ML23251A071

Confirmatory Survey Extent of Condition Review

ML23251A071
Person / Time
Site:	Zion  File:ZionSolutions icon.png
Issue date:	09/08/2023
From:	Hazelhoff A ZionSolutions
To:	Office of Nuclear Material Safety and Safeguards, Office of Nuclear Reactor Regulation, Document Control Desk
References
ZS-2023-018
Download: ML23251A071 (1)

Text

September 8, 2023 ZS-2023-018 10 CFR 50.82 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Zion Nuclear Power Station, Units 1 and 2 Facility Operating License Nos. DPR-39 and DPR-48 NRC Docket Nos. 50-295 and 50-304

Subject:

Confirmatory Survey Extent of Condition Review for the Zion Nuclear Power Station

References:

1. Gerard van Noordennen, ZionSolutions, LLC, Letter to U.S. Nuclear Regulatory Commission, Zion Nuclear Power Station Request for Partial Site Release, dated June 5, 2020 (ML20164A096)

2. Zion Nuclear Power Station, Unit Nos 1 and 2: Final Summer 2023 Confirmatory Survey Criteria, dated August 10, 2023 (ML23221A243)

3. Amy Snyder, U.S. Nuclear Regulatory Commission, Email to Amy Hazelhoff, Zion Nuclear Power Station, Unit Nos. 1 And 2: Extent Of Condition Request For 2023 Confirmatory Survey, dated August 11, 2023 (ML23233A150)

4. Amy Hazelhoff, ZionSolutions, LLC, Letter to U.S. Nuclear Regulatory Commission, Response to Summary of May 4, 2023, Clarification Meeting Regarding the Partial Site Release for the Zion Nuclear Power Station, Units 1 and 2, ZS-2023-017, dated August 25, 2023 (ML23237B413)

The U.S. Nuclear Regulatory Commission (NRC), with support from the Oak Ridge Institute for Science and Education (ORISE), recently conducted confirmatory surveys at the Zion Nuclear Power Station. ORISE conducted these surveys to support the NRC staffs review of the request made by ZionSolutions, LLC (ZS) to release areas of the site from the Part 50 license, in accordance with 10 CFR 50.82 (Reference 1). The scope, methods, and criteria used to conduct, and then evaluate the confirmatory surveys are outlined in Reference 2.

Following completion of the confirmatory surveys in early August 2023, the NRC communicated in Reference 3, that an extent of condition evaluation was needed, consistent with the criteria in Reference 2. The attachment to this letter provides descriptions and conclusions of ZS extent of condition reviews.

U.S. Nuclear Regulatory Commission ZS-2023-018 Page 2 of 2 The attachment also provides updated information related to a previous request for additional information (RAI). In Reference 4, ZS communicated an intent to provide updates to RAI-1g, if needed.

This letter contains no regulatory commitments. If you should have any questions regarding this submittal, please email Justin Wheat at jtwheat@energysolutions.com.

Respectfully, Amy C Digitally signed by Amy C Hazelhoff Hazelhoff Date: 2023.09.08 08:54:54 -04'00' Amy C. Hazelhoff Senior Vice President, Regulatory Affairs Attachment - Extent of Condition Review and Updated Information Related to RAI-1g cc: w/Attachment NRC Inspector and Health Physicist - Zion Nuclear Power Station, Units 1 and 2 NRC Senior Project Manager - Zion Nuclear Power Station, Units 1 and 2 Manager, Nuclear Facility Inspection - Illinois Emergency Management Agency Senior Health Physicist - Illinois Emergency Management Agency Manager - Lake County Emergency Management Agency

Zion Nuclear Power Station - Units 1 and 2 ZS-2023-018 Attachment 1 Extent of Condition Review and Updated Information Related to RAI-1g ZS-2023-018 Page 1 of 5 NRC Request for ZionSolutions to Conduct an Extent of Condition Review

Background

The U.S. Nuclear Regulatory Commission (NRC) held a clarification meeting with ZionSolutions, LLC (ZS), on May 4, 2023 (ML23167A069). The purpose of the meeting was to discuss certain aspects of multiple submittals that were associated with ZS request for partial site release (ML20164A096). The information discussed during the May 4, 2023, meeting was useful in developing the confirmatory surveys that were to be conducted by the Oak Ridge Institute for Science and Education (ORISE). The NRC then developed the scope, methods, and criteria that would be used to conduct, and then evaluate the confirmatory surveys (ML23221A243).

The NRC and ORISE completed all confirmatory surveys (surface and sub-surface surveys) in early August 2023. Following completion of the confirmatory surveys, the NRC communicated that an extent of condition evaluation was needed (ML23233A150). A summary of the two issues that needed evaluation are provided below.

Extent of Condition - Issue 1 As a result of the findings from the ORISE confirmatory surveys, the NRC staff requested an evaluation of the extent of condition for the southeastern portion of the site. The NRC stated that one acceptable approach would be to perform hand-scanning of survey units near the south rail loading area (i.e., survey units 10211A and B and survey units 10221E, F, G and H).

Extent of Condition - Issue 2 During the ORISE confirmatory survey, a sample was collected from survey unit 12101 that contained Eu-152 at 5.19 pCi/g. The NRC staff requested an evaluation of the extent of condition to determine whether Eu-152 should be a radionuclide of concern for the soil in and adjacent to survey unit 12101. The NRC stated that one acceptable approach would be to evaluate the gamma spectroscopy results for the final status survey samples collected in and adjacent to survey unit 12101, to determine if detectable Eu isotopes were present, and if so, whether the data is consistent with the insignificant radionuclide contributor criteria.

ZS Extent of Condition Review Issue 1 ZS conducted an evaluation of the extent of condition for the southeastern portion of the site by completing hand-scanning of survey units 10211 A and B and survey units 10221 E, F, G and H.

The scans were performed under a Special Surveillance and consisted of hand-held gamma ZS-2023-018 Page 2 of 5 walkovers of 100% of the surface area of the survey units listed above. Technicians employed a scan speed of 0.25 m/sec, which is the primary discrete radioactive particle (DRP) data quality objective (DQO).

The results of these hand-scanning activities are outlined in Table 1.

Table 1 Findings from Extent of Condition Review for Issue 1 Survey Unit Findings A None 10211 One DRP identified and remediated. Gamma spectroscopy analysis B revealed only Co-60 positively identified with an activity of 1.89E+05 pCi. DRP coordinates (meters): 343695.03, 641555.46 E None F None 10221 G None H None A map depicting the six Special Surveillance survey units and the location of the DRP identified and remediated within 10211B is provided as Figure 1.

ZS evaluation of the extent of condition determined that there is not widespread cross contamination of DRPs resulting from decommissioning activities in the southeastern portion of the site.

ZS-2023-018 Page 3 of 5 Figure 1 Location of DRP in Special Surveillance Survey Units ZS-2023-018 Page 4 of 5 Issue 2 ZS conducted an evaluation of the extent of condition to determine whether Eu-152 should be a radionuclide of concern for the soil in and adjacent to survey unit 12101. The evaluation consisted of reviewing the final status survey gamma spectroscopy reports, which are provided in the release records for survey unit 12101 and the surrounding survey units (12201E, 10202D, 10201D, 12102, 10222, and 10223) to identify any positive detections of Eu-152 or Eu-154. The review identified only one positive detection of Eu-152 in survey unit 12101 with a concentration of 7.11E-02 pCi/g. The survey units directly adjacent to survey unit 12101 did not have positive detections of Eu-152 or Eu-154.

The concentration of Eu-152 from survey unit 12101 contributes to less than 10% of the dose based on evaluation using the derived concentration guideline levels (DCGLs); therefore, Eu-152 remains an insignificant dose contributor in soil, per LTP Section 5.1, and no adjustments to the DCGLs or radionuclides of concern are necessary.

ZS evaluation of the extent of condition determined that the concentration of Eu-152 identified in the sample from survey unit 12101 (during the ORISE confirmatory survey) is not indicative of the overall radiological conditions for Eu-152 in 12101 and the surrounding survey units. The results indicate that Eu-152 is not a radionuclide of concern in survey unit 12101 and adjacent survey units.

NRC Request to Update RAI-1g In ML23167A069, the NRC requested the following:

Provide the latest version of ZS response to RAI-1g. The RAI requested: Given the observations in the survey units listed above, as well as any additional observations resulting from ongoing licensee activities under the Final Status Survey Due Diligence Plan, provide an explanation for why the licensee surveys are adequate.

ZS Updated Information Related to RAI-1g ZS determined that a formal update to the response to RAI-1g, dated October 17, 2022 (ML22293A431) is not needed. The context of RAI-1g is not entirely relevant given the recent completion of ORISE confirmatory surveys and the ZS extent of condition evaluations that followed. However, the RAI-1g response does provide details related to the ZS DRP Survey Plan, which was a key part of the overall strategy. Survey activities, to include the DRP Survey Plan, were also summarized in ZS letter to the NRC, dated August 25, 2023 (ML23237B413).

ZS-2023-018 Page 5 of 5 On March 23, 2022, ZS submitted a license amendment request (LAR) to revise the license termination plan (LTP) for Zion Nuclear Power Station (ML22084A058). The proposed changes to the LTP included the use of a methodology for calculating dose and risk from DRPs that may hypothetically remain on site. The LAR proposed that the LTP consider the less likely but plausible (LLBP) scenario for exposure to hypothetical DRPs. ZS withdrew the LTP LAR on March 3, 2023 (ML23068A012). This is relevant to the RAI-1g response as it was submitted while the LTP LAR was on the docket, which influenced the RAI-1g response at that time. For example, on the first page of the response, in the third paragraph, it states, Particles are a source term, and it is ZionSolutions intention to not leave any particles in site soil that present an unacceptably high risk. This statement is no longer relevant since the LTP LAR to adopt the LLBP scenario for exposure to hypothetical DRPs was withdrawn. Furthermore, in ZS letter to the NRC dated August 25, 2023, it was stated that ZS does not intend to leave DRPs behind at the site, and there are no known DRPs remaining at the site.

In summary, a formal update to the ZS response to RAI-1g is not needed. The NRC, with support of ORISE, recently completed confirmatory surveys. As stated earlier in this attachment, ZS performed extent of condition evaluations that address the issues raised in ML23233A150.

The surveys conducted at the Zion Nuclear Power Station have been adequate, and the site is acceptable for unrestricted release in accordance with 10 CFR 20, Subpart E and 10 CFR 50.82.