ML20236Y384
| ML20236Y384 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 12/04/1987 |
| From: | Standerfer F GENERAL PUBLIC UTILITIES CORP. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| RTR-NUREG-0683, RTR-NUREG-683 4410-87-L-0179, 4410-87-L-179, NUDOCS 8712110284 | |
| Download: ML20236Y384 (9) | |
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GPU Nuclear Corporation
., Nuclear
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Middletown. Pennsylvania 17057-0191 717 944-7621 TELEX 84 2386 Writer's Direct Dial Number:
(717) 948-8461
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December 4, 1987 4410-87-L-0179/0245P US Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555
Dear Sirs:
Three Mile Island Nuclear Station, Unit 2 (TMI-2)
Operating License No. DPR-73 Docket No. 50-320 Post-Defueling Monitored Storage Environmental Evaluation Comment Responses NRC TMICPD Letter NRC/TMI-87-069, dated September 2, 1987, provided 18 additional NRC comments on the Environmental Evaluation for Post-Defueling Monitored Storage submitted by GPU Nuclear letter 4410-87-L-0025, dated March 11, 1987.
GPU Nuclear letter 4410-87-L-0155, dated November 5, 1987, submitted responses to NRC Comments 1, 3, 4, 8, 9, 14, 17, and 18.
GPU Nuclear letter 4410-87-L-0170 dated November 25, 1987, submitted responses to comments 2, 5, 6, 11, 12, and 13.
Attached are responses to comments 7, 15, and 16.
Response to the remaining comment (i.e., Comment 10) is being prepared and will be forwarded under separate cover.
Sincerely,
. R. Standerfer Director, TMI-2
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! I cc: Regional Administrator, Region 1 - W. T. Russell Director, TMI-2 Cleanup Project Directorate - Dr. W. D. Travers 87121102B4 871204 PDR ADOCK 05000320 p
PDR GPU Nuclear Corporation is a subsidiary of the General Public Utihties Corporation
ATTACHMENT 1 4410-87-L-0179 NRC COMMENT 7 Your submittal states, " additionally, various other radionuclides will be present in the residual contamination." What are the other radionuclides and what percentages of residual contamination do they represent?
GPU NUCLEAR RESPONSE The following isotopic percentages are characteristic of, but not limited to, the activity of the residual contamination the Reactor Building with the exception of the blockwall and Reactor Building basement sludge.
Isotopes Fractional Activity Cs-137 4.70 E-1 Ba-137M 4.45 E-1 Sr-90 3.78 E-2 i
Y-90 3.78 E-2 Cs-134 8.42 E-3 Ni-63 1.94 E-4 Fe-55 1.66 E-4 Co-66 3.95 E-5 Tc-99 1.39 E-5 Total 1.0 E+0 Analyses to date indicate that the predominant isotopes in the blockwall are Sr-90, Cs-134, and Cs-137 in the following percentages. Tracer elements have not been identified but constitute less than one (1) percent of the total activity in the blockwall.
Isotope Percentage Cs-137 92.7%
Sr-90 4.0%
Cs-134 3.3%
Total 100.0%
The activity of the remaining sludge in the Reactor Building basement is expected to consist primarily of Cs-137 and Sr/Y-90 as discussed in the following response to NRC Comment 15. Due to ongoing activities in the Reactor Building basement, estimates of tracer elements in the remaining sludge are not readily obtainable.
NRC COMMENT 15 Please provide your best estimate of the amount of sludge remaining in the RB basement after completion of sludge removal as well as an estimate of the activity in the remaining sludge. 0245P
ATTACHMENT 1 4410-87-L-0179 GPU NUCLEAR RESPONSE i
GPU Nuclear estimates, based on currently scheduled Reactor Building basement activities which include desludging operations, that approximately 3.9 E 6 grams of sludge will remain in the Reactor Building basement during PDMS. GPU Nuclear estimates that the remaining sludge will contain approximately 760 C1 (i.e., approximately 350 Ci of Cs-137 and 410 Ci of Sr/Y-90).
Desludging operations in the Reactor Building basement took place in Zones 1, 3, and 4 (Figure 1). Better than 90 percent of the sludge in accessible areas of these zones has been removed. Ninety to ninety-five percent of the remaining sludge is located in the zones outside of Zone 1 (NOTE: Zone 1 contains the blockwall). The sludge estimate includes sludge throughout the Heactor Building basement including the D-rings and cubicles.
Page 10 of the PDMS Environmental Evaluation states, "...about 1000 Ci of suspendable contamination in the vicinity of the blockwall which,...is considered the largest single potential single for airborne contamination."
Therefore, since the great majority of the remaining sludge is separate from the blockwall, this assumption continues to be valid.
NRC COMMENT 16 Table 1, which is attached, illustrates our understanding of the Phase III Endpoint Criteria. This table is synopsized from the AFHB and RB Status Report as well as from TP0/TMI-188. Our analysis of the environmental impacts of PDMS will be based in part on the conditions in the RB and AFHB at the end of Phase III cleanup. Therefore, it is important that the information in this Table be reviewed to ensure that it is correct.
If this information is incorrect, please provide the correct information.
The following questions related to the AFHB and RB Decontamination Status Report:
a.
Does " Surface Contamination" as used in the Status Report, refer to smearable surface contamination? if yes, please provide an estimate (if available) of the amount of fixed contamination that will be left in each If not, please provide estimate of smearable surface contamination, area.
b.
The RB and AFHB Decontamination Status Report estimates the surface area for the floor, walls and overheads of each specific area. The surface areas of equipment, piping, etc. located in these areas are not specified and we assume that for most areas of the RB the surface area will be approximately double if the surface area of equipment, piping, etc. is included. For the AFHB the surface area will double or triple (depending on the amount of equipment in an area) when the equipment and piping are considered. If you feel these assumptions are incorrect, please provide better estimates as well as their basis. 0245P
ATTACHMENT 1 4410-87-L-0179 c.
Will the Phase III endpoint criteria be applied to contamination found on surfaces of the equipment, piping, etc. located in each area? If not, please indicate the amount of contamination (smearable and fixed) that will remain in the equipment, piping, etc. in each of the areas.
Include equipment and piping that are currently shielded (if they will have potential for airborne contamination),
d.
The AFHB Decontamination Status Report indicates that the maximum alpha contamination at the end of Phase III cleanup will be 20 dpm/100 sq.cm.
What is the maximum alpha contamination expected in the RB at the end of Phase III cleanup?
e.
Does the use of "N/A" for the amount of contamination in certain areas of the AFHB (in the AFHB Decontamination Status Report) mean that the level of surface contamination is below detectable limits?
GPU NUCLEAR RESPONSE l
Table 1 (Attachment 2) referenced in the above NRC comment contains a summary of information from the following documents:
1.
TP0/TMI-188, Revision 0, January 1987, " Technical Plan TMI-2 Cleanup Program Post-Defueling Monitored Storage." This document provided the basis for the plan submitted to the NRC via GPU Nuclear letter 4410-86-L-0201, dated December 2, 1986, "TMI-2 Cleanup Program -
Post-Defueling Monitored Storage (PDMS)."
2.
TP0/TMO-186, Revision 0, July 1986, "A Strategy for Recovery Program Completion and Post-Recovery Configuration." This document preceded the above referenced document and provided more specific TMI-2 objective and i
goals for the cleanup program.
3.
" Reactor Building Status Report for 3rd Quarter 1986," GPU Nuclear memorandum 4250-86-0554, dated October 23, 1986. This document summarized the radiological and decontamination status of the Reactor Building and reflected the goals in the above referenceo documents.
Periodic issuance of this document has been discontinued.
i 4.
"AFHB Status for February 1987," GPU Nuclear memorandum 4252-87-0015, dated March 26, 1987. This document summarizes the radiological and decontamination status of the AFHB and reflects the goals in above l
I l
References 1 and 2.
l l
A revised Table 1 is included in Attachment 3 which provides goals consistent with those stated in above References 1 and 2.
The differences between i
Attachments 2 and 3 are noted below.
o is titled, " Phase III Endpoint Criteria." A more appropriate title is "TMI-2 Cleanup Program Radiological Goals," since the information provided in Attachment 3 is dependent on ALARA ar.d budgeting considerations. 0245P 1
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ATTACHENT 1 4410-87-L-0179 o
The column " Hot Spot, R/hr," in Attachment 2 has been deleted in.
This information was obtained from Reference 3 which is an informational document. The specific radiological and decontamination
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goals in References 1 and 2 apply te the general area dose rates and surface contamination, and do not include hot spots which may exceed the defined goals.
o identifies the criteria for surface contamination above i
seven (7) feet in various areas or the Reactor Building as 100,000 dpm/100 cm2 However, this is more appropriate defined as "As Is" consistent with References 1 and 2.
The definition of "As Is," per these references, is included in Attachment 3.
The four (4) categories for the AFHB in Attachment 2 were not identified o
by areas and could cau;e confusion if taken out of context. Rather, provides a summation of Table 2.2-4 from Reference 2.
The following are the responses to NRC Comments 16 A-E.
RESPONSE TO COMMENT 16A Surface contamination does refer to smearable surface contamination.
Estimates of fixed contamination levels in each area have not been determined and are not readily obtainable at this time. Program objectives / goals are based on loose surface contamination and general area dose rates. Fixed contamination and radiation levels will be reduced by shielding, scabbling, etc. in order to achieve these goals.
RESPONSE TO COMMENT 168 GPU Nuclear estimates for the surface area in the RB and AFHB do not include the equipment, piping, etc. GPU Nuclear believes that doubling the amount of surface area would be a valid assumption; however, this should be the maximum number used.
RESPONSE TO COMMENT 16C The Phase III endpoint criteria, presented as goals in Attachment 3, will be applied to all external surfaces of equipment, piping, etc. in each area.
RESPONSE TO COMMENT 16D Currently alpha contamination on the 305' and 347' levels of the Reactor 2 in the areas where defueling equipment is Building are above 20 dpm/100 cm stored and on the defueling platform. After defueling, accessible areas are expected to be decontaminated to below the 20 dpm/100 cm2 goal.
RESPONSE TO COMMENT 16E The use of "N/A" in the AFHB decontamination spreadsheet means that there is no surface area above seven (7) feet. 0245P
ATTACHMENT 2 4410-87-L-017 9 PHASE III Endpoint Criteria
- General Area SurfaceContam{ nation, Dose Rate, Hot Spot, dpm/100 cm
. Location R/h R/h (7 ft
>7 ft Reactor Building Refueling Canal (0.015 0.075 (50,000 (100,000 Elevation 347 ft (0.03 0.150 (50,000 (100,000 and Above with Exception of D-Ring (0.07 0.350 (50,000 (100,000 NW-Seal Table (0.07 0.35 (50,000 (100,000 Elevation 305 ft (0.07 0.35 (50,000 (100,000 to 347 ft Basement (282 ft)
(35 7
(1E+9 (1E+9 Auxiliary and Fuel Handling Building Areas as given in (0.0025 (1,000 (10,000 l
"AFHB Status Report for February (0.05 (1,000 (10,000 1987" (Hemo from PR Bengel to (0.5 (50,000 (50,000 S. Levin, March 26, 1987 (1.0 (50,000 (50,000 4252-87-0015)
Other Buildings Turbine Building (0.0025 Chemical Cleaning (0.0025 Building Service Building (0.0025 Containment Orain Tank Area
- As referenced in Comment 16 of NRC Letter NRC/T!il-87-060, dated Se~ptember 2, 1987.
TABLE 1
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ATTACHMENT 3 4410-87-L-0179 TMI-2 CLEANUP PROGRAM RADIOLOGICAL GOALS General Area Surface Contamination, Dose Rate, dpm/100 cm2 Location R/h
<7 ft.
>7 ft.
Reactor Building Refueling Canal
< 0.015
<50,000 As Is (Note 1)
Elevation 347'
< 0.03 (50,000 As Is (Note 11 and above with Exception of D-Ring
< 0.07
<50,000 As Is (Note 1)
NH-Seal Table
< 0.07
<50,000 As Is (Note 1)
Elevation 305'
< 0.07
<50,000 As Is (Note 1) to 347' Basement (282')
<35 As Is (Note 2)
As Is (Note 2)
Auxiliary and Fuel Handling Building Below is a summation of Table 2.2-4 of TP0/TMI-186
< 0.0025
< 1,000
< 10,000 to to to
< 1.0
<50,000
<100,000 Other Buildings Turbine Building
< 0.0025
< 1,000 1,000 Chemical Cleaning
< 0.0025
< 1,000 1,000 Building Service Building
< 0.0025
< 1,000 1,000 Containment Drain Tank Area
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ATTACHMENT 3 4410-87-L-0179 TMI-2 CLEANUP PROGRAM RADIOLOGICAL GOALS (Cont'd)
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l NOTE 1:
In TP0/THI-186, Table 1.4-3 Note 4 states, "Since access is not required above 7' and the overheads are generally not the major contributors to the general area dose, they may be left as 1s; (i.e.,
in the condition that exists at the present time.")
NOTE 2:
This area was specifically not identified in Table 1.4-3 of TP0/TMI-186, however, Note 3 of this table states, " Areas of the reactor building not listed in this Table should be left 'as is' at the beginning of PDMS."
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