facility tours verified the field status of the
      ventilation/filtration equipment.

   b. The contractor, Westinghouse-Hanford, WHC, has studied and
      analyzed the amount of plutonium in the duct work of the
      system.  This information is summarized in  a slide
      presentation submittal (DNFSB Log # 94-3144).  Discussions
      with the contractor about the role of the ventilation system
      and the impact of plutonium in the duct work on future
      decontamination and decommissioning activities revealed that
      present considerations are only at the formative stages of
      development.
 
   c. The contractor maintains a filter test group that preforms
      all of the OSR surveillance requirements for the filtration
      systems.  The test group strictly follows the requirements
      of the nationally recognized standard for filter testing,
      ASME N510-1989.  In addition to the requirements of the
      standard for test instrumentation calibration, the
      contractor maintains their own certifiable instrument
      calibration and repair program.  Also, the individuals who
      perform the filter tests must be trained under a
      comprehensive program (Course Number 060048, entitled
      Ventilation System Testing and Adjusting, 94-3128).

5. Future Staff Actions:  The staff will perform follow-up reviews,
   as necessary, on the role of the ventilation system in future
   decontamination and decomissioning activities.