ML17065A034

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Final Status Survey Summary Report
ML17065A034
Person / Time
Site: Rancho Seco
Issue date: 02/28/2017
From: Tallman D
Sacramento Municipal Utility District (SMUD)
To: Cruz Z
Document Control Desk, Office of Nuclear Material Safety and Safeguards
Shared Package
ML17065A032 List:
References
DPG 17-038
Download: ML17065A034 (15)


Text

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DPG 17-038 February 28, 2017 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Docket No. 50-312 Rancho Seco Nuclear Generating Station License No.: DPR-54 Final Status*survey Report Submittal Attention: Zahira Cruz The purpose of this letter is to submit the Final Status Survey Summary Report for NRC review.

The NRC approved the Rancho Seco License Termination Plan (LTP) on November 27, 2007. LTP Section 1.4.2 discusses SMUD's intent to release the Rancho Seco site for unrestricted use in two phases. We have now completed the second and final phase of Rancho Seco decommissioning and are requesting that the NRC review the Final Status Survey documentation in preparation for our subsequent License Termination request to release the remainder of the Rancho Seco Part 50 licensed facility for unrestricted_ use ..

Attachment 1, the FSS Final Report, provides a summary of the assessment performed for the remainder of the Part 50 site. SMUD has reviewed the survey area results to ensure that the proposed action will have no adverse impact on the ability of the site, in aggregate, to meet 10 CFR Part 20, Subpart E "Radiological Criteria for License Termination."

Attachment 2 contains the 35 individual Final Status Survey Reports described in the FSS Final Report.

Following NRC approval of the FSS Final Report and several programmatic and licensing transitions currently being processed under separate docketing, SMUD will submit a License Amendment request that the Nuclear Regulatory Commission (NRC) terminate the Rancho Seco 10 CFR Part 50 License, Number DPR-54. The spent nuclear fuel and the Greater than Class C (GTCC) waste remain stored at the Rancho Seco Independent Spent Fuel Storage Installation (ISFSI), licensed under 10 CFR Part 72.

Rancho Seco Nuclear Generating Station I 14440 Twin Cities Road I Herald, CA 95638-9799 I 916.452.3211 I smud.org

Members of your staff with questions requiring additional information or clarification may contact me at (916) 732-4893.

Sincerely, Dan Tallman Manager, Rancho Seco Assets BG/OT Attachments (2)

Cc: Jack Parrot (w/o attachment)

NRC, Region IV (w/o attachment)

RIC: 1F.099 (w/o attachment)

RANCHO SECO FSS FINAL REPORT Final Status Survey Report Phase 11 - IOSB February 28, 2017 1

FSS FINAL REPORT Final Status Survey Report 1.0 Overview As discussed in Section 1.4 of the Rancho Seco License Termination Plan (LTP), SMUD intends to release the Rancho Seco site for unrestricted use in two phases, with the license being terminated after completion of the second phase. The first phase included the release of the majority of the site, including impacted and non-impacted areas, except for the Interim Onsite Storage Building (IOSB) and the area immediately surrounding it.

SMUD shipped all Class B & C radioactive waste once stored in the IOSB to a licensed disposal facility in 2014. In accordance with the LTP, after disposing of the Class B & C radioactive waste, SMUD completed the final status survey for the IOSB and the area immediately surrounding the IOSB and will submit a license amendment request to terminate the 10 CFR Part 50 license and release the remainder of the site for unrestricted use. The spent nuclear fuel and the Greater than Class C (GTCC) waste are stored at the Rancho Seco Independent Spent Fuel Storage Installation (ISFSI), which is licensed under 10 CFR Part 72, independent of the 10 CFR Part 50 licensed site.

Section 1.4 of the LTP discusses the information to be provided to support release of land from the Rancho Seco 10 CFR Part 50 license. The information provided in this report includes a discussion of final status survey results for each survey unit completed.

The information contained in this submittal, will be sufficient for the NRC to conclude that, for the land and structures associated with the release, the terminal radiation survey and associated documentation demonstrates that the facility and site are suitable for release in accordance with the criteria for decommissioning in 10 CFR Part 20, Subpart E by meeting a site release criterion of25 millirem TEDE per year over background.

Once these lands and structures are released, no additional surveys or decontamination of these areas will be required unless the NRC determines that the criteria of 10 CFR Part 20, Subpart E were not met.

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2.0 Site Information and Physical Description 2.1 Physical Description of Land or Structures to be Released The land and structures to be released will be described in the application for license amendment and is unchanged by this submittal.

2.2 Survey Unit Information Included in this Submittal As discussed in section 1.0 above, this submittal provides detailed discussion on final status survey results for 34 survey units located within the IOSB and surrounding land to be released. Details are provided for each survey unit on survey methods, results, data analysis, and conclusions. In all cases, Rancho Seco is providing a complete package of information relating to each survey unit so that the NRC staff can verify that the License Termination Plan has been fully implemented for each survey unit and that the final status survey results support unrestricted release of the land from License DPR-54 in accordance with the proposed license amendment.

This submittal addresses FSS information for survey units associated with the IOSB and surrounding land. Table 1 provides a description of the survey units addressed

  • in this submittal.

T a ble 1 Survey U DI"tDescr1p *rion ,, ... ,

> Survey Unit.': '

Class *. 'General Descr:iptionofSur-VeyUiiif' ..

DAW Bay- The back bay of the IOSB. The F8300001 3 survey unit has a surface area of348 m2

  • DAW Staging Bay - The center bay of the F8300002 3 IOSB. The survey unit has a surface area of 225 m2
  • DAW Staging Bay Floor - A small elevated F8300003 I area located on the DAW Staging* Bay floor.

The survey unit has an area of0.74 m2 .

DAW Staging Bay Floor - A buffer to the class I survey unit area located on the DAW Staging F8300004 2 Bay floor. The survey unit has an area of 2.22 m2.

Truck Bay - The entry bay of the IOSB where vehicles were loaded excluding the loading F8300005 3 dock and the buffer area around the loading dock. The survey unit has an area of379 m2

  • Hot Cell - A segregated area in the Truck Bay F8300006 I designed to hold containers with high dose rate.

The survey unit has an area of 8 m2 .

Hot Cell - A buffer area around the class I F8300006 2 survey unit. The survey unit has an area of 7.6 mz.

Loading Dock - The area at the end of the truck F8300007 I bay used to load material onto vehicles. The survey unit has an area of7.5 m2 .

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Survey Unit Class General Description of Survey Unit Loading Dock Buffer - An area surrounding F8300008 2 the class 1 survey unit at the loading dock. The survey unit has an area of 19.9 m2

  • Cell Deck - The area above the lids of the storage cells with the northern end open to the F8300009 3 Truck Bay. The size of the survey area is 460 mi.

Sumps - The upper and lower sump areas.

While these were one survey unit, each sump F8300010 3 was surveyed as a standalone survey unit. The two sumps combined survey area is 79.6 m2

  • Hot Cell Embedded Pipe -The 4-foot-long run of drain pipe from the hot cell floor to the 90° F8300011 1 elbow connection. No size was determined for the embedded piping as the survey design was the same for all segments of pipes.

Embedded Piping - All runs of embedded piping leading to the sumps from the DAW, DAW Staging and Truck Bays. No size was F8300012 3 determined for the embedded piping as the survey design was the same for all segments of pipes.

Office - The area outside the RCA with the F8300013 3 training and control rooms and the mezzanine.

The size of the area is 370 m2*

Outside Area - The asphalt and soil berm F8300014 3 surrounding the ISOB. The outside area is 5,853 m2 .

Asphalt area - Small area where remediation F8300014 1 occurred of an area less than DCGL. The survey area is 0.37 m2

  • Buffer area surrounding the class 1 area. The F8300014 2 survey area is 1.85 m2
  • Roof - The roof of the IOSB. The survey area F8300015 3 is 1,735 m2
  • Cell A The storage cell A-1. The survey F8300016 3 area is 27.5 m2
  • Cell A The storage cell A-2. The survey F8300017 3 area is 28.3 m2
  • Cell A The storage cell A-3. The survey F8300018 3 area is 27.5 m2
  • Cell B The storage cell B-1. The survey F8300019 3 area is 23.1 m2
  • Cell B The storage cell B-2. The survey F8300020 3 area is 23.7 m2
  • Cell B The storage cell B-3. The survey F8300021 3 area is 23.1 m2 .

Cell C The storage cell C-1. The survey F8300022 3 area is 23.1 m2

  • Cell C The storage cell C-2. The survey F8300023 3 area is 23.7 m2 .

Cell C The storage cell C-3. The survey F8300024 3 area is 23.1 m2 .

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Survey Unit Class General Description of Survev Unit Cell D The storage cell D-1. The survey F8300025 3 area is 23.1 m2.

Cell D The storage cell D-2. The survey F8300026 3 area is 23.7 m2.

Cell D The storage cell D-2. The survey F8300027 3 area is 23.1 m2.

Cell E The storage cell E-1. The survey F8300028 3 area is 26.1 m2.

Cell E The storage cell E-2. The survey F8300029 3 area is 28.3 m2.

Cell E The storage cell E-3. The survey F8300030 3 area is 27.5 m2.

Exterior surface ofIOSB - The outside wall F8300031 3 surface of the IOSB. The survey area is 2,750 m2.

Cask Wash Down Area-The cask wash down F8300032 3 area is located in the Truck Bay separated by a berm. The survey area is 13.9 m2.

The locations of the structures listed in Table 1 above are shown in Figure 1-3.

3.0 Potential for Cross-Contamination from Subsequent Activities There were no other decommissioning activities occurring at the site during this survey effort. As each FSS was completed for the individual survey units, the area was posted as required in the LTP to preclude further entry into the area. Where possible, the entry doors were shut and locked or for the storage and hot cells, the lids were placed to preclude entry. Additionally, the entry gate to the area surrounding the IOSB was posted to restrict access to only decommissioning survey crew personnel. Since the number of personnel having access to the IOSB was limited to the survey crew, the potential for cross contamination was low.

4.0 Final Status Survey Report Rancho Seco LTP section 5. 7.3 identifies the contents of the written reports of final status survey results that are to be submitted to the NRC. The contents include the items described in NUREG-1757, Vol. 2, Section 4.5. The survey unit design details and results are provided below in summary fashion. Specific survey unit design details and results are provided in a copy of each survey unit summary report in Attachment 1 of this submittal.

4.1 Overview of Results Only the IOSB and surrounding land is included in this report. The summary report for each survey unit contains a description of the survey unit; design information, including classification, size, number of measurements, map, scan coverage, and DCGL; survey results; survey unit investigations (anomalous data); data assessment results, including statistical evaluations, if applicable; changes in initial survey unit assumptions on extent of residual activity, and survey unit conclusions.

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Note that classification for the embedded piping does not affect the survey density (number of samples) as that is specified in the RSLTP as a measurement every six inches. As such, for the Hot Cell Pipe, the designation of the vertical section of pipe as a Class 1 was made to distinguish that section from the other sections as decontamination was performed on the Hot Cell pipe. No Class 2 buffer was established for this section of piping. The remainder of the embedded piping was designated as a Class 3 to denote the lack of detectable residual radioactivity.

Overall, the attached survey unit summary reports demonstrate that the survey units meet the criteria for release for unrestricted use in accordance with the NRC approved Rancho Seco License Termination Plan.

4.2 Discussion of Changes to FSS Program The purpose of this section is to discuss changes to the FSS program. At the time of this submittal there have been no changes made to the FSS Program so there are no effects on the surveys.

4.3 Final Status Survey Methodology This section summarizes the implementation of the LTP Final Status Survey methodology for the survey units that are included in this report supporting the release of the IOSB and surrounding land. Table 2 is provided below that lists the key FSS design features for each survey unit. These design features include the survey unit classification and size, the standard deviation and Lower Boundary of the Gray Region (LBGR) used for determining the number of direct measurements taken, the percent scan coverage, the design DCGLEMC and the number of measurements required. The standard deviations listed were obtained from site characterization data or survey unit specific measurements. The Type 1 and 2 Errors are the default values of 0.05 and the LBGR is initially based on 50% of the DCGL.

Table 2, Survey Unit Design Parameters SU O/o Survey Standard Design Number of Class Size LBGR Unit ID (m2) Deviation DCGLEMC Measurements Scan F830001 3 348 1,055 21,500 NA 14 I F830002 3 225 598 21,500 NA 14 1 F830003 1 0.74 598 21,500 640,700 5 100 F830004 2 2.22 598 21,500 NA IO 50 F830005 3 379 466 21,500 NA 14 1 F830006 1 8 740 21,500 141,900 14 100 F830006 2 7.6 740 21,500 NA 14 100 F830007 1 7.5 466 21,500 146,200 14 100 F830008 2 19.9 466 21,500 NA 14 50 F830009 3 460 275 21,500 NA 14 1 F830010 3 79.6 466 21,500 NA 14 1 6

SU Survey Standard Design Number of O/o Class Size LBGR Unit ID (m2) Deviation DCGLEMC Measurements Scan F830011 I NA NA 50,000 NA Every 6 inches 100 F830012 3 NA NA 50,000 NA Every 6 inches 100 F830013 3 370 334 21,500 NA 14 1 F830014 1 0.37 513 21,500 950,300 5 100 F830014 2 1.85 513 21,500 NA 10 50 F830014 3 5,853 513 21,500 NA 14 1 F830015 3 1,735 707 21,500 NA 14 1 F830016 3 27.5 303 21,500 NA 14 1 F830017 3 28.3 170 21,500 NA 14 1 F830018 3 27.5 175 21,500 NA 14 1 F830019 3 23.1 177 21,500 NA 14 1 F830020 3 23.7 183 21,500 NA 14 1 F830021 3 23.1 136 21,500 NA 14 1 F830022 3 23.1 198 21,500 NA 14 1 F830023 3 23.7 182 21,500 NA 14 1 F830024 3 23.1 365 21,500 NA 14 1 F830025 3 23.l 198 21,500 NA 14 -

1 F830026 3 23.7 174 21,500 NA 14 1 F830027 3 23.l 145 21,500 NA 14 1 F830028 3 26.l 197 21,500 NA 14 1 F830029 3 .. 28.3 197 21,500 NA 14 1 F830030 3 27.5 182 21,500 NA 14 1 F830031 3 2,750 175 21,500 NA 14 1 F830032 3 13.9 466 21,500 NA 14 1 7

4.4 Final Status Survey Results The methods used to determine the number of direct measurements to be taken is described in the LTP and the specific survey unit summary reports provided in . Key survey results are given in Table 3 below.

Table 3, Survey Unit FSS Result Summary No.

Scan Mean Maximum Direct No. Scan Direct Measurement Direct Direct Standard Units Elevated Meas.

Range (dpm) Result Result Deviation Areas Taken F830001 DAW Bay 1,717 - 3,017 15 2025 2,535 325 dpm/100 cm 2 0 F830002 DAW Stae:ine: Bay 1,896-3, 192 15 2,050 2,961 323 dpm/100 cm' 0 F830003 DAW Stae:ine: Bay Class 1 1,750' 5 2,617 3,946 747 dpm/100 cm2 0 F830004 DAW Stae:ine: Bay Buffer Class 2 777 1 10 2,226 2,357 111 dpm/100 cm' 0 F830005 Truck Bay 1,992 - 2,708 15 2,240 3,402 582 dom/100 cm' 0 F830006 Hot Cell Class 1 1,633 - 20,041 15 2,976 4,583 550 dom/100 cm 2 0 F830006 Hot Cell Buffer Class 2 2,550 - 23 ,583 15 2,324 2,970 296 dom/100 cm 2 0 F830007 Loadine: Dock Class 1 1,407 - 4,354 15 3,297 7,265 1,376 dpm/100 cm 2 0 F830008 Loadine: Dock Buffer Class 2 1,310 - 6,963 15 2,807 3, 106 231 dpm/100 cm 2 0 F830009 Cell Deck 1,713 - 2,961 15 1,980 2,348 242 dpm/100 cm' 0 F830010 Sumos 2, 157 - 2,883 30 1,891 2,364 249 dpm/100 cm' 0 F830011 Hot Cell Embedded Pipe NA JO 15,669 16,718 806 dpm/100 cm' 0 F830012 Embedded Pipe NA 504 5,038 12,437 1,355 dpm/100 cm2 0 F830013 Office 1,381 - 2, 122 30 1,972 2,409 215 dpm/100 cm 2 0 F830014 Outside Area 1,808 - 2, 115 15 2,676 3,083 223 dom/100 cm 2 0 F830014 Asphalt Class 1 2,592 1' 2 5 2,626 2,803 158 dom/100 cm 2 0 F830014 Asphalt Buffer Class 2 2,400 - 2,832 10 2,572 2,826 247 dom/100 cm2 0 8

No.

Scan Mean Maximum Direct No. Scan Direct Measurement Direct Direct Standard Units Elevated Meas.

Range (dpm) Result Result Deviation Areas Taken F830015 Roof 1,692 - 3,317 15 1,552 2,341 425 dpm/100 cm' 0 F830016 Stora2e Cell A-1 1,986 - 2,645 15 1,850 2,093 145 dpm/100 cm 2 0 F830017 Storaee Cell A-2 2, 192 - 2,858 15 2,010 2,349 165 dpm/100 cm' 0 F830018 Stora2e Cell A-3 2,367 - 2,858 15 2,012 2,167 91 dpm/100 cm' 0 F830019 Stora2e Cell B-1 1,527 - 2,679 15 1,842 2,078 123 dpm/100 cm 2 0 F830020 Stora2e Cell B-2 2,203 - 2,646 15 2,013 2,333 173 dpm/100 cm 2 0 F830021 Stora2e Cell B-3 2,225 - 2, 709 15 1,926 2, 106 124 dpm/100 cm 2 0 F830022 Stora2e Cell C-1 1,682 - 2,54 7 15 1,869 2,078 124 dpm/100 cm 2 0 F830023 Stora2e Cell C-2 2, 125 - 2,658 15 2,011 3,318 383 dpm/100 cm 2 0 F830024 Stora2e Cell C-3 1,961 - 2,512 15 2,045 2,288 127 dpm/100 cm 2 0 F830025 Stora2e Cell D-1 1,589 - 2,295 15 1,956 2,295 186 dpm/100 cm 2 0 F830026 Stora2e Cell D-2 2,242 - 2,817 15 2,012 2,250 135 dpm/100 cm 2 0 F830027 Storaee Cell D-3 1,958 - 2,658 15 2,008 2,333 161 dpm/100 cm 2 0 F830028 Stora2e Cell E-1 1,566 - 2,171 15 1,901 2,154 170 dpm/100 cm' 0 F830029 Stora2e Cell E-2 2, 192 - 2,625 15 2,035 2,326 180 dpm/100 cm' 0 F830030 Stora2e Cell E-3 2,230 - 2, 795 15 2,088 2,409 118 dpm/100 cm 2 0 F830031 Exterior Surface ofIOSB 1,646 - 2,808 15 2, 104 2,380 175 dpm/100 cm' 0 F830032 Cask Wash Down Area 2,518 - 3,270 15 2, 197 2,644 237 dpm/100 cm' 0 1

0nly a single scan measurement was collected due to the small size of the survey unit.

2 Data was collected with a large area detector (584 cm 2) and normalized to activity per 100 cm2 to be consistent with scanning data from other survey units.

NA- Not applicable. For survey units F83001 l and F830012 embedded piping, scanning is not performed as measurements are collected every 6 inches of piping.

4.5 Survey Unit Conclusions Rancho Seco concludes that this information is sufficient for the NRC to make a determination equivalent to IOCFR50.82 (a)(l 1) regarding the survey units contained in this submittal. The surveys for these survey units and associated documentation demonstrate that these areas of the facility and site are suitable for release in accordance with the criteria for decommissioning in 10CFR20, subpart E by meeting a site release criteria of 25 millirem TEDE per year over background for all dose pathways in accordance with the approved License Termination Plan.

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As stated in section 4 of the Rancho Seco LTP, as long as the residual activity within a survey unit is less than the DCGL (i.e., the survey unit average activity is less than the DCGL and the EMC criterion has been met), the ALARA criterion has been achieved.

6.0 References Rancho Seco License Termination Plan, rev. 2, submitted 10/2014.

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