ML18288A257
| ML18288A257 | |
| Person / Time | |
|---|---|
| Site: | NuScale |
| Issue date: | 10/15/2018 |
| From: | NRC |
| To: | NRC/NRO/DLSE/LB1 |
| References | |
| Download: ML18288A257 (4) | |
Text
NuScaleDCRaisPEm Resource From: Cranston, Gregory Sent: Monday, October 15, 2018 12:46 PM To: Request for Additional Information Cc: Lee, Samuel; Scheetz, Maurin; Tabatabai, Omid; Chowdhury, Prosanta; NuScaleDCRaisPEm Resource; Bowman, Gregory
Subject:
Request for Additional Information No. 505 eRAI No. 9612 (14.3.9)
Attachments: Request for Additional Information No. 505 (eRAI No. 9612).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.
1
Hearing Identifier: NuScale_SMR_DC_RAI_Public Email Number: 544 Mail Envelope Properties (BN1PR09MB0258E9C193260F61095B4DC590FD0)
Subject:
Request for Additional Information No. 505 eRAI No. 9612 (14.3.9)
Sent Date: 10/15/2018 12:45:50 PM Received Date: 10/15/2018 12:46:04 PM From: Cranston, Gregory Created By: Gregory.Cranston@nrc.gov Recipients:
"Lee, Samuel" <Samuel.Lee@nrc.gov>
Tracking Status: None "Scheetz, Maurin" <Maurin.Scheetz@nrc.gov>
Tracking Status: None "Tabatabai, Omid" <Omid.Tabatabai-Yazdi@nrc.gov>
Tracking Status: None "Chowdhury, Prosanta" <Prosanta.Chowdhury@nrc.gov>
Tracking Status: None "NuScaleDCRaisPEm Resource" <NuScaleDCRaisPEm.Resource@nrc.gov>
Tracking Status: None "Bowman, Gregory" <Gregory.Bowman@nrc.gov>
Tracking Status: None "Request for Additional Information" <RAI@nuscalepower.com>
Tracking Status: None Post Office: BN1PR09MB0258.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 369 10/15/2018 12:46:04 PM Request for Additional Information No. 505 (eRAI No. 9612).pdf 83775 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:
Recipients Received:
Request for Additional Information No. 505 (eRAI No. 9612)
Issue Date: 10/15/2018 Application
Title:
NuScale Standard Design Certification 048 Operating Company: NuScale Power, LLC Docket No.52-048 Review Section: 14.03.09 - Human Factors Engineering - Inspections, Tests, Analyses, and Acceptance Criteria Application Section: 14.3.9 QUESTIONS 14.03.09-5 This is a follow-up RAI to RAI 9412 (ADAMS Accession Number ML18219D571) regarding Remote Shutdown Station (RSS) ITAAC, which is currently unresolved-closed.
Title 10 of the Code of Federal Regulations (CFR) Part 50, Appendix A, "General Design Criteria for Nuclear Power Plants," Criterion 19, "Control Room," (GDC 19) requires, in part, that equipment is provided at appropriate locations outside the control room (1) with a design capability for prompt hot shutdown of the reactor, including necessary instrumentation and controls to maintain the unit in a safe condition during hot shutdown, and (2) with a potential capability for subsequent cold shutdown of the reactor through the use of suitable procedures. 10 CFR 52.47(b)(1) requires a design certification application to contain the proposed 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 plant that incorporates the design certification is built and should operate in accordance with the design certification, the provisions of the Atomic Energy Act, and the NRC's regulations.
NuScale DCD Tier 2, Section 1.2.2.1, "Main Control Room," states that in the event that the Main Control Room (MCR) becomes uninhabitable, a remote shutdown station in the Reactor Building provides a secondary location for safe shutdown of the reactors. NuScale DCD Tier 2, Section 7.1.1.1, "Design Bases," states that consistent with GDC 19, the equipment within the remote shutdown station provides the controls necessary to place each NuScale Power Module (NPM) in a hot shutdown condition, maintain each NPM in a safe condition during hot shutdown, and to bring each NPM to cold shutdown. NuScale DCD Tier 1, Table 2.5-7, "Module Protection System and Safety Display and Indication System ITAAC," identifies the displays, alarms, and controls that NuScale has selected to be verified by ITAAC. However, DCD Tier 1, Table 2.5-7 does not contain ITAAC to verify any displays, controls or alarms in the RSS.
The staff issued RAI 9412 to understand why the applicant did not include ITAAC to verify any displays, controls or alarms in the RSS. In response to RAI 9412 (ADAMS Accession Number ML18172A320), the applicant explained that there are no ITAAC for RSS HSI displays, alarms and controls for the following reasons:
x There are no safety-related controls at the RSS.
x There are no important human actions performed at the RSS.
x The RSS contains Module Control System and Plant Control System displays and controls identical to those in the main control room.
x During a main control room evacuation, the operators are expected to trip the reactors and initiate decay heat removal and containment isolation for each reactor prior to exiting the main control room.
The staff does not find this explanation to be an adequate justification for excluding ITAAC to verify the remote shutdown capabilities required by GDC 19. The NRC staff understands the design of the main control room and the RSS and the actions required by operators to place the NPMs into a hot shutdown condition. However, GDC 19 requires equipment outside the control room that will place the NPMs into hot shutdown, maintain the NPMs in hot shutdown, and have the potential capability of subsequent cold shutdown of the NPMs through the use of suitable procedures. The NuScale DCD Tier 2 describes the RSS as meeting the above requirements of GDC 19. However, the NuScale DCD Tier 1 does not contain ITAAC to verify the displays, alarms, and controls in the RSS that are used to meet GDC 19 are built and can be operated as designed. The NRC staff requests that NuScale provide the ITAAC for the verification of displays, alarms and controls in the RSS that are used to meet the requirements of GDC 19 and provide reasonable assurance that operators can use the RSS to shut down the plant in an event where the main control room is unavailable or if the operators could not shut down all units and take other required actions prior to evacuating the main control room.
Additionally, the staff is seeking this information to better understand the redundant means of shutting down the plant in the event that the main control room becomes uninhabitable. The RAI 9412 response assumes that these actions can be completed prior to evacuation, but no evidence has been provided to support that claim. The NRC staff is concerned that in the event that a control room evacuation is necessary, the operators may not be able to successfully complete all the tasks necessary to shut down the plant without a redundant means of doing so that is spatially separate from the main control room. As a result, the NRC staff requests NuScale to identify any necessary updates to the application regarding how the NuScale design satisfies the remote shutdown capabilities required by GDC 19.