ML18092B231
| ML18092B231 | |
| Person / Time | |
|---|---|
| Site: | NuScale |
| Issue date: | 04/02/2018 |
| From: | NRC |
| To: | NRC/NRO/DNRL/LB1 |
| References | |
| Download: ML18092B231 (7) | |
Text
1 NuScaleDCRaisPEm Resource From:
Chowdhury, Prosanta Sent:
Monday, April 02, 2018 2:09 PM To:
Request for Additional Information Cc:
Lee, Samuel; Cranston, Gregory; Markley, Anthony; Dudek, Michael; Lavera, Ronald; NuScaleDCRaisPEm Resource
Subject:
Request for Additional Information No. 406 eRAI No. 9303 (12.03-12.04)
Attachments:
Request for Additional Information No. 406 (eRAI No. 9303).pdf Attached please find NRC staffs request for additional information (RAI) 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.
If you have any questions, please contact me.
Thank you.
Prosanta Chowdhury, Project Manager Licensing Branch 1 (NuScale)
Division of New Reactor Licensing Office of New Reactors U.S. Nuclear Regulatory Commission 301-415-1647
Hearing Identifier:
NuScale_SMR_DC_RAI_Public Email Number:
437 Mail Envelope Properties (BN7PR09MB2609D71068042A6BEFFE64BB9EA60)
Subject:
Request for Additional Information No. 406 eRAI No. 9303 (12.03-12.04)
Sent Date:
4/2/2018 2:09:11 PM Received Date:
4/2/2018 2:09:19 PM From:
Chowdhury, Prosanta Created By:
Prosanta.Chowdhury@nrc.gov Recipients:
"Lee, Samuel" <Samuel.Lee@nrc.gov>
Tracking Status: None "Cranston, Gregory" <Gregory.Cranston@nrc.gov>
Tracking Status: None "Markley, Anthony" <Anthony.Markley@nrc.gov>
Tracking Status: None "Dudek, Michael" <Michael.Dudek@nrc.gov>
Tracking Status: None "Lavera, Ronald" <Ronald.LaVera@nrc.gov>
Tracking Status: None "NuScaleDCRaisPEm Resource" <NuScaleDCRaisPEm.Resource@nrc.gov>
Tracking Status: None "Request for Additional Information" <RAI@nuscalepower.com>
Tracking Status: None Post Office:
BN7PR09MB2609.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 551 4/2/2018 2:09:19 PM Request for Additional Information No. 406 (eRAI No. 9303).pdf 110803 Options Priority:
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Recipients Received:
Request for Additional Information No. 406 (eRAI No. 9303)
Issue Date: 04/02/2018 Application
Title:
NuScale Standard Design Certification 048 Operating Company: NuScale Power, LLC Docket No.52-048 Review Section: 12.03-12.04 - Radiation Protection Design Features Application Section: 12.3, Tier 1 3.11, Tier 1 3.12 QUESTIONS 12.03-52 Regulatory Basis 10 CFR 52.47(b)(1), requires that the application contain the Inspections, Tests, Analyses, and Acceptance Criteria (ITAAC), that are necessary and sufficient to provide reasonable assurance that, if the inspections, tests, and analyses are performed and the acceptance criteria met, a facility that incorporates the design certification (DC) has been constructed and will be operated in conformity with the DC, the provisions of the Atomic Energy Act (AEA), and NRC regulations.
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 50.34(f)(2)(xvii) requires instrumentation to measure, record and readout in the control room containment radiation intensity (high level). 10 CFR 50.34(f)(2)(vii) requires radiation and shielding design reviews of spaces around systems that may, as a result of an accident, contain accident source term quantities of radioactive material, and design as necessary to permit adequate access to important areas and to protect safety equipment from the radiation environment. 10 CFR 50.34(f)(2) (xxvii) requires monitoring of in plant radiation and airborne radioactivity as appropriate for a broad range of routine and accident conditions.
Appendix A to 10 CFR Part 50 General Design Criteria (GDC) for Nuclear Power Plants, Criterion 61Fuel storage and handling and radioactivity control, requires systems which may contain radioactivity to be designed with suitable shielding for radiation protection and with appropriate containment, confinement, and filtering systems.
GDC Criterion 60 Control of releases of radioactive materials to the environment, requires that the nuclear power unit design include means to control suitably the release of radioactive materials in gaseous and liquid effluents and to handle radioactive solid wastes produced during normal reactor operation, including anticipated operational occurrences.
GDC Criterion 4 Environmental and dynamic effects design bases, states that Structures, systems, and components (SSC) important to safety shall be designed to accommodate the effects of and to be compatible with the environmental conditions associated with normal operation, maintenance, testing, and postulated accidents, including loss-of-coolant accidents.
Appendix A to 10 CFR Part 50 states that Anticipated operational occurrences (AOO) mean those conditions of normal operation which are expected to occur one or more times during the life of the nuclear power unit.
10 CFR 20.1201 requires controlling the occupational dose to individuals to within the limits of 10 CFR Part 20. 10 CFR 20.1301 requires controlling the dose to members of the public to within the limits of 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 Acceptance Criteria of DSRS Section 12.3-12.4, Radiation Protection Design Features, contains a number of criteria related to the design of the shielding, including:
x Where the applicants shielding design incorporates material subject to degradation, such as through the effects of radiation (e.g., depletion of boron neutron absorbers),
temperature extremes (e.g., degradation of polymer based materials because of high temperature), density changes (e.g., sagging or settling of shielding material with age),
methods are in place to ensure that ORE remains ALARA, and the equipment exposures are maintained in accordance with the provisions of 10 CFR 50.49 should be specified x
The application should identify the allowable constraints (e.g., minimum cooling air flow, maximum shielding material temperature, and maximum allowable neutron flux), and how those parameters are measured and assessed over the design life of the facility.
x The area radiation monitoring systems will be acceptable if they meet the provisions of 10 CFR 20.1501, General, 10 CFR 50.34(f)(2)(xvii), the guidance in NUREG-0737 using the NuScale-specific source term, and the in-containment high-range radiation monitors meet the criteria of 10 CFR 50.34(f)(2)(xvii).
x Systems, Structures and Components (SSC) that are described in the application, should be designed to maintain radiation exposures to operating and maintenance personnel ALARA. Structures housing radioactive waste processing systems or components should be classified using the guidance for potential exposure to site personnel found in RG 1.143.
=
Background===
DCD Tier 2 Revision 0 Section 12.3.2, Shielding, describes some of the design considerations for radiation shielding, such as stating that material used for a significant portion of plant shielding is concrete.
DCD Section 12.3.2.2, Design Considerations, states that the selection of shielding materials considers the ambient environment and potential degradation mechanisms. The material used for a significant portion of plant shielding is concrete. In addition to concrete, other types of materials such as steel, water, tungsten, and polymer composites are considered for both permanent and temporary shielding. DCD Section 12.3.2.4.3, Reactor Building, states that cubicle walls are concrete supported by carbon steel plates, called structural steel partition walls.
DCD Table 12.3-6, Reactor Building Shield Wall Geometry, provides the nominal thickness of concrete for some of the walls in the RXB. DCD Table 12.3-8, Reactor Building Radiation Shield Doors, lists the shielded doors located in the RXB. DCD Table 12.3-7, Radioactive Waste Building Shield Wall Geometry, provides the nominal thickness of concrete for some of
the walls in the RWB. DCD Table 12.3-9, Radioactive Waste Building Radiation Shield Doors, list the shielded doors located in the RWB.
In a letter issued by the NRC to NuScale, NuScale Letter on Draft Standard ITAAC, and Draft Standardized DCA ITAAC Tables - Enclosure to NuScale Letter on Draft Standard ITAAC, dated April 8, 2016 (ADAMS Accession Nos. ML16096A132 and ML16097A123,) the staff described the ITAAC that are applicable to the staff review of the NuScale application. These standard ITAAC included:
x R07 As-Built Inspection and Reconciliation Analysis, to verify that the structures, systems and components of the non-Seismic Category I radioactive waste system are designed and constructed to the standards of RG 1.143 to withstand the design loads without loss of structural integrity. RG 1.143 Table 1 Codes and Standards for the Design of SSC in Radwaste Facilities, describes the design codes and standards expected to be met to demonstrate that the health and safety of members of the public and workers at the facility will be protected for the operational conditions described within RG 1.143 Table 2 Natural Phenomena and Internal/External Man-Induced Hazard Design Criteria for Safety Classification and Table 3 Design Load Combinations.
x R09 As-Built Inspection and Analysis Containment High Range Radiation Monitor -
Location, checks that either the radiation monitors were installed in the location described, and no obstructions to the view of the radiation monitor(s) were added to the design, or if the design specified a percent of the containment atmosphere free volume view for each radiation monitor, that the radiation monitors have been installed in a location and manner that provides for appropriate monitoring of the containment radiation levels following an accident.
Key Issue DCD Tier 1 Revision 0 Chapter 1 Certified Design Descriptions and Inspections, Tests, Analyses, and Acceptance Criteria (ITAAC), subsection 3.12 Radioactive Waste Building, does not contain ITAAC corresponding to R07, with respect to verifying that the SSCs containing radioactive waste were designed and constructed, consistent with the guidance contained within RG 1.143 provided for demonstrating compliance with the provisions of 10 CFR Part 20 related to the protection of the health and safety of members of the public and protection of occupational radiation workers.
Question To facilitate staff understanding of the application information sufficient to make appropriate regulatory conclusions regarding the ITAAC for ensuring that the radioactive waste SSCs have been designed and constructed in a manner that protects the health and safety of the public and the occupational workers, the staff requests that the applicant:
x Justify/explain the basis for not including an ITAAC for verifying that the radioactive waste SSCs are design and constructed in accordance with the aforementioned
- guidance, x
As necessary, revised section DCD Tier 1 Section 3.12, to describe the ITAAC for verifying that the radioactive waste SSCs are design and constructed in accordance with the aforementioned guidance, OR Provide the specific alternative approaches used and the associated justification.
12.03-53 The Regulatory Basis and Background are in Question 12.03-52 above.
Key Issue DCD Tier 1 Revision 0 Chapter 1 Certified Design Descriptions and Inspections, Tests, Analyses, and Acceptance Criteria (ITAAC), subsection 3.9 Radiation Monitoring - NuScale Power Modules 1 - 12, does not contain ITAAC corresponding to R09, with respect to verifying that the containment high range radiation monitors installed consistent with the intent of 10 CFR 50.34(f)(2)(vii).
Question To facilitate staff understanding of the application information sufficient to make appropriate regulatory conclusions regarding the adequacy of the ITAAC for the containment high range radiation monitor, the staff requests that the applicant:
x Justify/explain the basis for not including an ITAAC for the containment high range radiation monitor, x
As necessary, revised section DCD Tier 1 Section 3.9, to include the ITAAC for the containment high range radiation monitor, OR Provide the specific alternative approaches used and the associated justification.
12.03-54 The Regulatory Basis and Background are in Question 12.03-52 above.
Key Issue The Acceptance Criteria of DSRS Section 12.3-12.4, Radiation Protection Design Features, states that where the applicants shielding design incorporates material subject to degradation, such as through the effects of radiation (e.g., depletion of boron neutron absorbers),
temperature extremes (e.g., degradation of polymer based materials because of high temperature), density changes (e.g., sagging or settling of shielding material with age), methods are in place to ensure that ORE remains ALARA, and the equipment exposures are maintained in accordance with the provisions of 10 CFR 50.49 should be specified. It further states that the application should identify the allowable constraints (e.g., minimum cooling air flow, maximum shielding material temperature, and maximum allowable neutron flux), and how those parameters are measured and assessed over the design life of the facility.
DCD Section 12.3.2.2, Design Considerations, states that in addition to concrete, other types of materials such as steel, water, tungsten, and polymer composites are considered for both permanent and temporary shielding. However, DCD Tier 2 Revision 0 Section 12.3.2, Shielding, does not identify any areas of the plant shielding (e.g., penetration shielding around hot pipes,) that have limitations associated with the shielding material or for which specific
design criteria (e.g., maximum temperature, radiation resistance etc.,) are required for the integrity of the shielding to be maintained.
DCD Tier 1 Section 3.11, Reactor Building, states that the RXB includes radiation shielding barriers for normal operation and post-accident radiation shielding. It further states that DCD Tier 1 Table 3.11-2, Reactor Building Inspections, Tests, Analyses, and Acceptance Criteria, contains the inspections, tests, and analyses for the RXB. DCD Tier 1 Section 3.12, Radioactive Waste Building, states that the RWB includes radiation shielding barriers for normal operation and post-accident radiation shielding. It further states that that DCD Tier 1 Table 3.12-2: Radioactive Waste Building ITAAC contains the inspections, tests, and analyses for the RWB. However, neither DCD Tier 1 Section 3.11 nor DCD Tier 1 Section 3.12, describe ITAAC provided for verification of the design features (e.g., minimum air flow rate around hot pipes to prevent degradation of concrete, minimum spacing between hot pipes and structural components provided to prevent degradation of materials,) provided to ensure the continued integrity of the radiation shielding. Since routine tests or inspections of shielding material are not capable of assessing the degradation (e.g., dehydration of concrete due to high temperature) of the shielding material that may adversely impact its ability to perform under design basis conditions (i.e., accident or AOO source terms following design basis events, such as earth quakes,) provision and function of design features for protection of shielding are important for ensuring the continued integrity of the shielding.
Question To facilitate staff understanding of the application information sufficient to make appropriate regulatory conclusions regarding the adequacy of the design features for ensuring the continued integrity of the radiation shielding, the staff requests that the applicant:
x Justify/explain the basis for not including an ITAAC for the inspecting design features provided for protecting the integrity of radiation shielding, x
As necessary, revised section DCD Tier 1 Section 3.11 and section DCD Tier 1 Section 3.912, to include the ITAAC for inspecting design features provided for protecting the integrity of radiation shielding, OR Provide the specific alternative approaches used and the associated justification.