ML24085A792
| ML24085A792 | |
| Person / Time | |
|---|---|
| Site: | Vallecitos Nuclear Center |
| Issue date: | 03/25/2024 |
| From: | Murray S GE Hitachi Nuclear Energy, NorthStar Group Services |
| To: | Office of Nuclear Material Safety and Safeguards, Document Control Desk |
| References | |
| M240037 | |
| Download: ML24085A792 (1) | |
Text
March 25, 2 024
M240037
Via Electronic Information Exchange
ATTN: Document Control Desk 10 CFR 50.82 U.S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Rockville, MD 20852
Vallecitos Boiling Water Reactor (VBWR)
License No. DPR-1 NRC Docket No. 50-18
Subject:
GEH/NorthStar Response to NRC Request for Additional Information Regarding the License Termination Plan for VBWR
References:
- 1) License Termination Plan for the Vallecitos Boiling Water Reactor License DPR-1, September 7, 2023 (ML23250A267)
- 2) Letter, Jack Parrott (NRC) to Scott P. Murray (GEH), "Request for Add itional Information Regarding the License Termination Plan for VBWR " (ML24051A168),
February 22, 2024
On September 7, 2023, GE Hitachi Nuclear Energy Americas, LLC (GEH) submitted a license termination plan for the Vallecitos Boiling Water Reactor (VBWR). (Reference 1 ).
GEH and Northstar hereby respond to the NRC request for addition al information dated February 22, 2024 (Reference 2)..
Please contact me or Mr. Thomas Silko at (802) 451-5354, Ext. 2506 if you have any questions regarding this information.
Sincerely,
F1:;hi N~ clM :;; ** LLC
Scott P. Murray,.. C /
Facility Licens ing, Manager GE Hitachi Nuclear Energy Americas, LLC US NRC M240037 March 25, 2024 Page 2 of 2
For the NorthStar Companies:
Gregory G. DiCarlo Vice President, General Counsel & Secretary NorthStar Group Services, Inc.
Enclosure:
- 1) RAI Responses
cc:
J. Parrott, NMSS/DUWP/RDB SPM 24-015 Enclosure 1
RAI Responses
Vallecitos Boiling Water Reactor License Termination Plan Request for Additional Information
Licensing Licensing RAI 1 - License Amendment Request Basis:
The regulation in 10 CFR 50.82(a)(10) states that.the Commission shall approve the [license termination] plan, by license amendment, subject to such conditions and limitations as it deems appropriate and necessary and authorize implementation of the license termination plan.
Issue:
GEH did not address the evaluate whether or not a significant hazards consideration is involved with the proposed amendment as set forth in 10 CFR Part 50.92, Issuance of amendment.
Request:
Please provide your significant hazard consideration for this License Termination Plan (LTP).
Response
GEH has reviewed the proposed amendment against each of the criteria in 10 CFR 50.92 Issuance of amendment and has concluded that the amendment request does not involve a significant hazards consideration. The following provides an analysis of the issue of no significant hazards consideration.
- 1) Does the proposed license amendment involve a significant increase in the probability or consequences of an accident previously evaluated?
Response: No.
The change allows for the approval of the LTP submitted in support of the termination of DPR-1 for the Vallecitos Boiling Water Reactor (VBWR). The change does not affect possible initiating events for any accidents previously evaluated or alter the configuration or operation of the facility. Safety limits, limiting safety system settings and limiting control systems are no longer applicable to the VBWR and therefore are not relevant. Therefore, the proposed license amendment does not involve a significant increase in the probability of consequences of an accident previously evaluated.
- 2) Does the proposed license amendment create the possibility of new or different kinds of accidents from any accident previously evaluated?
Response: No.
The change allows for the approval of the LTP submitted in support of the termination of DPR-1 for the Vallecitos Boiling Water Reactor (VBWR). The change does not affect 1
possible initiating events for any accidents previously evaluated or alter the configuration or operation of the facility. Safety limits, limiting safety system settings and limiting control systems are no longer applicable to the VBWR and therefore are not relevant. Therefore the proposed license amendment does not involve a significant increase in the probability of consequences of an accident previously evaluated.
- 3) Does the proposed license amendment involve a significant reduction in a margin of safety?
Response: No.
There are no changes to the design or operation of the facility resulting from this amendment. The proposed change does not affect the boundaries used to evaluate compliance with liquid or gaseous effluent limits and has no impact on plant shutdown operations. Accordingly, none of the postulated accident assumptions for the VBWR are affected. Therefore, the proposed change does not Involve a significant reduction in a margin of safety.
Licensing RAI 2 - Submittal of Related Licensing Actions Basis:
Regulations in 10 CFR 50.82(a)(11)(ii) require that to terminate a license the Commission shall determine that -
The final radiation survey and associated documentation, including an assessment of dose contributions associated with parts released for use before approval of the license termination plan, demonstrate that the facility and site have met the criteria for decommissioning in 10 CFR part 20, subpart E.
Issue:
Section 5.0 of the LTP states that an exemption from 10 CFR 50.82(a)(11) requiring that the VBWR meet the requirements for release according to 10 CFR Part 20, subpart E, has been submitted, and that it includes a license amendment request to transfer the remaining VBWR facility and its in-situ residual radioactivity to the authority of the ESADA Vallecitos Experimental Superheat Reactor (EVESR) DR-10 license.
Request:
These additional licensing actions have not yet been submitted. As part of the license termination plan, please provide a schedule for the submittal of these additional licensing requests.
Response
As discussed with NRC staff on May 16, 2023, GEH has announced its intent to transfer ownership of the VNC to a subsidiary of NorthStar Group Services, Inc (NorthStar Vallecitos, LLC). A request for NRC consent for the direct transfer of the VNC radioactive material licenses to NorthStar was submitted on September 1, 2023 (ML23244A247) and approval is expected within the next few weeks.
2 As a result, the additional licensing actions in this request and a revised LTP will be submitted by NorthStar within 1 20 days after the request for consent to the direct license transfers has been approved.
Technical Technical RAI 1 - Continuing Characterization Basis:
The regulations in 10 CFR 50.82(a)(9) outline the requirements regarding the content and submittal of a license termination plan to the U.S. Nuclear Regulatory Commission (NRC) for approval, which includes a site characterization. Applicable guidance on site characterization and characterization surveys can be found NUREG-1757, NUREG-1700, Regulatory Guide 1.179, and NUREG-1575 (MARSSIM) that cover purpose, extent and methods.
Issue:
During review of Vallecitos Nuclear Center (VNC) Vallecitos Boiling Water Reactor (VBWR)
License Termination Plan (LTP), NRC will need sufficient site characterization information and data of the VBWR site to support evaluations needed for license termination and ensure a reasonable estimate of the level and amount of residual contamination that will be transferred to the ESADA Vallecitos Experimental Superheat Reactor (EVESR) license.
In the VBWR LTP, the licensee identified several areas and items remaining where characterization still should be conducted in order to support license termination evaluations, including post-vessel removal radiation surveys performed in previously inaccessible areas. At the time of this review, reactor vessel removal has been completed pursuant to 10 CFR 50.59.
Request:
a) Please confirm if post-vessel removal radiation surveys have been performed in previously inaccessible areas or describe when these are planned to be performed.
b) Provide a summary of the post-vessel removal radiation surveys or other additional characterizations to supplement the LTP.
c) Provide a list of any characterization activities still to be performed, if any.
Response
a) Post removal surveys have been completed. Direct radiation levels were measured; smear samples were collected and analyzed for gross alpha/beta activity levels. Core samples of the bioshield were collected at six locations; samples represented a 4.5-inch depth core; the inner 1-inch and outer 1-inch segments were extracted. These segments were counted on-site by gamma spectroscopy. From these twelve (12) segments, five (5) were selected to be representative of the upper, middle, and lower core regions and sent to GEL for a complete 10 CFR 61 type analysis (gamma spectroscopy and hard-to-detect radionuclides). No additional samples or surveys are planned for characterizing the radioactivity inventory. Review of analytical results is on-going. The LTP will be updated to include the additional information on radiological conditions and updating the inventory for transfer to EVESR.
3 b) Following vessel removal, radiation surveys for direct gamma and loose surface contamination were conducted. The dose rate inside the bioshield was less than 1 mRem/hr. Analysis of smears for loose surface contamination showed no detectable alpha activity and beta/gamma levels below 1,000 dpm/100 cm2. Core samples were collected from the region of the bioshield that would have received the higher levels of neutron flux and resulting levels of neutron activation products. Low levels of Ni-63, Co-60, Cs-137, Eu-152, Eu-154 were detected in the 10-6 to 10-4 µCi/g range. The LTP will be updated to include the additional information on radiological conditions and an updated radioactive material inventory for transfer to EVESR.
c) None remain to be performed.
Technical RAI 2 - Fractional Abundances Basis:
Regulations in 10 CFR 50.82(a)(9)(ii) outline the required components of a license termination plan, which includes a site characterization. Applicable guidance on site characterization can be found in NUREG-1700 Section 2.2 and NUREG-1757 Vol.2, Section 4.
Issue:
VBWR LTP Section 2.3.2.1, Site Specific Radionuclides of Concern, states that smear/wipe samples collected during characterization surveys, described in Enclosure 3, SDR Radiological Characterization Report, TR-22- 011 Revision 1, were analyzed for radionuclides and fractional abundances. Enclosure 3, Section 3.1, Radionuclides of Concern, gives additional information, stating that these samples consist of composited smear/wipe samples from both VBWR and EVESR. However, the licensees methodology for establishing fractional abundances does not appear to include a justification for how the calculated fractional abundances are representative of the VBWR site specifically.
In addition, in Table 3-4, Detected Radionuclides Comparison, of the Characterization Report, which in part, displays results from the samples sent to GEL analysis of ROCs and fractional abundances, includes H-3 and Cm-243/244 as detected above critical level. However, Table 2-9, VBWR Radionuclides of Concern and Fractional Abundance, of the LTP lists the fractional abundances of H-3 and Cm-243/244 as N/D.
Request:
a) Explain how the calculated fractional abundances are representative of VBWR specifically.
b) Explain the inconsistencies found in Table 3-4 as described above between the Characterization Report and LTP regarding fractional abundances.
Response
a) The calculated abundances were based on smear samples collected from VBWR during a campaign to characterize the shutdown reactor source term during 2019. This characterization effort targeted areas throughout VBWR that exhibited the higher levels of radioactivity, thereby providing data most representative of the remaining radioactive inventory. The LTP will be updated to include the smear data as well as the method used for derivation of the distribution.
b) The additional characterization as performed in 2022, is documented in the 4
SDR Radiological Characterization Report, REN-TR 011 Revision 1 (Enclosure 3 to the LTP). The positive samples as referenced in Table 3-4 (as from the 2019-2020 Characterization) were not for the VBWR smear samples as analyzed for the 2019 report. The referenced positive measurements for H-3 are related to water samples from on-site groundwater monitoring wells.
Refer to Table 2-2 of the LTP. The reported measurable levels of Cm-243/244 were not from VBWR but were from samples collected at GETR. The LTP will be updated to clarify this otherwise apparent discrepancy in detectable levels of radionuclides between LTP Table 2-9 and Enclosure 3, Table 3-4.
Technical RAI 3 - Embedded Piping
Basis:
Regulations in 10 CFR 50.82(a)(9)(ii) outline the required components of a license termination plan, which includes a site characterization. Guidance on characterization and surveying of embedded piping can be found in DUWP-ISG-02 (ML23177A008) and NUREG-1757, Vol. 2, Rev. 2, Appendix G.
Issue:
VBWR LTP Section 2.4, Estimate of VBWR Radiological Inventory for Transfer to EVESR, contains information on penetrations and embedded piping as part of the discussion regarding the estimate of VBWR radiological inventory for transfer to EVESR. In each case, the LTP assumes that contamination levels inside the pipe are the same as the external contamination levels around it. For example, the LTP states that the contamination levels in 10 embedded pipes running from the containment building to the exterior Valve Pit is assumed to be the same as the contamination levels in the Valve Pit.
Request:
Provide justification of assumptions for embedded piping and penetrations contamination such that the valve pit contamination levels are representative of those inside the pipe, or how this aligns with current guidance on embedded piping.
Response
Direct surveys inside embedded pipes were not performed; Many were capped, while others were identified as used for non-radiological purposes, such as electrical conduit. All of these pipes are to be remediated during the decommissioning of EVESR. Additional radiological characterization will be performed at that time. Contamination levels are relatively low in the valve pit (<1000 dpm/100 cm2 loose surface beta/gamma); and dose rate inside the pit is 400
µR/h, which considering the geometry is not indicative of high radioactive contamination levels.
The assumption that the inside of the pipes is not different from the source (containment basement) and/or endpoint (valve pit), the assumption that the inside contamination levels can be effectively characterized based on these source and endpoint measurements is reasonable for the purpose of quantifying total activity for transfer to EVESR.
5 Technical RAI 4 - Concrete Core Samples
Basis:
Regulations in 10 CFR 50.82(a)(9)(ii) outline the required components of a license termination plan, which includes a site characterization. NUREG-1700 Section 2.2 and NUREG-1757 Vol. 2, Rev. 2, Section 4.2.2 give additional guidance on what should be discussed in the site characterization portion of an LTP.
Issue:
VBWR LTP Section 2.1.4, VBWR Containment Concrete Core Samples makes the statement that No radionuclides other than Co-60 and Cs-137 were identified. All hard to detect (Ni-63, alpha emitters or transuranic radionuclides were identified. This statement is unclear and seems inconsistent.
Request:
Clarify this statement and explain if hard-to-detect radionuclides such as Ni-63, H-3, C-14, Sr-90, etc., were identified.
Response
The sentence should have stated: No hard to detect (Ni-63, alpha emitters or transuranic radionuclides) were identified. The LTP will be updated to correct Section 2.1.4.
Technical RAI 5 - Remediation Basis:
Regulations in 10 CFR 50.82(a)(9)(ii) outline the required components of a license termination plan, which includes plans for site remediation. Both NUREG-1757 Vol. 2, Rev. 2, Appendix N and Regulatory Guide 8.8, Rev. 3 (ML003739549) give specific guidance regarding ALARA principles.
Issue:
The VBWR LTP appears to contain inconsistent statements in several sections regarding site remediation activities. VBWR LTP Section 3.3 states that key areas will be evaluated and decontaminated as needed including the bioshield and external pump. Then, in Section 4.1, the VBWR LTP states that the bioshield will be remediated and the external ventilation system, spent fuel pool, and external pump will not be remediated based on current radiological readings and from an ALARA standpoint. Further on in Section 4.4, the VBWR LTP states that very little, if any remediation will occur.
More generally, the LTP states that areas will not be remediated from an ALARA standpoint, as noted in the paragraph above, but does not contain a discussion of the methods or ALARA analysis used to determine that these areas will not be remediated.
Request:
a) Clarify the inconsistent statements above and describe what areas have planned remediation, will not be remediated, or will be evaluated for remediation.
b) Provide the method used to determine if areas will be remediated or not from an ALARA 6
standpoint.
Response
The apparent inconsistency appears to be related to what will be remediated prior to transfer to EVESR license versus what will ultimately be remediated prior to the EVESR license termination.
In Section 4.1, these items do not require remediation prior to transfer of VBWR residual radioactivity transfer to EVESR license. These items will be remediated for EVESR license termination. In Section 4.4, the statement is correct in that little remediation will occur to complete transfer of residual radioactivity to the EVESR license.
Note: The referral to external pump, should be external sump.
Specific LTP modifications in response to Technical RAI 5 Remediation
3.3 Future Decommissioning Activities The activities remaining to be completed to support license termination are:
- Removal of the reactor vessel and its internals with its packaging and transport for permanent disposal at a commercial site.
- Packaging decommissioning generated material for transport and disposal as radioactive waste. It is intended that all radioactive waste from the dismantling and decommissioning activities will be transported offsite for disposal at a licensed disposal facility.
- Complete radiation surveys for areas of the bioshield which were inaccessible due to reactor vessel location (see Table 3-1 third row) and update estimates of residual radioactivity remaining (see Section 2) as needed for supporting the transfer of residual radioactivity to the EVESR license and support the requested exemption to 50.82(a)(11)(ii) in accordance with 10 CFR 50.12.
4.1 Decommissioning Objectives The primary objective is to remove the reactor vessel, which contains the majority of the remaining radioactive material. Based on current known radiological conditions of the external ventilation system, spent fuel pool and the external sump, no remediation will be performed on these items. Soil remediation is not anticipated as there is no soil associated with the VBWR license. Residual radioactive materials will be controlled to prevent spread and contamination of the environment. (See Section 4.2, below.)
4.4 Remediation Actions Remediation actions are performed throughout the decommissioning process. The remediation action taken is dependent on the material contaminated and extent of contamination. The principal materials that may be subjected to remediation are hardened structural surfaces and residual DAW and sludges. No decontamination is anticipated.
Technical RAI 6 - Neutron Activation
Basis:
Regulations in 10 CFR 50.82(a)(9)(ii) outline the required components of a license termination plan, which includes a site characterization. Applicable guidance on site characterization can be found in NUREG-1700 Section 2.2 and NUREG-1757 Vol. 2, Rev. 2, Section 4.
7 Issue:
VBWR LTP Section 2.4, Estimate of VBWR Radiological Inventory for Transfer to EVESR, discusses the method used to estimate the types and quantities of radioactive material associated with VNC VBWR to be transferred to the EVESR license. In part, this includes an estimate of the neutron activation in the bioshield concrete using NUREG/CR-3474, Table 5.5 and reference [7] (D. W. James Consulting, "Vallecitos Nuclear Center VBWR Reactor Vessel and Internals Characterization and Classification - 2022," March 2022). However, there are no sample calculations and minimal discussion included on how the final estimates of 3.55E-11 Ci/g or 1.8 mCi were obtained.
Request:
Expand upon the methods used to estimate how the radioactivity in the bioshield associated with neutron activation was calculated. Include calculations or tables as necessary.
Response
Core samples of the bioshield were collected at six locations for the purpose of evaluating the neutron activation component. Twelve locations were sampled reflecting the upper, middle, and lower core region. The samples represented a 4.5-inch depth core; the inner 1-inch and outer 1-inch segments were extracted to allow evaluation of depth of activation. These segments were counted on-site by gamma spectroscopy. From these twelve (12) segments, five (5) were analyzed for 10 CFR 61 identified transuranics and other hard-to-detect (HTD) radionuclides.
Low levels of Ni-63, Co-60, Sr-90, Cs-137, Eu-152, and Eu-154 were detected in the 10-6 to 10-4
µCi/g range. No TRUs were detected. The LTP will be updated to include the additional information on radiological conditions, describe the methodology for calculating the bioshield inventory, and an updated radioactive material inventory for transfer to EVESR.
Environmental Environmental RAI 1 -
Basis:
In accordance with the requirements of 10 CFR 51.45(b)(1), information is needed in the Environmental Report (ML23261A593) to determine the scope of the review and provide a basis for staffs evaluation.
Issue:
In Section 1.1, Introduction, the Environmental Report (ER) states, It is the intent of GEH to decommission the Vallecitos Boiling Water Reactor (VBWR) at the VNC and terminate its Nuclear Regulatory Commission (NRC) license Developmental Power Reactor (DPR) - 1. Later in that same section, the ER states that For the VBWR license termination, the residual radioactive materials will remain under the Empire State Atomic Development Associates Incorporate Vallecitos Experimental Superheat Reactor license until it is terminated. In Section 1.3, Purpose, the ER states The purpose of this ER is to present a current evaluation of the actual or potential environmental impacts resulting from the preparation, removal, and disposal of the VBWR vessel. The vessel removal is the remaining component that is inseparable from the DPR-1 license.
Request:
8 Revise the scope of the proposed action and the resulting environmental impacts based on the request for supplemental information (RSI) response dated October 31, 2023 (ML23304A300).
The ER should be updated to describe the proposed action, affected environment and environmental impacts for all resource areas. Based on RSI response, the reactor vessel removal has been completed under 10 CFR 50.59. Confirm that is no longer within the scope of the LTP review and update the ER accordingly.
This information is needed to determine the scope of the review and provide a basis for staffs evaluation. This information is required for compliance with 10 CFR 51.45(b)(1).
Response
It is the intent of GEH to decommission the Vallecitos Boiling Water Reactor (VBWR) at the VNC and terminate its Nuclear Regulatory Commission (NRC) license Developmental Power Reactor (DPR) -1. This decommissioning and license termination will be conducted in accordance with the applicable requirements of 10 CFR 50.82 as identified in removing and disposing of materials and decontaminating both facilities meeting conditions for unrestricted release in accordance with the criteria for decommissioning in 10 Code of Federal Regulations (CFR) 20.1401 and 20.1402. For the VBWR license termination, the residual radioactive materials will remain under the Empire State Atomic Development Associates Incorporated (ESADA) Vallecitos Experimental Superheat Reactor (EVESR) license until it is terminated.
GEH prepared and submitted an Environmental Report (ER) by letter dated September 7, 2023 and supplemented by letter dated September 15, 2023 to evaluate the potential radiological and non-radiological impacts associated with the removal and disposal of the VBWR in Building 300 Area at VNC.
The submitted ER was in accordance with the requirements of 10 CFR 50.82 (a)(9) and 10 CFR 51.53 (d) to address the post-operating license stage of the facility. As required by these regulations the ER addressed new information and environmental changes associated with the proposed termination activities including the VBWR vessel removal. The VBWR vessel was removed and shipped offsite in October 2023. As a result, the vessel removal is no longer within the scope of the license termination plan (LTP) review.
There is no new information or significant environmental changes associated with GEHs proposed license termination activities, including the transfer of residual radioactivity to the EVESR license.
NRC prepared and issued a generic environmental impact statement (GEIS), NUREG-0586, Final Generic Environmental Impact Statement on Decommissioning of Nuclear Facilities, Supplement 1, Volume 1 dated November 2002 to assess the environmental effects associated with decommissioning alternatives for various types of nuclear facilities.
Where applicable, the VBWR license termination actions are consistent with the generic assessments of NUREG- 0586.
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