ML14204A150
| ML14204A150 | |
| Person / Time | |
|---|---|
| Site: | Humboldt Bay |
| Issue date: | 04/02/2014 |
| From: | Sokoisky D Pacific Gas & Electric Co |
| To: | John Hickman NRC/FSME |
| References | |
| Download: ML14204A150 (46) | |
Text
Hickman, John From: Sokolsky, David <DDS2@pge.com>
Sent: Wednesday, April 02, 2014 6:05 PM To: Hickman, John Cc: Baldwin, Thomas (DCPP); Post, Jennifer (Law); Erickson, Martin; Barley, William H; Sharp, Loren; Strehlow, Michael
Subject:
REVISED LTP RAI RESPONSES IN HBL-14-008 Attachments: HBL-14-008-Rev-l.docx Follow Up Flag: Follow up Flag Status: Flagged
- John, Attached is a copy of the previously submittal RAI response letter HBL-14-008, that includes additional information pertaining to responses to RAIs 11, 20 and 28. This information is highlighted in red and with underlines, and is the result of discussions held during the NRC/HBPP LTP Public Meeting on March 12, 2014.
Please contact me if you need additional information. Thank you.
David Sokolsky HBPP Supervisor of Licensing 415-973-5024 office 707-601-6703 cell PG&E is committed to protecting our customers' privacy.
To learn more, please visit http://www.pge.com/about/company/privacy/customer/
I
February 14, 2014 PG&E Letter HBL-14-008 U.S Nuclear Regulatory Commission 10 CFR 50.90 ATTN: Document Control Desk 10 CFR 50.82 (a)(9)
Washington, D.C. 20555 Docket No. 50-133, License No. DPR-7 Humboldt Bay Power Plant, Unit 3 Humboldt Bay Power Plant, Unit 3, License Termination Plan Responses to Requests for Additional Information
Dear Commissioners and Staff:
On May 13, 2013, Pacific Gas and Electric Company (PG&E) submitted a proposed License Termination Plan (LTP) for Humboldt Bay Power Plant (HBPP), Unit 3. On December 24, 2013, the NRC sent PG&E a Request for Additional Information (RAI) based on NRC review of the HBPP Unit 3 LTP. PG&E is responding to the majority of NRC RAIs in the enclosures to this letter as described below: , Chapter 2 - Site Characterization, RAIs 01 through 10 , Chapter 5 - Final Status Survey Plan, RAIs 11 through 28 , Draft Sample Buried Piping Survey Plan , Environmental, RAIs 48 through 57 , Matrix of RAIs and Associated Changes to the License Termination Plan In the December 24, 2013 letter, the NRC also requested PG&E to provide copies of additional documents. PG&E is providing these additional documents in the following enclosures to this letter: , Bechtel Civil & Minerals, Inc.: "Interoffice Memorandum, Humboldt Bay Power Plant Unit #3 Report of 1984 Geologic Activities." August 1984 , PG&E Department of Engineering Research: "Effects of Tides on Groundwater Flow at Humboldt Bay Power Plant," January 1987 , PG&E Technical and Ecological Services, Water Resources Unit: "Humboldt Bay Power Plant Wastewater Treatment Impoundments Hydrogeologic Characterization Study," November 1988 , PG&E Geosciences: "Technical Report TR-HBIP-2002-01, Seismic Hazard Assessment for the Humboldt Bay ISFSI Project, Revision 0," December 27, 2002 0, ENERCON Services, Inc.: "Humboldt Bay Power Plant Tritium Evaluation,"
December 2006 1, PG&E: "DECON-POS-H01 1: Groundwater Investigation History, Control, and Management, Revision B." May 2009 Where appropriate, PG&E will revise the LTP to include information from several RAI responses. Enclosure 5 contains a matrix that identifies those LTP sections that will be revised for the specific RAIs. The LTP Revision 1 will be sent to the NRC in a separate submittal when all required changes have been incorporated.
PG&E is currently developing responses to NRC RAIs for LTP Chapter 6 and Supplemental Information (RAIs 28 through 47) and will send these responses in a separate submittal.
If you wish to discuss the information in the enclosure, please contact Mr. William Barley at (707) 444-0856.
I state under penalty of perjury that the foregoing is true and correct.
Executed on February 14, 2014.
Sincerely, Edward D. Halpin Enclosures cc: HBPP Humboldt Distribution cc/enc: John B. Hickman, NRC Marc Dapas, NRC Region IV Gonzalo L. Perez, California Department of Public Health
Enclosure 1 PG&E Letter HBL-14-008 Enclosure 1 Chapter 2 - Site Characterization RAIs 01 through 10 Pages 1 to 9 1
Enclosure 1 PG&E Letter HBL-14-008 NOTE - Acronyms used in the PG&E responses are defined in the LTP Section "Terms and Acronyms."
Chapter 2- Site Characterization
RAI 01
Basis for Request:
SRP Section B.2 acceptance criterion states that the LTP sufficiently details the site characterizationto allow the NRC staff to determine the extent and range of radiologicalcontamination. 10 CFR 50.75(g)(4)(iii) and § 50.83(a)(2) require the licensee to perform a historical site assessment (HSA) and maintain records of the assessment before the site is released for unrestricted use. 10 CFR 50.2 defines the HSA as the identification of sources of radioactive material and radioactive contamination based on existing or derived information for classifying a site as impacted or non-impacted. The licensee describes spills and events that may have affected the site and states in LTP Sections 2.1.4.4 and 2.1.4.5 that the licensee used personnel interviews and historical photographs to develop the HSA.
However, the licensee states in LTP Section 2.1.4.2 that records maintained in accordance with 10 CFR 50. 75(g)(1) provided a major source of documentation for the HSA review process. The licensee does not provide any additional information on what other information it used or derived to complete the HSA.
RAI Describe other sources that the licensee used or derived to complete the HSA review.
PG&E RESPONSE Additional documents reviewed were (HSA Section 5.3):
" Environmental Reports
- Radiological Environmental Monitoring Reports
- Radioactive Effluent Release Reports
" Licensee Event Reports
" Plant Operating Reports
- Plant Safety Analyses
" Radiological Surveys
" Plant Operating Logs PG&E will revise Section 2.1.4.2 to include this list of documents.
2
Enclosure 1 PG&E Letter HBL-14-008
RAI 02
Basis for Request:
SRP Section B.2 acceptance criterion states that the LTP sufficiently details the site characterization to allow the NRC staff to determine the extent and range of radiologicalcontamination. SRP Section B.4 acceptance criterion states that the LTP discuss in detail how facility and site areas will be remediated and summarize the radiation protection methods and control procedures that the licensee will use including a summary of the procedures already authorized under the existing license. 10 CFR 50.75(g)(4)(iii) and § 50.83(a)(3) require the licensee to perform surveys adequate to demonstrate compliance with the radiologicalcriteria for unrestricted use specified in 10 CFR 20.1402. LTP Section 2.1.5.3 text states that contaminated soils were disposed at an NRC-licensed facility and soils deemed noncontaminatedaccording to procedures were placed on either side of the discharge canal. The licensee has not described how it determined if contamination was present or whether or not the licensee used threshold activity concentrations to determine if soils were contaminated vs. noncontaminated.
RAI Describe how the licensee determined if soils were contaminated and threshold activity concentrations used to determine if contamination is present.
PG&E RESPONSE Soil samples are counted down to see an LLD of 0.18 pCi/g Cs-137. If any plant related radionuclide, other than Cs-137 is identified, the soils are considered contaminated. If Cs-1 37 is identified in soils greater than 6 inches from the surface, the soils are considered contaminated. If the soils are less than 6 inches from the surface any Cs-137 concentration greater than 0.4 pCi/g is considered contaminated.
PG&E will revise Section 2.1.5.3 to include a note comprised of the above paragraph.
RAI 03
Basis for Request:
SRP Section B.2 acceptance criterion states that the LTP (sic) sufficiently details the site characterizationto allow the NRC staff to determine the extent and range of radiologicalcontamination. 10 CFR 50.75(g)(4)(iii)and § 50.83(a)(3) require the licensee to perform surveys adequate to demonstrate compliance with the radiological criteriafor unrestricteduse specified in 10 CFR 20.1402. The last paragraphbefore 3
Enclosure 1 PG&E Letter HBL-14-008 Table 2-4 states that the licensee performed an extensive characterizationin 1997 and that Table 2-4 provides a summary of the characterizationwithin the NOLO1 survey area. The table lists only Cs-137 and Co-60. The licensee has not described whether it analyzed samples for other radionuclides,such as hard-to-detectradionuclides(HTD).
RAI Provide a more complete description of the 1997 site characterization,additional analyticalresults, and the justification or rationale for not analyzing for other radionuclidesof interest and HTD radionuclides.
PG&E RESPONSE Hard-to-detect radionuclides were analyzed for in this Survey Area:
- Fifty nine samples were analyzed for Am-241. Thirty detections were indicated with the maximum result of 0.26 pCi/g. The LLD range for the analysis was 0.06 to 0.33 pCi/g.
- Eighteen samples were analyzed for Cm-243/244/245/246. One detection of Cm-243/244 at 0.08 pCi/g which was above the LLD of 0.06 pCi/g. Five detections of Cm-245/246 with a maximum value of 0.05 pCi/g which was above the LLD range of 0.01 to 0.07 pCi/g.
- Eighteen samples were analyzed for Ni-63. Two detections were identified with the maximum value of 4 pCi/g with a LLD range of 1.22 to 1.69 pCi/g.
" Eighteen samples were analyzed for Pu-238/239/240/241. One detection of Pu-238 at 0.14 pCi/g at an LLD of 0.08 pCi/g. Two detections of Pu-239/240 with a maximum of 0.14 pCi/g and an LLD range of 0.01 to 0.10 pCi/g. No detections of Pu-241 were observed.
PG&E will revise Section 2.1.8.1 to include the above data.
RALI Basis for Request:
SRP Section B.2 acceptance criterion states that the LTP sufficiently details the site characterization to allow the NRC staff to determine the extent and range of radiologicalcontamination. 10 CFR 50.75(g)(4)(iii) and § 50.83(a)(3) require the licensee to perform surveys adequate to demonstrate compliance with the radiologicalcriteria for unrestricted use specified in 10 CFR 20.1402. The last paragraph before Table 2-5 states that the licensee performed an extensive characterizationin 1997 and that Table 2-5 provides a summary of the characterization within the OOL01 survey area. The table lists only Cs-137 and Co-60, but the text does not explain if the licensee analyzed for other isotopes.
4
Enclosure 1 PG&E Letter HBL-14-008 RAI Provide a more complete description of the 1997 site characterization, additional analytical results, and the justification or rationale for not analyzing for other radionuclides of interest and HTD radionuclides.
PG&E RESPONSE Six samples were analyzed for Am-241 and five samples were analyzed for Cm-242/243/244/245/246, Ni-63 and Pu-238/239/240/241. One detect for Cm-245/246 was observed at a value of 0.04 pCi/g with an LLD of 0.01 pCi/g. The lone Cm detection represents a fraction of a DCGL (fDCGL) of 5.62E-04 which would neither affect the classification of the Survey Area nor alter the DQOs associated with the planning of the surveys.
PG&E will revise Section 2.1.8.2 to include the above data.
RAI 05
Basis for Request:
SRP Section B.2 acceptance criterion states that the LTP sufficiently details the site characterization to allow the NRC staff to determine the extent and range of radiologicalcontamination. 10 CFR 50.75(g)(4)(iii) and § 50.83(a)(3) require the licensee to perform surveys adequate to demonstrate compliance with the radiological criteria for unrestricted use specified in 10 CFR 20.1402. The last paragraph in this section states that the licensee performed an additional site characterizationin 2008 to examine the concentrationsat depths greater than those sampled in 1997 did. The licensee states that the results of these surveys determined that the contamination was limited to the top 2 feet in the sediment. The licensee does not state what radioisotopes it analyzed.
RAI Provide a more complete description of the 2008 site characterization,additional analyticalresults, and the justification or rationale for not analyzing for other radionuclidesof interest and HTD radionuclides.
PG&E RESPONSE The 2008 characterization survey was analyzed for the radionuclides-of-concern (Cs-137 and Co-60) as determined in the characterization plan.
5
Enclosure 1 PG&E Letter HBL-14-008 PG&E will revise Section 2.1.8.2 to include the above sentence.
RAI 06
Basis for Request:
SRP Section B.2 acceptance criterion states that the LTP sufficiently details the site characterization to allow the NRC staff to determine the extent and range of radiologicalcontamination. 10 CFR 50.75(g)(4)(iii) and § 50.83(a)(3) require the licensee to perform surveys adequate to demonstrate compliance with the radiological criteria for unrestricted use specified in 10 CFR 20.1402. This section describes the activity measured in survey area OOL02-1ntake East, but like the NRC staffs comments for the previous sections in Chapter 2, the licensee only lists Co-60 and Cs-137 and does not describe any other isotopes that the licensee analyzed.
RAI Provide a more complete description of what isotopes were included in the analysis.
PG&E RESPONSE Ten samples were analyzed for Am-241 and five samples were analyzed for Cm-242/243/244/245/246, Ni-63 and Pu-238/239/240/241. One detect was observed for Pu-238 at 0.13 pCi/g with an LLD of 0.12 pCi/g. One detect of Pu-239/240 was observed at 0.22 pCi/g with an LLD of 0.08 pCi/g. There were no other detects observed with the other radionuclides greater than their respective LLDs.
PG&E will revise Section 2.1.8.3 to include the above data.
RAI 07
Basis for Request:
SRP Section B.2 acceptance criterion states that the LTP sufficiently details the site characterization to allow the NRC staff to determine the extent and range of radiologicalcontamination. 10 CFR 50.75(g)(4) (iii) and § 50.83(a)(3) require the licensee to perform surveys adequate to demonstrate compliance with the radiologicalcriteria for unrestricted use specified in 10 CFR 20.1402. These sections describe the activity measured, but like the NRC staff's comments for the previous sections in Chapter 2, the licensee only lists Co-60 and Cs 137 and does not describe any other isotopes that the licensee analyzed.
6
Enclosure 1 PG&E Letter HBL-14-008 RAI Provide a more complete description of what isotopes were included in the analysis.
PG&E RESPONSE Twenty one samples were analyzed for Am-241 and one sample was analyzed for Cm-242/243/244/245/246, Ni-63 and Pu-238/239/240/241. No detects above the LLD were observed for these isotopes.
PG&E will revise Sections 2.1.8.4 through 2.1.8.10 to include this data.
RAI 08
Basis for Request:
SRP Section B.2 acceptance criterion states that the LTP sufficiently details the site characterizationto allow the NRC staff to determine the extent and range of radiologicalcontamination. 10 CFR 50.75(g)(4)(iii) and § 50.83(a)(3) require the licensee to perform surveys adequate to demonstrate compliance with the radiological criteria for unrestricted use specified in 10 CFR 20.1402. This section describes unit survey area OOL 10, Remainder of Land Area, as a Class 3 survey area and reports the Cs-137 mean activity in Table 2-13. As discussed in previous NRC staff comments on LTP Chapter 2, the licensee does not state that it analyzed for any other radioisotopes.
RAI Provide a more complete description of what isotopes were included in the analysis.
PG&E RESPONSE All samples were analyzed for Cs-1 37, Co-60 and Mn-54. Four samples were analyzed for Am-241 with no activity above the LLD for Co-60 and Am-241.
PG&E will revise Section 2.1.8.11 to include this data.
RAI 09
Basis for Request:
SRP Section B. 2 acceptance criterion states that the L TP sufficiently details the site characterizationto allow the NRC staff to determine the extent and range of radiological 7
Enclosure 1 PG&E Letter HBL-14-008 contamination. 10 CFR 50.75(g)(4)(iii) and§ 50.83(a)(3) require the licensee to perform surveys adequate to demonstrate compliance with the radiologicalcriteriafor unrestricteduse specified in 10 CFR 20.1402. This section describes unit survey area OOL 11, Intake West and reports the Co-60 and Cs-137 mean activity in Table 2-14. As discussed in previous NRC staff comments on L TP Chapter2, the licensee does not state that it analyzed for any otherradioisotopes.
RAI Provide a more complete description of what isotopes were included in the analysis.
PG&E RESPONSE Ten samples were analyzed for Am-241 and one sample was analyzed for Cm-242/243/244/245/246, Ni-63 and Pu-238/239/240/241. One detect was observed for Cm-245/246 with an activity of 0.05 pCi/g with an LLD of 0.03 pCi/g. One each detect was observed for Pu-238 and Pu-239/240 with activities of 0.13 and 0.22 pCi/g respectively. The LLDs for the Pu-238 and Pu-239/240 were 0.12 and 0.08 pCi/g respectively.
PG&E will revise Section 2.1.8.11 to include this data.
RAI 10
Basis for Request:
SRP Section B.2 acceptance criteria states that the LTP (1) sufficiently details the site characterization to allow the NRC staff to determine the extent and range of radiologicalcontamination, and (2) identifies the background levels used during seeping or characterizationsurveys. 10 CFR 50.75(g)(4)(iii) and§ 50.83(a)(3) require the licensee to perform surveys adequate to demonstrate.compliance with the radiological criteria for unrestricted use specified in 10 CFR 20.1402. This section describes potential contaminants at the site. The licensee explains that although the primary radioisotopes of concern are Fe-55, Co-60, Cs 134, Cs 137, Ni 63, Pu-238/241, and Am-241, but because the plant shutdown in 1976 and has been in SAFSTOR since 1976, Fe-55 and Co-60, both with short half-lives, have decayed to 0. 1 percent and 1.6 percent, respectively. The licensee states that the most abundant radioisotopesof concern are Cs-1 37 (sic) and Ni-63. The licensee states that it has observed an increase in Am-241 from the beta decay of Pu-241 to Am-241. The licensee states that Am-241 will not reach equilibrium with Pu-241 and that the Am-241 will reach 90 percent of its maximum in 2013, approximately 48 years from the date of the last fuel cladding failure in 1965. The licensee should have included this information in the beginning, which would explain the analysis of 8
Enclosure 1 PG&E Letter HBL-14-008 Co-60 and Cs-137, but does not explain the rationale for the licensee omitting Ni-63 or Am-241 analysis in the site characterization. In addition, analysis should have confirmed the licensee's assumption that the radioisotopes of concern had decayed below activities of interest.
RAI Provide a more complete description of what isotopes were included in the analysis and a justification or rationale for not analyzing other potential contaminants.
PG&E RESPONSE The following Table depicts the isotopes analyzed for in the 1997 characterization sampling program. The radionuclides were chosen based on historical sampling information.
Analyte Fe-55 Mn-54 Ni-63 Co-60 Sr-90 Zn-65 Tc-99 Sb-125 Am-241 Cs-134 Pu-238 Cs-137 Pu-239/240 Eu-154 Cm-242 Eu- 155 Cm-244 Pu-241 All of the samples taken were analyzed for gamma emitters and randomly selected samples were analyzed for hard-to-detect isotope analysis. Analyses for Am-241 and Ni-63 revealed very low concentrations present in the soils relative to the concentration of Cs-1 37.
PG&E will revise Section 2.1.8 to include the above information.
9
Enclosure 2 PG&E Letter HBL-14-008 Enclosure 2 Chapter 5 - Final Status Survey Plan RAIs 11 through 28 Pages 1 to 14 1
Enclosure 2 PG&E Letter HBL-14-008 NOTE - Acronyms used in the PG&E responses are defined in the LTP Section "Terms and Acronyms."
Chapter 5- Final Status Survey Plan
RAI 11
Basis for Request:
Chapter 5, Section 5.2.1.3, Page 5-11. It was noted in Section 5.2.1.3 of the LTP that "when a surrogate ratio is established using data collected prior to remediation, post-remediationor FSS measurements will be reviewed to ensure that the established ratios are still appropriate."
RAI When will surrogate ratios be developed? Once developed, what quality assurance measures will be taken to ensure that a surrogate ratio remains valid for a given data set? How many confirmation measurements will be performed to confirm the surrogate ratio? If such an analysis leads to a conclusion that the ratios were not appropriate, what contingencies are in place to handle hard to detect radionuclides?
PG&E RESPONSE PG&E will delete the last paragraph in Section 5.2.1.3 and replace it with the following:
The following process will be applied to assess the need to use surrogate ratios for final status surveys during the DQO process:
" Determine whether HTD radionuclides (e.g., TRU, Sr-90, H-3) are likely to be present in the survey unit based on process knowledge and historical data or characterization.
" When HTD radionuclides are likely to be present, establish a relationship using a representative number of samples (typically six or more). The samples may come from another survey unit if the source of the contamination and expected concentrations are reasonably the same.
These samples will be analyzed for ETD and HTD radionuclides using gross alpha, alpha spectroscopy, gross beta analysis, or gamma spectroscopy techniques.
Surrogate relationships will be determined using one of the methods described below:
2
Enclosure 2 PG&E Letter HBL-14-008
- Develop a surrogate relationship for each HTD radionuclide.
" Determine the average surrogate DCGL and the standard deviation from the surrogate relationships.
If the mean values for individual samples for a given media are within two standard deviations of the overall mean value for the media, the surrogate ratio is acceptable. If this criterion is not met, the following steps will be applied:
- The lowest surrogate DCGL from the observed radionuclide mix may be applied to the entire survey unit.
" Additional samples may be collected and analyzed to allow for a detailed analysis and documented evaluation of the radionuclide distribution in order to establish a DCGL specific to that survey unit.
- A corrective action document will be initiated and entered into the Corrective Action System.
A general expression for the surrogate equation based on recursive relationships is provided by the following equation for i HTD radionuclides.
DCGLETD H -=1DCGL n DCaLsurrogate = F17i=1 DCGLi + DCGLETD 1Z 7 In== DCGLm where:
DCGLETD = the DCGL for the easy-to-detect radionuclide DCGLi = the DCGL for the ith hard-to-detect radionuclide fi = the activity ratio of the ith hard-to-detect radionuclide to the easy-to-detect radionuclide Surroqate relationships will be verified by either performing HTD analyses on post-remedial samples (e.g. 6 or more) or by analyzing a minimum of 10% of the FSS samples for HTD. All FSS samples are held in storage on-site until the survey unit is approved for release by the NRC. In the event that additional analyses are required to reconfirm HTD ratios, these FSS samples will be available for analysis.
RAI 12
Basis for Request:
Chapter 5, Section 5.2.2, Pages 5-13 to 5-14. Section 5.2.2 of the LTP discusses reclassificationof survey areas and notes that "Once the FSS of a given survey unit begins, the basis for any reclassificationwill be documented, requiring a redesign of the survey unit package, if required(e.g., a Class 3 to a Class 2) and the initiation of a new survey using the redesigned survey unit package." The NRC staff 3
Enclosure 2 PG&E Letter HBL-14-008 encourages HBPP to consider the guidance in Appendix A. I of NUREG-1757 which notes that "If a licensee plans to make use of reclassificationduring the RSSI process, the licensee should provide in the DP the criteria and methodology the licensee plans to use for reclassification. In addition, a licensee contemplating use of reclassification is encouraged to consult with NRC staff" RAI Please clarify your criteria for reclassification.
PG&E RESPONSE Reclassification of a Survey Unit to a less restrictive classification requires a 14-day notice prior to commencement of the survey as referenced in proposed License Condition 2.C.5 and Section 1.6 of the HBPP LTP. Reclassification to a more restrictive classification will be performed in accordance with Section 5.3.6.4 of the LTP. New DQOs will be developed with a new survey plan developed. Reclassification to a more restrictive classification does not require prior NRC notification provided that the Type I error is not increased. The reclassification will be addressed in the new survey plan, as well as the final report on the Survey Area.
PG&E will revise Section 5.2.2 to include the following:
"Reclassification to a more restrictive classification will be performed in accordance with Section 5.3.6.4 of the LTP. New DQOs will be developed with a new survey plan developed. Reclassification to a more restrictive classification does not require prior NRC notification provided that the Type I error is not increased. The reclassification will be addressed in the new survey plan, as well as the final report on the Survey Area."
RAI 13
Basis for Request:
Chapter 5, Section 5.2.2.2, Page 5-14. Section 5.2.2.2 (Impacted Areas) of the LTP defines Class 1, 2, and 3 impacted areas and refers to NUREG-1757, Volume 2, Page A2 as the source. However, the L TP does not specify DCGLW (sic) in Class 1 and 2 definitions, but only refers to a "DCGL." Similar instances were also found in Section 5.3.6 and throughout the document.
RAI 4
Enclosure 2 PG&E Letter HBL-14-008 Please ensure that DCGLw or DCGLEMC (sic) are being accurately distinguished in the discussion of Class I and Class 2 areas throughout the L TP.
PG&E RESPONSE In the HBPP LTP, DCGLw is a reference criterion or radioactivity level for residual radioactivity evenly distributed in a survey unit. DCGLEMc is used when small areas of elevated radioactivity exist within larger areas. If there is no subscript associated with DCGL then it is understood to mean DCGLw. DCGLw and DCGLEMc are accurately distinguished in the discussion of Class 1 areas. DCGLEMc is not applicable in Class 2 areas.
PG&E will revise LTP section "Terms and Acronyms" to clarify DCGL and DCGLw.
RAI 14
Basis for Request:
Chapter 5, Section 5.2.4, Pages 5-17 to 5-18. An overview of access control measures is provided in Section 5.2.4 of the LTP, but limited details are provided on specific measures to prevent recontamination of remediated areas.
RAI What procedures are in place to prevent recontamination of areas where Final Status Surveys have been performed? What administrative and engineering controls will be maintained to ensure that remediated areas are not recontaminated by ongoing site operations?
PG&E RESPONSE When an area is turned over for Final Status Survey, an FSS Area Turnover Sheet will be initiated. The Site Closure Manager will insure all decommissioning activities in areas either adjacent to the area to be isolated or that could otherwise impact it are either complete or deemed not to have the potential to spread plant-related radioactive material to the area. The Site Closure Manager will determine what combination of measures will be employed to prevent recontamination of the FSS area in accordance with HBPP procedure RCP FSS-4. A combination of personnel training (General Employee Training), postings (RCP FSS-4) and periodic surveillance surveys (RCP FSS-1 3) are some of the measures routinely employed.
PG&E will revise Section 5.2.4 to add the above paragraph.
RAI 15
5
Enclosure 2 PG&E Letter HBL-14-008 Basis for Request:
Chapter 5, Section 5.4.2, Page 5-35. Surveys of structures are discussed in Section 5.4.2, where it was noted that scan surveys, direct measurements, and when necessary, volumetric sampling will be performed. Beta/gamma surveys were discussed under Section 5.4.2.1 (Scan Surveys), and no particulardetector or types of radiation being measured were discussed under Section 5.4.2.2 (Direct Measurements).
RAI Please provide additional details on the types of instrumentation that will be used for direct structure surveys and demonstrate that they are capable of adequately detecting the expected radionuclides. Since there is a concern for alpha contamination due to failed fuel, how will alpha contamination be measured?
PG&E RESPONSE Table 5-9 lists the 2350-1 with the 43-68 and/or 43-37 detectors being utilized for beta/gamma scans. Table 5-9 lists the 2350-1 with the 43-68 detector being utilized for direct beta and alpha measurements. The a priori static MDCs at the estimated background associated with these instruments listed in Table 5-10 are approximately 2% of the structure DCGLs. Alpha contamination will be measured by static measurements utilizing the 23-50 with the 43-68 detector as well as by smears taken on the structure.
RAI 16
Basis for Request:
Chapter 5, Section 5.4.2.4, Page 5-36. It was noted that "the thickness of the layer of building surface to be removed as a sample should be consistent with the development of the HBPP site model and the DCGLs (i.e., less than 10 mm in depth)."
RAI Please provide additional details on the establishment of the site model and the usage of a 10 mm thickness. No other mention of this thickness was found in the discussion of DCGL development.
PG&E RESPONSE 6
Enclosure 2 PG&E Letter HBL-14-008 Input parameters in the RESRAD-Build model assumes all the activity at the surface (LTP, Chapter 6, Appendix B), therefore it would be appropriate to posit that the activity is less than 10 mm in depth. For the radionuclides-of-concern, a 10 mm thickness provides a minimal degree of shielding.
PG&E will revise Section 5.4.2.4 to include this detail.
RAI 17
Basis for Request:
Chapter 5, Section 5.4.2.5.2, Page 5-37. It was indicated under the Volumetric Sampling discussion that "If a survey area has already been excavated and remediated to the soil DCGL, this area will be treated as surface soil, and the.()FSS will be performed on the excavated area. Soil samples will be collected to depths at which there is high confidence that deeper samples will not result in higher concentrations."
RAI What defines a depth at which there is a high confidence that deeper samples will not result in higher concentrations?
PG&E RESPONSE Soil sample depth will be determined during the DQO phase of the survey design.
Surface soil samples will normally be taken at a depth of 0 to 15 cm. Areas of potential subsurface soil contamination (e.g. areas identified where spills were present, areas found to contain contamination during remediation, etc.) may require sampling at a depth exceeding 15 cm up to a depth of one meter. If contamination below 15 cm is suspected, split spoon sampling or similar methods, will be used for the final survey.
Section 5.4.2.5.2 will be revised to include the above information.
RAI 18
Basis for Request:
Chapter 5, Section 5.4.2.5.2, Page 5-37. It was noted under the Volumetric Sampling discussion that 'Alternatively, a sodium iodide detector or in situ object counting system (ISOCS) of sufficient sensitivity to detect DCGL concentrations may be used to identify the presence or absence of subsurface contamination (i.e. greater than 15 cm in depth), and the extent of such contamination. If the detector identifies the presence of contamination at a significant fraction of the 7
Enclosure 2 PG&E Letter HBL-14-008 DCGL (as referenced in Table 5-5), confirmatory investigation and analyses of soil samples of the suspect areas will be performed." The staff reviewed the "In Situ Object Counting SystemTM (ISOCS) as Applied to Scan Requirements in Support of the Final Status Survey at HBPP" document provided as an Enclosure to the HSA and noted that it relates to surface soil scanning. As such, it has not been demonstrated that sodium iodide or ISOCS instrumentation would be sufficient to quantify sub-surface contamination.
RAI Please provide a technical basis document for review to demonstrate these instruments' subsurface detection capabilities. This RAI also relates to the RAIs on Characterizationand Remedial Action Support Surveys in that the survey methodologies and approaches to verify the full extent of contamination and to demonstrate that remediation has been successful have not been discussed.
PG&E RESPONSE It was not the intent of HBPP to utilize the ISOCS or sodium iodide detectors to quantify the residual activity at depths greater than 15 cm; therefore a technical basis document was not developed. The mentioned detectors may indicate the presence of elevated activity and therefore the potential of activity at depth triggering an investigation. Soil sampling would be performed in response to an investigation.
PG&E will revise Section 5.4.2.5.2 to read:
"Alternatively, a sodium-iodide detector or in situ object counting system (ISOCS) of sufficient sensitivity to detect DCGL concentrations may be used to identify the potential presence of subsurface contamination (i.e. greater than 15 cm in depth) triggering an investigation."
RAI 19
Basis for Request:
Chapter 5, Section 5.4.3.1, Page 5-38. The LTP states that "the survey design of paved/concrete areas will be based on soil survey unit sizes since they are outdoor areas where the exposure scenario is most similar to direct radiation from surface soil," and that "the applicable DCGL will be the soil DCGL."
RAI 8
Enclosure 2 PG&E Letter HBL-14-008 Has an analysis been performed to justify this usage of soil DCGLs for paved/concrete areas?Is this a conservative approach?
PG&E RESPONSE Since there is no asphalt exposure modeling in RESRAD, it is more appropriate to apply the volumetric DCGLs to the asphalt than building surface DCGLs and is a more conservative approach. The statistical samples for the survey unit will be the soils below the engineered surface.
RAI 20
Basis for Request:
Chapter 5, Section 5.4.3.2, Page 5-38. It was noted in the Bulk Materials discussion that "Excavated soil may be reused onsite. Prior to reuse, excavated soil will be characterized to determine its suitability. Any surface scanning or volumetric analyses will be directly compared with DCGL values."
RAI Additiohal details should be provided on the characterization methodology and instrumentationthat will be utilized for reused soils. The NRC staff notes that other licensees have been allowed to reuse excavated soils from impacted areas on site, but only after a demonstration that surveys and characterizationof soils are comparable to the rigor of a Final Status Survey. This process can be complex, and has generally necessitated the removal and survey of soils via automated sorting systems or in systematic lifts where the depth of soil is limited to a height that can be adequately scanned by a technician. Please provide additional details on the methodologies for soil reuse and demonstrate that surveys will be performed to the rigor of a Final Status Survey.
PG&E RESPONSE Prior to performing an FSS, excavated soil will be characterized to determine suitability for transport to an area dedicated for excavated soils. Soils that do not contain residual radioactivity greater than DCGL values will be relocated to an area dedicated for soil I evaluation and leveled to a maximum depth of six inches. A Class 1 FSS will then be conducted with soil measurements averaged over the total depth of soil.
Sample/measurement density will be equal to that needed for a surface soil survey of the same volume. Surface scanning and volumetric analyses will be directly compared with DCGL values. Any measurement location identifying residual radioactivity above the DCGL will be investigated and remediated as necessary.
9
Enclosure 2 PG&E Letter HBL-14-008 Controls will be instituted to prevent mixing of soils from different survey areas prior to evaluation. Soils satisfying the criteria for unrestricted release will be stockpiled for use as onsite backfill material. (Class 2 material could be used in either Class 1 or 2 areas and Class 1 material could only be used in Class 1 areas.) The radiological evaluation of soils resulting from minor trenching and digging efforts in Class 3 defined areas (no reasonable potential for subsurface contamination) will be-performed by characterization survey in accordance with site procedures. Excavated soils that demonstrate residual radioactivity consistent with Class 3 status will be released for use as onsite excavation backfill.
Bulk survey methods (i.e. Defender) may be employed as an alternative survey technique provided the methodology can accurately assess the materials. The GARDIAN-Ill system includes a total of six HPGe detectors that have been characterized for ISOCS (in-situ obiect counting system) measurements to allow modeling of large volume geometries for accurate quantification of results. The detectors are housed in two semi-trailers parked in a parallel configuration.
Additionally, two large volume plastic scintillation detectors are included with the system and are mounted outside on the in-board ends of each trailer.
PG&E will revise Section 5.4.3.2 to include the above two paragraphs.
RAI 21
Basis for Request:
Chapter 5, Section 5.4.3.2, Page 5-38. The discussion of reuse soils also indicated that "Soils satisfying the criteria for unrestrictedrelease may be stockpiled for use as HBPP onsite backfill material."
RAI Please describe the administrative and engineering controls that will be maintainedto prevent recontaminationof stockpiled soils.
PG&E RESPONSE All soil stockpiles at HBPP are under the Stormwater Pollution Prevention Plan Best Management Practices and are therefore required to have a lower and upper cover and be waddled in the middle.
PG&E will revise Section 5.4.3.2 to include this information
RAI 22
Basis for Request:
10
Enclosure 2 PG&E Letter HBL-14-008 Chapter5, Section 5.4.3.3, Page 5-38 to 5-39. The section on Embedded Piping and Buried Piping states that separate FSS plans will be developed for embedded/buriedpiping, which will include survey unit DQOs. A general overview was provided in the text, but further details are requiredfor the staff to perform an adequate technical review.
RAI Pleaseprovide the FSS Plan for embedded piping be provided for staff review.
PG&E RESPONSE An example of a draft FSS plan for the survey of buried piping beneath the Admin. Annex Building is provided in Enclosure 3 to this letter (HBL-14-008).
Note: There are very few buried piping that will remain at license termination. All of these will be Class 3. Class 1 and 2 piping will be removed. Also, the sample plan for the piping shows a 100% survey, because for that piping it is easily accomplished (i.e.
short run and easily accessed). We could just reclassify the survey plan to a Class 1 and make no other changes; however that would be inaccurate for that section of piping.
RAI 23
Basis for Request:
Chapter5, Section 5.4.3.6, Page 5-40 to 5-41. Section 5.4.3.6 discusses surveys of exterior surfaces of building foundations. Core boring through foundation walls and soil sampling were proposed, and it was indicatedthat the HSA would be used to evaluate the potential for exterior surface contamination.
RAI Has this approach changed based upon plans to remove the caisson? If these areas are considered impacted, have they been classified as a Class 1, 2, or 3 area with plans for a MARSSIM based Final Status Survey?
PG&E RESPONSE The caisson structure is a Class 1 structure. The structure will have a disposition survey performed in order to determine the appropriate burial site. The structure will not 11
Enclosure 2 PG&E Letter HBL-14-008 undergo an FSS since it will not be present on-site at the time of license termination.
The excavation will undergo a Class 1 FSS.
PG&E will revise Section 5A4.3.6 to include this information
RAI 24
Basis for Request:
Chapter5, Section 5.4.4.1, Page 5-44. Instrument selection was discussed in Section 5.4.4.1 of the LTP, and Table 5-10 provides "Typical FSS Detection Sensitivities."
RAI Is there a reference for these sensitivities?
PG&E RESPONSE There is no reference document for these sensitivities. The sensitivities provided in Table 5-10 are based on the HBPP instrumentation present at the site.
RAI 25
Basis for Request:
Chapter 5, Section 5.4.4.4.7, Page 5-53. Section 5.4.4.4.7 of the LTP describes pipe survey instrumentationand notes that "accessibleportions of the remaining embedded piping will be surveyed to ensure residual remaining activity is less than the DCGL."
RAI How will inaccessible areas be accounted for? If piping is impacted and considered to be a Class I area, how would a 100% surface scan be performed?
PG&E RESPONSE Class 1 piping will be surveyed at 1 foot intervals with 100% coverage. Inaccessible portions will be made accessible by cutting access ports in the piping. In Class 2 and Class 3 piping where 100% coverage is not required, an evaluation will be performed as to the percent of survey.
PG&E will revise Section 5.4.4.7 to include this information
RAI 26
12
Enclosure 2 PG&E Letter HBL-14-008 Basis for Request:
Chapter 5, Section 5.5.3, Page 5-55. Under "Data Verification and Validation" one of the review criteria is that "the instrumentationMDC for fixed or volumetric measurements was below the DCGLW or if not, it was below the DCGLEMC for Class 1, below the DCGLW for Class 2, and below 0.5 DCGLW for Class 3 survey units." This is not consistent with MARSSIM, which states that "for direct measurements and sample analyses, minimum detectable concentrations (MDCs) less than 10% of the DCGL are preferable while MDCs up to 50% of the DCGL are acceptable."
RAI Please update the review criteria and direct measurement MDCs to be consistent with MARSSIM.
PG&E RESPONSE PG&E will revise Section 5.5.3 to read:
"The instrumentation MDC for fixed or volumetric measurements are less than 10% of the DCGL (preferable) while MDCs up to 50% of the DCGL are acceptable."
RAI 27
Basis for Request:
Chapter 5, Section 5.7.2, Page 5-63 to 5-64. The Final Status Survey Report is discussed in Section 5.7.2 of the L TP. The minimum topics presented appearto be consistent with NUREG- 1700 acceptance criteria.
RAI The NRC staff encourages the licensee to consider a slightly more comprehensive acceptance checklist provided in NUREG- 1757, Vol. 1, Rev. 2, Appendix D, XIV.e., "FINAL STATUS SURVEY REPORT'. Additional topics are included, such as ALARA and discussions of investigations that are taken in the event of a failed survey unit.
PG&E RESPONSE Section 5.7.2 provides a minimum of topics. In accordance with plant procedure HBAP C-202, the final report will provide the unit-specific or generic ALARA evaluation as well as any investigation performed, regardless of whether the survey unit failed or not.
PG&E will revise Section 5.7.2 to add the following:
13
Enclosure 2 PG&E Letter HBL-14-008 "In accordance with plant procedure HBAP C-202, the final report will provide the unit-specific or generic ALARA evaluation as well as any investigation performed, regardless of whether the survey unit failed or not."
RAI 28
Basis for Request:
Chapter 4 and 5. As noted in NUREG-1757, Vol. 2, Rev. 1, a description of field screening methods and instrumentation,and a demonstration that field screening should be capable of detecting residual radioactivity at the DCGLW RAI Please describe the in-process or Remedial Action Support Surveys that will be performed to demonstrate that site remediation is complete.
PG&E RESPONSE The remedial action support survey relies on a simple radiological parameter, such as direct radiation near the surface (i.e. surface scans using a 44-10 detector), as an indicator of effectiveness. The investigation level (the level below which there is an acceptable level of assurance that the established DCGLs have been attained) is determined and used for immediate, in-field decisions. There will be radionuclides and media that cannot be evaluated at the DCGLW using field monitoring techniques. For these cases, field samples will be collected and analyzed and compared to the release DCGLs.
Characterization surveys will be performed of the remediated areas to the rigors of FSS to determine if the area is ready for a FSS (i.e. the area will pass an FSS).
14
Enclosure 3 PG&E Letter HBL-14-008 Enclosure 3 Draft Sample Buried Piping Survey Plan Pages 1 to 12 1
Enclosure 3 PG&E Letter HBL-14-008 GENERAL SECTION Survey Area No: DRN01 Survey Unit No: 01 Survey Unit Name Buried piping beneath the Admin Annex Building FSS Survey Number: HBPP-FSSP-DRN01-01-00 PREPARATION FOR CHARACTERIZATION ACTIVITIES Check marks in the boxes below signify affirmative responses and completion of the action.
1.1 Files have been established for survey unit FSS records. Yes 2 No Li N/A Li 1.2 ALARA review has been completed for the survey unit. Yes 1.3 The survey unit has been turned over for final status survey. Yes 1.4 An initial walkdown has been performed Z 1.5 Activities conducted within area since turnover has been reviewed. Z]
Based on reviewed information, subsequent walkdown: Z] not warranted LI warranted If warranted, subsequent walkdown has been performed and documented OR The basis has been provided to and accepted for not performing a subsequent walkdown. L0 1.6 A final classification has been performed. [-
Classification: CLASS 1 Li CLASS 2 Li CLASS 3 Z]
DATA QUALITY OBJECTIVES (DQO) 1.0 State the problem:
Survey Area DRN01 consists of the section of buried drain piping beneath the Admin. Annex Building.
Survey Unit DRN01-01 is a sub unit of the west yard drains. The Survey Unit is a section of 12 inch concrete drain piping 37.5 feet long. The section of piping tied into the west yard drain system which was impacted due to an historical spill. The main section of the west yard drain will be removed, however, due to the location of the DRN01-01 piping (i.e. located beneath the Admin. Building which is to remain), the DRN01-01 will be surveyed in place and grouted.
2
Enclosure 3 PG&E Letter HBL-14-008 The objective of this survey plan is to demonstrate that the years of plant operation did not result in an accumulation of plant-related radioactivity that exceeds the release criteria.
The planning team for this effort consists of the Site Closure Manager, FSS Engineers, FSS Foreman and FSS Technicians. The FSS Engineers will make primary decisions with the concurrence of the Site Closure Manager.
2.0 Identify the decision:
Does residual plant-related radioactivity, if present in the survey unit, exceed the release criteria?
Alternative actions may include no action, investigation, resurvey, remediation and reclassification.
3.0. Identify the inputs to the decision:
Survey media: Concrete buried piping Types of measurements: One minute static readings Radionuclides-of-concern: Cs-137 Applicable DCGL: 100,000 dpm/1OOcm 2 corresponding to the buried piping
_gross DCGL Thirty-seven (37) measurements from a previous characterization (8/9/2012) were used to provide the characterization data for survey area DRN01. The data is sufficient to support the planning of Survey Unit DRN01-01.
Based on a review of radionuclide activities taken in the off-gas tunnel, Cs-137 is the primary radionuclide present with minor amounts of Co-60, Sr-90 and Am-241. The results from the characterization data are summarized below:
o Cs-137 99.02%
o Co-60 0.4%.
o Sr-90 0.5%
o Am-241 0.1%.
A sample of sediment and scrapings was taken in the drain pipe and analyzed for all plant related gamma emitters. Results revealed a Cs-137 concentration of 0.02 pCi/g with no other plant-related gamma emitters present.
Survey Design /Release Criteria Classification: Class 3 2 Average concentration: 2551 dpm/1OOcm 2 Standarddeviation Cs- 137 (q): 95 dpm/1 00cm 2 Gross Activity DCGL: 100,000 dpm/1 00cm 3
Enclosure 3 PG&E Letter HBL-14-008 LBGR: Initial = 0.5xDCGL = 50,000 dpm/100cm" Adjusted LBGR( set Ala = 1-3) = 99,800 dpm/100cm 2 Cs-137 (A/a = 2.11)
Number of Measurements: 15 calculated 2
(increased to 37)
Survey Unit Area: 10.9 m Grid Area (A/N): N/A Class 3 DCGLemc Cs-137: N/A Class 3 2
Investigation Level for measurements: > 50% DCGL = 50,000 dpm/100cm Gamma scanning Coverage: 100%
Predominateradionuclide: Cs-137 MDCs for gamma analysis: Soil DCGLs will be used for screening/verification Nuclide 10% to %50 of the DCGL (nCi/a) 3.82E-01 to 1.91 E+00 Nb-94 7.13E-01 to 3.57E+00 1-129 4.83E-01 to 2.42E+00 Cs-137 7.93E-01 to 3.97E+00 Eu-1 52 1.01E+00 to 5.05E+00 Eu-154 9.40E-01 to 4.70E+00 Np-237 1.11E-01 to 5.55E-01 The desired MDCs in the laboratory analyses of FSS samples will be the 10% DCGL values. If it is impractical to achieve those, the 50% DCGL values must be achieved in the laboratory analyses of the samples.
MDC's for HTD nuclide: Soil DCGLs will be used for screening/verification Nuclide 10% to 50% of the DCGL (pCi/q)
H-3 6.86E+01 3.43E+02 C-14 6.30E-01 3.15E+00 Ni-59 1.97E+02 9.85E+02 Ni-63 7.24E+01 3.62E+02 Sr-90 1.51E-01 7.55E-01 Tc-99 1.24E+00 6.20E+00 Pu-238 2.97E+00 1.49E+01 Pu-239/240 2.67E+00 1.34E+01 Pu-241 8.61 E+01 4.31 E+02 Am-241 2.58E+00 1.29E+01 Cm-243 2.90E+00 1.45E+01 Cm-244 4.81 E+00 2.41 E+01 4
Enclosure 3 PG&E Letter HBL-14-008 Cm-245 1.78E+00 8.90E+00 Cm-246 2.58E+00 1.29E+01 The MDC values for difficult to detect nuclides will be conveyed to the outside laboratory via the sample chain-Of-custody form which will accompany the samples.
QC checks for the 44-157 will be performed in accordance QC checks and measurements:
with RCP-7U2 Fixed-point measurements 19 and 28 will be QC recount 4.0 Define the boundaries of the survey:
o Boundaries of Survey Unit DRN01-01 are as shown on the attached map.
o The survey will be performed under appropriate weather conditions (as defined by instrumentation limitations and human factors). Surveys may be performed on any shift of work.
5.0 Develop a decision rule:
Upon review of the FSS data collected under this survey plan:
(a) If all the sample data show that the measurements are below the DCGL, then reject the null hypothesis (i.e., Survey Unit DRN01-01 meets the release criteria).
(b) If the investigation levels are exceeded, then perform an investigation survey.
(c) If the average concentration exceeds the DCGL then accept the null hypothesis (i.e., Survey Unit DRN01-01 fails to meet the release criteria).
Note: Alternate actions beyond investigations include, remediation, reclassification and resurvey 6.0 Specify tolerable limits on decision errors:
Null hypothesis: Residual plant-related radioactivity in Survey Unit DRN01-01 exceeds the release criteria.
Probabilityof type I error: 0.05 Probabilityof type II error: 0.05 LBGR: Adjusted to 99,800 Cs-1 37 5
Enclosure 3 PG&E Letter HBL-14-008 7.0 Optimize Design:
Type of statistical test: WRS Test 0 Sign Test WI (background will not be subtracted)
Number and Location of Thirty-seven (37) fixed measurements will be collected Measurements: at one foot increments along the entire length Biased samples: Smears and sediment/scrapings will be taken at accessible areas of the piping and notated on the map Biased sample locations: Any biased sample locations will be determined in field by the FSS Foreman and/or the FSS Engineer based on historical data and process knowledge of the area.
GENERAL INSTRUCTIONS
- 1. Chain of Custody form/process will be used for samples sent to the off-site laboratory.
- 2. All sediment/scraping samples will be received and prepared as directed by the FSS Engineer.
- 3. Survey instrument: Operation of the 2350-1 w/44-157 will be in accordance with RCP-7U3 with QC checks performed in accordance with RCP-7U2. The instrument response checks shall be performed before issue and after use.
- 4. The job hazards associated with the Survey described in this package will be addressed in the pre-job brief.
- 5. All personnel participating in this survey shall be trained in the operation of the instrumentation.
SPECIFIC INSTRUCTIONS
- 1. Measurement Requirements:
Note: As required for the survey of piping, a gamma direct will be taken every 12" resulting in 100% coverage of the pipe interior.
- 1. A line will be fished through the pipe for the purpose of pulling the detector through the pipe.
- 2. A cable/line will be marked every 12".
- 3. The detector will be pulled starting at one manhole to the first mark on the line/cable.
- 4. Perform a one minute reading
- 5. Log and record the reading 6
Enclosure 3 PG&E Letter HBL-14-008
- 6. Perform steps 4 and 5 for each location as marked on the line/cable
- 7. Locations 19 and 28 will be counted twice for QC o Source checks will be performed pre and post daily.
Note: Perform smear sampling prior to performing sediment/scraping sampling
- 2. Smear Requirements:
" Smears will be taken at the opening of each pipe section.
" Smears will be taken at the opening and every 6" in the pipe up to 3'.
" The total number of smears obtained is 12.
- Record the date and time of smear collection.
" Count the smears for beta/gamma and alpha lAW site procedures
- 4. Sediment/scraping Requirements:
" Scrape and collect scrapings/sediment samples from each end of the drain pipe from the bottom of the pipe up six inches on each side
" Place scrapings/sediment into a plastic bag from each sampling site
" Seal and label each sample bag. Label the samples with the designator indicated on the map attached to this survey plan
" Transfer the samples to the sample prep area
" Count the samples for gamma emitters to the MDCs in section 3
" Send both samples to the off-site laboratory for analysis to include all radionuclides in the HBPP LTP site-specific suite. Nuclide MDCs, listed in section 3, will be transmitted to the laboratory via the chain-of-custody form
- 5. Investigations:
o If any fixed-point measurement exceeds 50,000 dpm/1 00cm 2 immediately inform the FSS Engineer o Investigations will be performed as follows:
- 1. Reposition the detector at the location exceeding the investigation level
- 2. Perform a one minute static count
- 3. Log and record the static reading
- 4. Perform steps 2 and 3 at 12" locations on either side of the investigation location 7
Enclosure 3 PG&E Letter HBL-14-008 Prepared by: Date:
FSS Engineer Reviewed by: Date:
FSS Engineer Approved by: Date:
Site Closure Manager 8
Enclosure 3 PG&E Letter HBL-14-008 Piping Survey Data Sheet Piping System Location Background Location Start Date /time Background (cpm)
End Date / time Pre Source Check Source Check Passed Post Source Check (Y/N) PostSourceChec Ludlum 2350-1 SN Pipe material Detector Model Pipe diameter Cs-137 Efficiency Calibration Date (cpm/dpm/100 cm 2)
Measurement Number Reading (cpm) Measurement Number Reading (cpm) 1 20 2 21 3 22 4 23 5 24 6 25 7 26 8 27 9 28 10 28R 11 29 12 30 13 31 14 32 15 33 16 34 17 35 18 36 19 37 19R Technician(s) sign/date 9
Enclosure 3 PG&E Letter HBL-14-008 DRN01-01 Prospective Power Curve 12: MAPS
-Decision Err s -- Required Sample Size-Survey Unit ]D: Alpha- &We Survey Units1 R~adiozmc-lide: ICs-37 Statistical Test ZJ 105 IV 100.
r SignTest PCGL I110W0 r Wks Test 0 _ I A02. ooo Critical Value: LBGK 1998 A/a =2.11
-aigma 19 11 Probabillity that the Survey Unit Passes Click 1.U anywhere on the graph to 0.8 pdate the power curve 0.6 using newly entered parameter 0.4 values 0.2 0.0 0% 30%~ 53 70% 90% 1=.110% 13F0% 10%%
EL&Program True Survey Unit Concentration (percent of DCGL)
Note: Values have been scaled by 100 for the MARSSIM 2000 software 10
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Enclosure 4 PG&E Letter HBL-14-008 Enclosure 4 Environmental RAIs 48 through 57 Pages 1 to 7 1
Enclosure 4 PG&E Letter HBL-14-008 NOTE - Acronyms used in the PG&E responses are defined in the LTP Section "Terms and Acronyms."
Environmental Basis for Requests:
Approval of the license amendment associated with the LTP requires development of an Environmental Assessment. The following information is necessary to adequately prepare that document.
RAI 48
Section 1.4 "Plansfor Site Remediation." In addition to the proposed plan and the no action alternative, did PG&E consider any other means of decommissioning and remediating the site?
PG&E RESPONSE Alternative means and methods were considered for accomplishing the decommissioning. These include the decision of whether to release the site to industrial or residential standards. Also, extensive consideration as to whether the reactor building caisson could remain intact under either an industrial or residential clean-up criteria, and if a freeze wall could be used in place of the slurry wall to accomplish the removal of the reactor caisson. Much of this information is discussed in the PG&E Capstone Document (LTP Reference 8-22).
PG&E will continue to seek better, safer and more cost effective methodologies and options leading to the successful completion the decommissioning project.
RAI 49
Section 3.3.1, Table 3-1 "MajorRemaining Activities and Completion Dates."
Please update this table. Also, what other activities will take place once decommissioning is complete?
PG&E RESPONSE PG&E will revise Table 3-1 with an updated version as shown below:
2
Enclosure 4 PG&E Letter HBL-14-008 Table 3-1 Major Remaining Activities and Completion Dates*
Projected Completion Activity Date Reactor vessel removal Late 2014 Reactor Building above grade removal Late 2015 Spent Fuel Pool removal Mid 2016 Caisson removal Mid 2018 LRW Building removal Late 2014 Turbine Building removal Mid 2013 - Completed Waste Buildings and vaults removal Mid 2014 Slurry Wall installation Mid 2014 GTCC waste moved to ISFSI Late 2013 - Completed Intake Canal dredging/remediation Mid 2015 Discharge Canal dredging/ remediation Mid 2015 Site restoration Late 2018 FSS activities Late 2019
- Some of these dates are tentative as detailed planning for the canals remediation, slurry wall installation, and peripheral decommissioning activities continues.
Additional activities to take place after the decommissioning process is complete include the ongoing operation of the HBGS, ISFSI, and continuing site restoration and wetlands recovery projects.
RAI 50
Section 8.5.1.3 "Storage and Disposal of Low-Level Radioactive Waste Where will .-
this waste (Solid and liquid) be taken to be disposed of? How many, and what types of trucks will be used?
PG&E RESPONSE There are currently three options for low-level radioactive waste disposal. These are:
" US Ecology's facility located in Grand View, ID;
" Energy Solutions' facility in Clive, UT; and
" Waste Control Specialists' (WCS) facility in Andrews, TX.
Any liquid wastes will require treatment. Potential treatment facilities currently available include:
" ToxCo in Oak Ridge, TN;
" PermaFix in Gainsville, FL;
" Permafix Northwest in Richland, WA; and
" US Ecology facility located in Grand View, ID.
The majority of the volume of LLRW is going to be contaminated soils and concrete.
Currently, this material is shipped in intermodal containers; however, it is possible that future soil shipments may be made in Super Sacks loaded in the intermodal containers.
3
Enclosure 4 PG&E Letter HBL-14-008 A limited volume of higher dose rate materials will need to be shipped in Type A or Type B shipping casks.
Most liquids will be shipped after on site processing in a tanker vehicle to US Ecology.
Additionally, some small number of liquids may be shipped in 55 gallon drums for processing at the other above listed facilities. The number of liquid shipments are anticipated to be a small number of shipments relative to the total number of waste shipments.
Experience has shown that the Intermodal containers tend to be weight limited (as opposed to volume limited). Consequently, a typical intermodal shipment would contain 20 cubic yards (15.3 M3) of material. Thus, the total number of shipments can be estimated by dividing the cited total volume of LLRW (64,200 M 3 ) by 15.3 M3 . This results in approximately 4,300 individual shipments of LLRW.
RAI 51
Section 8.5.2.10 "Socioeconomics." A comparison of the number of workers employed at the height of Unit 3's operation to the number of workers to be employed during decommissioning should be made. The time periods for each activity should also be made.
PG&E RESPONSE During operations there were approximately 90 employees. This number was reduced to a low of approximately 40 during SAFSTOR. At the height of decommissioning approximately 500 are estimated. We are now at 500 full time employees who presently staff the decommissioning project. This number is expected to slowly ramp downward to approximately 250 personnel by 2017.
After the decommissioning is complete (2020) an estimated 40 employees are projected to remain to operate the HBGS. An unspecified number of additional security and administrative employees will also remain to maintain staffing for ISFSI operations.
RAI 52
Section 8.5.2.12 "Cultural,Historical and Archaeological Resources." Are there any State-identified historic places along the proposed truck routes?
PG&E RESPONSE A preliminary search on California's registry determined that at least one state-identified historic landmark is located along the truck route that will be taken by the majority of truck traffic traversing to the disposal sites.
4
Enclosure 4 PG&E Letter HBL-14-008
RAI 53
Section 8.5.2.14 "Noise." What activity will generate the loudest noise? How loud?
Will it be continuous or intermittent? What are the nearest sensitive receptors? At what times during the day will the noise be most noticeable? Will the noise be louder than the traffic from Route 101?
PG&E RESPONSE The nearest and presumed most sensitive receptors are identified in Section 8.5.2.14. Most construction noise will occur between the hours of 7:00AM and 5:30PM. It is presumed that the Loudest Activities as evaluated in the US Department of Transportation's Handbook on construction noise will be:
" Slurry Trenching Machine 80 (Actual measured LMAX @50 feet (dBA, Slow)
" Vibratory Pile Driver 101 (Actual measured LMAX @ 50 feet (dBA, Slow)
- Mounted Impact Hammer (hoe ram) 90 (Actual measured LMAX @ 50 feet (dBA, Slow)
Due to the planned work hours, it is believed that the noise will be most noticeable during the day and that it will be moderately louder than the background noise from Route 101 traffic during regular work hours.
The U.S. Department of Transportation's Handbook on construction noise is located at:
http://www.fhwa.dot.govlenvironmentlnoiselconstruction noise/handbook/handbook 09.cfm%20%20%20#top
RAI 54
Section 8.5.2.15 "Irretrievable Resources." What resources are irreversible (never recovered)? What resources are irretrievable (lost only for a period of time)?
PG&E RESPONSE The irreversible resources that were identified include supplies that will be consumed in the process of decommissioning including tools, decontamination supplies, fuel oil and land used for waste disposal. Irretrievable resources include on-site land use, which may include the temporary use of wetland areas. All such activities would be regulated as described in Section 8.6.
RAI 55
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Enclosure 4 PG&E Letter HBL-14-008 Section 8.5.2.16 "Traffic Transportation." Will ingress and egress interfere with Humboldt Bay Generating Station (HBGS)? Will any of the proposed truck routes pass through populatedareas? Will any of the truck routes overlap, spatially and temporally, with school bus routes? Is there a traffic control plan?
PG&E RESPONSE The ingress and egress routes may interfere with HBGS operations as shown in LTP Figure 8-2, "Site Features." The lower parking lot depicted on Figure 8-2, near the intake structures, is called Parking Lot A. There is expected to be some limited interference as Parking Lot A shares a road which is the ingress/egress for the HBGS.
Parking Lot A is largely utilized by HBPP Unit 3 decommissioning project personnel.
The proposed truck route will pass through populated areas beginning with Route 101 passing through downtown Eureka and may overlap with local school bus routes at King Salmon. A traffic control plan has been developed and seeks to minimize impact of site shipments on local traffic.
RAI 56
Cumulative Effects. Will the proposed action have an effect on any concurrent actions in the same vicinity (e.g., HBGS)? Will the proposed action have any long-lasting effects on the surroundingnatural and human environment?
PG&E RESPONSE With the exceptions of an intrusion into the outer boundary of the current HBGS fence line to remove discharge piping, the project is not believed to have any effect on the HBGS. Also, a temporary disruption of the Humboldt Bay walking path during the discharge canal remediation is expected. It is believed that the planned restoration of the site will result in a long-lasting improvement to the surrounding natural and human environment.
RAI 57
For the soil that is to be excavated please provided estimated quantities for: (1) soil will be re-used on-site; (2) soil that will be disposed off-site; and (3) soil that will be stockpiled off-site?
PG&E RESPONSE
- 1. The quantity of soil to be re-used on-site is expected to be a small percentage of total quantity to be excavated (approximately 25 m 3 reused).
- 2. The volume of soil to be disposed of off-site is estimated to be 44,800 M 3 .
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Enclosure 4 PG&E Letter HBL-14-008
- 3. There are at present no plans to stockpile soil off-site.
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Enclosure 5 PG&E Letter HBL-14-008 Enclosure 5 Matrix of RAIs and Associated Changes to the License Termination Plan Pages 1 to 2 1
Enclosure 5 PG&E Letter HBL-14-008 Matrix of RAls and Associated Changes to the License Termination Plan RAI Number Change to LTP? Location of Change(s) 01 Yes Section 2.1.4.2 02 Yes Section 2.1.5.3 03 Yes Section 2.1.8.1 04 Yes Section 2.1.8.2 05 Yes Section 2.1.8.2 06 Yes Section 2.1.8.3 07 Yes Sections 2.1.8.4 through 2.1.8.10 08 Yes Section 2.1.8.11 09 Yes Section 2.1.8.11 10 Yes Section 2.1.8 11 Yes Section 5.2.1.3 12 Yes Section 5.2.2 13 Yes "Terms and Acronyms" Section 14 Yes Section 5.2.4 15 No N/A 16 Yes Section 5.4.2.4 17 Yes Section 5.4.2.5.2 18 Yes Section 5.4.2.5.2 19 No N/A 20 Yes Section 5.4.3.2 21 Yes Section 5.4.3.2 22 No N/A 23 Yes Section 5.4.3.6 24 No N/A 25 Yes Section 5.4.4.7 26 Yes Section 5.5.3 27 Yes 5.7.2 28 No N/A 48 No N/A 49 Yes Section 3.3.1, Table 3-1 50 No N/A 51 No N/A 52 No N/A 53 No N/A 54 No N/A 55 No N/A 56 No N/A 57 No N/A 2