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Technical Basis ument for Tritium Contamination Limit in LCW

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Technical Basis ument for Tritium Contamination Limit in LCW Powered By Docstoc
					                      Jefferson Lab
        Technical Basis Document for
        Radioactivity Limits in Liquids

                            Jlab Tech Note
                           JLAB-TN-06-01

            Keith Welch, Erik Abkemeier, Bob May
                        January 20, 2006
                       Revised April 6, 2009



  Thomas Jefferson National Accelerator Facility
            12000 Jefferson Avenue
           Newport News, VA 23606



Authorization:

Vashek Vylet           _____________________Date: ____________
RadCon Manager         Signature

Mary Logue            _____________________ Date: ____________
Associate Director,    Signature
ESH&Q
            Technical Basis Document for Radioactivity Limits in Liquids


Table of Contents

Revision History………………………………………………………………….. ii

I.     Introduction……………………………………………………………….. 1
       1. Scope…………………………………………………………………… 1
       2. Background……………………………………………………………. 1

II.    A Review of Regulatory and Jefferson Lab Specific
       Limits and Guidelines……………………………………………………… 2
       1. EPA Regulations……………………………………………………….. 2
       2. NRC Regulations………………………………………………………. 2
       3. DOE Regulations………………………………………………………. 2
       4. Jefferson Lab Requirements…………………………………………… 3
               A. Action Level Development……………………………………. 3
               B. Bases fro Action limits for Liquids……………………………. 4

III.   Action Levels for Water…………………………………………………… 4

A. ENVIRONMENTAL PROTECTION………………………………………….. 4

       1. Groundwater Discharge………………………………………………… 4
       2. Other Releases to the Surface………………………………………….. 5
       3. System Limits and Controls……………………………………………. 5
       4. Releases to Sumps……………………………………………………… 7
              A. Accelerator Ring Sumps……………………………………...... 8
              B. End Station Floor Sump……………………………………..... 8
       5. Posting………………………………………………………………….. 9
       6. Discharge to Sanitary Sewer……………………………………………. 9

B. OCCUPATIONAL EXPOSURE CONTROL………………………………….. 10

       1. Surface Contamination…………………………………………………. 10
       2. Airborne Radioactivity…………………………………………………..12

IV.    Action Levels for Oils……………………………………………………… 13

       1. Clearance of Oil as Indistinguishable from Background……………….. 13
       2. Action Levels for Exposure Control…………………………………… 13

V.     Analytical Requirements………………………………………………….. 14

VI.    References…………………………………………………………………. 15

VII.   Appendices…………………………………………………………………. 15

       Appendix A. Summary of Action Levels and Actions…………………… 16

                                         i
           Technical Basis Document for Radioactivity Limits in Liquids



Document Revision History


Date                              Nature of Revision

January 20, 2006                  Original Issue

April 6, 2009                     Update removes some references to specific
                                  historical events in order to make more general.
                                  Implements provisions of DOE 5400.5 into
                                  document due to changes in primary contract.
                                  - Removed dated information from Scope and
                                  other sections
                                  - Added reference to JLAB-TN-08-063 (release of
                                  resin media)
                                  - Added O5400.5 to regulatory references
                                  - Added implementation guidance for O5400.5 to
                                  references
                                  - Removed the technical basis discussion for resin
                                  release
                                  - Modified release criteria for non-aqueous liquids
                                  to conform to the “indistinguishable from
                                  background” approach
                                  - Updated description of accelerator sump
                                  configuration for accuracy




                                        ii
          Technical Basis Document for Radioactivity Limits in Liquids

I. Introduction

      1. Scope

      This document addresses the control of radioactivity in water, water-borne media
      and other liquids in order to (a) control dose to exposed workers, (b) prevent the
      spread of contamination, and (c) minimize the potential for exceeding statutory,
      contract or permit limits on environmental releases in the event of a spill or leak
      from an affected system. This document also describes the conditions and
      allowable methods for release of these liquids from radiological control. Action
      levels will be established requiring certain controls or mitigating actions,
      depending on the type and location of the system.

      2. Background

      Historically, activity levels in Low Conductivity Water (LCW) systems have been
      so low that controls for handling and disposition of the water have not been
      required. The activity concentration in (non-beam dump) LCW has never
      exceeded the EPA drinking water limit. Detectable levels of some radionuclides
      have been found, as expected, in filter and resin media used to maintain water
      purity. The August, 2008 document entitled Radiation Control Policy and
      Technical Basis for the Clearance of Ion-Exchange Resins(1) (JLAB-TN-08-063)
      addresses release of resin media.

      Tritium (H-3) is a primary nuclide of concern in LCW, in that it is easily
      producible in water, has a relatively long half-life of 12.3 years, and has a
      tendency to disperse rapidly throughout fluids and surfaces. Be-7 is also easily
      produced in water via spallation of oxygen, but has a relatively short half-life of
      53.7 days. Some other nuclides are produced which have longer half-lives than
      Be-7 (e.g., Mn-54, Co-58, Co-60), but their production rates are considerably
      lower. All these nuclides (except H-3) have been detected in LCW resins, but not
      in the cooling water itself.

       In 2005, LCW samples containing measurable levels of H-3 and Be-7 were
      obtained from components in Hall C. These samples were taken during the
      removal of HKS (E01-011) experimental equipment (magnets in the chicane
      region of the beamline). (Note: beam loss in this region was unusually high with
      this experiment, due to an unprecedented beam line configuration involving a
      “split beam” setup, including steering of the beam downstream of the target. This
      resulted in considerable beam loss into the downstream magnets and their
      associated cooling water jackets.) Local cooling water samples from the LCW
      within Hall C showed a tritium concentration of 1.92E-6 uCi/ml and Be-7 activity
      on the order of 3E-5 uCi/ml. Samples were also taken of the LCW system at the
      main system headers in both Hall A and Hall C, and in building 92 at the main
      system ion-exchange sidestream loop. Be-7 was detected at the Hall C header
      (comparable to the concentration at the magnets). No activity above MDA for
      any nuclide was detected in the water at building 92 (end station LCW supply
      system).

                                          -1-
          Technical Basis Document for Radioactivity Limits in Liquids

      These results highlighted the need to review and systematically address handling
      and control of potentially activated liquids at JLab. This technical basis document
      was developed to meet this need. The present revision provides updates to
      address changes in accelerator operational configuration, and to fully implement
      requirements of DOE Order 5400.5, within the radiological environmental
      protection program.

II. A Review of Regulatory and Jefferson Lab Specific Limits and Guidelines

      1. EPA Regulations

      EPA drinking water standards as, delineated in 40 CFR 141.66, specify a limit of
      20,000 pCi/l (2E-5 uCi/ml) of tritium concentration in drinking water, as well as a
      combined limit of 4 mrem/year total dose equivalent from all beta-gamma
      emitting radionuclides (in the absence of any other nuclides, this implies a limit of
      40,000 pCi/l or 4E-5 uCi/ml for Be-7 alone). The tritium dose by ingestion of
      drinking water at this limit would be 1 mrem/year.

      2. NRC Regulations

      NRC regulations (10 CFR 20.1301) establish a primary dose limit of 100 mrem/y
      to any member of the public. Accordingly, §20.1302 allows release of liquid
      effluents in concentrations of 1E-3 uCi/ml (1E6 pCi/l) tritium to the boundary of
      an unrestricted area (values are listed in Appendix B, Table 2 of the rule). This
      concentration corresponds to a dose of 50 mrem/yr from continuous exposure
      based on annual oral ingestion for standard Reference Man; however, the NRC
      rule does not imply a dose limit of 50 mrem from drinking water. The more
      restrictive EPA drinking water standard would still apply to a drinking water
      source to which an effluent stream containing 1E-3 uCi/ml of tritium is directed.

      Disposal of tritium to the sewer is limited by 10 CFR 20.2003 to a monthly
      average concentration of 1E-2 uCi/ml, a factor of 10 higher than the effluent
      discharge limits discussed above. In addition, a total discharge limit of 5 Ci/y for
      tritium, 1Ci/y for C-14 and 1Ci/y for all other nuclides combined is established
      for sewer discharges.

      3. DOE Regulations

      DOE O 5400.5 Chg.2 of 1/7/93 also begins with a primary dose limit of 100
      mrem/yr to members of the public. The Order uses an approach similar to 10
      CFR 20 in controlling effluents, listing Derived Concentration Guide (DCG)
      values, which are based on the same dose-to-concentration relationship as Part 20
      (and those referenced in EPA standards). For instance, the DCG value for tritium
      is 2E-3 uCi/ml (2E6 pCi/l), which corresponds to a dose of 100 mrem/y under the
      same exposure conditions as are used in Part 20. Order 5400.5 explicitly states
      that the DCG values “are not release limits, but rather are screening values for
      considering BAT (Best Available Technology) for these [liquid] discharges and
      for making dose estimates.”

                                          -2-
    Technical Basis Document for Radioactivity Limits in Liquids


Rulemaking for environmental regulation by DOE is contained in 10 CFR 834,
which has been stalled in a draft version for many years. Primary dose limits in
the draft mirror the 5400.5 limits.

4. Jefferson Lab Requirements

JLab is required by its DOE contract to comply with DOE Order 5400.5, and
through state and local permitting processes to comply with our permits under the
Virginia Pollutant Discharge Elimination System (VPDES) and the Hampton
Roads Sanitation District (HRSD). VPDES permit #VA0089320 addresses
groundwater quality, both in-situ (well monitoring) and related to discharges of
groundwater to the surface (end station dewatering).

The VPDES permit limits surface discharges to the EPA drinking water standard
(at the point of dewatering sump discharge). Other discharges to surface waters
are not addressed by this permit unless they exceed specified action thresholds.
Monitoring for permit compliance is conducted at the dewatering sump.
However, additional monitoring of the surface discharge channels is conducted,
and any degradation of this effluent at any location would be cause for concern
and action. All surface water discharges are subject to O5400.5 requirements.
The ALARA process must be used to manage all discharges, and BAT must be
applied if such discharges would otherwise exceed the DCG.

HRSD permit #0117 addresses discharges to the sanitary sewer. The primary
limit is a total annual discharge of 5 Ci of H-3 and 1 Ci of all other gamma
emitting nuclides. In addition, a monthly average H-3 concentration limit of 0.1
uCi/ml applies to these discharges, and a daily limit of 10 mCi is also specified.
O5400.5 requires application of BAT if monthly average radionuclide
concentrations would otherwise exceed 5 times the DCG.

       A. Action Level Development

       Given the impact of a non-compliance event involving exceedance of a
       permit limit, it is reasonable and prudent to establish internal action limits
       for controlling liquids contained in cooling systems or other potentially
       activated/contaminated liquid-handling systems.

       In 1997, JLab established action levels for aqueous demineralizer resins of
       one tenth of the concentration in 10 CFR 20 Appendix B, Table 2, Column
       2, in order to allow release of resin bottles for reprocessing. JLab revised
       its resin clearance protocol to be consistent with O5400.5 in 2008 as part
       of its implementation of the Order (see JLAB-TN-08-063). This policy
       invokes the release criterion of “indistinguishable from background”, in
       accordance with implementation guidance for the Order (5). This technical
       basis now applies the indistinguishable from background release criterion
       to oils and other liquids that cannot be disposed of in the wastewater
       effluent stream. Internal procedures (2) establish action levels for sewer

                                    -3-
            Technical Basis Document for Radioactivity Limits in Liquids

               disposal of End Station Floor Drain sump water and for addressing
               contamination in soil. These action levels are reviewed in subsequent
               sections of this note.

               B. Bases for Action Limits for Liquids

               Controls on liquids and liquid systems are based on a number of factors,
               such as the location of the system, the type of liquid, statutory limits on
               environmental release, contamination of surfaces and materials, and the
               potential for dose from introducing the material into a given environment.
               Action limits are associated as closely as possible with existing permits
               where applicable. Wherever feasible, the DOE 5400.5 DCGs are used
               (with basic dose pathway evaluations) to derive action limits for liquids
               not addressed by a permit. The action limits contain considerable
               conservatism, such that in most cases, liquids containing activity below
               the action levels need not be controlled as radioactive material (specific
               requirements for control and handling are contained in the sections
               addressing each media/effluent type).

III. Action Levels for Water

A. ENVIRONMENTAL PROTECTION

This section deals primarily with limits and controls targeted at preventing environmental
impacts or doses to the public.

       1. Groundwater Discharge

       The VPDES permit limits radioactivity concentration in groundwater discharged
       to the surface to the EPA drinking water standard. Quarterly grab samples are
       taken for permit compliance purposes. Radcon tracks the activity of the
       dewatering sump discharge on an ongoing basis.

       Action Level
       An action level consistent with the limit for C-ring wells (<MDA, where MDA is
       specified as 1000 pCi/l for H-3) will be applied to this continuing monitoring.

       The permit specifies MDA values for four nuclides and gross beta. Adopting
       these values for action levels with regard to the dewatering sump is analogous to
       their use in the C-ring monitoring well system as a means to ensure that no
       degradation of offsite surface waters occurs.

       Action Triggered
       Should the action level be exceeded, immediate corrective action is warranted,
       and would include:
       (1) an investigation into the possible sources of the radioactivity, and
       (2) follow-up sampling of the sump at increased frequency.
       Potential corrective actions could include:

                                           -4-
              Technical Basis Document for Radioactivity Limits in Liquids

         (3) curtailment of accelerator operations,
         (4) discussions with the Virginia Department of Environmental Quality regarding
         temporary variance to the permit limits, or
         (5) diversion of the discharge flow to the sanitary sewer (which would require
         consultation with HRSD).

         It should be noted that MDA for H-3 analysis at Jlab is routinely about a factor of
         two better (lower) than the permit-required MDA. Any detectable activity in a
         location for which MDA is the action level will trigger action, including
         anomalous sample results that indicate activity but do not meet the statistical
         requirements for MDA.

         2. Other Releases to the Surface

         Although the VPDES permit does not specifically address radioactivity in surface
         discharges other than from groundwater, it is reasonable to follow a similar
         approach for all surface water regardless of the source. That approach is applied
         as follows.

         Discharge Limit
         Primary onsite limit for all surface discharges: Under normal conditions of
         operation, no liquids with activity greater than the EPA drinking water standard*
         shall be intentionally discharged to the surface without the express written
         permission of the Radcon Manager.

         Action Level
         For the system of surface water discharge (stormwater) channels around the site,
         an action level equal to the C-ring wells (<MDA) will be used.

         Action Triggered
         Should this action level be exceeded at the site surface water outflow points
         (location of routine sampling), immediate remedial action is warranted, and would
         include:
         (1) investigation to determine the source of the activity,
         (2) follow-up sampling in additional water channels leading to points of site
         outflow, and if necessary
         (3) isolation of the sluice gates at the site outflow.

         3. System Limits and Controls

         Controls on activity levels in various liquid systems will be implemented to
         minimize the potential for environmentally significant discharge events.



*Reference to the EPA drinking water limit refers to the stated limit of 2E4 pCi/l for tritium, and the
implied concentration limit (based on dose) of four percent of the DCG for other single nuclides. For
mixtures, the sum of the fractions of the concentration of each nuclide to four percent of its DCG must be
less than 1.

                                                   -5-
    Technical Basis Document for Radioactivity Limits in Liquids


The threat to surface water quality exists mainly from two broad categories of
discharge: (1) discrete spills of small quantities of significantly contaminated
water, and (2) large volume or long term leaks or spills from mildly or minimally
radioactive systems.

Large releases of highly radioactive water (i.e., >> 10 times the drinking water
limit) directly to the environment are not considered credible events due to
enhanced integrity and containment design employed in the affected systems.

It is unlikely that small spills of water (even if highly contaminated) could present
a condition that would jeopardize the quality of the surface water leaving the site.
High activity water (or other liquids) will be primarily controlled based on
limiting conditions such as potential surface contamination or uptake by workers.
However, controls on handling such water must also ensure that environmental
hazards are minimized. The specific criteria for establishing these controls are
described elsewhere in this document.

The most likely scenario for environmental releases is the loss of water from a
large volume system such as a low conductivity cooling water (LCW) system.
Action levels addressing this condition will be conservatively applied to all
systems or storage tanks meeting the following criteria:

-   System or storage tank capacity greater than 100 gallons, and;
-   System piping or tanks located outside, or in buildings which, in the event of a
    system rupture, have no features designed to contain a spill

Action Level
An action limit equivalent to the EPA drinking water standard is applied to these
cases, such that any such system or storage tank exceeding the limit is scheduled
for remediation at the earliest possible time. Normally, this would be in
conjunction with scheduled accelerator maintenance periods.

Action Triggered
(a) Remediation for an LCW system will entail purging the system (to the sanitary
sewer) and refilling with clean water (this process requires about three days).
(b) Portable or fixed storage tanks exceeding the action limit will be moved,
drained or equipped with secondary containment provisions if the concentration
can not reasonably be reduced.

Maintaining these systems to levels below the drinking water limit minimizes the
impact of spills to the surface, even in the case of a complete loss of the system
contents due to a catastrophic rupture. A hypothetical example is given below.




                                    -6-
    Technical Basis Document for Radioactivity Limits in Liquids

If we assume the loss of the entire contents of a typical LCW system onto the
surface, the spill volume is assumed to be 5000 gallons (personal communication
w/Bill Rust of Facilities Management). If the H-3 concentration in the water was
at 20,000 pCi/l, the total activity would be:

(2E4 pCi/l) (3.785 l/gal) (5000 gal) = 3.8E8 pCi (380 uCi) in 1.9E4 liters.

We estimate that the site has approximately 3 linear kilometers of surface
drainage channels. But, even a large spill would probably only impact a portion
of the ditch system. For this estimate, we estimate 1000 meters of the channel is
directly impacted. A channel is assumed to have a semi-circular cross section
with a radius of about 180 cm. The storm channels typically contain a volume of
standing water that varies with weather conditions. We will assume a baseline
condition where the ditches contain 10 cm of water. The initial volume of water
in the surface channel is:

[R2 cos-1{d/R} – d(R2-d2)1/2 ] [1E5 cm] = 7.9E8 cm3 = 7.9E4 liters

Where:
d = 170 cm
R = 180 cm

Another 1.9E4 liters is added by the spill, giving a total of 9.8E4 liters.

The average concentration caused by the spill would be:

3.8E8 pCi/9.8E4 liters = 3877 pCi/l

Although the local concentration near a spill area would be higher than the
average value, it is extremely unlikely that the entire contents of an LCW system
could be lost to the environment. Also, only a portion of the water lost during
such an event would go directly to the stormwater ditch. Much of the activity
would be distributed over a large area of the ground, limiting the movement of the
activity into the surface channels. And of course, activation of the LCW to a
concentration approaching the drinking water standard is highly improbable. In
any event, the mitigating actions described above would be invoked in order to
minimize impact on the environment.

4. Releases to Sumps

LCW systems of concern (as well as other, smaller volume liquid systems) all
have the potential to impact accelerator enclosure sumps in the event of rupture or
leakage. The action levels imposed on LCW systems with regard to
environmental releases should also protect the various pathways that exist via
sump discharge.




                                     -7-
Technical Basis Document for Radioactivity Limits in Liquids


  A. Accelerator Ring Sumps

  Accelerator ring floor sumps are pumped to the end station floor drain
  sump (FDS) for discharge to HRSD, except in the possible case of
  emergencies. These sumps can also be configured to flow to the surface,
  where the contents would either be captured in holding tanks, or in some
  cases, released directly to the storm ditch. Due to the pathway established
  through these sumps, this represents another potential route for LCW
  impact on surface waters.

  Action Level
  In the event the action level is reached for LCW supplying the accelerator
  ring (EPA drinking water limit), the following mitigating action will be
  taken.

  Action Triggered
   The default configuration, in which all sumps are routed to the FDS, is to
  be confirmed by physical inspection of piping and valves.

  B. End Station Floor Sump

  The FDS is discharged to the sanitary sewer, and its contents are regulated
  under the HRSD permit. The tritium concentration in the FDS often
  exceeds the drinking water standard. An LCW discharge into the end
  stations therefore has comparatively low impact on the sump. The
  primary impact of a catastrophic rupture of the end station LCW system
  on the sump would be a potential to cause overflow into one or more of
  the end stations, potentially contaminating the floor, and possibly
  impacting the end station dewatering sump. The capacity of the FDS is
  approximately 6000 gallons, so it is possible that draining the entire end
  station LCW system into the sump could occur without overflowing the
  sump (however, due to make-up system response, the potential exists for
  the LCW system to continue to supply water in excess of the static system
  volume). This would cause a high level sump alarm, as well as many
  other equipment failures and alarms that make it unlikely for such an event
  to persist unabated.

  If the LCW system was contaminated at a concentration of ten times the
  drinking water standard, and its entire contents were lost to the FDS, the
  total activity in the sump would be less than half the daily discharge limit.
  Therefore, no additional action levels are established for the FDS due to
  the potential for impact by the LCW system. Specific action levels for the
  end station dewatering sump (EES) are discussed below.




                              -8-
    Technical Basis Document for Radioactivity Limits in Liquids


5. Posting

Buildings that house LCW systems with the potential to become measurably
radioactive, or to build up radioactivity in filter/resin media, should be posted
appropriately to notify personnel of the condition. Although water with activity
in the vicinity of the drinking water limit does not pose a radiological hazard to
workers, conduct of maintenance that could potentially result in a significant loss
of water to the environment should be coordinated with Radiation Control staff.

6. Discharge to the Sanitary Sewer

Liquids being disposed of by means of the sanitary sewage system are regulated
through O 5400.5 and the HRSD permit. The annual limit on H-3 discharge of 5
Ci is effectively mitigated by a daily limit of 10 mCi (10 mCi per day, for 365
days yields 3.65 Ci). Therefore, the daily discharge limit is the primary
“working” limit to which we are held. Standard operating procedures (2) are in
place to address monthly average concentration limits in both the Order and the
permit.

Action Level
A previous incident in which this daily limit was exceeded was the catalyst for a
set of action levels now contained in HPP-ENV-003(2). The action levels apply
specifically to the FDS. These action levels are considered appropriate for
purposes of ensuring the permit limits are not exceeded based on sump activity.

Action Triggered
See Appendix A .or HPP-ENV-003(2)


The high power beam dump water disposal system (“TMDU”) also discharges to
the sewer. The total activity discharged through the TMDU and the FDS must be
below the HRSD permit limits. The higher activity water disposed of through the
TMDU drives the controls on discharges to HRSD. TMDU and FDS discharges
are initiated manually, following sampling and analysis of the contents. A goal of
no more than 8 mCi has been adopted to determine TMDU discharge volumes.
The goal was chosen to allow for FDS discharges to occur if necessary on the
same days as TMDU discharges.

Action Level
Consistent with this, the primary action limit for TMDU discharges is set at 8 mCi
in any one day. No intentional TMDU discharge above this level shall be made.

Action Triggered
 If it is determined that this level has been or will likely be exceeded, the
discharge process will be halted immediately, and no TMDU discharges will
occur until an investigation is conducted and the RadCon manager is satisfied that
adequate controls are in place.

                                    -9-
            Technical Basis Document for Radioactivity Limits in Liquids


       Administrative Process Controls
       Given that FDS and TMDU systems operate independently from each other, the
       following conditions also apply.

       (1) Normally, discharges from the TMDU and HFD will not be scheduled on the
           same day.
       (2) If discharge of the TMDU is made on the same day as the FDS, following a
           FDS discharge, the total activity discharged from the FDS for the day will be
           verified prior to TMDU discharge. The TMDU discharge volume shall be
           determined such that the calculated total activity from both sources does not
           exceed 8 mCi.
       (3) If a discharge from the FDS becomes necessary following a discharge of the
           TMDU, the cumulative total activity shall be calculated before discharge.
           Total discharge activity shall not exceed 9 mCi for both sources.

       Given these conditions, the maximum anticipated daily activity that could be
       discharged is less than 90% of the HRSD limit. The activity of the gamma
       emitting nuclides in the water must meet the same criteria scaled to the applicable
       limits.

B. OCCUPATIONAL EXPOSURE CONTROL

This section addresses action levels that apply primarily to workplace contamination
limits and doses to workers due to spills or leaks from contaminated systems. We will
derive triggers at which liquids and liquid systems are to be considered radioactive for
occupational exposure purposes.

None of the action levels or controls described in this section are intended to replace or
reduce the need for surveys and practices to assess and control radioactivity in the
workplace, particularly with respect to release of potentially contaminated items or areas.
These levels and controls supplement procedures and practices used to control
radioactive materials, and provide consistent standards for handling potentially
radioactive liquids.

       1. Surface Contamination

       The most direct and limiting condition in which aqueous radioactivity can impact
       a work area is a spill or leak of the water, causing surface contamination above
       the limits. The primary limits for surface contamination are contained in 10 CFR
       835. For H-3, the limit for removable contamination is 10,000 dpm/100 cm2. All
       other beta-gamma emitters applicable to Jefferson Lab are limited to 1000
       dpm/100 cm2. However, for Be-7 in Controlled Areas, Jefferson Lab has a
       specific limit of 30,000 dpm/100 cm2 (3).

       We will conservatively estimate a concentration in water at which a spill would
       not create a surface contamination level above the limit. Experimentation shows
       that 1 ml water covers approximately 3.14 cm2 surface area in a controlled

                                           - 10 -
    Technical Basis Document for Radioactivity Limits in Liquids

pouring situation (the area is limited due to surface tension, suggesting a
conservative estimate compared to larger volume spills).

If we assume that the total quantity of radioactivity in the water is instantaneously
deposited on the surface, we can estimate the water concentration necessary to
create an area contaminated above the limits:

For H-3:
pCi/L = (10,000 dpm/100 cm2) (0.45 pCi/1 dpm) (1000 ml/1 L) (3.14 cm2/1 ml)

Yielding 141,000 pCi/L

Rounding this value down to 1E5 pCi/L (1E-4 uCi/ml) provides even more
conservatism, allowing for the potential for buildup of activity from slow leaks or
multiple spills, and ties conveniently with an action limit in HPP-ENV-003.

Action Level
We will consider water (or any liquid) containing tritium activity greater than 1E-
4 uCi/ml, and any system or container in which it is housed, to be radioactive.

Action Triggered
Specific actions required above this level include:
(1) such systems and containers will be housed indoors,
(2) these systems and containers (except for small quantities for samples, etc.)
must have secondary containment systems in place capable of preventing any
credible breach or spill from the system from entering the environment (surface or
groundwater) or unmonitored sewage discharge point,
(3) posting of rooms or buildings housing such systems as radioactive material
areas,
(4) conspicuous marking of piping/system components such that workers are
made aware of the particular systems or containers containing the water, and
(5) a requirement for the use of PPE when work occurs that might expose workers
directly to the water or internal surfaces of the systems (type and extent of PPE to
be determined based on job and system-specific conditions).

For Be-7 and other beta-gamma emitters:
Using the same unit analysis methodology as above for tritium yields a limit of
423,000 pCi/l for Be-7 if the parameter of concern is exceeding a 30,000 dpm/100
cm2 surface contamination limit.

Action Level
Again, to provide conservative control, and in keeping with the approach for H-3,
a value of 200,000 pCi/l, or 2E-4 uCi/ml (five times the implied drinking water
limit for Be-7 alone) is established as the action level for Be-7. Likewise, the
action level for other beta-gamma emitters produced at JLab is set at five times
the implied drinking water limit for the individual nuclide, or equivalently, one
fifth of the DCG value in 5400.5.


                                    - 11 -
    Technical Basis Document for Radioactivity Limits in Liquids

The action level for mixtures is unity for the sum of the ratios of the concentration
of each nuclide to its corresponding action level (nuclides with activity below the
implied drinking water limit for those nuclides need not be considered in the sum
of the ratios calculation).

Action Triggered
The specific actions listed above for H-3 shall apply to all nuclides and mixtures.

Notes pertinent to Section 1.
(1) Systems containing more than 4000 gallons of water may require posting as
radioactive material even when the activity concentration is below the action
level, in order to meet the requirements of 10 CFR 835. This is not likely to
occur, however, given the relatively low concentration normally present in larger
systems.
(2) Liquids not exceeding the action limit do not meet the definition of radioactive
material for purposes of transportation regulations, as long as the quantities
transported are less than approximately 350 gallons. However, onsite transport of
such water shall be done in accordance with the protocols for onsite radioactive
material transport.
(3) Although systems containing water with activity below the action level
normally need not be controlled as radioactive material, the controls in section A
apply if the activity exceeds the thresholds in that section.

2. Airborne Radioactivity

Some potential exists with contaminated systems (especially H-3) for the
exposure of personnel to airborne radioactivity or the spread of contamination
through evaporation of the contents of open containers or systems operating at
high temperatures. Since tritium is by far the most mobile of such contaminants,
we will conservatively estimate the H-3 concentration that corresponds to an
airborne concentration of concern.

We will assume a saturation vapor density of 17.3 g/m3 at standard conditions and
that one gram of water is equivalent to 1 ml. We also conservatively assume that
in a closed space containing contaminated water, we achieve 100% relative
humidity by saturation of the air with the contaminated water. The DAC for H-3
in air is 2E-5 uCi/cc. The required activity concentration in the water to equal the
DAC for air is:

uCi/ml = (1E6 cc/17.3 ml) (2E-5 uCi/cc) = 1.16 uCi/ml

This far exceeds the typical activity of the most contaminated systems at Jlab;
however to ensure the potential for any uptake is minimized, the following action
level is established.

Action Level
H-3 activity concentration above 0.1 uCi/ml.


                                   - 12 -
           Technical Basis Document for Radioactivity Limits in Liquids

      Action Triggered
      When the H-3 activity exceeds the action level,
      (1) the air or gas headspace in the container or system is considered radioactive,
      and shall not be purged to the atmosphere except through a system designed to
      retain the H-3 activity (i.e. a “bubbler”), and
      (2) Such tanks and systems shall, to the extent practical, be kept tightly sealed (i.e.
      not subject to evaporation), or
      (3) If it is not practical to keep such a system sealed, periodic surveys and samples
      will be taken to ensure the radioactivity does not adversely affect the surrounding
      area. For instance, samples of air-conditioning condensate and smears of surfaces
      will be taken and analyzed for tritium.

IV. Action Levels for Oils

      1. Clearance of Oil as Indistinguishable from Background

      From time to time, lubricating oils and other non-aqueous liquid wastes are
      generated in accelerator enclosures and systems, where there is some potential for
      activation or contamination of the material. These liquids may present difficulties
      in analysis for nuclide content, particularly H-3, due to interferences in the liquid
      scintillation counting process. However, JLab has developed a method for H-3
      analysis in oil that can reliably achieve an MDA of 10,000 pCi/l (1E-05 µCi/ml)
      or less. Consistent with Ref. 1 and with O 5400.5 guidance, oil and other non-
      aqueous liquids with no detectable activity (when MDA is no greater than10,000
      pCi/l) will be considered indistinguishable from background, and may be released
      from control. All H-3 analysis done on such liquids shall be conducted using
      written, approved procedures that include spikes and duplicates in the method.

      To meet the release criteria, these media must also be free of any detectable
      gamma emitting nuclides. Given the limited exposure pathways for these
      materials, the detection criteria established in Ref. 1 are conservatively sensitive
      for this purpose.

      2. Action Levels for Exposure Control

      Since oils and coolants are not consumed, and are not disposed of through
      discharge to surface or ground water, effluent limits and guides are only roughly
      applicable in determining an appropriate action level for control. A thorough
      examination of every possible exposure scenario for these materials is beyond the
      scope of this document.

      Contact with residual films and coatings in containers or with materials used to
      absorb and clean up spills is assumed to be the primary exposure pathway for
      radioactivity in oils and coolants. The biological behavior of organically bound
      tritium (OBT) is the subject of current study within DOE and elsewhere.
      However, current guidelines(4) suggest that dose conversion factors for these
      materials are on the order of 2-3 times greater than for aqueous tritium (HTO). In
      addition, DOE has produced air concentration values (ACV) for controlling

                                          - 13 -
           Technical Basis Document for Radioactivity Limits in Liquids

       uptakes of OBT. For insoluble OBT in stable aerosols (such as oil vapors), the
       ACV is about a factor of 13 more restrictive than the DAC for HTO. Since
       surface contamination limits are derived in part for purposes of limiting uptakes,
       our approach will limit radioactivity in oily films and residues to a similar fraction
       of the contemporary release limits for surface contamination.

       We wish to address conditions that may occur in the course of disposing of waste
       oil. This may include incidental contact with oily surfaces or materials used to
       clean up spills. It takes very little oil to form a residual oily film on a surface.
       One ml of oil can easily cover 100 cm2 or more of surface area. However, the
       further we assume the material is spread, the less conservative our limit becomes.
       Using the same approach as in earlier sections of this document, we calculate the
       activity concentration necessary to result in contamination on a given surface
       area. Again, through experiment, we determined that approximately 5 ml of oil
       will thoroughly cover an area about the size of the palm of the hand
       (approximately 100 cm2), and that more than this is not readily retained on the
       surface.

       We apply a factor of 15 to the usual surface contamination limit for H-3, (to
       conservatively address OBT) and our result is:

       uCi/ml = (667 dpm/100cm2) (4.5E-7 uCi/dpm) (100 cm2/5 ml) = 6.0E-5 uCi/ml

       Action Level
       For H-3 in oil, a control level of 6E-5 uCi/ml (6E4 pCi/l) is set. This is ~ one 33rd
       the 5400.5 DCG for aqueous H-3.

       For other nuclides of concern, the action levels for aqueous liquids in Section III
       B apply. Mixtures are assessed using the sum of the fractions method.

       Action Triggered
       If any nuclide exceeds this action level in a waste oil, oil-based product, glycol-
       based coolant or solvent, the material will be handled as described in Section III B
       1. and 2.

V. Analytical Requirements

Samples of aqueous liquids shall be counted under MDA conditions equivalent to those
specified in the VPDES groundwater permit. MDA requirements for release of resin
media and oil as indistinguishable from background are specified in Ref.1 and Section
IV. 1. of this document.

Samples analyzed at Jefferson Lab shall be analyzed using equipment and methods which
are evaluated by participation in the Mixed Analyte Performance Evaluation Program,
conducted by the DOE Radiological and Environmental Sciences Laboratory. Other
laboratories used to conduct sample analysis applicable to the activities in this standard
shall participate in a similar quality assessment program.


                                           - 14 -
           Technical Basis Document for Radioactivity Limits in Liquids


VI. References

1. Radiation Control Policy and Technical Basis for the Clearance of Ion Exchange
   Resins; JLAB-TN-08-063, August 2008. K. Welch, V. Vylet, and B. May

2. HPP-ENV-003: Monitoring for Hall Floor Drain Sump Pit Discharge, Rev. 2. March
   2009.

3. DOE Exemption from Surface Contamination Limits for Be-7 (10 CFR 835,
   Appendix D), dated June 8, 1998.

4. Radiological Control Technical Position RCTP 2001–02, Acceptable Approach for
   Developing Air Concentration Values for Controlling Exposures to Special Tritium
   Compounds; Department of Energy Office of Worker Protection Policy and
   Programs, September 11, 2001.

5. Draft Handbook for Controlling Release for Reuse or Recycle of Non-real Property
   Containing Residual Radioactive Material, DOE-HDBK-xxxx-97; Washington, D.C.;
   June 1997.


VII. Appendices

Appendix A. Summary of Action Levels and Actions




                                        - 15 -
                                          Technical Basis Document for Radioactivity Limits in Liquids

                                                                Appendix A
                                                     Summary of Action Levels and Actions

                        Parameter                                        Action Level                             Action or Restriction
                                                                                                       Investigation
                                                                                                       Follow-up sampling
Groundwater discharge to surface (dewatering sump)         > MDA in sump                               **Halt accelerator operations
                                                                                                       **Permit variance
                                                                                                       **Dispose via HRSD
                                                           > EPA primary drinking water standard       No discharge to surface w/o RCM approval
Other discharges to surface                                                                            Investigation
                                                           > MDA at surface water outfall              Follow-up sampling
                                                                                                       **Isolate sluice gates
                                                                                                       Post areas for Radcon contact
                                                                                                       Purge and refill system
LCW and other systems or storage tanks                     > EPA primary drinking water standard       Drain, move or contain tanks
                                                                                                       - For accelerator ring LCW
                                                                                                       (a) Configure all sumps to tanks, or
                                                                                                       (b) Disable sumps discharging to surface
Discharges to sewer from FDS                               Increase by X 10 > MDA                      Notify RCM
                                                           >1E-4 uCi/ml                                Notify RCM
Discharge to sewer from TMDU                               >8 mCi/day                                  No discharge > A.L. w/o RCM approval
                                                                                                       System considered radioactive
Any liquid system                                          H-3 > 1E-4 uCi/ml                           Secondary containment
                                                           Other nuclides > 1/5 DOE 5400.5 DCG         Posting of areas and components
                                                                                                       PPE
                                                           H-3 > 0.1 uCi/ml                            Controlled venting only
                                                                                                       Monitoring required if open to atmosphere
Ion Exchange Resins                                        > MDA from Ref. 1                           No free release
                                                           H-3 > MDA (MDA < 10,000 pCi/l)              No free release
Oils, oil-based solvents, glycols, etc.                    Other nuclides > MDA from Ref. 1
                                                           H-3 > 6E-5 uCi/ml                           Containment and contamination control as
                                                           Other nuclides > 1/5 DOE 5400.5 DCG         applied to “Any liquid system” above
                         This table is a summary only; see text for full description of action levels and required actions

** These actions and others are optional, and would be considered if necessary to mitigate the issue


                                                                      - 16 -

				
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