DEFENSE NUCLEAR FACILITIES SAFETY BOARD
May 19, 1994
MEMORANDUM FOR:   G. W. Cunningham, Technical Director
COPIES:           Board Members
FROM:             J. T. Arcano, Jr.
SUBJECT:          Review of Facilities and Unirradiated Fuel Storage at the
                  Reactor Materials Area of the Savannah River Site, March -
                  April 1994
1.   Purpose:  This memorandum describes the observations of Defense Nuclear
     Facilities Safety Board (DNFSB) staff during a review of facilities and
     unirradiated fuel storage at the Reactor Materials Area (M-Area) of the
     Savannah River Site (SRS).  A walk-through of the M-Area facilities was
     conducted on March 31, 1994, followed by briefings from the Department of
     Energy Savannah River Operations Office (DOE-SR) and Westinghouse
     Savannah River Company (WSRC) and another walk-through between April 19-
     21, 1994.  The review was conducted by DNFSB staff members J. Arcano,
     Jr., J. Blackman, A. DeLaPaz, P. Gubanc, and R. Schapira.
2.   Summary
     Safety issues stemming from a review of the planned storage of
     unirradiated fuel at K-Reactor prompted a DNFSB staff tour of Building
     321-M on March 5, 1994.  During this tour, numerous fuel rods and
     assemblies stored on hand-carts (dollies) were seen, while a large number
     of storage positions in a nearby borated concrete storage rack were
     vacant, raising concerns for the adequacy of criticality safety within M-
     Area.  These concerns prompted additional building tours and subsequent
     reviews of M-Area safety analyses, the status of M-Area authorization
     basis documentation, and an Unreviewed Safety Question Determination
     (USQD) which had originally been found positive by WSRC (based upon their
     inability to verify the adequacy of existing structural analyses of
     Building 321-M) but was subsequently determined by DOE-SR to be negative.
      DOE-SR's determination was based on a broad interpretation of DOE Order
     5480.21 and is an example of over reliance on probabilistic methods
     without considering the prudency of using deterministic principles
     involved with the development of defense-in-depth concepts.  This issue
     is further elaborated in an April 29, 1994 letter from the DNFSB Chairman
     to The Honorable Charles B. Curtis, Under Secretary of the Department of
     Energy.
     During the April 1994 DNFSB staff tour of Building 321-M, only one fuel
     rod was stored on a dolly (because it could not fit into the borated
     concrete rack).  WSRC had also issued a standing order limiting the
     amount of fuel storage on dollies and the number of dollies on which fuel
     is loaded.   Issues of concern to DNFSB staff include the following:
     a.    The approval process for updated authorization basis documentation
           for M-Area has progressed very slowly and it is conceivable that if
           the pace is not hastened, the documentation might not be approved
           prior to completion of the de-inventory operations currently in
           progress.
     b.    An emergency response procedure to secure the building water supply
           within one hour after a natural disaster to assure criticality
           safety has not been fully demonstrated by WSRC.
     c.    Various radiological control discrepancies were noted in and around
           the Building 321-M Furnace Casting Room.
     The enclosed Attachment contains an overview of M-Area facilities, and a
     more detailed description of Building 321-M.
3.   Background
     As a result of issues raised regarding the safety of the planned storage
     of unirradiated fuel at K-Reactor, a DNFSB staff member toured Building
     321-M on March 5, 1994 and discovered numerous fuel rods and assemblies
     stored on hand-carts (dollies).  Fuel had been removed from the uppermost
     row and outermost columns of the building's borated concrete fuel storage
     racks in response to a structural evaluation of the racks which
     questioned their integrity under tornado wind loads.  No limit existed
     for the total number of fuel elements allowed in Building 321-M and there
     was no limit on the total number of fuel elements allowed out of the
     borated concrete racks or in-process in the building at any time.
     DOE-EH Nuclear Safety Site Representatives had surveyed M-Area in October
     1993 for conduct of operations issues, and in March 1994 for radiological
     controls issues.  However, no criticality concerns had been noted.
     Unirradiated fuel is currently being stored at the  K-Reactor, the L-
     Reactor, and M- Area.  DOE-SR intends to start transferring fuel from L-
     Reactor to the K-Reactor and M-Area facilities by May 1994.
4.   Discussion:
     a.    Unirradiated Fuel Storage:  At the time of the DNFSB staff tour of
           Building 321-M on March 31, 1994, only six fuel tubes were being
           stored outside of the borated concrete storage racks.  WSRC had
           performed a USQD showing that natural phenomenon-induced
           criticality accidents in the racks were incredible (less than 10-6
           occurrences per year), and had returned the previously removed fuel
           to the periphery of the borated concrete storage racks.
           During the April, 1994 DNFSB staff review, only one fuel tube was
           being stored on a dolly.  As a result of questions raised by DNFSB
           staff regarding the safety adequacy of fuel storage on dollies,
           WSRC issued a standing order for Building 321-M which limits fuel
           storage on dollies to four fuel tubes per dolly, and also limits
           the number of dollies on which fuel is loaded to ten.  The number
           of tubes and dollies allowed has been determined based on
           operational considerations.  The staff noted that the number of
           dollies upon which fuel can be stored is not adequately controlled
           since greater than ten carts currently have Nuclear Safety Emblem
           (NSE) tags which allow fuel to be placed on them.
           During a May 12, 1994 tour of M-Area, the DNFSB staff was advised
           that nuclear safety emblems had been removed from all but the 10
           dollies currently in use at Building 321-M.  WSRC reiterated their
           position that the Safety Analysis Report (SAR) permits fuel storage
           on dollies and that administrative limits on fuel storage on
           dollies are not required; standing order limits are being
           implemented as a "best management practice."  WSRC also stated that
           their standing order limits can be modified or removed at the
           facility manager's discretion without concurrence or approval by
           DOE-SR since fuel storage on dollies is permitted by the SAR.
           WSRC presented preliminary results of natural phenomenon-initiated
           criticality events at Building 321-M related to storage of fuel
           tubes in both the borated concrete racks and on the tube dollies.
           In both cases, the accident sequences had probabilities of
           occurrence well below the threshold of credibility (10-6 per year).
           These accident analyses assume that a criticality accident would
           produce 5 x 1017 fissions as opposed to 1 x 1019 fissions,
           prescribed by Nuclear Regulatory Commission Regulatory Guide 3.34,
           Assumptions Used for Evaluating the Potential Radiological
           Consequences of Accidental Nuclear Criticality in a Uranium Fuel
           Fabrication Plant.  WSRC personnel stated that justification for
           the lower number of fissions requires demonstrating that a
           criticality accident in Building 321-M would be self-limiting.
           DNFSB staff will review the accident analysis results when they are
           completed and approved by DOE-SR.
     b.    Safety Authorization Basis:  The current DOE-approved authorization
           basis for M-Area include the 1987 Building 321-M SAR and the 1988
           Operational Safety Requirements (OSR) for Building 321-M.  A WSRC
           plan to generate an M-Area Justification for Continued Operation
           (JCO), in lieu of a revision to the SAR, was accepted by DOE-SR in
           December 1992.  This cost-saving action to generate a JCO was
           considered a compensatory measure as part of an exemption request
           from DOE Order 5480.21, Technical Safety Requirements, and DOE
           Order 5480.23, Nuclear Safety Analysis Reports.
           In July 1993, WSRC submitted the M-Area JCO to DOE-SR for review
           and approval after which a period of discussion and comment has
           ensued.  Because a Basis for Interim Operation (BIO) is required by
           DOE Order 5480.23 to be submitted with the SAR upgrade plan and
           schedule, it became evident to DOE that the elements of a BIO are
           required in a JCO in order to approve the JCO and exemption
           requests for M-Area facilities.  Therefore, in March 1994, DOE-SR
           tasked WSRC to compare the JCO against the draft DOE BIO guidance,
           draft DOE Standard Guidance for Preparation of DOE 5480.22 (TSR)
           and DOE 5480.23 Implementation Plans.  WSRC plans to resolve the
           additional DOE-SR comments, complete the BIO comparison, and
           formally transmit this information to DOE-SR in May 1994.
           According to DOE-SR, the path forward will be to task WSRC to
           prepare an addendum to the JCO which identifies areas which were
           highlighted by the JCO/BIO comparison as missing from the JCO.  The
           most significant item missing from the JCO appears to be a
           Preliminary Hazards Analysis (PHA) for all M-Area facilities.  DOE-
           SR intends to make the case to DOE headquarters that the JCO
           provides the substantive information required by a PHA and that the
           cost involved to create a PHA is not justified.  Other areas
           required for a BIO which are lacking in the JCO include:
           discussion of the operational history and occurrences, and a
           discussion of compliance schedule agreements for Order compliance
           at M-Area facilities.
           DOE-SR estimated that the JCO would be submitted by WSRC to DOE-SR
           in May 1994, and forwarded to DOE headquarters by June 1, 1994.
           DOE-DP headquarters line management estimates that their review of
           the JCO will take about two months.
           Throughout the lengthy and iterative JCO review process, Building
           321-M and other M-Area facilities have continued to operate, albeit
           in a de-inventory mode, for almost one year under a SAR and OSR
           which only address Building 321-M.  It is anticipated that the
           current de-inventory campaign will complete near the end of
           calendar year 1994.  However, if it is decided to also de-inventory
           the Mark 22 charges currently being stored in K Reactor facilities,
           de-inventory operations could last up until the end of calendar
           year 1995.  Thus, at the rate at which the JCO approval process is
           progressing, it is conceivable that DOE approval including
           headquarters will not be attained before de-inventory operations
           have completed.  The DNFSB staff believes the DOE-SR JCO approval
           process needs improvement to make it more timely in establishing
           authorization basis documentation for the M-Area facilities.
     c.    USQ Status and Ten Compensatory Actions:  When the original M-Area
           JCO
           was submitted to DOE-SR in July 1993, WSRC completed an Unreviewed
           Safety Question Determination (USQD) for the upgraded analysis.
           The USQD was determined by WSRC to be positive based upon WSRC's
           inability to verify the adequacy of existing structural analyses of
           Building 321-M following various natural phenomena events.  This
           led to a revision of the probabilities for several natural
           phenomena-induced criticality events.  Along with the positive
           USQD, WSRC identified ten interim actions to reduce the likelihood
           of such a criticality accident.  These actions included: maximizing
           the use of the borated-concrete storage racks; relocating cans
           containing loose scrap metal to a storage room which afforded
           additional structural protection by the room's steel walls;
           issuance of an emergency procedure to secure the building water
           supply within one hour in response to certain natural disasters;
           and storing floor sweepings from de-inventory casting operations in
           sealed cans to reduce the potential for dispersion of the fissile
           material in flood water.
           In December 1993, WSRC was informed that DOE-SR had determined that
           the USQD was not positive and that only three of the ten interim
           actions should be maintained.  WSRC, however, had implemented most
           of the other interim actions and intends to keep them in place as
           good management practice.  The DNFSB staff believes that additional
           actions are warranted with regard to the emergency procedure for
           securing the building water supply.  Specifically, WSRC stated that
           the procedural steps to secure water to the building were
           demonstrated the week previous to the April DNFSB staff review and
           that all shifts would be trained in the procedure by April 22.
           However, the practicality of the M-Area-wide emergency response
           actions, particularly on back shift, has not been reviewed or
           demonstrated for M-Area by WSRC.
           DOE-SR's rejection of the positive USQD was based on NE-70 guidance
           provided in a memorandum dated December 1992: "The term inadequate
           safety analysis as used throughout DOE 5480.21 should be
           interpreted to refer only to those situations in which the safety
           analysis supporting the current/interim authorization basis is
           found not to be bounding."  DOE-SR has interpreted the "bounding"
           accidents to include all Building 321-M accident events which were
           analyzed, not limited to the subset of natural phenomena-induced
           criticality events.  This interpretation may allow degradation of
           defense-in-depth without any further action required to determine
           the potential impact resulting from the increased probability of
           building structural failure as a result of natural occurrences.
           This is an example of overreliance on probabilistic methods without
           considering the prudency of using deterministic principles involved
           with the development of defense-in-depth concepts.  This issue is
           further elaborated in an April 29, 1994 letter from the DNFSB
           Chairman to The Honorable Charles B. Curtis, Under Secretary of the
           Department of Energy.
     d.    Radiological Controls:  During DNFSB tours in and around the
           Building 321-M Furnace Casting Room (a High Contamination and
           Airborne Area), several radiological control discrepancies were
           noted including: donning instructions not posted; undressing
           instructions not posted where required; and lack of a buffer zone
           between the High Contamination/Airborne Area and the Radiologically
           Controlled Area where various items are routinely passed across the
           boundaries. WSRC has taken corrective actions to post donning and
           undressing procedures, and to establish a buffer zone just outside
           of the High Contamination/Airborne Area.
5.   Future Staff Action:  The DNFSB staff will:
     a.    Continue to monitor WSRC and DOE efforts to approve the JCO for M-
           Area.
     b.    Review Building 321-M safety analysis calculations for natural
           phenomenon-induced criticality events, once completed and approved.
     c.    Review the verification of emergency actions in response to natural
           disasters at Building 321-M.
     d.    Continue to monitor radiological control practices in the Building
           321-M High Contamination Area.
Description of M-Area Facilities
The Reactor Materials Area (300 M-Area) is located adjacent to the Savannah
River main administration buildings (700 Area).  The primary mission of M-Area
was to produce fuel and target assemblies for Savannah River production
reactors.  Currently, however, most M-Area facilities are in various stages of
shutdown, de-inventory, and clean-up.   M-Area facilities have been conducting
de-inventory operations for almost one year with anticipation that they will
be completed near the end of calendar year 1994.  However, if it is decided to
also de-inventory the Mark 22 charges currently being stored in K Reactor
facilities, de-inventory operations could last up until the end of calendar
year 1995. The primary de-inventory process is a casting operation which
produces ingots from uranium-aluminum scrap and fuel tubes.  The ingots are
then shipped to the Oak Ridge Y-12 Plant for storage.
M-Area Facilities
Building 321-M, the Fuel Fabrication Facility, previously produced fuel tubes
of enriched uranium-aluminum alloy with aluminum cladding.  The fuel tubes
were assembled into fuel assemblies and used as a fuel to produce 238Pu,
239Pu, 254Cf, and tritium in SRS reactors.  Currently, the primary activity in
this building is casting chopped-up pieces of excess fuel tubes and pieces of
U-Al alloy scrap into ingots to consolidate materials into a form more
suitable for transport.  Almost all fissile material in M-Area is located in
Building 321-M.
The 311-M tank farm consists of two tanks:  a nitric acid tank, and a
Trichloroethylene (TCE) tank which is no longer used.
The 312-M tank farm tanks have been cleaned and physically disconnected from
any process, and are no longer used.
Building 313-M, the slug fabrication process building, produced depleted
uranium slugs clad with aluminum for producing plutonium in SRS reactors.
However, this process has been discontinued and the facility is currently in
cold standby.
Building 316-M, the mixed waste storage shed, contains minimal amounts of
fissile material (1.1% enriched uranium) in sludge which resulted from
processing Mark 15 fuel assemblies.  The sludge is awaiting processing and
future vitrification.
Building 320-M was where the alloy fabrication process was conducted for
target tubes and control rods (lithium-aluminum alloy cores with aluminum
cladding).  Fabrication operations have been discontinued and all lithium
target tubes have been removed from the facility.
Building 322-M is the Reactor Materials Quality metallurgical and physical
testing laboratory where both fissile and non-fissile materials are
metallurgically examined.  The building vault was being used to store fissile
material in the form of 10 cans of floor sweepings, 3 cans of grinding sludge,
and a uranium- aluminum standard.  This material is awaiting shipment to
Building 321-M for final disposition.
Buildings 330-M and 331-M are warehouses where depleted uranium cores and
slugs are stored.  Building 331-M is currently storing one box containing
several target pieces which contain 1.1% enriched uranium.
Building 340-M, a liquid waste handling facility, is in operation to support
Building 322-M and contains residual contamination.
The Liquid Effluent Treatment Facility (LETF) is an industrial waste-water
treatment system consisting of three close-coupled treatment facilities: the
Dilute Effluent Treatment Facility (DETF), the Chemical Transfer Facility
(CTF), and the Interim Treatment/Storage Facility (IT/SF).  The DETF treats
spent process solutions and low-contamination process effluents from M-Area.
CTF operations were discontinued in early 1992, except for the slurry system,
which transports filtercake from the DETF to the IT/SF tanks.  The IT/SF
stores slurried waste awaiting chemical stabilization and solidification for
permanent disposal.
Fuel Fabrication Facility (Building 321-M)
Building 321-M, the Fuel Fabrication Facility, is located within one half mile
of the SRS main administration buildings (700 Area).   This facility has
historically manufactured aluminum clad fuel assemblies for the Savannah River
Site production reactors.
During the manufacturing process, enriched uranium metal was alloyed with
aluminum in concentrations required for reactor irradiation.  The alloy was
cast into hollow cylindrical ingots from which pre-extrusion billet cores were
machined.  These cores, encased in aluminum, were then extruded into logs,
which were machined into sections, encased in aluminum, and coextruded into
tubes.  Each tube was then sized, cut to length, and straightened.
Today, the primary mission of Building 321-M is to de-inventory existing scrap
and fuel tubes by casting them into ingots suitable for offsite shipment.
Building 321-M was constructed to be a "high resistance" facility, designed to
withstand straight winds up to 150 mph, a Fujita Intensity F-3 Tornado (median
wind speed of 180 mph), or a Modified Mercalli Intensity VII earthquake
(horizontal ground acceleration of 0.1G).  Although Building 321-M is of "high
resistance" construction, the building is not seismically qualified nor has it
been seismically evaluated.  Following are descriptions of key areas currently
being used in the building:
Assembly Area:  During de-inventory operations, existing fuel assemblies are
being disassembled in this area.  Also within this area, fuel elements are
stored in a borated concrete storage rack; in-process fuel is stored on hand
carts (dollies) in this area.
The borated concrete storage rack consists of stacks of concrete slabs.  Each
individual slab is 8 inches high x 6 feet wide x 13.5 feet deep and has 9
polyvinyl chloride-lined storage holes with 5-inch inside diameters.  The
racks, capable of storing 1764 fuel tubes and assemblies, are maintained
subcritical by at least 0.50 wt.% boron in the concrete.  The behavior of the
tube storage racks during tornadoes or earthquakes has not been fully
evaluated.
Tube cleaning room:  Some of the extruded U-Al logs and fuel and target tubes
are cleaned in tanks in the tube cleaning room.  Seven tanks (a degreaser
tank, three cold rinse tanks, a caustic [NaOH] tank, a nitric acid tank, and a
hot rinse tank) are available for cleaning.
Machining Area:  For de-inventory operations, some logs are cut with the log
saw, and fuel tubes are cut into sections to facilitate the casting of
defueling ingots.
Casting Area:  The casting area produces defueling ingots from U-Al scrap and
excess fuel tubes.
Enriched Uranium Storage Vault:  The enriched uranium storage vault is
constructed of reinforced concrete with walls and roof twelve inches thick.
It was constructed as a "maximum resistance" area to withstand a Fujita
Intensity Five (F-5) tornado (290 mph) or a Modified Mercalli VIII earthquake
(0.2 G) with little or no damage.  All fissile material has been removed from
the vault.
Safety Systems within Building 321-M include:
          8 Nuclear Incident Monitor (NIM) systems, designed to activate
           evacuation alarm bells in the event of a nuclear incident.
          A ventilation system with HEPA filters.  Structural analysis of the
           ventilation system is not available, but estimated to be capable of
           withstanding a Fujita Intensity 3 tornado or a Modified Mercalli
           VII earthquake.
          Two fire protection systems.  The process computer room and the pit
           under the extrusion press are equipped with automatic total
           flooding Halon-type fire suppression equipment.  Halon-type manual
           fire extinguishers (40 total) are used for fire suppression in all
           other facility locations.  The use of water in regulated areas is
           prohibited to reduce the hazards and risks of a nuclear criticality
           incident.