CNL-18-126, Response to Request for Additional Information, Erai 9602, Related to EIS Postulated Accidents in Support of Early Site Permit Application for Clinch River Nuclear Site
| ML18282A227 | |
| Person / Time | |
|---|---|
| Site: | Clinch River |
| Issue date: | 10/05/2018 |
| From: | James Shea Tennessee Valley Authority |
| To: | Document Control Desk, Office of New Reactors |
| References | |
| CNL-18-126 | |
| Download: ML18282A227 (10) | |
Text
Tennessee Valley Authority, 1101 Market Street, Chattanooga, TN 37402 CNL-18-126 October 5, 2018 10 CFR 52.17 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Clinch River Nuclear Site NRC Docket No.52-047
Subject:
Response to Request for Additional Information, eRAI 9602, Related to EIS Postulated Accidents in Support of Early Site Permit Application for Clinch River Nuclear Site
References:
- 1. Letter from TVA to NRC, CNL-17-151, Revision 1 of Application for Early Site Permit for Clinch River Nuclear Site, dated December 15, 2017
- 2. Email from TVA to NRC, Daniel Stout to 'ClinchRiverESPEIS@nrc.gov',
TVA Response to NRC request for comments on CRN ESP DEIS, dated June 29, 2018
- 3. USNRC Request for Additional Information Number Env-1, eRAl 9602, ESPA Application Sections: ER 3.1, 3.8 and 5.7, dated September 10, 2018 By letter dated December 15, 2017 (Reference 1), Tennessee Valley Authority (TVA) submitted Revision 1 of the application for an early site permit (ESP) for Clinch River Nuclear Site. By email dated June 29, 2018, TVA provided comments on the Clinch River Small Modular Reactor ESP Application Draft Environmental Impact Statement (DEIS) (Reference 2). Based on the staffs review of the comments, electronic request for additional information (eRAI) 9602 was issued (Reference 3).
The purpose of this letter is to provide the TVA response to eRAI 9602. Enclosure 1 provides the response to eRAI 9602. Enclosure 2 provides supplemental information related to the level of detail used to describe the required spent fuel pool capacity in Environmental Report (ER)
Subsection 3.8.2, when compared to ER Table 3.1-2, Item 18.0.4 and ER Subsection 5.7.2.1.6.
Enclosure 1 to Letter CNL-18-126 TVA Response to NRC Electronic Request for Additional Information (eRAI) 9602, Related to EIS Postulated Accidents in Support of Clinch River Nuclear Site ESPA CNL-18-126 E1-1
ENCLOSURE 1 TVA Response to NRC Electronic Request for Additional Information (eRAI) 9602, Related to EIS Postulated Accidents in Support of Clinch River Nuclear Site ESPA NRC Introduction EIS Postulated Accidents-01 10 CFR 51.41 states that the Commission may require an applicant for a permit to submit such information as may be useful in aiding the Commission in complying with section 102(2) of NEPA. Additionally, this regulation also requires that the Commission will independently evaluate and be responsible for the reliability of any information which it uses.
TVA's ER Table 3.1-2 (Sheet 5 of 5) on page 3.1-9 (ADAMS accession number ML18003A471) states:
PPE Section 18.0.2, Fuel assemblies x Number of fuel assemblies per core: "Number of Fuel Assemblies: 96" PPE Section 18.0.4 x Refueling frequency: "Frequency 2 years" x Average number of assemblies per refueling: "Assemblies per Refueling: 96" x Fuel pool capacity (in years), and cooling time in pool: "Capacity 6 years,"
ER Section 3.8.2, Transportation of Irradiated Fuel, is the only place in the ER that refers to a 6 year spent fuel storage capacity in terms of a minimum, stating that "each unit is to have a spent fuel pool with a capacity for a minimum of 6 yr of fuel discharges" and "[a]fter a minimum 5-year decay period, the fuel is to be removed from the pool and packaged in casks for storage onsite at an independent spent fuel storage installation and may be transported offsite." ER Section 5.7.2.1.6, Time After Discharge of Irradiated Fuel Before Shipment, states that five years is considered the minimum decay time that spent fuel would need to be stored in the spent fuel pool and that "the CRN Site would have a 6-yr storage capacity which exceeds that needed to accommodate 5-yr cooling of irradiated fuel before removal from the spent fuel pool and either transferred to onsite dry storage or transport offsite."
The staff's analysis in DEIS Section 5.11.2.5 is based on the associated Plant Parameter Envelope (PPE) values from TVA's ER Table 3.1-2 for the above PPE Sections 18.0.2 and 18.04.
In an attached file to an email dated June 29, 2018, under ADAMS accession number ML18180A386, the Tennessee Valley Authority (TVA), the Clinch River Nuclear Site (CRNS) Early Site Permit (ESP) applicant, provided comments on the Clinch River Small Modular Reactor ESP Application Draft Environmental Impact Statement (DEIS). On page 22 of the attachment, TVA had the following comments on DEIS Section 5.11.2.5, Spent Fuel Pool Accidents:
Section: 5.11.2.5 Page: 5-86 Line: 22 and 33 CNL-18-126 E1-2
ENCLOSURE 1 TVA Response to NRC Electronic Request for Additional Information (eRAI) 9602, Related to EIS Postulated Accidents in Support of Clinch River Nuclear Site ESPA Comment: DEIS Section 5.11.2.5, page 5-86, Lines 22 and 33 mention a 6 year cooling time for the spent nuclear fuel. [Environmental Report] ER Section 5.7.2.1.6 does not specify a cooling time; it only provides a minimum spent fuel pool storage capacity of 6 years.
And Section: 5.11.2.5 Page: 5-86 Line: 23 Comment: DEIS Section 5.11.2.5, page 5-86, Line 23 states that the spent fuel pool holds 288 assemblies. It would actually hold more than 288 assemblies, because enough space is provided for a full core off load and the new fuel to be loaded. TVA suggest NRC consider revising this description.
Further, on page 30 of the attachment, TVA included a related comment regarding the timing of the ISFSI development in Appendix J of the DEIS:
Technical Area: Accidents Representations/Assumptions: An appropriately sized ISFSI would be constructed and operational within 6 years from the commencement of operations. After a sufficient decay period of at least 5 years, the fuel would be removed from the pool and packaged in spent fuel shipping/storage casks either for storage onsite at an (ISFSI or for transportation offsite.
Source (differences noted): The DEIS states that an ISFSI would be constructed and operational within 6 years from the commencement of operations. This explicit commitment is not made in the ER.
The information in the above comments provided by TVA appears inconsistent with ER Sections 3.8.2, 5.7.2.1.6, 18.0.2 and 18.0.4 (PPE Table 3.1-2). Therefore, please provide the correct values to clarify:
- a. The reasonable capacity of the spent fuel pool in years;
- b. The number of spent fuel assemblies in the spent fuel pool at a reasonable capacity; and
- c. When an ISFSI would need to be operational at the CRN Site.
The staff request that any associated revisions to the ER be provided as a markup as part of the response to this RAI.
TVA Response The CRN ESPA reflects a plant parameter envelope (PPE) approach and does not reference a specific Small Modular Reactor (SMR) Technology. The PPE is a composite of proposed SMR and owner engineered parameters that bound the environmental impacts of both the construction and the operation of the facility. The PPE is based on preliminary design information from four different light water SMR Vendors.
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ENCLOSURE 1 TVA Response to NRC Electronic Request for Additional Information (eRAI) 9602, Related to EIS Postulated Accidents in Support of Clinch River Nuclear Site ESPA If TVA moves forward with a combined license application, a specific SMR technology would be identified at that time. Once an SMR technology is selected, specific information associated with a design would be available.
In the review of DEIS section 5.11.2.5, TVA identified that certain details provided in that section, specifically, the mention of required cooling time and number of assemblies in the dedicated spent fuel pool, were not specifically mentioned in the ESPA. The ESPA only mentions a minimum 6 year storage capacity supporting a 5 year spent fuel decay/cooling requirement.
Additionally, during the DEIS review, TVA identified that information contained in DEIS Appendix J, Table J-2, Accidents discussion was not provided in the ESPA. Specifically, Table J-2 states, [an]
ISFSI would be constructed and operational within 6 years from the commencement of operations.
This explicit commitment is not made in the ER.
In response to this RAI, TVA has reviewed ER Subsections 3.8.2, 5.7.2.1.6, and Table 3.1-2, Items 18.0.2 and 18.0.4 for inconsistent information with respect to the comments provided to the NRC on June 29, 2018. TVA noted a different level of detail describing the required spent fuel pool capacity in ER Subsection 3.8.2, when compared to ER Table 3.1-2, Item 18.0.4 and ER Subsection 5.7.2.1.6.
TVA provided the capacity of the onsite storage facilities to store irradiated fuel and the minimum fuel storage time between removal from the reactor and transportation offsite as required per NUREG-1555.
To provide clarity and similar level of detail, ER Table 3.1-2, Item 18.0.4 and ER Subsection 5.7.2.1.6 are updated to specify that the spent fuel pool has a minimum fuel storage capacity of 6 years. This will align the spent fuel pool capacity description in Table 3.1-2, Item 18.0.4 and ER Subsection 5.7.2.1.6 with the similar description in ER Subsection 3.8.2. The changes to the ER will be incorporated in a future revision of the ESP application.
The following supplemental information is being provided to support NRC NEPA evaluations that compare reasonable TVA data to previous studies on potential fuel pool accidents. The supplemental information was developed using information provided by the SMR vendors considered in the TVA ESPA PPE.
- a. The reasonable capacity of the spent fuel pool in years; The SMR vendors considered for the ESPA provided a range of capacities for the spent fuel pool in their preliminary designs. Based on this preliminary vendor design information, a reasonable spent fuel pool at the CRN Site could provide up to 20 years of spent fuel storage.
- b. The number of spent fuel assemblies in the spent fuel pool at a reasonable capacity; and The SMR designs considered in the CRN ESPA PPE have a range of active fuel lengths and spent fuel pool (SFP) capacities. Developed consistently with the PPE approach described above in the first paragraph of the TVA Response, an SMR considered in the CRN ESPA PPE could have as many as 1,800 spent fuel assemblies (<5% U-235 enriched, 17x17 array, approximately 6.5 linear feet of active fuel length) in the SFP. That is equivalent to approximately 983 typical large light water reactor spent fuel assemblies (<5% U-235 enriched, 17x17 array, approximately 12 linear feet of active fuel length).
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ENCLOSURE 1 TVA Response to NRC Electronic Request for Additional Information (eRAI) 9602, Related to EIS Postulated Accidents in Support of Clinch River Nuclear Site ESPA Because of the variety of parameters provided for the multiple designs considered in the CRN ESPA, the spent fuel pool capacity of 1,800 spent fuel assemblies does not correlate to the same SMR vendor as the 20 years worth of storage provided in part (a) of this response.
- c. When an ISFSI would need to be operational at the CRN Site.
An independent spent fuel storage installation (ISFSI) or offsite repository would be operational prior to removing spent fuel from the spent fuel pool for transfer to an ISFSI or offsite repository. Transfer of spent fuel to an ISFSI or an offsite repository would not be utilized until after a minimum 5-year decay period as described in ER Subsection 3.8.2. Thus an operational ISFSI or shipment of spent fuel to an offsite repository would be accomplished prior to losing the ability to store additional spent fuel in the storage pool, but no sooner than the minimum decay period of 5 years, as described in ER Subsection 3.8.2.
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ENCLOSURE 2 Supplemental Information Related to EIS Postulated Accidents in Support of Early Site Permit Application for Clinch River Nuclear Site ER Table 3.1-2 (Sheet 5 of 5) is being revised as indicated. Strikethroughs indicate text to be deleted.
Underlines indicate text to be added.
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ENCLOSURE 2 Supplemental Information Related to EIS Postulated Accidents in Support of Early Site Permit Application for Clinch River Nuclear Site Table 3.1-2 (Sheet 5 of 5)
CRN Site Related Design Parameters 1 Parameter PPE Section Definition PPE Value ER Section Type 17.3 Construction 17.3.1 Noise The maximum expected sound level due to construction activities, Eng 101 dB at 50 ft 3.9 measured at 50 ft from the noise source.
17.4 Plant Population 17.4.1 Construction Maximum number of people onsite during construction. Eng 2200 (value per site) 3.10
- 18. Miscellaneous Items 18.0.1 Fuel Characteristics What is the form of the reactor fuel and the burnup (GWd/MTU)? Rx UO2, 51 GWD/MTU 5.7, 7.4 18.0.2 Fuel assemblies Provide the active length of the reactor fuel. Provide the number of fuel Rx Number of Fuel Assemblies: 96 3.8, 5.7, 7.4 assemblies per core and the weight (in MTU) of each assembly. Weight of Each Assembly: 0.304 MTU 18.0.4 Refueling Provide the refueling frequency, average number of assemblies per Rx Frequency 2 years, Assemblies 3.8, 5.7, 5.8 refueling, and fuel pool capacity (in years), and cooling time in pool. per Refueling: 96, Capacity:
Minimum of 6 years ,
18.0.5 Irradiation fuel Provide the weight of irradiated fuel per spent fuel shipping cask (MTU). Rx 21.2 MTU 5.7 transportation 18.1 Maximum Fuel Enrichment Concentration (weight percent fraction) of U-235 in the fuel uranium. Rx <5% U-235 3.2, 5.7, 7.4 18.2 Maximum Average Maximum assembly average burn-up at end of assembly life. Rx 51 GWD/MTU 3.2, 5.7, 7.4 Assembly Burnup 18.3 Peak fuel rod exposure at Peak fuel rod exposure at end of life. Rx 62 GWD/MTU 3.2 end of life 18.7 Clad Material Fuel rod clad material. Rx Zirc Alloy 5.7 (Zircaloy) 1 The numbering of the PPE listing is not meant to be sequential, and was compiled from and is consistent with the list developed by industry and refined for this ESPA.
Notes:
RX = Reactor Parameter Eng = Owner Engineered Parameter COC = Cycles of Concentration CNL-18-126 E2-2
ENCLOSURE 2 Supplemental Information Related to EIS Postulated Accidents in Support of Early Site Permit Application for Clinch River Nuclear Site ER Subsection 5.7.2.1.6 is being revised as indicated. Strikethroughs indicate text to be deleted. Underlines indicate text to be added.
5.7.2.1.6 Time After Discharge of Irradiated Fuel Before Shipment Subparagraph 10 CFR 51.52(a)(3) requires that no irradiated fuel assembly be shipped until at least 90 days after it is discharged from the reactor. The analysis provided by the NRC and referenced in Table S-4 assumes 150 days of decay time before shipment of any irradiated fuel assemblies (Reference 5.7-12). NUREG/CR-6703 assumes a minimum of 5 yr between removal from the reactor and shipment. NUREG-1437, Rev. 1, indicates that the NRC specifies 5 yr as the minimum cooling period when it issues certificates of compliance for casks used for shipment of power reactor fuel. Therefore, five years is considered the minimum decay time expected before shipment of irradiated fuel assemblies. In Table 3.1-2, 18.0.4, SMRs at the CRN Site would have a minimum 6-yr storage capacity, which exceeds that needed to accommodate 5-yr cooling of irradiated fuel before removal from the spent fuel pool and either transferred to onsite dry storage or transport offsite. Therefore, the requirement is met.
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