ML050980002
| ML050980002 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 04/07/2005 |
| From: | Gillen D NRC/NMSS/DWMEP/DD |
| To: | Meisner M Maine Yankee Atomic Power Co |
| Buckley J (301) 415-6607 | |
| References | |
| Download: ML050980002 (7) | |
Text
April 7, 2005 Mr. Michael J. Meisner, Chief Nuclear Officer Maine Yankee Atomic Power Company 321 Old Ferry Road Wiscasset, Maine 04578-4922
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION (RAI) REGARDING FINAL STATUS SURVEY (FSS) SUPPLEMENT NO. 6 On December 22, 2004, Maine Yankee Atomic Power Company (MY) submitted Final Status Survey (FSS) Supplement No. 6, for U.S. Nuclear Regulatory Commission (NRC) review and approval. FSS Supplement No. 6 includes the following 18 survey units:
FA-2600 LSA Building Slab Footprint FB-1700 Staff Building Footprint FB-2400 Staff Building Tunnel FR-0400 Forebay (9 survey units)
FR-0111 Soil Remediation Areas (5 survey units)
FR-2000 Diffuser The attachment provides the staffs comments requiring resolution before the U.S. Nuclear Regulatory Commission (NRC) approval of FSS Supplement No. 6. NRCs request for additional information is the result of: (1) missing or insufficient technical information; or (2) missing or insufficient basis for technical conclusions. Maine Yankee is requested to provide the information identified in the attachment. NRC staff discussed the technical issues with Maine Yankee staff on April 6, 2005. A schedule for Maine Yankees resubmittal of the survey information, and NRC subsequent review, will be established during an upcoming biweekly teleconference.
In accordance with 10 CFR 2.390 of the NRC's "Rules of General Applicability," a copy of this letter will be available electronically in the NRC Public Document Room or from the Publically M. Meisner Available Records (PARS) component of the NRC's document system (ADAMS). ADAMS is accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html.
Questions regarding this letter should be directed to John Buckley at 301-415-6607.
Sincerely,
/RA/
Daniel M. Gillen, Deputy Director Decommissioning Directorate Division of Waste Management and Environmental Protection Office of Nuclear Material Safety and Safeguards Docket No.: 50-309 License No.: DPR-36
Attachment:
As stated cc: See next page M. Meisner Available Records (PARS) component of the NRC's document system (ADAMS). ADAMS is accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html.
Questions regarding this letter should be directed to John Buckley at 301-415-6607.
Sincerely,
/RA/
Daniel M. Gillen, Deputy Director Decommissioning Directorate Division of Waste Management and Environmental Protection Office of Nuclear Material Safety and Safeguards Docket No.: 50-309 License No.: DPR-36
Attachment:
As stated cc: See next page DISTRIBUTION:
DWMEP r/f DCD r/f MRoberts, RI RBellamy, RI MY Distribution List ML050980002
- See previous concurrence OFFICE DCD*
DCD*
DCD*
DCD*
DCD NAME JBuckley BWatson CBurkhalter CCraig DGillen DATE 4/4/05 4/6/05 4/6/05 4/6/05 4/07/05 OFFICIAL RECORD COPY
Maine Yankee Atomic Power Plant Service List cc:
Thomas G. Dignan, Jr., Esquire Ropes & Gray One International Place Boston, MA 02110-2624 Ms. Paula Craighead, Esquire State Nuclear Safety Advisor State Planning Office State House Station #38 Augusta, ME 04333 Mr. P. L. Anderson, Project Manager Yankee Atomic Electric Company 580 Main Street Bolton, MA 01740-1398 First Selectman of Wiscasset Municipal Building U.S. Route 1 Wiscasset, ME 04578 Friends of the Coast P.O. Box 98 Edgecomb, ME 04556 Mr. Jonathan M. Block Attorney at Law P.O. Box 566 Putney, VT 05346-0566 Joseph Fay, Esquire Maine Yankee Atomic power Company 321 Old Ferry Road Wiscasset, ME 04578-4922 Mr. Patrick J. Dostie State of Maine Nuclear Safety Inspector Maine Yankee Atomic Power Company 321 Old Ferry Road Wiscasset, ME 04578-4922 Mr. William Henries, Director Engineering Maine Yankee Atomic Power Company 321 Old Ferry Road Wiscasset, ME 04578-4922 Mr. Paul Bemis Stone & Webster Engineering &
Construction c/o Maine Yankee Atomic Power Company P.O. Box 727 Bailey Point Road & Old Ferry Road Wiscasset, ME 04578 Mr. Mark Roberts U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 David Lewis, Esquire Shaw Pittman 2300 North Street, NW Washington, DC 20037 Mr. Ted C. Feigenbaum President and Chief Executive Office Maine Yankee Power Company 321 Old Ferry Road Wiscasset, ME 04578-4922 W. Clough Toppan, P.E., Director Division of Health Engineering Department of of Human Services
- 10 State House Station Augusta, ME 04333 Mr. Michael J. Meisner Chief Nuclear Officer Maine Yankee Atomic Power Company 321 Old Ferry Road Wiscasset, ME 04578-4922
Request for Additional Information Final Status Survey - Supplement 6 I.
Generic ISOCS Comments During the NRC staff review of Supplement 6, the staff reviewed Maine Yankee Engineering Calculation, Use of Canberra In Situ Object Counting System (ISOCS) for FSS Surveys, EC-003-04, Rev. 1, dated November 18, 2004. Engineering Calculation EC-003-04, Rev. 1, is identified as the technical basis document (TBD) for FSS of soil remediation areas. Engineering Calculation EC-003-04, Rev. 1, is based on the NRC reviewed and approved Technical Basis Document - Forebay FSS Survey Measurement Methods (In situ Gamma Spectroscopy), dated September 3, 2003.
The staff is unable to verify that Maine Yankee submitted EC-003-04, Rev. 1, for NRC review 30-days prior to use as required by LTP Section 5.5.1. As such, the staff was unable to comment on the use of the ISOCS for soil surveys, specifically scan surveys, following remediation. The staff agrees that the ISOCS system may be a preferred method for performing FSS. However, there are fundamental technical differences in the use of the ISOCS for soil surveys versus the Forebay that must be addressed in either an Engineering Calculation or the FSS report. The staff has the following comments concerning EC-003-04, Rev. 1, and the soil surveys as submitted in Supplement 6.
1.
General comment: EC-003-04, Rev. 1, relies heavily on the NRC reviewed and approved TBD for Forebay ISOCS measurements. EC-003-04, Rev. 1, did not draw comparisons and distinctions between the measurements in the two areas. Maine Yankee needs to add discussion to EC-003-04, Rev. 1, to clarify changes made to the Forebay ISOCS measurement approach.
2.
EC-003-04, Rev. 1, Page 3 of 15: The bottom paragraph needs clarification, but does not impact the measurements. ISOCS models the measurement environment and resulting detector response function using point-kernel methods, not the Monte Carlo N Particle Transport Code (MCNP). EC-003-04, Rev. 1, should be corrected.
3.
EC-003-04, Rev. 1, Page 4 of 15, Application of In Situ Gamma Survey Techniques to Forebay Surveys: This paragraph begins to address the issue of how one sets the measurement height, z, the size/type of collimator, and the overall measurement geometry. All of these parameters, including adjustments for background, affect measurement sensitivity. As a result, if the objective of the document is to prove that the measurement method meets sensitivity requirements, relative to the DCGLW and/or the DCGLEMC, then these parameters need to be explicitly listed. In EC-003-04, Rev. 1, it is stated, "The source-to-detector distance is typically 20-50cm, however, the distance used is adjusted based on sample K-40 activity which has been found to be the best indication of proper source-to-detector distance." The use of K-40 activity was employed for the Forebay surveys, but the application to soil surveys is unclear. The fundamental geometric configuration, for example detector height, in conjunction with the count time, must be specifically stated in EC-003-04. If these values are to be measurement specific, EC-003-04, should reference procedures for determining the parameters and include the resultant values in the FSS release records. The staff believes that the source to detector distances must be clearly established in either EC-003-04, or the FSS release records.
4.
EC-003-04, Rev. 1, Page 12 of 15, Summary of Experience with Other FSS Surveys: This section addresses the question related to edge effects and the fact that the effective areal efficiency of the detector decreases as r increases from 0 out to r (field of view). The results table shows that the MDCs are less than the DCGLEMC of 10.9 and 28.4 pCi/g, for Co-60 and Cs-137, respectively. However, EC-003-04, Rev. 1, does not contain ISOCS input data sets or provide assumptions for the analysis. The derivation of the MDCs for comparison to the DCGLEMC cannot be independently validated because essential technical details were not included in EC-003-04, Rev. 1. Please provide the ISOCS input data sets and assumptions for the analysis.
5.
EC-003-04, Rev. 1, Page 12 of 15: EC-003-04, Rev. 1, discusses 2 soil geometries (3m and 1m edge effect), however in FR-0111-SU1, Section B states that, "scans covering 100% of the 212.6 m2 area were accomplished by the use of an in situ gamma spectroscopy detector configured at a 4-meter distance from the surface to obtain overlapping 50-m2 fields of view." FR-0111-SU2 refers in Table 2-2 to a "Well" geometry. In FR-0111-SU3, the ISOCS was used at four distances including 2m, 3m, 9ft and 9in, and in SU7 a "hole" geometry is referenced. In FR-0111 SU4 and SU5, a "U-Channel" geometry is noted as been applied. Please provide a technical justification for all ISOCS geometries utilized in the Maine Yankee FSS release records.
6.
EC-003-04, Rev. 1, Page 12 of 15: EC-003-04, Rev. 1, discusses the 1m edge effect with the detector at a height of 3m and a field of view of 28 m2. The staff questions whether the ISOCS is able to adequately detect hot spots on the fringe or marginal areas of the scan areas. EC-003-04, Rev. 1, does not appear to have fully addressed the marginal edge scan areas.
In FR-0111-SU1, the ISOCS is used at a 4m distance and a field of view of 50m2 area. The staff is concerned that the ability of the system to detect elevated activity in the outer 1m2 area has not been adequately justified.
- In FR-0111-SU2, the ISOCS was used at a 2m height (8m diameter hole geometry) and a 100 m2 field of view.
7.
FR-0111 SUs 1 - 5: Table 2-2, lists ISOCS scan MDCs in ranges from 0.09 to 0.9 pCi/g. Please provide a technical justification for the MDCs for both Cs-137 and Co-60 in EC-003-04, Rev. 1, and the specific MDCs used in each survey unit.
II.
Supplement 6 FSS Release Record Specific RAIs 1.
FA-2600-SU1 LSA Test Pit: Page 2 of 25, Section B states, "In addition, there were four junctures scanned as shown on Map FA-2600-01g." LTP Sections 5.5.1 (a & d) establish methods for determining contamination at depth for wall interfaces (junctures), cracks and crevices. Please provide information, juncture sample results or gamma surveys, that demonstrates the contamination at depth and the level of residual radioactivity in the junctures to ensure no under foundation contamination.
2.
FB-1700-SU1 Staff Building Basement:
Section D describes the investigation of an alarm in Grid 179 and concluded that the volumetric sample results verified the absence of plant related activity. Please provide the sample results including the nuclides identified in the gamma spectroscopy.
3.
FR-0111-SU3 Yard Area West Excavations: Attachment 1, Page 12 of 22, states, "Elevated H-3 concentrations were detected in excavations in FR-0111 Survey Unit 3." The tritium results were not quantified. Please provide the tritium results.
III. FR-0400 Forebay FSS-RRs
- 1.
In SU-7 and SU-8, the Scan MDCs in Table 2-2 are < 70 pCi/g for Co-60 and < 35 pCi/g for Co-60 respectively. In both survey units, the scan MDC exceeds the DCGLEMC of 16.8 pCi/g for Co-60. Given that the reported scan MDC exceeds the DCGLEMC, the survey design and implementation appears inadequate and both survey units should have failed. Please clarify.
In addition, Note 1 to Table 2-2 states that, "the effective activity for non-detect Co-60 is 25% of the reported MDC as discussed in Section E." Please justify the 25%
adjustment.
- 2.
In SU-7 and SU-8, Table 2 provides two types of FSS data, in situ and soils samples.
The two methods may vary considerably in the precision and accuracy in the Data Quality Assessment. It is not clear that the Data Quality Objectives evaluated to determine the impact. Please clarify.