ML18192A158
| ML18192A158 | |
| Person / Time | |
|---|---|
| Issue date: | 07/12/2018 |
| From: | Aron Lewin NRC/NRR/DIRS/IRIB |
| To: | |
| Lewin A, NRR/DIRS, 415-2259 | |
| References | |
| Download: ML18192A158 (2) | |
Text
DRAFT Basis Summary Sheet Inspectable Area: Surveillance Testing Cornerstone(s): Mitigating Systems and Inspection Procedure: IP 71111.22 Barrier Integrity Scope: This inspection will focus on verifying that surveillance testing (including inservice testing) of risk-significant structures, systems, and components (SSCs) are capable of performing their intended safety functions and assessing their operational readiness. The inspector will review surveillance test results for adequacy in meeting the requirements, observe ongoing testing to evaluate human performance, and ensure that appropriate test acceptance criteria is in agreement with design requirements.
This inspection will also verify that testing activities provide objective evidence that FLEX SSCs remain capable of performing their intended functions and maintain their operational readiness consistent with their licensing bases.
Basis: Inspection of this area ensures that safety systems are capable of performing their safety function and support the Mitigating Systems and Barrier Integrity Cornerstones. The failure to identify and resolve performance degradation of structures, systems and components, could result in long periods of unknown equipment unavailability. This inspection procedure verifies aspects of the associated cornerstones not measured by performance indicators.
Surveillance testing including inservice testing of pumps and valves are required to verify that systems and components are reliable and functionally capable of performing their design function. Inspection will review the adequacy of test procedures to test those design functions being verified. Important design functions not verified by testing will be subject to risk informed design inspection. Surveillance testing is the minimum required testing specified in the facility license and ensures that a conservative safety margin exists for system capability. Operating experience has shown that test procedure deficiencies may invalidate previously acceptable test results and improper testing could result in undisclosed problems that last until the next required testing creating long periods of unknown equipment inoperability.
After Fukushima, the NRC ordered every U.S. commercial reactor to have mitigation strategies for dealing with the long-term loss of normal safety systems following the occurrence of a beyond-design-basis external event (NRC Order EA-12-049, ML12054A735). FLEX increases defense-in-depth for beyond-design-basis scenarios to address loss of power and loss of the ultimate heat sink occurring simultaneously at all units on a site.
Performance Indicators: The PIs indirectly verify the adequacy of required surveillance test activities. This inspection is performed to provide insights into licensee performance in addition to those provided by the PIs.
Significant Changes in Scope or Basis:
April 2000 - Procedure incorporated requirements and guidance to review licensees inservice testing activities, containment isolation valve and ice condenser system surveillances.
January 2002 - Revised to incorporated minor changes to the inspection requirements. In Issue Date: To be included in next IMC 0308 Attachment 2 revision (no later than Spring 2019)
DRAFT Basis Summary Sheet Inspectable Area: Surveillance Testing addition, inspection resources estimates and inspection level of effort are revised to provide a band for more inspection flexibility.
May 2004 - Revised to include RCS leak detection system surveillance as part of the surveillance testing sample. Revision also includes surveillance testing attributes for reviewing annunciators/alarms setpoints and alarms response procedure actions.
Month 2018 - Revised to allow for oversight of FLEX testing, and as a minimum, require one inspection sample per year.
Figure 22 Surveillance Testing Basis Summary Sheet (IP 71111.22)
Issue Date: To be included in next IMC 0308 Attachment 2 revision (no later than Spring 2019)