ML20137H284
| ML20137H284 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 06/28/1996 |
| From: | Robertson D External (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20137H228 | List: |
| References | |
| FRN-59FR43200, RULE-PR-20, RULE-PR-30, RULE-PR-40, RULE-PR-50, RULE-PR-51, RULE-PR-70, RULE-PR-71, RULE-PR-72, RULE-PR-MISC SECY-97-046A-C, SECY-97-46A-C, NUDOCS 9704020120 | |
| Download: ML20137H284 (16) | |
Text
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Evaluation of the Residual Radionuclide Source Term j
at the Trojan Nuclear Power Plant at the Start of Decommissioning (1994) 1 4
l by I
David E. Robenson i-Pavinc Nonhwest National Laboratory i
Richland, WA 99352 l
June 28,1996 i
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i 9704020120 970331 PDR PR MISC 59FR432OO PDR i
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CONTENTS 2
Summary...............................
4 1.0 Introduction 1.1 NRC Request for Evaluation and Update of the Radionuclide Source Term at Trojan Nuclear Plant at the Time of Decommissioning 4
1.2 Trojan Nuclear Plant Operating Summary and Decommissioning Plans / Schedule......................
5 2.0
- Current Radiological Status of Trojan Nuclear Plant......
5 2.1 Radionuclide Inventories in Plant Systems 6
2.2 Radionuclide Composition of Radioactive Contamination Associated with Trojan Nuclear Plant Structures and Systems 9
11 2.3 Environmental Contamination 14 2.4 Tritium Contamination of Containment Vessel Concrete...
15 3.0 References..........................
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SUMMARY
To provide a more comprehensive radionuclide source term for the reference PWR station for decommissioning, the current radiological status of the Trojan Nuclear Plant (TNf) was reviewed and assessed. A comparison was then made between the current radionuclide inventory and composition at TNP with the values predicted to be present in the 1978 report, NUREG/CR-130, " Technology, Safety and Costs of Decommissioning a Reference Pressurized Water Reactor Power Station."
This assessment showed that the current radionuclide inventory and composition
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of predominant isotopes at TNP are in reasonably good agreement with the This current assessment predicted values published earlier in NUREG/CR-130.
includes a number of radionuclides not considered in the earlier NUREG/CR report, but these additional radionuclides do not significantly impact the radistion doses, waste classification, waste volumes, or costs associated with As a result, none of the conclusions regarding the station decommissioning.
the technology, safety, and costs of decommissioning a PWR station reported in NUREG/CR-130 and it's update, NUREG/CR-5884, " Revised Analysis of Decommissioning for the Reference Pressurized Water Reactor Power Station" would significantly change.
Fe and Ni presently dominate the residual radionuclide As expected, ' Co, 55 spectrum and inventory at TNP in both the neutron-activated radioactive contamination deposited with corrosion products in piping and The concentrations of the long-other primary and auxiliary g2'Cs, 'ystems.Tc, and "'I were very low in the residual iant s lived fission products ' Sr.
radionuclide contamination, primarily because these fission products tend to be relatively soluble in the primary and auxiliary systems and do not Also, TNP had relatively substantially deposit with the corrosion products.
few fuel element failures which released fission products to the primary As a result, the transurani. radionuclide concentrations were also The external cool ant.
relatively low in the residual radioactivity deposits at TNP.
gamma dose estimates from the residual radionuclide contamination is Fe and Ni are very low energy beta or photon 63 predominately due to ' Co (65 emitters) and the internal dose from ingest mCs.
According to information contained in the " Radiological Site Characterization Report for the Trojan Nuclear Plant," no significant environm including both the terrestrial as well as the surface and subsurf ace aquatic environs.
Tritium contamination was recently discovered in the TNP containment vessel The mechanism for this concrete at extremely low concentrations. contamination is unclear, but gaseous tritium in the form of HT from the containme feet of the concrete containment vessel wall.
action for this concrete because the contamination level is well belo 2
i acceptable residual contamination criteria and the concrete dome would not even be considered radioactive material when the site license is terminated.
In conclusion, this review and assessment of the current radiological status l
of TNP has not identified any additional radionuclides or contamination of i
plant systems or the environs which would further impact the technology, safety, and costs for decommissioning the TNP.
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1.0 INTRODUCTION
f NRC RE0 VEST FOR EVALUATION AND UPDATE OF THE RADIONUCLID 1.1 TROJAN NUCLEAR PLANT AT THE TIME OF DECOMMISSIONING 1
In December,1995, the U.S. Nuclear Regulatory Comission (NRC) requested l
Pacific Northwest National Laboratory (PNNL) to evaluate and up(date the residual radionuclide source term at the Trojan Nuclear Plant TNP) at the i
time of decomissioning.
i When the draft GEIS for the Radiological Criteria for Decommissioning rulemaking was written, only "7Cs, Co, and "Sr were included in the source This was because dose conversion factors (DCFs) for other radionuclidesj term.
At the time, it was thought to be adequate as these were not available.
In fact, "Sr radionuclides should represent the vast majority of the doses.
1 and "'Cs, being relatively soluble radionuclides, are usually not major contaminants in residual radioactivity associated with primary system 7
components and piping.
Since the publication of the draft, the work on the DCFs for all radionuclides Also, more data has become available for Trojan suggesting was completed.
that tritium might be a significant contributor to remediation costs, if not PNNL was, therefore, requested to investigate the impact of including a I
dose.
more realistically complete source term in the calculations.
Specifically, the following tasks were to be addressed:
3 1.
Evaluate the Trojan Nuclear Plant.
Calculate a source term including all radionuclides that will i
impact dose or remediation costs.
Calculate the additional volumes of soil and concrete requiring remediation if these are included in the calculations.
2.
Specifically look at the tritium problem.
If the Trojan data show a problem, is it generic or is it a result of something unique to Trojan?
- 1) provides an assessment and update of the radionuclide This letter report:
source term presently existing at TNP, 2) compares current radionuclide inventories and composition with predicted values contained in the original decomissioning assessment report (NUREG/CR-130, " Technology, Safety and Costs of Decomissioning a Reference Pressurized Water Reac apprizes the environmental radiological conditions at the TNP site, and 4) provides an evaluation of the recenti, observed low-level tritium contamination of the containment vessel concrete.
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i 1.2 TROJAN NUCLEAR PLANT OPERATING
SUMMARY
AND DECOMMISSIONING PLANT SCHEDULE The Trojan Nuclear Plant operated by Portland General Electric Company (PGE)
J achieved initial criticality in December 1975 and began commercial operation in May 1976.
The reactor output was licensed at 3411 MWt with an approximate net electrical output of 1130 MWe.
TNP shutdown for the last time in November 1992, because of a steam generator tube leak precipitated by a failed sleeve.
Commercial operation was formally discontinued in January 1993, after The plant operated for 14 fuel cycles approximately 17 years of operation.
and approximately 3300 effective full power days or 9.04 effective full power years.
PGE chose the DECON alternative for decomissioning.
Following plant shutdown
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a transition period of approximately six years is scheduled to allow for decay heat dissipation prior to transferring fuc1 to an Independent Spent Fuel i
Storage Installation (ISFSI). During the transition period, limited dismantlement activities will occur.
A sumary of the scheduled decomissioning activities is shown in Table 1.1.
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Schedule for Decomissioning/ Site Restoration Activities at TNP Table 1.1 (from: " Trojan Nuclear Plant Decomissioning Plan", PGE,1994)
January 1993 - Mid 1998 Transition period Late 1994 - Late 1995 Large Component Removal Project (steam generators and pressurizer)
Decontamination and dismantlement Late 1996 - Mid 1998 planning Complete planning / building an ISFSI Late 1996 - Mid 1998 Reactor vessel internals removal Early 1997 - Early 1998 Transfer spent nuclear fuel to the Mid 1998 IJFSI Full-scale decontamination and Mid 1998 - Late 2001 dismantlement Complete final radiation survey Late 2001 Late 2001 - Mid 2018 Caretaking Mid 2018 - Late 2019 Demolish buildings I
i CURRENT RADIOLOGICAL STATUS OF TROJAN NUCLEAR PLANT 2.0 TNP site characterization is an ongoing process similar to that described in f
NUREG/CR-5849, " Manual for Conduc.ing Radiological Surveys in Support of 5
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License Termination." TNP site characterization will be completed in three phases:
Phase I, scoping survey / site characterization; Phase II, radiological surveys to support TNP dismantlement and decommissioning; and Phase III, final radiation survey.
4 Phase I, has been completed and the results are compiled in the " Trojan Nuclear d
Plant Radiological Site Characterization Report," Revision 0.1, dated February 8, 1995.
Data from this report were used to characterize the current radiological i
status of the facility, estimate the site source term and isotopic mixture to j
support decommissioning cost estimates and decision making, determine the location and extent of contamination outside the RCA, and collect background information to Phase II is ongoing and help facilitate release of the site for unrestricted use.
involves routine radiological surveys in support of PGE's current ~ Part.50 license.
Phase II will be used to help support facility decontamination and dismantlement.
j Phcse II will continue using the existing radiation protection program and Phase III includes the final radiation survey, which will demonstrate J
procedures.
TNP radiological conditions are within the site release criteria to support license i
Final survey implementation details will be submitted later. Areas termination.
I that were'not, or could not be surveyed during Phase I will be surveyed during Phase j
II or Phase III.
2.1 RADIONUCLIDE INVENTORIES IN PLANT SYSTEMS A calculated 1994 radioactivity inventory has been estimated by PGE that included i
both surface contamination and neutron activated components.
A summary of this scoping survey is shown in Table 2.1.
Summary of Radionuclide Inventories in TNP Components (1994) 2 Table 2.1
(
i Activity (Ci)
Major Radionuclides l
Components
(% Activity) 1 55 Structures
- 0.03u3
- Co (15%)
t l
Systems
- 2470 "Fe (61%)
i
L i 191)
C o 15%)
k 1
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4.2x10' N
Co(51%)-
i Activation "Fe (441)
Ni (2.9%)
N 4
m Environment I'
4.2x10' q
TOTAL Surface contamination associated with primary and auxiliary plant systems two b
( *)
years after shutdown.
Activation curies for Most activity is contained in the vessel internals. reactor vessel, c N
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Ci.
No activity above release criteria.
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More detailed estimates of the 1994 inventories of radioactive material associated with contaminated structures is given in Table 2.2, and inventories associated with various plant systems is given in Table 2.3.
The total curies associated with surface contamination on plant structural components shown in fable 2.0 is relatively very small, totaling only 0.03 Ci in 1994.
Estimated total curies of radioactive contamination associated with the plant systems shown in Table 2.3 amounted to 2470 Ci in 1994.
Table 2.2 Contamination
- Activity (') (1994) and Structural Volume Building Area Volume Activity i
(ft')
(f t')
(millicuries) j Containment 20346 668 20.4 i
(floors)
Containment 68956 2262 2.71 (walls) 3 Auxiliary 7135 234 2.31 Fuel 5360 176 1.13 MSSS/EP 1302 43 1.36 Turbine 2296 75 2.39 TOTAL 105395 3458 30.30 1
Includes removable and fixed contamination.
(*)
Percent activity for primary systems is:
Fe (61%),'3Ni (19%), ' Co 65 (15%), *Cs (<1%).
Percent activity for auxiliary systems is:
tli (52%), ' Co (23%), 55Fe (5.9%),"7Cs (<1%).
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I Estimated Volumes and Activity (1994) of Contaminated Primary and Table 2.3 Auxiliary Systems at TNP Sys i System Name Contamin.
Total Total Activity Surf. Area Volume Weight (f t')
(f t')
(lbs)
(Ci) 16 Component Cooling Water 33,529 6,115 475,874
<1 32 HVAC - Fuel & Aux Buildings 30,335 10,283 45,800
<1 35 Spent Fuel Pool Cooling &
5,257 970 57,281 5.6 Demineralizer 36 Spent Fuel Pool 101,993 N/A 628,378 100 39 Condensate Demineralizers 980 2.262 18,000
<1 430 Discharge & Dilution System 4,939 3,834 63,505
<1 49 Residual Heat Removal 13,816 1,702 183,855 36 77 380 43,041 534,034 25 50 Chemical & Volume Control 52 Safety Injection &
7,077 9,680 493,765
<1 Accumulators 55 Control Rod Drive Mechanisms 1,634 225 106,318 83 60 HVAC - Containment 32,838 18,307 407,328
<1 61 Containment Spray ~
5,808 1.563 75,252
<1 i
i 196,696 45,727 2,650,448 1416 63A Steam Generators 2,689 1,183 39,449
<1 63B SG Blowdown 64A Reactor Coolant Pumps 2.644 3,912 768,400 134 64B Reactor Coolant System 4,352 2,205 ll 296,460 221 Piping 1 371 2,459 195.508 52.1 64C Pressurizer 64D Reactor Vessel and internals 2,831 see TNP see TNP 357.9 Rad. Char.
Rad. Char.
(surfacecontaminationonly)
Plan Plan 67AB Primary Makeup Water System 10,338 31,330 90,006
<1 67D Refueling Water Storage Tank 9,401 69,942 97.928 7
654 496 10,341
<1 68 Solid RadWaste 9,610 13,021 110,634 14 69 Clean RadWaste 2,106 2,147 24.116
<1 71 Dirty RadWaste 4.087 3,624 77,261
<1 72 Gaseous RadWaste 452 14 3.093 4
76 Process Sampling System 99A Miscellaneous Sumps 1,512 257 19.136
<1 510,850 274,399 7,484,770 2,469.6 Total 8
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The estimated curies of radioactive contamination on various system components from the 1994 TNP scoping survey can be compared with predicted inventories calculated in NUREG/CR-0130 published in 1978 for a reference PWR Station (which happened to be TNP).
This comparison is shown in Table 2.4.
Table 2.4 Comparison of Predicted (NUREG/CR-0130) Versus Empirically Estimated (1994 TNP Scoping Survey) Curie Contents of Contaminated TNP Systems Estimated Curies at Shutdown NUREG/CR-0130 System 1994TNPScoping Predicted")
Survey" l
Reactor Vessel & Internals 504 130 Steam Generators 2000 4400 Pressurizer 73 4
RCS Piping 310 160 Includes "Fe, "Co, and 'Ni, the most predominant radionuclides decay 6
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corrected to shutdown in 1992.
Predicted from dose-to-curie conversion of contaminated piping systems b) at Turkey Point Nuclear Power Station.
This comparison shows reascnably good agreement considering the many uncertainties associated with these estimates, and gives credibility to the decommissioning conclusions regarding technolog;, safety, and costs published in 1978 in NUREG/CR-0130, " Technology, Safety, and Costs of Decommissioning a Reference Pressurized Water Reactor Power Station."
RADION'JCLIDE COMPOSITION OF RADI0 ACTIVE CONTAMINATION ASSOCI 2.2 TNP STRUCTURES AND SYSTEMS l
j Various mixtures of radionuclides were evident in survey samples throughout Predominant nuclides are shown in Table 2.5.
These the contaminated areas.
nuclides are typical of those found in pressurized water reactor plants and are similar to those discussed in NUREG/CR-130, " Technology, Safety and Costs of Decommissioning a Reference Pressurized Water Reactor," This was expected since TNP was the reference plant used for NUREG/CR-130.
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Table 2.5 Isotopic Composition of Radioactive Contamination at TNP Decay correctedto1994and1998(from: " Radiological Site Characterization Report for Trojan Nuclear Dlant",PGE,1995)
Radionuclides 1 Activity
- 1 Activity **
l Auxiliary Systems Primary Systems 1994 / 1998 1994 / 1998 1
Mn-54 1.0 / <1
<1 / <1 61 / 43 Fe-55 SJ/2.6 Co-57
<1 / <1 N1 J
Co-58
<1 / <1
<1 / <1 Co-60 23 / 18 15 / 18 Ni-63 52 / 66 19 / 38 Sr-89
<1 / <1
<1 / <1 i
<1 / <1
<1 / <1 Zr-95
<1 / <1
<1 / <1 Ru-106 3.7 / <1
<1 / <1 Ag-108m
<1 / <1 N1 Ag-110m
<1 / <1 N1 Cd-109 1.3 / <1 NI Sn-113
<1 / <1 N1 Sb-125 1.2 / <1
<1 / <1 1-129
<. / <1
<1 / <1 Cs-134
<1 / <1 N1 Cs-137
<1 / <1
<1 / <1 i
Ce-144 1 / <1
-l / <1 k
Pu-238 1 / <1
<1
<1 Pu 239/240
'. / <1
<1 / <1 Pu-241 11 / 11
<1 / <1 Am-241
<1 / <1 N1 Cm-242
<1 / <1
<1 / <1 N1 Cm-243/244
<1 / <1
.I N1 = Not Identified
= based on Clean Waste Filter analysis ',10CFR61 Waste Stream 1992)
- = based on Steam Generator tube analysis (1992) 10
The only somewhat surprising feature of Table 2.5 is the small (<1%) relative contribution of "'Cs reported in the contaminated primary and auxiliary systems of TNP.
PNNL participated in an EPRI-sponsored study in 1988 in which large quantities of dry active waste (DAW) was sampled from TNP and other nuclear power stations.
PNNL performed comprehensive 10CFR61 radionuclide analyses of this DAW and "'Cs was a significant (4.6%) contributor to the total radionuclide composition in the DAW at TNP (see Table 2.6).
Since the percent activity composition reported by PGE in Table 2.5 came from analysis of contaminated steam generator tubing, this would suggest that the residual radionuclide contamination associated with the corrosion products in primary system piping and components is relatively depleted in "'Cs and other soluble long-lived fission products, e.g., "Sr, ' Tc, and "I.
Table 2.6 also shows 2
the percent external and internal dosas contributed by8 the isotopic mixture of Co dominated the radionuclide contamination. Obviously for the DAW, external gamma dose, whereas "Co and 'ICs are the predominant internal dose contributors from ingestion.
Since PbE found "'Cs to be a ver
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component of the residual contamination of TNP systems, the
"'y minor (<1%
Cs would not be a major contributor to the ingestion dose.
Table 2.7 provides a comparison of the residual radionuclide composition of contamination deposited in primary and secondary systems predicted in NUREG/CR-130 for the reference PWR and measured by PGE in their 1994 scoping The neutron activation produts Fe, "Co, and "Ni dominate the 55 study at TNP.
residual radioactivity, and the comparison of the predicted versus the measured percent activity is in fair agreement.
Certainly, the differences observed between the two studies would not change any of the conclusions reached in NUREG/CR-130 and NUREG/CR-5884 with respect to dose impacts or remediation costs associated with station decommissioning.
Table 2.8 compares the radionuclide composition of neutron activated reactor internal components as calculated in the 1994 TNP scoping study and as calculated in NUREG/CR-130.
As shown in the table, the comparison of the percent activity for these two sets of calculations is quite good. As a result, the conclusions reached in NUREG/CR-130 and NUREG/CR-5884 with respect to dose impacts or remediation Since the radionuclide inventories for the costs will still be quite valid.
neutron activated components (pressure vessel and internals, plus the concrete bioshield) were calculated for the two studies using similar methodology, it is not surprising that the fractional radionuclide compositions were quite similar.
2.3 ENVIRONMENTAL CONTAMINATION PGE staff indicated that there was no significant residual radionuclide
- Thus, contamination of the environs surrounding the Trojan Nuclear Plant.
there should not be any additional volumes of soil, concrete, or other environmental materials that would require remediation.
The specific question of potential tritium contamination of groundwater at the site was discussed in a later telephone conversation between Davio Robertson of PNNL and PGE staff, and the staff indicated that they have not observed radioactive contamination of well waters at the Trojan site.
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Table 2.6 Fractional Residual Radionuclide Composition Determined in 1988 by PNNL for TNP Dry Active Waste and Dose Contributions for Primary System Contamination at TNP Radionuclide
% Activity (*)
% External Dose 3)
% Internal Dose h) 2'C
<4.5E-4 0
<8E-5 5'Mn 0.17 0.21 0.04
)
Fe 58.3 0
3.0 55
'"Co 27.5 93.1 62.7 63Ni 5.8 0
0.28
' Sr/Y 0.01 neg;igible 0.14 2'Ru/Rh 2.1 0.65 4.9 Sb 0.71 0.43 0.17 25 tr'I
<2E-7 0
<4E-6
"'Cs 0.49 1.1 3.1
"'Cs/Ba 4.6 4.4 19.6 2"Ce 0.25 0.01 0.45 z39.24oPu 0.02 0
4.7 Pu 0.0023 0
0.73 238 The i activity was determined from radiochemical analysis of TNP dry
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active waste (DAW) and decayed two years to be compatibla with the %
distribution in Table 2.5.
The DAW was sampled in 1988 by an EPRI contractor and the radionuclide analyses were performed at PNNL.
D)
% external dose and internal dose was determined by mu'.t4 plying the fractional isotopic activity by the external and ingestion dose conversion factors for each nuclide.
Dose conversion factors were taken from NUREG/CR-5512.
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Table 2.7 Comparison of Residual Radionuclide Composition of Contamination Deposited in Primary and Secondary Systems at TNP 1994 TNP NUREG/C2-130 Scoping Study Adapted from Table 7.3-7
% Activity l*)
(Predicted (Measured)
Radionuclide
% of Activity (')
Primary System Auxiliary System Primary System 5'Mn
<1 1.0 1.5 Fe 61 5.9 22.3 )
0 55 "Co 15 23 53.1 5'Ni 19 51 23.1*)
"'Cs
<1
<1
<1
\\
%activitydecayedtotwoyearsfollowingreactorshutdown.Fe and ' Ni w
(*)
55
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reported in NUREG/CR-130, but were added to this table by using activity scaling factors relative to "Co reported by Vance, et.al. in EPRI NP-5983.
All other radionuclides amounted to less than 1% of the total activity Note:
Table 2.8 Comparison of Radionuclide Composition of Neutron-Activated Reactor Internals
')
I 1994 TNP NUREG/CR-130 Scoping Study Adapted From Table 7.3-2 Radionuclide
% Activity
% Activity "C
0.004 0.01 5'Mn 2.9 1.4 Fe 43.5 57.3 55 "Co 50.7 35.5 5'Ni 0.02 0.05 I
Ni 2.9 5.7 "Nb 0.00007 0.0001 Comparison was made for the lower core barrel percent activities at
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2.4 TRITIUM CONTAMINATION OF CONTAINMENT VESSEL CONCRETE
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PGE staff discussed the measured tritium concentrations in containment vessel concrete.
This contaminatiun is still somewhat of a mystery, but entirely possible to occur.
The observed tritium concentrations are in the 10'5 uCi/g range, with a 10-fold concentration gradient extending from the inside to outside surfaces of the vessel wall (personal communication with PGE staff, March,1996).
Estimated "oackground" tritium concentrations fixed in the concrete at the time of construction (1970-1972) were calculated to currently be approximately 10-a uCi/g, so the observed concentrations are two to three orders of magnitude above the " background" levels.
The present observed tritium levels in the concrete do not appear to be an crtifact of sampling (coring) contamination, since new coring equipment was used for this sampling.
The 4" diameter concrete cores were taken from large blocks (about 3'x3'x3')
of concrete cet from the containment wall to provide egress and disposal of the steem generators.
There is a 0.25" thick steel liner on the inside surface of the containment concrete, so any tritium reaching the concrete would have to diffuse through this steel layer. At first thought, this would seem highly unlikely, but diffusion may certainly be possible in trace amounts.
PGE staff mentioned that during reactor operating periods the containment atmosphere did have significant levels of airborne tritium.
If a significant amount of the tritium in the containment atmosphere was in the form of HT gas, it would be possible for some diffusion through the steel to occur, since substantial HT diffusivity through steel is well-documented i
(LeClaire,1984; Van Deventer, et al,1980). Diffusion through the concrete i
would probably be much faster compared to steel, and thus produce the concentration gradients observed at Trojan.
The tritium in the containment concrete does not appear to have been formed by in situ neutron activation of lithium in the concrete, since the concrete cores were analyzed by gamma-ray sp"ectrometryandnotracesofotherneutronactivationproducts(e.g.,"Co, Eu) were detected. The present strategy that PGE is considering for the Trojan containment dome is to leave it in place after decommissioning of the station, because the tritium levels in the concrete are well below the acceptable residual contamination criteria and the concrete dome would not even be considered radioactive material once the site license is terminated.
This observed tritium contamination of containment vessel concrete does not appear to b. o phenomenon unique to TNP. "ritirn contamination of concrete could occur at any PWR station where the containment atmosphere contains traces of gaseous HT which could penetrate the steel liner.
In plants where there is no steel liner, the tritium contamination would be even much higher.
If NRC is interested in pursuing the issue of tritium contamination of containment dome concrete, PNNL could recomend a program that would be a
- 1) a field / laboratory sampling and analysis task to combination of:
empirically determine tritium levels in the concrete, and 2)a theoretical modeling task to predict the diffusion of tritium from the containment PNNL has atmosphere into the steel liner and containment vessel concrete.
recognized experts on tritium diffusion through metal and other materials that could help in this modeling task.
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3.0 REFERENCES
Berger, J.D. (1992). Manual for Conducting Radiological Surveys in Support of License Termination, NUREG/CR-5849, U.S. Nuclear Regulatory Commission, Washingson, DC 20550, June, 1992.
Konzek, G.J., et al. (1992).
Revised Analysis of Decommissioning for the Reference Pressurized Water Reactor Power Station.
NUREG/CR-5884, U.S.
Nuclear Regulatory Commission, Washington, DC 20555, September, 1992.
i LeClaire, A.D. (1984).
Permeation of Hydrogen Isotopes in Structural Alloys, J. Nucl. Mat. 122-123, 1558,1559.
Portland General Electric Company (1995).
"Radioloaical Site Characterization Report for the Tro.ian Nuclear Plant".
Portland General Electric Company (1994).
" Trojan Nuclear Plant Decomissioning Plan," PGE-1061.
Smith, R.I., G.J. Konzek, W.E. Kennedy, Jr. (1970).
Technology. Safety and Costs of Decommissioning a Reference Pressurized Water Reactor Power Stativt..
NUREG/CR-130, U.S. Nuclear Regulatory Commission, Washington, DC 20555, June, 1978.
Van Deventer, E.H., et al. (1980). Hydrogen Permeation Characteristics of Aluminum-Coated and Aluminum Modified Steels, J. Nucl. Mat. 88, 168-173.
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