ML17194A325

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E-Mail from Nike Williams, Zion Solutions, to John Hickman, NRC, Dated May 4, 2017, Forwarding TSO 17-004 Rev. O, Operational Dcgls
ML17194A325
Person / Time
Site: Zion  File:ZionSolutions icon.png
Issue date: 05/04/2017
From: Williams N
ZionSolutions
To: John Hickman, Vaaler M
Office of Nuclear Material Safety and Safeguards
References
TSD 17-004, Rev 0
Download: ML17194A325 (16)
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Text

Hickman, John From: Nick Williams <dewilliamsl@energysolutions.com>

Sent: Thursday, May 04, 2017 4:13 PM To: Hkkman, John; Vaaler, Madayna Cc: Gerard P. Van Noordennen

Subject:

[External_Sender] Zion Ops-DCGL TSD Attachments: 2017-05-04 TSD 17-004 Rev 0 Operational DCGLs FINAL.pdf .

Good Afternoon John and Marlayna, I've attached the approved Rev 0 of our Ops DCGL TSD for your review. I wanted to call your attention to one section that Eric Darois had suggested relative to implementation. Recognizing that we have waived AF/EMCs which would have allowed measurements above Base Case (25 mrem DCGLs) for small areas, we plan to implement surveys using our lower Operational DCGLs as follows:

"In a Class 1 FSS unit, the SOF (based on the Operational DCGL) fo~ a systematic sample/measurement(s) may exceed one without remedi.ation as long as the survey unit passes the Sign Test and, the SOF for the sample/measurement(s) does not exceed one when using the Base Case DCGLs" (i.e. A Survey Unit must pass the Sign Test based on the lower Operational DCGLs.) Single -measurements (i.e. small areas) in the passing Survey Unit may exceed the lower Ops DCGL, but must be below the Base Case (25 mrem) DCGL. .I understand that Gerry is lining up a call for us next week so if possible could you guys give us some feedback on this approach when we talk.

Thanks! Nick Donald E. Williams Jr. (Nick)

VP-Radiological and Environmental Controls ENERGYSOLUTIONS 151 Lafayette Avenue, Suite 201 Oak Ridge TN 37830 407 *314-5414 1

.~

ZionSolutions, LLC. ZlONSOLUTIONSuc An EnellJYSolul!oll* Ccmpany

  • Technical Support Document TSD 17-004 OPERATIONAL DERIVED CONCENTRATION GUIDELINE LEVELS FOR FINAL STATUS SURVEY
  • Revision 0 PREPARED BY I DATE: _D_._W_o_,,_~t_k_ow_i_ak_ _ _- __N_c_::_d __--~___0_5/_04_/_17_ _

Radiological Engineer REVIEWED BY I DATE: _E_r_ic_D_a_ro_is_ _ _ ___,_~--=-=----=*~~=-:__*

-~---0_5/_04_/_17_ _

CHP APPROVED BY I DATE:

05/04/17 VP Radiological & Environmental Controls

[O]

Zion Station Restoration Project TSD 17-004 Technical Support Document Revision 0 TABLE OF CONTENTS

1. PURPOSE--------------------------------------------------,--------------------------------------------------------------------*2
2. DISCUSSION----------------------------------------------------------------------------------------------------:------------;2
3. BASIS FOR DETERMINING OPERATIONAL DCGLS-----------------------------------------5
4. DETERMINATION OF A PRIOR/DOSE FRACTIONS ------------------------------------9
5. OPERATIONAL DCGL VALUES-------------------------------------------------------------------------------12
6. REFERENCES--------------------------.-------------------------------------------------------------------------------------14

[I]

Zion Station Restoration Project TSD 17-004 Technical Support Document Revision 0

1. PURPOSE Derived Concentration Guideline Levels (DCGL) are established to demonstrate compliance with the 25 mrem/yr unrestricted release criterion. DCGLs are calculated by analysis of various pathways (direct radiation, inhalation, ingestion, etc.), media (e.g., concrete, pipe, soils and groundwater) and scenarios through which exposures could occur. Chapter 6 of the Zion License Termination Plan (LTP) (Reference 1) describes in detail the approach, modeling parameters and assumptions used to develop the DCGLs (referred to as Base Case DCGLs) that will be used for the Final Status Survey (FSS) of the Zion Nuclear Power.

Station (ZNPS). Each Base Case DCGL represents a total dose of25 mrem/yr. At ZNPS, compliance is demonstrated through the summation of dose from four distinct source terms for the end-state (basements, soils, buried pipe arid groundwater). Basements are comprised of the summation of four structural source terms (surfaces, embedded pipe, penetrations and fill). As the summation of dose from each source term must be 25 mrem/yr or less, the Base Case DCGLs are reduced based on an expected, or a priori, fraction of total dose from each source term. These reduced DCGLs will be called Operational DCGLs. This Technical Support Document (TSD) details the Operational DCGLs derived for each dose component and the basis for the dose fractions used.

2. DISCUSSION Each radionuclide-specific DCGL is equivalent to the level ofresidual radioactivity (above background levels) that could, when considered independently, result in a Total Effective Dose Equivalent (TEDE) of25 mrem per year to an Average Member of the Critical Group (AMCG). When applied to backfilled basement surfaces below 588 foot elevation, embedded pipe and penetrations, the DCGLs are expressed in units of activity per unit of area (pCi/m2). When applied to soil, the DCGLs are expressed in units of activity per unit of mass (pCi/g). For buried piping, DCGLs are calculated and expressed in units of aCtivity per surface area (dpm/100 cm2).

There will be four distinct source terms for the end-state at Zion: backfilled basements, soil, buried piping and groundwater. Demonstrating compliance wi_th the dose criterion requires the summation of dose from the four source terms as shown in Equation 1 (reproduced from Equation 6-11 from LTP Chapter 6, section 6-17).

The final compliance dose will be calculated using Equation 1 after FSS has been completed in all survey units. The results of the FSS performed for each FSS unit will be reviewed to determine the maximum mean dose from each of the four source terms (e.g., basement, soil, buried pipe and existing groundwater if applicable). The compliance dose must be less than 25 mrem/yr. As the summation of dose from each source term must be 25 mrem/yr or less, the Base Case DCGLs are reduced based on an expected, or a priori, fraction of total dose from each media type. The reduced DCGLs are the Operational DCGLs.

[2]

, Zion Station Restoration Project TSD 17-004 Technical Support Document Revision 0 Equation 1 Compliance Dose Max Backfilled Basement+ Max Soil +Max Buried Pipe+

Max Groundwater where:

Compliance Dose Dose to Resident Farmer AMCG (mrem/yr),

Max Backfilled Basement = Maximum Basement survey unit dose (including surface, embedded pipe, penetrations and fill [if required]),

Max Soil = Maximum dose from open land survey units (mrem/yr),

Max Buried Pipe Maximum dose from buried piping (mrem/yr),

Max Groundwater Maximum dose from existing groundwater The terms for Backfilled Basement, Soil and Buried Pipe use the maximum observed mean dose from FSS. The mean dose fraction is derived by dividing the mean dose by 25 mrem/yr.

The dose fraction for the "Max Groundwater" term will be determined based on the analysis of water samples taken from sample wells established at and around Zion. There has been no groundwater contamination identified.by the groundwater monitoring program to date at Zion. It is expected that the potential for future groundwater contamination is also very low.

Consequently, the a priori dose fraction .assumed for groundwater is based on the Minimum Detectable Concentration (MDC) for groundwater analysis, which results in a dos.e of 1 mrem/yr (or a dose fraction of 0.040).

The dose fraction for the "Max Soil" and "Max B*uried Pipe" variables will be determined based on the result of FSS. The Radionuclide-of-Concern (ROC) concentration in each systematic sample/measurement taken in each FSS unit will be divided by its applicable Operational DCGL (OpDCGLss for surface soil, OpDCGLss for subsurface soil and '

OpDCGLsP for buried pipe) to derive a Sum-of-Fraction (SOF) for the ROC. The actual recorded value will be used as the recorded FSS result for measurement and/or sample values that are less than MDC. The SOF for each ROC will be summed to derive a SOF that represents the sample/measurement. The sample/measurement SOF will be used as the weighted sum (Ws) for performing the Sign test. If the number of positive differences is greater than or equal to the critical value for the number of sample/measurements (n) and chosen Type 1 Error (a), then the null hypothesis will be rejected and the FSS data set will pass the Sign test.

The dose fraction for the "Max Backfilled Basement" variable includes the dose contributions from walls and floors (including the steel liner in Containment), defined as structural surfaces, plus the dose contributions from embedded pipe, penetrations and concrete fill (applicable where clean concrete debris is used as fill). Each of these dose

[3]

Zion Station Restoration Project TSD 17-004 Technical Support Document Revision 0 components are surveyed separately during FSS. The summation of the rriean dose from each of these dose components provides the total backfilled basement dose for the Baseip.ent FSS unit. The backfilled basement with the maximum mean dose will be used for the "Max Backfilled Basement" term in Equation 1.

The dose from concrete fill is predetermined in accordance with LTP Chapter 5, Table 5-16, and is currently based on a maximum allowable MDC of 5,000 dpm/100cm 2, which is a conservative assumption. This is solely a bounding Value and not indicative of the actual MDC values experienced when unrestricted release surveys (URS) were performed on the concrete, which were significantly lower. After all URS have been completed on the remainder of the concrete that will be reused as clean fill, the dose from fill in Table 5-16 will be recalculated based on the actual maximum MDC observed during the performance of the URS.

For structural surfaces, embedded pipe and penetrations, the ROC concentration in each systematic sample/measurement taken in each FSS unit will be divided_ by its applicable Operational DCGL (OpDCGLs for structural surfaces, OpDCGLEP for embedded pipe and -

OpDCGLPN for penetrations) to derive a SOF for the ROC. The SOF for each ROC will be summed to derive a SOF that represents the sample/measurement. The sample/measurement -

SOF will be used as the weighted sum (Ws) for performing the Sign test. If the number of positive differences is greater than or equal to the critical value for the number of sample/measurements (n) and chosen Type 1 Error (a), then the null hypothesis will be rejected and the FSS data set will pass the Sign test.

In all cases (backfilled basements, soil and buried pipe),if the SOF for a systematic sample/measurement (based on the Operational DCGL) exceeds-"one", or "0.5 in a Class 3 survey unit, then an investigation will be initiated in accordance with LTP Chapter 5, section 5.6.4.6 (Table 5-20). In Class 3 and Class 2 FSS units, the result_ of the investigation may prompt the reclassification of the survey unit (or a portion of the survey unit). In a Class 1 FSS unit, the SOF (based on the Operational DCGL) for a systematic sample/measurement(s) may exceed one without remediation as long as the survey unit passes the Sign Test and the SOF for the sample/measurement(s) does not exceed one when using the Base Case DCGLs.

The results of any judgmental sample/measurements will also be compared to the Operational DCGL. As with a systematic sample/measurement, any judgmental sample/measurement that exceeds a SOF of one, or 0.5 in a Class 3 survey unit, will prompt an investigation, reclassification and/or resurvey as applicable. However, remediation will not be required unless the sample/measurement exceeds unity when compared to the applicable Base Case DCGLs.

In Class 1 open land FSS units, any areas of elevated residual radioactivity above the DCGLEMC will be remediated. The DCGLEMc calculation will use Base Case DCGLs (DCGLss from Table 2 and/or DCGLss from Table 3). In Class 1 buried pipe, any residual

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Zion Station Restoration Project TSD 17-004 Technical Support Document Revision 0 radioactivity greater than the Base Case DCGL for buried pipe (DCGLBP from Table 4) will be remediated. In all Class 1 structural surfaces, any residual radioactivity greater than the Base Case DCGLs for structures (DCGLB from Tab.le 1) will be remediated. For all Class I embedded pipe and penetrations, any residual radioactivity greater that the Base Case DCGLs for* embedded pipe (DCGLEP from Table 5) or penetrations (DCGLPN from Table 6) will be remediated. Any residual radioactivity in Class I embedded pipe and penetrations greater than the Base Case DCGLs for the structural surfaces (DCGLB from Table 1) where the pipe or penetration interface will require further remediation and/or grouting of the pipe .

. Once a FSS unit passes the Sign test, the mean concentration for each ROC based on the systematic sample/measurements will be divided by the applicable Base Case DCGL to derive a mean dose SOF for each ROC (with the LTP Chapter 5 Equation 5-9 equation applied as applicable). The mean dose SOF for each ROC is then summed and multiplied by 25 mrein/yr to provide the mean dose _for the FSS unit.. For Basement FSS units, the mean dose for each dose component (structural surfaces, embedded pipe and penetrations) is summed and added to the applicable fill dose to derive the mean dose for the Basement FSS unit. The mean dose from FSS will also include the dose from judgmental sample/measurements based on an area-weighted average approach using the applicable Base Case DCGL.

3. BASIS FOR DETERMINING OPERATIONAL DCGLS The Base Case DCGLs from LTP Chapter 5 are reproduced as follows; Table l Base Case Basement DCGLs IDCGLs) - (from L TP Chapter 5, Table 5-3)

....* Auxiliary* SFP!fransfer Turbine Crib House Containment . WWTF Nuclide'. Building Canal Building /Forebay

  • 2 (pCi/m ) (pCi/m )2 2 (pCi/m ) (pCi/m ) 2 (pCi/m )2 (pCi/m2 )

H-3 5.30E+08 2.38E+08 2.38E+08 l.29E+08 l.93E+08 l.71E+07 Co-60 3.04E+08 l.57E+08 l.57E+08 7.03E+07 5.52E+07 2.83E+07 Ni-63 l.15E+IO 4.02E+09 4.02E+09 2.18E+09 3.25E+09 2.89E+08 Sr-90. 9.98E+06 1.43E+06 l.43E+06 7.74E+05 l.16E+06 l.03E+05 Cs-134 2.11E+08 3.01E+07 3.0!E+07 l.59E+07 2.13E+07 2.31E+06 Cs-137 1.l IE+08 3.94E+07 3.94E+07 2.1 IE+07 2.96E+07 2.93E+06 Eu-152 6.47E+08 3.66E+08 3.66E+08 l.62E+08 l.23E+08 7.55E+07 Eu-154 . 5.83E+08 3.19E+08 3.19E+08 l.43E+08 l.12E+08 5.74E+07 Note I: The DCGL for the SFP/Transfer Canal was set equal to the lower of either the Auxiliary Building or Containment DCGLs. The Containment DCGLs were lower for all ROC; therefore, the SFP/Transfer Canal DCGLs were set equal to Containment DCGLs.

[5].

Zion Station Restoration Project TSD 17-004 Technical Support Document Revision 0 Table 2 Base Case DCGLs for Surface Soils (DCGLss) - (from L TP Chapter 5, Table 5-4)

Surface Soil DCGL Radionuclide

. (pCi/g)

Co-60 4.26 Cs-134 6.77 Cs-137 14.18 Ni-63 3572.10 Sr-90 12.09 Table 3 Base Case DCGLs for Subsurface Soils (DCGLss) - (from L TP Chapter 5, Table 5-5)

Subsurface Soil DCGL R,.adion ucli,fo>.: *

.. . '\*

  • :(pCi/g) *.. . .

Co-60 3.44 Cs-134 4.44 Cs-137 7.75 Ni-63 763.02 Sr-90 1.66 Table 4 Base Case DCGLs for Buried Pipe (DCGLsr)-(from LTP Chapter 5, Table 5-6)

.Buried ~iping ..QCGI,>**

Radioriuclid"' *  : (dpm/100 cm2) * .,

Co-60 2.64E+04 Cs-134 4.54E+04 Cs-137 1.0IE+05 Ni-63 4.89E+07 Sr-90 4.50E+04

[6]

Zion Station Restoration Project TSD 17-004 Technical Support Document Revision 0 Table 5 Base Case DCGLs for Embedded Pipe (DCGLEr) - (from LTP Chapter 5, Table 5-7)

  • * , ** :t'Auxiliai"y Bldg:YP *. TurbiDeBldgt:, .unitl & Dijit~ *
  • Unit 1 & :Unit 2* .,::unin'&>Dnit*2**
.,. Basement * *
  • Base.lneni *
  • ContainrrienHn- Steam Tunnel : **. Tendoll'Tunnel:

Embedded Embedded . C~re:Sump* . * *Embedded

  • Embedded
,,;,/Floor Drains .
FIOi>r*D~ains .* :Embedded: * ... */lj~looi:n,rains *~****I::: Floor¥~rains :.:.

.. (pCi/m 2) ...

(pCVm 2)

" ' D;ain Pipe

. ( i>Ci/m2)

. (pCi/m2).

. '. I' .* . . ':

  • (pCi/m2)

H-3 NIA NIA 8.28E+09 NIA l.61E+l0 Co-60 7.33E+09 6.31E+09 5.47E+09 4.07E+10 l.06E+l0 Ni-63 2.78E+ll l.96E+l l l.40E+l l l.26E+l2 2.72E+ll Sr-90 2.41E+08 6.94E+07 4.98E+07 4.48E+08 9.70E+07 Cs-134 5.10E+09 l.43E+09 l.05E+09 9.22E+09 2.04E+09 Cs-137 2.68E+09 l.89E+09 l.37E+09 l.22E+l0 2.67E+09 Eu-152 NIA NIA l.28E+l0. NIA 2.48E+l0 Eu-154 NIA NIA 1.1lE+10 NIA 2.16E+l0 Table 6 Base Case DCGLs for Penetrations (DCGLrN) - (from LTP Chapter 5, Table 5-8)

,Auxiliary, Containment SFP/ Turbine Crib House/ WWTF 1 Bldg.,. :rransrer. * * .Bldg. Fore~ay (t)

    • Nuclide. *,;:;-> ,; * >i/'f~" ' ,*',, ' ,.

.,,, . " 1.'

', "'0 ~

'**canal* '.;; ' ':>*, " \le

. (pCi/m2j . (pCilm2) .{PCilm2) ,. .(pCi/m2) (pCi£m2) (p~i/m2)

H-3 3.99E+09 3.42E+09 4.84E+16 3.23E+09 NIA NIA Co-60 8.82E+07 2.26E+09. 4.45E+08 l.76E+09 NIA NIA Ni-63 6.79E+l0 5.78E+l0 l.86E+ 14 5.48E+ 10 NIA NIA Sr-90 2.41E+07 2.06E+07 9.26E+l0 l.94E+07 NIA NIA Cs-134 3.28E+08 4.32E+08 7.48E+08 4.00E+08 NIA NIA Cs-137 6.17E+08 5.66E+08 l .46E+09 5.29E+08 NIA NIA Eu'-152 3.29E+08 5.26E+09 9.44E+08 4.06E+09 NIA NIA Eu-154 2.33E+08 4.58E+09 8.53E+08 3.58E+09 NIA NIA As the Base Case DCGLs represent the dose criterion, a reduction is required to ensure compliance with Equation 1. The reduced DCGLs, or "Operational" DCGLs can be related to the Base Case DCGLs as an expected fraction of dose based on an a priori assessment of what the expected dose should be based on the results of site characterization, process knowledge and the extent of planned remediation.

[7]

Zion Station Restoration Project TSD 17-004 Technical Support Document Revision 0 Equation 2 Dexp f =25 -

where:

f expected fraction of dose Dexp a priori expected dose based on characterization, process knowledge and the extent of planned remediation 25 25 mrem/yr dose criteria for unrestricted release 3.1. Operational DCGLs for Basement FSS Units An a priori fraction of dose will be applied to each source term in a basement FSS unit (structural surfaces, embedded pipe and penetrations). The a priori fracti_on of dose for the fill variable is determined by dividing the appropriate assigned dose from fill in LTP Chapter 5, Table 5-16, by 25 mrem/yr.

The sum of the a priori fraction of allowable dose for a basement FSS unit ([Basement),

including the dose assigned from the use of concrete debris as fill (Table 5-16) is; Equation 3 fBasement = fB + f PN + fEP + fcp where:

fe a priori fraction of dose for surfaces (walls and floors) fPN a priori fraction of dose for penetrations fEP a priori fraction of dose for embedded pipe fcF a priori fraction of dose for concrete fill (LTP Chapter 5, Table 5-16)

Operational DCGLs for Basement FSS units are derived by multiplying the applicable Base Case DCGL (DCGLs from Table 1, DCGLEP from Table 5 or DCGLPN from Table 6) by the expected fraction of allowable dose for each basement dose component.

The Operational DCGL is then used as the DCGL for the FSS design of the survey unit (calculation of surrogate DCGLs, investigations levels, etc.).

As stated previously, the dose from fill is currently based on a maximum allowable MDC of 5,000 dpm/l 00cm2

  • After all URS have been completed on the remainder of the concrete that will be reused as clean fill, the dose from fill in Table 5-16 will be recalculated based on the actual maximum MDC observed during the performance of the URS. At that time, this TSD will be revised to incorporate tI:ie revised fraction for fill for the feasement term using the actual maximum observed MDC.

[8]

Zion Station Restoration Project TSD 17-004 Technical Support Document Revision 0 3.2. Operational DCGLs for Soil and Buried Pipe FSS Units The same process described above for the determination of operational DCGLs for Basement FSS units will also be applied to the site compliance equation. An a priori fraction of dose will be applied to soils and buried pipe such that the sum of the expected fraction of allowable dose for soils, buried pipe and groundwater, when added

. to the maximum apriori dose from basement structures, is less than or equal one.

Equation 4 1 2:: !Basement + !soil + fBP + few where:

/Basement a priori fraction of dose for maximum basement survey unit

/soil a priori fraction of dose, for maximum soil survey unit fep a priori fraction of do.se for maximum buried pipe survey unit few a priori fraction of dose for maximum groundwater Once the FSS of basements is complete, an actual fraction of allowable dose will be

.calculated for each Basement FSS unit based on the measured mean*SOF for each ROC. The actual fraction of allowable dose from the Basement FSS unit with the highest dose will be used in Equation 4 for the /Basement term. It is anticipated that the actual maximum dose fraction will be significantly less than the a priori fraction used to derive the Operational DCGLs, mostly due to conservative assumptions used for remediation effectiveness.

When Basement FSS is completed, the actual fraction of allowable dose from the Basement FSS unit with the highest dose will be subtracted from the a priori fraction assigned to basements and the difference will be allocated to the a priori fractions for soil ([sou) and/or buried pipe (feP). This TSD will be revised at that time to reflect the new a priori dose fractions and new Operational DCGLs for soil and buried pipe. All FSS performed on soil and buried pipe survey units prior to the completion of FSS of all Basement survey units will comply with the Operational DCGLs documented in this TSD.

4. DETERMINATION OF A PRIORI DOSE FRACTIONS Using the results of characterization data, process knowledge and the extent of expected remediation, the a priori dose fractions assigned to each basement dose component are presented in Table 7. The fractions were determined based on the mean concentrations for each ROC measured during characterization and also takes into account anticipated remediation for ALARA purposes. These fractions will be used as the a priori fractions for determining operational DCGLs for basements (structural surfaces, embedded pipe and penetrations).

[9]

Zion Station Restoration Project TSD 17-004 Technical Support Document Revision 0 The maximum a priori total dose fraction for a basement FSS unit when summing each dose component fraction within each basement is 0.448. This is the value that will be currently applied to the site compliance equation for the expected fraction of dose for the maximum basement survey unit variable (feasement). The remaining dose fraction for the compliance

. equation, assuming/Basement at 0.448, is 0.552. The expected fraction of dose for the groundwater term (few) due to instrument MDC is assumed to be 0.040. The remaining dose fraction of 0.512 is distributed between soil and buried pipe at 0.456 each. FSS surveys of open land and buried pipe survey units performed prior to the completion of the FSS of structures will be performed using these a priori fractions and the resulting Operational DCGLs. Once the FSS of structures is complete, the soil and buried pipe Operational DCGLs will be revised by incorporating the difference between the a priori fraction of dose for the maximum basement (feasement) and the actual fraction of dose for the maximum basement as measured by FSS results.

For example, if following FSS, the maximum dose attributed to a backfilled basement based on the mean SOF for each ROC equals 10 mrem/yr (summation of mean dose from structures, embedded pipe, penetrations and fill), with a corresponding actual fraction of allowable dose of 0.400.

The a priori dose fraction for structures (/Basement) was 0.488. The difference between the a priori dose fraction (0.488) and the measured dose fraction (0.400) would be 0.088. This difference would then be added to increase the a priori dose fraction for soils ({sou), the a priori dose fraction for buried pipe (/BP), or a combination of both by 0.088. The establishment of final soil and buried pipe Operational DCGLs wiU be. documented in a revision to this TSD and in subsequent FSS survey design packages and release records. Revision of any completed release records for any FSS performed prior to the establishment of final soil and buried pipe Operational DCGLs will not be necessary as the Operational DCGLs used will .be based on a lower a priori dose fraction.

[10]

Table7 0.068 Fill 0.071 0.448 0.125 0.020 0.084 Tunnel Drain 0.209 In-Core Sump 0.080 Drain 0.068 Fill 0.071 0.448 0.125 Tendon 0.020 0.084 Tunnel Drain 0.209 NIA NIA Penetrationsc31 0.233 Fill 0.006 0.448 Floors and Walls, Circulating Water Intake Pipe, Circulating 560 ft Floor 0.145 0.040 Water Discharge Pipe (Total) Drains Ul Steam (Dose Fraction Allocation by Area) 0.040 Tunnel Drains U2 Steam Penetrations . 0.080 Fill 0.063 0.448 DisCharge Twmel Wall/Floor O.o75 O.D40 Tunnel Drains UlTendon 0.020 Turbine Walls/Floors, Buttress Pit!fendon Tunnels, Circulating Tunnel Drain 0.070 Wate~ Intake Pipe, Ci~culating Water Discharge Piping U2 Tendon 0.020 Tunnel Drain 0.385 NIA NIA NIA NIA Fill 0.063 0.448 0.192 NIA NIA NIA NIA Fill 0.256 0.448 The FSS of the Auxiliary Building 542 ft. embedded floor drain has been completed. The FSS results produced a mean SOF of0.1696, equating to a dose of 4.2410 mrem/yr: Following FSS, the Auxiliary Building 542 ft. embedded floor drains were grouted to refusal. The a priori dose fraction is based on a conservative estimate of diffusion release through the grout and the FSS dose.

(2) SFP!fransfer Canal Floor/Wall dose set equal to Containment Floor/Wall dose to ensure Operation DCGL is equal to the lesser of Containment or Auxiliary Basement Operational DCGL, consistent with approach used to calculate SFP!fransfer Canal DCGL in.LTP Rev I section 6.6.8.1 and Footnote (I) to LTP Rev.I Table 6-26.

(3) Dose'fraction by calculation only to add margin allowed to sum basement dose to maximum basement dose of0.44_8. A~tual dose estimate is less.

\

[II]

5. OPERATIONAL DCGL VALUES Opera~ional DCGLs are deriv~d by multiplying the Base Case DCGLs (Table 1 through Table 6) 1 by the applicable a priori fraction of dose in Table 7. The structural surface dose component for Unit 1 and Unit 2 Containment structural surfaces are*further divided into two distinct areas, the surface area above the 565 ft. elevation and the Under-vessel Area below the 565 ft .. elevation.

The structural surfaces in the Turbine Building are also divided into two distinct areas, the summation of the surface area for the floors and walls, the buttress pits, the tendon tunnels, the Circulatirig Water Discharge Pipe and the Circulating Water Intake Pipe and the surface area attributed to the Circulating Water Discharge Tunnels. In these cases, the Operational DCGLs were calculated using a weighted average approach using the following equation.

Equation 5 Arearotal)

DCGL 0 p = DCGL 8 c

  • f 8 * ( A reasurf where; DCGLoP Operational DCGL DCGLsc Base Case DCGL

\

fB a priori Dose Fraction for Structural Surface area (from Table 7)

AreaTotal = Total Area of all Structural Surfaces in Basement FSS unit (from LTP Chapter 5, Table 5-18) in m2 Areaswf Surface Area of the specific structural surface area (e.g. In-Core Area=

294 m 2, Discharge Tunnel = 4,868 m 2) or, the Total Area minus the Surface Area of the specific structural surface area (e.g. total Containment Area of3,482 m2 minus the In-Core Area of294 m2 = 3,188 m 2 or, total Turbine Area of27,135 m2 minus the Discharge* Tunnel Area of 4,868 m2

= 22 267 m2

  • The operational DCGLs for FSS at Zion are presented in the following tables; Table 8 Operational Basement DCGLs (OpDCGLB) (pCi/m 2)

"Auxiliary . Unit 1 Containment * . * ; . Uµit 2c;ontainment. .... ** SFP/Transfer Building (above 565 ft); ;und~r-ve~sel * * (above 565 ft)* Under-vessel . . Canal H-3 l.71E+08 3.25E+07 2.37E+08 3.25E+07 2.37E+08 4.98E+07 Co-60 9.81E+07 2.15E+07 l.56E+08 2.15E+07 1.56E+08 3.28E+07 Ni-63 3.71E+09 5.50E+08 4.00E+09 5.50E+08 4.00E+09 8.41E+08 Sr-90 3.22E+06 l.96E+05 l.42E+06 1.96E+05 l.42E+06 2.99E+05 Cs-134 . 6.81E+07 4.12E+06 2.99E+07 4.12E+06 2.99E+07 6.30E+06 Cs-137 3.58E+07 5.39E+06 3.92E+07 5.39E+06 3.92E+07** 8.24E+06 Eu-152 2.09E+08 5.00E+07 3.64E+08 5.00E+07 3.64E+08 7.66E+07 Eu-154 l.88E+08 4.36E+07 3.17E+08 4.36E+07 3.17E+08 6.67E+07

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Zion Station Restoration Project TSD 17-004 Technical Support Document Revision 0 Table 8 (cont) Operational Basement DCGLs (OpDCGLB) (pCi/m2)

Turbine .Building ROC (Circ Water Crib House/

  • (Floors & WWTF Discharge Forebay Walls)

Twinel)

H-3 l.10E+07 5.39E+07 7.43E+07 3.28E+06 Co-60 5.98E+06 2.94E+07 2.13E+07 5.43E+06 Ni-63 l.85E+08 9.l 1E+08 l.25E+09 . 5.55E+07 Sr-90 6.58E+04 3.24E+05 4.47E+05 1.98E+04 Cs-134 l.35E+06 6.65E+06 8.20E+06 4.44E+05 Cs-137 1.79E+06 8.82E+06 1.14E+07 5.63E+05 Eu-152 1.38E+07 6.77E+07 4.74E+07 1.45E+07 Eu-154 l.22E+07 5.98E+07 4.31E+07 1.IOE+07 Table 9

  • Operational DCGLs for Embedded Pipe (OpDCGLEr) (pCi/m2)
t . Auxjliary . 'Unit I
Unit2. Unit 1 & Unit * *" .  ;

.Turbine Bldg. ,

  • Unit l Tendon Unit .2 Tendon**.

~ Bldg. . : . Containment Containment, .2Steam

  • ! " ., ", { .. ,
.Basement Tunnel .. , Tunnel' Radionuclide Basement "
fu
::core Sump* *.. In-Cpre Sump . Tunnel

}:Embedded Embedded" * *Embedded*

Embedded Embedded Embedded Embedded.

.Floor Drains Floor Drains Floor Drains Floor DrainsC 1J DrainPioe

  • DrainPioe Floor Drains H-3 NIA NIA 6.62E+08 6.62E+08 NIA 3.22E+08 3.22E+08 Co-60 7.33E+09 2.52E+08 4.38E+08 4.38E+08 1.63E+09 2.12E+08 2.12E+08 Ni-63 2.78E+ll 7.84E+09 l.12E+10 l.12E+10 5.04E+10 5.44E+09 5.44E+09 Sr-90 2.41E+08 2.78E+06 3.98E+06
  • 3.98E+06 1.79E+07 l.94E+06 l.94E+06 Cs-134 5.IOE+09 5.72E+07 8.40E+07 8.40E+07 3,69E+08 4.08E+07 4.08E+07 Cs-137 2.68E+09 7.56E+07 1.IOE+08 l.10E+08 4.88E+08 5.34E+07 5.34E+07 Eu-152 NIA NIA l.02E+09 . l.02E+09 NIA 4.96E+08 4.96E+08 Eu-154 NIA

.. NIA 8.88E+08 8.88E+08 NIA 4.32E+08 4.32E+08 (I) The FSS of the Aux1hary Bmldmg 542 ft. embedded floor dram has been completed. The.DCGLs hsted are the DCGLAD values used to demonstrate compliance from Table 2 of the Release Record Table 10 Operational DCGLs for Penetrations (OpDCGLrN) (pCi/m 2)

Unit l 1 SFP/

Auxiliary Unit2 . Turbine. Crib House/.

  • Radionuclide Transfer WWTF *

~,,

M Bldg.' '* <::;pntainment, .,

Containment Canal Bldg:. . Forebay.*

H-3 3.14E+08 2.33E+08 2.33E+08 l.13E+l6 2.58E+08 NIA NIA Co-60 6.95E+06 l.54E+08 l.54E+08 l.04E+08 l.41E+08 NIA NIA Ni-63 5.35E+09 3.93E+09 3.93E+09 4.33E+13 * . 4.38E+09 NIA NIA Sr-90 J.90E+06 l.40E+06

  • 1.40E+06 2.16E+IO l.55E+06 NIA NIA cs~134 2.58E+07 2.94E+07 2.94E+07 l.74E+08
  • 3.20E+07 NIA NIA Cs-137 4.86E+07 3.85E+07 3.85E+07 3.40E+08 4.23E+07 NIA NIA Eu-152 2.59E+07 3.58E+08 3.58E+08 2.20E+08 3.25E+08 'NIA NIA Eu-154 l.84E+07 3.l 1E+08 3. l 1E+08 l.99E+08 2.86E+08 NIA NIA

[13]

Zion Station Restoration Project TSD 17-004 Technical Support Document Revision 0 Table 11 a priori DCGLs Table 12 a priori DCGLs Table 13 a priori DCGLs for Surface Soils for Subsurface for Buried Pipe (OpDCGLss) Soils (OpDCGLBP)

(pCi/g) (OpDCGLsB) (dpm/100cm 2)

(1Ci/e;)

Radionuclide Surface Soil Radionuclide Subsurface Soil

  • Radionuclide Buried Piping DCGL  ; DCGL DCGL' Co-60 1.091 Co-60 0.881 Co-60 6.76E+03 Cs-134 1.733 Cs-134 1.137 Cs-134 l.16E+04 Cs-137 3.630
6. REFERENCES
1. ZSRP License Termination Plan (LTP)

[14]

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