RA-05-005, Response to NRC RAI on FSS Report No. 4
| ML050390365 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 01/27/2005 |
| From: | Meisner M Maine Yankee Atomic Power Co |
| To: | Document Control Desk, NRC/FSME |
| References | |
| MN-05-004, RA-05-005 | |
| Download: ML050390365 (14) | |
Text
MaineYankee 321 OLD FERRY RD.
- WISCASSET, ME 04578-4922 January 27, 2005 MN-05-004 RA-05-005 Proposed Change No. 218, Supplement 13 UNITED STATES NUCLEAR REGULATORY COMMISSION Attention: Document Control Desk Washington, DC 20555
References:
(I) License No. DPR-36 (Docket No. 50-309)
(2) Maine Yankee Letter to USNRC, MN-04-020, dated March 15, 2004, License Amendment Request: Release of Non-ISFSI Site Land, Proposed Change No. 218 (3) Maine Yankee Letter to USNRC, MN-04-056, dated November 17, 2004, Release of Non-ISFSI Site Land - FSS Final Report No. 4, Proposed Change No. 218, Supplement 7 (4) USNRC Letter to Maine Yankee dated January 5, 2005, Request for Additional Information (RAI) Regarding Final Status Survey (FSS)
Supplement No.4
Subject:
Response to NRC RAI on FSS Report No.4 On March 15, 2004, Maine Yankee submitted a request for amendment (Reference No. 2) to the facility operating license (Reference No. 1) pursuant to 10 CFR 50.90 and in accordance with the NRC Approved License Termination Plan (LTP) for Maine Yankee, to indicate NRC's approval of the release of the Non-ISFSI site land from the jurisdiction of the license. In support of that request, Maine Yankee supplied the information required in LTP section 1.4.2 and 5.9.3. The land area associated with the license amendment request included the entire non-ISFSI portion of the site land. Maine Yankee submitted dismantlement and survey information for the survey units contained in FSS Report No. 4 in Reference No.3 .
In Reference No. 4, USNRC requested additional information on technical information submitted by Maine Yankee in Reference No 3. This additional information is provided in an attachment to this letter.
A,&Sj D
UNITED STATES NUCLEAR REGULATORY COMMISSION Attention: Document Control Desk Page 2 of 2 If you have any questions, please contact me.
Sincerely, Michael J. Meisner Vice President and Chief Nuclear Officer Attachment Maine Yankee Response to NRC Request for Additional Information on FSS Final Report No. 4 cc: Dr. R. R. Bellamy, NRC Region I Mr. D. R. Lewis, Esq., Shaw Pittman Mr. C. Pray, State of Maine, Nuclear Safety Advisor Mr. P. J. Dostie, State of Maine, Division of Health Engineering Mr. D. Gillen, NRC Acting Director, Division of Waste Management Mr. M. Rosenstein, USEPA Region I Mr. S. J. Collins, NRC Regional Administrator, Region I Mr. J. Buckley, NRC NMSS Project Manager, Decommissioning Mr. M. Roberts, NRC Region I Mr. R. Shadis, Friends of the Coast
L Attachment Maine Yankee Response to NRC Request for Additional Information on FSS Final Report No. 4 On November 17, 2004, Maine Yankee submitted FSS Final Report No. 4 (Reference No. 7) to the NRC. This report contained the survey information for fifteen (15) survey units including the post-demolition Turbine Building footprint. These footprints were outside of the original Restricted Area boundary.
The License Termination Plan, Revision 3, (Reference No. 1) describes the dose model used to satisfy the radiological criteria for license termination and the State of Maine enhanced criteria.
This dose model evaluates two distinct geographical areas. One area consists of the area within the original Restricted Area boundary. This boundary is shown on LTP Figure 5-2 as the "Class I areas." This area is approximately 10,000 m2 and represents the size of the resident farmer's site. Within this area the doses from various contaminated materials are summed and provided in Table 6-11. The contaminated materials considered include: basement contaminated concrete, activated concrete, surface soil, deep soil, embedded pipe, buried pipe, groundwater and surface water.
The other area evaluated by the dose model consists of the area outside of the original Restricted Area boundary. LTP, Rev. 3, section 6.7, pg. 6-46 states the following:
"Soil areas outside of the RA boundary will not require consideration of dose from any other materials. The area of the RA is approximately 10,000 rn2 , which represents the size of the resident farmer survey unit and contains the other contaminated materials considered. The other contaminated materials have essentially no effect outside of the RA and the dose is assumed to result from the contaminated soil only. In this case, the DCGLs will be based on the NUREG-l 727 screening values corrected to represent 10 mrem./y."
Deep soil is defined as soil at depths greater than 15 cm. A separate calculation is required for deep soil because the NRC soil screening values apply to the top 15 cm of soil. The resident farmer is exposed to deep soil through the direct exposure pathway and groundwater. The deep soil could be brought to the surface at some time in the future through the activities of the resident farmer. Therefore, to simplify dose modeling for deep soil brought to the surface, the original intent of the License Termination Plan was to have the same DCGL's for Deep Soil as for Surface Soil.
The deep soil dose model applies to areas inside the restricted area (RA). The conceptual model for deep soil assumes a 15 cm layer of uncontaminated soil for the purpose of calculating the additional direct radiation exposure. The 15 cm cover represents the layer of surface soil. The direct radiation from residual contamination in the top 15 cm soil layer was accounted for in the surface soil screening values. A very large volumetric source term was assumed, i.e., 28,500 i 3
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Attachment Maine Yankee Response to NRC Request for Additional Information on FSS Final Report No. 4 for the purpose of conservatively determining the potential for groundwater contamination from deep soil - that is, the portion of the 3 meter soil depth not including the 15 cm surface soil (2.85 meters) times the area of the resident farmer's farm, which is the approximate area of the original restricted area (1 0,000 M2 ) This is considered a bounding source term volume and essentially represents the entire volume of soil within the restricted area down to bedrock. After remediation and backfill, the actual remaining volume of deep soil with any significant contamination will be a very small fraction of 28,500 i 3 .
Soil areas outside of the RA boundary do not require consideration of dose from any other materials unless contamination from materials other than surface soil is found to require remediation in order to meet the release criteria. If so, as a conservative measure, the contaminated material DCGL's found in Table 6-11 as modified by Reference Nos. 2, 3 and 4 may be applied, as applicable. In areas outside the RA boundary, soil uncovered as a result of the removal of concrete foundations/slabs, which would otherwise be at an elevation below the six-inch surface soil protocol, may be conservatively treated as surface soil, as long as remediation was not required in order to meet the release criteria.
On January 5, 2005, NRC requested additional information (RAI) (Reference No. 8) regarding FSS Final Report No. 4. In this letter, the NRC stated the following:
"LTP Section 3.2.4 and Table 3-3 state that the Turbine Building will be demolished to three feet below grade and backfilled. FSS-RR Report No. 4 (dated November 17, 2004) states that, "[a]ll demolition activities associated with the Turbine Building have been completed," and that "[s]urveys were perforned on the foundation footprint prior to the backfill." Therefore, the surveyed areas are approximately 3 feet below grade after backfilling. LTP Section 6.6.5 states that, "[djeep soil is defined as soil at depths greater than 15 cm." Given that the Turbine Building footprint is at an after backfill depth of 3 feet, it appears that the Surveys Units 3 and 4 should be designated as deep soil."
"The staff notes that in FSS-RR FB-0500-03, Turbine Building Footprint - Survey Unit 3 (a MARSSIM Class 2 Survey), Table 2, Note l, states, '[t]he Co-60 DCGL of 1.5 pCi/g is an 'adjusted DCGL' and can be derived from the unitized dose for surface soil, LTP Table 6-7.' The resulting DCGL for Co-60 alone is 1.5 pCi/g."
"The staff notes that in FSS-RR FB-0500-04, Turbine Building Footprint - Survey Unit 4 (a MARSSIM Class 1 Survey Area) Table 2, Note I, '[t]he Co-60 DCGL of 0.86 pCi/g is an 'adjusted DCGL' and can be derived from the unitized dose for surface soil, LTP Table 6-7 and the updated dose model in the activated concrete related license amendment (References 3 and 4)."'
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Attachment Maine Yankee Response to NRC Request for Additional Information on FSS Final Report No.44 "Given that the Turbine Building footprint is at an after backfill depth of 3 feet, the staff requires clarification of the following issues."
Since the Turbine Building was outside of the original 10,000 m2 Restricted Area boundary, no other contaminated materials are required to be considered besides contaminated surface soil.
Soil uncovered as a result of the removal of the Turbine Building structure down to three-feet below grade, which would otherwise be at an elevation below the six-inch surface soil protocol, can be conservatively treated as surface soil for Survey Unit No. 3, since the excavation was not necessitated by radiological remediation.
During the preparation and conduct of final status survey at Maine Yankee there have been a few instances where Maine Yankee has conservatively used the contaminated soil DCGL's specified in LTP Table 6-1 1 as modified by Reference Nos. 3, 4 and 5 for areas outside of the RA. When this was done, the release record reflected this decision. FB-0500 Turbine Building Survey Unit No. 3 was one of these instances. This Survey Unit was on the border of the Restricted Area and was classified as Class I, as a result of the removal of a Service Water discharge pipe and soil contamination that was found. As indicated in the release record, even though the survey unit was located outside of the RA, the lower soil DCGL (2.39 pCi/g for Cs-137) was conservatively selected due to the possible contamination from the contaminated service water discharge piping which was removed from the survey unit and contaminated soil which was remediated.
The dose contribution for deep soil identified in LTP Table 6-11 as modified by Reference Nos.
3, 4 and 5 was calculated by assuming the DCGL for Cs-l 37 was the same as the Cs-137 DCGL for surface soil. This was appropriate since Cs-137 generally makes up about 89% of the contaminated soil nuclide mix and is very oflen the only plant derived nuclide detected.
However, as a result of reviewing the NRC's RAI, Maine Yankee identified that the dose contribution for deep soil would result in a Co-60 DCGL for deep soil less than for surface soil.
This condition was documented in Condition Report No.05-001 (Reference No. 11). In order to restore the original intent of the License Termination Plan, Maine Yankee implemented a change (Reference No. 12) to the LTP under 10 CFR 50.59 to increase the Deep Soil Co-60 DCGL by a factor of 1.8. LTP change was described in FSS Final Report No. 7 (Reference No. 9) submitted to the NRC on January 20, 2005. The State of Maine and the NRC were notified of this change prior to its implementation on January 20, 2005 (Reference No. 10).
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Attachment Maine Yankee Response to NRC Request for Additional Information on FSS Final Report No. 4 NRC RAI I. Please justify the use of the LTP Table 6-7, "Surface Soil Unitized Dose Factors 1.0 pCi/g Cs-137" versus LTP Table 6-9, "Deep Soil Unitized Dose Factors" to derive the adjusted Co-60 DCGLs for what appears to be a deep soil condition?
Maine Yankee Response:
As described above, FR-0500 Turbine Building Survey Unit No. 3 was located outside of the Restricted Area boundary. Therefore, the use of the surface soil DCGL for Co-60 was appropriate since the soil uncovered as a result of the removal of the Turbine Building structure down to three-feet below grade was not necessitated by radiological remediation but simply structural demolition, even though the soil was otherwise at an elevation below the six-inch surface soil protocol.
FR-0500 Turbine Building Survey Unit No. 4 was located outside of the Restricted Area boundary. However, the lower soil DCGL (2.39 pCi/g for Cs-137) was conservatively selected due to the possible contamination from the contaminated service water discharge piping which was removed from the survey unit and contaminated soil which was remediated. In this case, since the DCGL for surface soil and deep soil were intended to be the same, the distinction, for this purpose, was viewed as merely academic. However, the deep soil Co-60 DCGL calculated from using Table 6-9 would be lower than the surface soil Co-60 DCGL calculated using Table 6-7. This condition was documented in Condition Report No. 005-01 (Reference No. 11). The original intent of the LTP of having the same DCGL's for surface soil and deep soil was restored by an LTP change implemented under 10 CFR 50.59. Therefore, the DCGL used in the survey unit is appropriate. The release record reconciliation Form I I for Turbine Building Survey Unit No. 4 will be revised to reference the LTP change and calculation of the Co-60 DCGL using Table 6-7. This reconciliation form will be available at the site for inspection.
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Attachment .
Maine Yankee Response to NRC Request for Additional Information on FSS Final Report No. 4 NRC RAI
- 2. Since the deep soil DCGLs were not applied, the Staff questions whether the subsequent annual dose limits were applied properly. Please clarify the relationship between the LTP Table 6.9 Deep Soil Annual Dose value for Total Dose Co-60 of 2.4 mrem/yr, and the LTP Table 6-11 Contaminated Material Annual Dose (Deep Soil) value of 1.52 mrem/yr.
Maine Yankee Response:
LTP Table 6.9 "Deep Soil Unitized Dose Factors" was developed along with the other Unitized Dose Factor tables to show the total annual dose of I pCi/g of each nuclide in the applicable contaminated material nuclide mix. These dose factors can be used to develop the appropriate nuclide specific DCGL for a given dose contribution assumption. The nuclide specific DCGL can then be used in the unity rule when multiple nuclides are identified.
For instance, the deep soil dose contribution identified in LTP Rev. 3, Table 6-11 was 1.52 mrem/yr. This dose contribution was revised downward in Reference Nos. 2, 3 and 4 to 1.14 mrem/yr. Thus, as shown in the Deep Soil Co-60 DCGL LTP Change, the inside-RA deep soil DCGL for Co-60 is calculated by dividing the total deep soil contribution from Table 6-1 1 as modified by Reference Nos. 2, 3 and 4 (1.14 mremlyr) by the deep soil unitized dose factor for Co-60 from Table 6-9 (2.40 mrem./yr per pCi/g). This calculation is shown below:
Equation No. 1 Deep Soil Total Dose Commitment (mrem/yr) Table 6-11 Deep Soil DCGL Co-60 = -- ------------------------------------------------------------
Unitized Co-60 Deep Soil Dose per pCi/g Table 6-9 1.14 mrem/yr
= 0.48 pCi/g 2.40 mrem/yr per pCi/g However, the LTP change increased the Deep Soil Co-60 DCGL and consequently the Table 6-11 Total Deep Soil dose contribution by a factor of 1.8 from 1.14 mrem/yr to 2.04 mrem/yr.
Thus the new inside-RA deep soil DCGL for Co-60 is calculated by dividing the total deep soil contribution from Table 6-11 as modified by the Deep Soil Co-60 DCGL LTP Change (2.04 mrcm/yr) by the deep soil unitized dose factor for Co-60 from Table 6-9 (2.40 mrem/yr per pCi/g). This calculation is shown below:
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Attachment Maine Yankee Response to NRC Request for Additional Information on FSS Final Rcport No. 4 Equation No. 2 Deep Soil Total Dose Commitment (mrem/yr)
Deep Soil DCGL Co-60= ----------------------------------------------------------- =
Unitized Co-60 Deep Soil Dose per pCi/g 2.04 mrem/yr
- -0.86 pCi/g 2.40 mremn/yr per pCi/g The LTP Table 6-1 1 contaminated material annual dose values are also used in calculating a simplified general retrospective dose estimate as described in LTP Section 5.9.3 from the average residual contamination level. For FB-0500 Survey Unit 3, the appropriate dose value to use was the surface soil dose (5.63 mrem/yr) since the only contaminated material outside the RA is surface soil. For FB-0500 Survey Unit 4, the deep soil dose of 2.04 mrem/yr (formerly 1.14 mrem/yr) should be used since we conservatively assumed a potential for deep soil contaminated media. However, in this case, use of the surface soil provides a conservative value. Therefore, the release record reconciliation form 11 will be revised to describe the effect on the simplified general retrospective dose estimate.
The survey information for Survey Units previously submitted to the NRC in FSS Report Nos. I through 7 were reviewed to determine the impact of implementing the LTP change on the Deep Soil Co-60 DCGL. The following Survey Units were inside the Restricted Area and/or evaluated using the Table 6-11 contaminated soil annual dose values and DCGL. The change to the DCGL did not affect any of the survey units since the LTP Change restored the original intent of the LTP to have the same DCGL for Deep Soil as for Surface Soil. However, the dose attributed to Deep Soil increased, therefore, the effect on the simplified general retrospective dose estimate was evaluated.
FSS Survey Evaluation of the effect on the Action Report Unit simplified general retrospective No. dose estimate 3 FB-1300- WART Building Footprint - The FSS Package Form 1 will be SU-1 mean survey unit sample activity revised to reference the change was less than the mean fallout to the Deep Soil DCGL and activity for disturbed soil, therefore dose contribution.
the net activity was zero and the net dose from the survey unit was zero.
No impact from the LTP Change.
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J:* l ii'o I
Attachment Maine Yankee Response to NRC Request for Additional Information on FSS Final Report No. 4 FSS Survey Evaluation of the effect on the Action Report Unit simplified general retrospective No. dose estimate 4 FA-1400- Personnel Hatch Soil Footprint- The FSS Package Form 11 will be SU-I net Cs-137 dose was not affected revised to reference the change since the net activity was zero to the Deep Soil DCGL/dose (sample mean less than contribution and describe the background). The mean value of effect on the simplified, general Co-60 was 0.0848 pCi/g which retrospective dose estimate.
would decrease from 0.55 mrem/yr to 0.20 mrem/yr if the deep soil dose were used.
4 FA-1900- HV 7 and 9 Area Soil Footprint - FSS Package Form 11 will be SU-1 The mean unitized residual revised to reference the change contamination level for net Cs-1 37 to the Deep Soil DCGL/dose and Co-60 was 0.147. This would contribution and describe the result in a decrease from 0.826 effect on the simplified, general mrem/yr to 0.30 mrem/yr. retrospective dose estimate.
4 FB-0200- Control and Computer Rooms / FSS Package Form 11 will be SU-l Service Building Soil Footprints - revised to reference the change The mean survey unit sample to the Deep Soil DCGL and activity was less than the mean dose contribution.
fallout activity for disturbed soil, therefore the net activity was zero and the net dose from the survey unit was zero. No impact from the LTP Change. -
5 FR-0I 10- PAB Alleyway - The net mean Cs- FSS Package Form 1I will be SU-1 137 and mean Co-60 activity was revised to reference the change 0.069 and 0.251 pCi/g, respectively. to the Deep Soil DCGUdose This would result in a decrease from contribution and describe the 1.8 mrem/yr to 0.65 mrem/yr. effect on the simplified, general retrospective dose estimate.
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I ... ;' I "I '
Attachment Maine Yankee Response to NRC Requcst for Additional Information on I FSS Final Report No. 4 ?
FSS Survey Evaluation of the effect on the Action Report Unit simplified general retrospective No. dose estimate 5 FR-OI 10- PAB Alleyway - The net Cs-137 FSS Package Form I I will be SU-2 dose was not affected since the net revised to reference the change activity was zero (sample mean less to the Deep Soil DCGLfdose than background). The mean value contribution and describe the of Co-60 was 0.149 pCi/g which effect on the simplified, general would decrease from 0.97 mremlyr retrospective dose estimate.
to 0.35 mrem/yr if the deep soil dose were used.
5 FR-OiI 0- PAB Alleyway - The net mean Cs- FSS Package Form I I will be SU-3 137 and mean Co-60 activity was revised to reference the change 0.092 and 0.267 pCi/g, respectively. to the Deep Soil DCGL/dose This would result in a decrease from contribution and describe the 1.96 mrem/yr to 0.73 mrem/yr. effect on the simplified, general retrospective dose estimate.
5 FR-OIl 0- PAB Alleyway - The net mean Cs- FSS Package Form II1will be SU-4 137 and mean Co-60 activity was revised to reference the change 0.188 and 0.180pCi/g, respectively. to the Deep Soil DCGL/dose This would result in a decrease from contribution and describe the 1.6 mrem/yr to 0.59 mrem/yr. effect on the simplified, general retrospective dose estimate.
6 FR-0l 11- Yard West Excavations - The net FSS Package Form 11 will be SU-1 mean Cs-137 and mean Co-60 revised to reference the change activity was 0.081 and 0.313 pCi/g, to the Deep Soil DCGL/dose respectively. This would result in a contribution and describe the decrease from 0.4 mrem/yr to 0.14 effect on the simplified, general mrem/yr. retrospective dose estimate.
6 FR-01 11- Yard West Excavations - The mean FSS Package Form 11 will be SU-2 survey unit sample activity was less revised to reference the change than the mean fallout activity for to the Deep Soil DCGL and disturbed soil, therefore the net dose contribution.
activity was zero and the net dose from the survey unit was zero. No impact from the LTP Change.
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- 1' . , ' '1 Attachment Mlaine Yankcc Response to NRC Request for Additional Information on FSS Final Report No.4 FSS Survey Evaluation of the effect on the Action Report Unit simplified general retrospective No. dose estimate 6 FR-O 11- Yard West Excavations - The net FSS Package Form I I will be SU-3 Cs-137 dose was not affected since revised to reference the change the net activity was zero (sample to the Deep Soil DCGL/dose mean less than background). The contribution and describe the mean value of Co-60 was 0.0749 effect on the simplified, general pCi/g which would decrease from retrospective dose estimate.
0.49 mrem/yr to 0.18 mrem/yr if the deep soil dose were used.
6 FR-01 11- Yard West Excavations - The net FSS Package Form 11 will be SU-4 mean Cs-137 and mean Co-60 revised to reference the change activity was 0.022 and 0.0591 pCi/g, to the Deep Soil DCGL/dose respectively. This would result in a contribution and describe the decrease from 0.44 mrem/yr to 0.16 effect on the simplified, general mrem/yr. retrospective dose estimate.
6 FR-0l 11- Yard West Excavations - The net FSS Package Form 11 will be SU-5 mean Cs-137 and mean Co-60 revised to reference the change activity was 0.04 and 0.0599 pCi/g, to the Deep Soil DCGL/dose respectively. This would result in a contribution and describe the decrease from 0.49 mrem/yr to 0.18 effect on the simplified, general mrem/yr. retrospective dose estimate.
In FSS Report No. 7 (Reference No. 9), Maine Yankee conservatively addressed the impact of the increase in deep soil dose contribution by calculating the simplified, general retrospective dose estimate as a function of the net activity times the annual dose contribution of surface soil and deep soil (5.63 mrem/yr + 2.04 mrem/yr = 7.67 mrem/yr).
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Attachment Maine Yankee Response to NRC Request for Additional Information on FSS Final Report No. 4 NRC RAI
- 3. Even though Survey Units 3 and 4 are adjacent areas, two different Co-60 soil DCGLS were derived and applied. Survey Unit 3 uses a Co-60 DCGL of 1.5 pCi/g and Footnote I to Table 2 states that the relationship is not impacted (by) the updated dose model in the activated concrete related license amendment (references 3 and 4). Whereas in Survey Unit 4, the Co-60 DCGL is 0.86 pCi/g and this amendment is referenced as the basis for deriving the Co-60 DCGL. Please clarify the use of two different DCGLs and the derivation bases.
Maine Yankee Response:
As described above, the difference between the treatment of the two survey units was the decision to use the lower soil DCGL's from LTP Table 6-11 as modified by Reference Nos. 3, 4 and 5 for Survey Unit No. 4. Both survey units are outside of the Restricted Area and, therefore, qualify for the DCGL that does not require consideration of dose from any other materials.
However, for Survey Unit No. 4, the lower soil DCGL (2.39 pCi/g for Cs-I 37) was conservatively selected due to the possible contamination from the contaminated service water discharge piping which was removed from the survey unit and contaminated soil which was remediated.
The derivation basis for the Deep Soil Co-60 DCGL (inside the RA) is provided above in Equation No. 2. Outside the RA, the only contaminated material considered is surface soil. The derivation basis for the Surface Soil Co-60 DCGL (Outside the RA) is provided below in Equation No. 3:
Equation No. 3 Surface Soil Total Dose Commitment (10 mrem/yr)
Outside the Restricted Area LTP Section 6.7, pg. 6-46 Surface Soil DCGL Co-60 --------------------------------------------- ----------------------
Unitized Co-60 Surface Soil Dose per pCi/g Table 6-7 10 mrem/yr
-- 1.5 pCi/g 6.58 mrem/yr per pCi/g Page 10
Attachment Maine Yankee Response to NRC Request for Additional Information on FSS Final Report No. 4 NRC RAI
- 4. Survey Unit 3, Investigation Table, Table 3-1, indicates that Grid S033 soil sample has specific activity of 0.968 pCi/g. Given the applicability of the Deep Soil Unitized Dose Factor, and an assumed lowering of the DCGL, it appears that this grid would have exceeded the DCGL and the survey unit should have been reclassified as a Class I area in accordance with LTP Table 5.8. In addition, it is noted that Grid S033 is bounded by areas that have been surveyed to ensure that activity was limited to this survey grid.
Please address.
MsIaine Yankee Response:
As discussed above, FB-0500 Survey Unit No. 3 was outside the Restricted Area and was, therefore, subject only to the surface soil DCGL. The appropriate Co-60 DCGL to apply to this survey unit was 1.5 pCi/g as shown in Equation No. 3 above. Notwithstanding, even if the FSS results were evaluated using the lower DCGL associated with areas within the Restricted Area, the survey unit would have passed the EMC Unity Rule criteria and the Survey Unit still would have met the release criteria, assuming a successful Class 1 (100%) scan versus the Class 2 (50%) scan that was done.
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Attachment Maine Yankee Responsc to NRC Request for Additional Information on FSS Final Report No.4 References
- 1. Maine Yankee Letter to USNRC, MN-02-048, dated October 15, 2002, Revision 3, Maine Yankee's License Termination Plan
168 to Facility Operating License No. DPR Maine Yankee Atomic Power Station -
Approval of the MY License Termination Plan
- 3. Maine Yankee Letter to the USNRC, MN-03-049, dated September 11, 2003, Proposed Change: Revised Activated Concrete DCGL and More Realistic Activated Concrete Dose Modeling - License Condition 2.B.(10), License Termination; Proposed Change No. 216.
170 to Facility Operating License NO. DPR Maine Yankee Atomic Power Station -
Approval of the Revised Activated Concrete DCGL and More Realistic Activated Concrete Dose Modeling
- 5. LTP Change Notice No. 04-07 "Implementation of License Amendment No. 170" dated 4/1/04
- 6. Maine Yankee Letter to USNRC, MN-04-020, dated March 15, 2004, License Amendment Request: Release of Non-ISFSI Site Land, Proposed Change No. 218
- 7. Maine Yankee Letter to USNRC, MN-04-056, dated November 17, 2004, Release of Non-ISFSI Site Land - FSS Final Report No.4, Proposed Change No. 218, Supplement 7
- 8. USNRC Letter to MYAPC dated January 5, 2005, Request for Additional Information (RAI) Regarding Final Status Survey (FSS) Supplement No.4
- 9. Maine Yankee Letter to USNRC, MN-05-001, dated January 20, 2005, Release of Non-ISFSI Site Land - FSS Final Report No. 7, Proposed Change No. 218 Supplement 12
- 10. Maine Yankee (Mike Whitney) E-mail to USNRC (John Buckley, Mark Roberts) and State of Maine (Patrick Dostie) dated January 20, 2005, LTP Change - Deep Soil Co-60 DCGL