ML17356A004
| ML17356A004 | |
| Person / Time | |
|---|---|
| Site: | NuScale |
| Issue date: | 12/22/2017 |
| From: | NRC |
| To: | NRC/NRO/DNRL/LB1 |
| References | |
| Download: ML17356A004 (4) | |
Text
NuScaleDCRaisPEm Resource From: Cranston, Gregory Sent: Friday, December 22, 2017 12:53 AM To: RAI@nuscalepower.com Cc: NuScaleDCRaisPEm Resource; Lee, Samuel; Chowdhury, Prosanta; Burkhart, Lawrence; Lavera, Ronald; Markley, Anthony
Subject:
Request for Additional Information No. 312 RAI No. 9267 (12.02)
Attachments: Request for Additional Information No. 312 (eRAI No. 9267).pdf Attached please find NRC staffs request for additional information concerning review of the NuScale Design Certification Application.
Please submit your technically correct and complete response within 60 days of the date of this RAI to the NRC Document Control Desk.
The NRC Staff recognizes that NuScale has preliminarily identified that the response to the question in this RAI is likely to require greater than 60 days.
If you have any questions, please contact me.
Thank you.
Gregory Cranston, Senior Project Manager Licensing Branch 1 (NuScale)
Division of New Reactor Licensing Office of New Reactors U.S. Nuclear Regulatory Commission 301-415-0546 1
Hearing Identifier: NuScale_SMR_DC_RAI_Public Email Number: 339 Mail Envelope Properties (MWHPR09MB120081975D124B525F96086F90020)
Subject:
Request for Additional Information No. 312 RAI No. 9267 (12.02)
Sent Date: 12/22/2017 12:53:21 AM Received Date: 12/22/2017 12:53:27 AM From: Cranston, Gregory Created By: Gregory.Cranston@nrc.gov Recipients:
"NuScaleDCRaisPEm Resource" <NuScaleDCRaisPEm.Resource@nrc.gov>
Tracking Status: None "Lee, Samuel" <Samuel.Lee@nrc.gov>
Tracking Status: None "Chowdhury, Prosanta" <Prosanta.Chowdhury@nrc.gov>
Tracking Status: None "Burkhart, Lawrence" <Lawrence.Burkhart@nrc.gov>
Tracking Status: None "Lavera, Ronald" <Ronald.LaVera@nrc.gov>
Tracking Status: None "Markley, Anthony" <Anthony.Markley@nrc.gov>
Tracking Status: None "RAI@nuscalepower.com" <RAI@nuscalepower.com>
Tracking Status: None Post Office: MWHPR09MB1200.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 721 12/22/2017 12:53:27 AM Request for Additional Information No. 312 (eRAI No. 9267).pdf 115262 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:
Recipients Received:
Request for Additional Information No. 312 (eRAI No. 9267)
Issue Date: 12/22/2017 Application
Title:
NuScale Standard Design Certification 048 Operating Company: NuScale Power, LLC Docket No.52-048 Review Section: 12.02 - Radiation Sources Application Section: 12.2, 11.4 QUESTIONS 12.02-7 Regulatory Basis 10 CFR 52.47(a)(5) requires applicants to identify the kinds and quantities of radioactive materials expected to be produced in the operation and the means for controlling and limiting radiation exposures within the limits set forth in 10 CFR Part 20.
10 CFR 20.1101(b) and 10 CFR 20.1003, require the use of engineering controls to maintain exposures to radiation as far below the dose limits in 10 CFR Part 20 as is practical. The DSRS Acceptance Criteria section of NuScale DSRS 12.2, Radiation Sources, states that the applications should contain the methods, models and assumptions used as the bases for all sources described in DCD Section 12.2. The DSRS Acceptance Criteria section of DSRS 12.3-12.4, Radiation Protection Design Features, states that the areas inside the plant structures, as well as in the general plant yard, should be subdivided into radiation zones, with maximum design dose rate zones and the criteria used in selecting maximum dose rates identified.
Background
NuScale DCD Tier 2, Revision 0 DCD Section 11.4.2.5.1, Tanks, regarding Spent Resin Storage Tanks, (SRST) states that there are two permanently installed SRSTs that are provided to receive spent resins from the chemical and volume control system (CVCS) and the Pool Clean Up System (PCUS) demineralizers.
DCD Tier 2, Revision 0 subsection 12.2.1.7, Solid Radioactive Waste System, states that the assumed values used to develop the solid radioactive waste system (SRWS) source terms are listed in Table 12.2-18. NuScale DCD Tier 2, Revision 0 Table 12.2-18, Solid Radioactive Waste System Component Source Term Inputs, list the dimensions of the SRST. DCD Table 12.2-19, Solid Radioactive Waste System Component Source Terms - Radionuclide Content, lists the radionuclide inventory of the SRST. DCD Table 12.2-20: Solid Radioactive Waste System Component Source Terms - Source Strengths, provides the Spent Resin Storage (SRST) gamma emission rate in photon/s.
Based on information made available to the staff during the RPAC Chapter 12 Audit, the model of the SRST contained in the analytical package reviewed by the staff appears to be significantly different than the model described in DCD Table 12.2-18. For instance, the height of the SRST as described in DCD Table 12.2-18 is 24.56 feet, however, based on the parameters used in the analytical model, the tank height is 17.96 feet. Furthermore, the height of the resin comprising the actual source of radioactive material in the tank, is only 7.9 feet.
Key Issue 1:
The radionuclide concentrations listed in DCD subsection 12.2 are the basis of the information used to establish plant source terms. NuScale DSRS 12.2 Acceptance Criteria, states that all of the sources of radiation exposure to workers and members of the public (from contained sources) are to be identified, characterized, and considered in the design and operation of the facility. This section of the DSRS also states that unless described within other sections of the FSAR, source descriptions should include the methods, models, and assumptions used as the bases for all values provided in FSAR Section 12.2.
Question 1:
To facilitate staff understanding of the application information sufficient to make appropriate regulatory conclusions with respect to radiation exposures, the staff requests that the applicant:
x Describe the sources of radioactive material contained in the SRST, how many cubic feet from each source demineralizer and the decay period for assumed for each bed, x As necessary, revise DCD Section 12.2 information needed to describe the source contained in the tank, OR Provide the specific alternative approaches used and the associated justification.
12.02-8 The Regulatory Basis and Background are in RAI-9267 Question 30994 Key Issue 2:
The DSRS Acceptance Criteria 12.3-12.4, Radiation Protection Design Features, states that the areas inside the plant structures, as well as in the general plant yard, should be subdivided into radiation zones, with maximum design dose rate zones and the criteria used in selecting maximum dose rates identified. The source size, magnitude and configuration are elements of the model used to establish the effects of the contained sources on areas adjacent to the contained source. Because the geometry of the source described in the DCD does not appear to model the analytical method used to evaluate the radiation effects, the staff is unable to assess the validity of the radiation zone designations.
Question 2:
To facilitate staff understanding of the application information sufficient to make appropriate regulatory conclusions with respect to radiation exposures, the staff requests that the applicant:
x Explain/justify the parameters of the dose rate calculation model used to describe the SRST, x As necessary, revise DCD Section Table 12.2-18 to include this information, x As necessary, revise DCD Section 12.3-12.4 radiation zone figures, OR Provide the specific alternative approaches used and the associated justification.