ML113220164

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TSTF Presentation Revision to TSTF-523
ML113220164
Person / Time
Site: Technical Specifications Task Force
Issue date: 11/17/2011
From:
NRC/NRR/DPR/PSPB
To:
References
TSTF-523
Download: ML113220164 (10)
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11/17/2011 Technical Specifications Task Force TSTF A Joint Owners Group Activity TSTF P Proposall tto Revise R i TSTF523, TSTF 523 "Generic Letter 200801, Managing Gas Accumulation" 1

Technical Specifications Task Force TSTF A Joint Owners Group Activity August 4, 2011 TSTF/NRC Public Meeting At the August 4, 2011 TSTF/NRC public meeting on TSTF 523 the TSTF proposed a revision to TSTF TSTF523, TSTF523 523 that would:

  • Revise the existing SRs to state:

- "Verify [system] locations susceptible to gas accumulation are sufficiently filled with water."

  • Add similar SRs to the other systems addressed in GL 200801 (ECCS, Containment Spray, and DHR) that do not currently have a "full of water" SR.

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11/17/2011 Technical Specifications Task Force TSTF A Joint Owners Group Activity August 4, 2011 TSTF/NRC Public Meeting

- For plants without an SFCP, the Frequency would be 31 days.

- For plants with an SFCP, the initial Frequency would be 31 days, subject to change under the SFCP.

  • The Bases of the Surveillance would acknowledge g that different locations in the system could have different performance Frequencies under the SFCP.

3 Technical Specifications Task Force TSTF A Joint Owners Group Activity August 4, 2011 TSTF/NRC Public Meeting

  • The Bases of the Surveillances would discuss acceptable methods of identifying locations susceptible to gas accumulation, gas volume acceptance criteria, and acceptable methods for performing the SR.
  • The LCO Bases of the systems within the scope of GL 2008 200801 01 would be revised to state that management of gas voids is important to system OPERABILITY.

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11/17/2011 Technical Specifications Task Force TSTF A Joint Owners Group Activity TSTF523 Will Not Reference NEI 0910

  • At the August 4 meeting, the TSTF left open the possibility that TSTF TSTF523 523 might reference NEI 0910. 09 10
  • Subsequently, the NEI Gas Accumulation Team determined that TSTF523 should not reference NEI 0910.

- This was stated in the NEI response to the NRC's RAI on NEI 09 0910.

10.

  • However, information consistent with statements in NEI 0910 are included in the proposed Bases.

5 Technical Specifications Task Force TSTF A Joint Owners Group Activity Draft Revision

  • The TSTF has prepared a draft Traveler revision for discussion that includes the affected LCOs for NUREG1431 (Westinghouse plants) and NUREG1433 (BWR/4 plants). These changes are representative of the other plant types.
  • A single Bases revision has been prepared. This is representative of the Bases changes for the other NUREGs.
  • The handout includes representative language for the Surveillances and their Bases.

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11/17/2011 Technical Specifications Task Force TSTF A Joint Owners Group Activity Draft Revision The following LCOs are affected:

W ti h Westinghouse Pl Plantst

  • 3.4.6 RCS Loops MODE 4 (New SR)
  • 3.4.7 RCS Loops MODE 5, Loops Filled (New SR)
  • 3.4.8 RCS Loops MODE 5, Loops Not Filled (New SR)
  • 3.5.2 ECCS Operating (Revised SR)
  • 3.9.6 Residual Heat Removal (RHR) and Coolant Circulation Low Water Level (New SR) 7 Technical Specifications Task Force TSTF A Joint Owners Group Activity Draft Revision BWR/4 Plants
  • 3.5.1 ECCS Operating (Revised SR)
  • 3.5.2 ECCS Shutdown (Revised SR)
  • 3.5.3 RCIC System (Revised SR)

11/17/2011 Technical Specifications Task Force TSTF A Joint Owners Group Activity Draft Revision 9

Technical Specifications Task Force TSTF A Joint Owners Group Activity Draft Revision

  • Examining the SR wording:

- "Verify Verify [system] locations susceptible to gas accumulation are sufficiently filled with water"

  • In order to allow the SR to be met when the system is Operable, the wording "sufficiently filled with water" was chosen instead of "full of water" or "within limits."
  • This recognizes that not all portions of a system may have pre established Operability limits on accumulated gas (i.e., the procedural limit may be zero)
  • An Operability evaluation can be performed to determine that the Surveillance is met if the preestablished acceptance criteria is exceeded.

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11/17/2011 Technical Specifications Task Force TSTF A Joint Owners Group Activity Draft Revision

  • Examining the SR wording:

- The phrase "locations locations susceptible to gas accumulation" accumulation was chosen so that portions of the system known to not be susceptible to gas accumulation do not need to be verified.

11 Technical Specifications Task Force TSTF A Joint Owners Group Activity Draft Revision

  • The LCO Bases for ECCS, Containment Spray, and DHR will be revised to state "Management of gas voids is important to [system]

OPERABILITY."

- In the STS, the LCO Bases define what is required for system Operability. This statement, in conjunction with the SR, makes clear that gas accumulation can render a system inoperable.

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11/17/2011 Technical Specifications Task Force TSTF A Joint Owners Group Activity Draft Revision

  • SR Bases

- Introductory paragraph on the purpose of the SR:

"[System] piping and components have the potential to develop voids and pockets of entrained gases. Preventing and managing gas intrusion and accumulation is necessary for proper operation of the [system] and may also prevent water hammer, pump cavitation, and pumping of noncondensible gas (e.g.,

(e g air, air nitrogen, nitrogen or hydrogen) into the reactor vessel."

13 Technical Specifications Task Force TSTF A Joint Owners Group Activity Draft Revision

  • Selection of Locations Susceptible to Gas Accumulation (very similar to NEI 0910): 09 10):

"Selection of [system] locations susceptible to gas accumulation is based on a review of system design information, including piping and instrumentation drawings, isometric drawings, plan and elevation drawings, and calculations. The design review is supplemented by system walk downs to validate the system high points and to confirm the location and orientation of important components that can become sources of gas or could otherwise cause gas to be trapped or difficult to remove during system maintenance or restoration."

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11/17/2011 Technical Specifications Task Force TSTF A Joint Owners Group Activity Draft Revision

  • Discussion of Acceptance Criteria:

"The The [system] must be sufficiently filled with water in order to be OPERABLE. Acceptance criteria are established for the volume of accumulated gas at susceptible locations. If accumulated gas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gas at one or more susceptible locations exceeds an acceptance criteria for gas volume at the suction or discharge of a pump), the Surveillance is not met met. If it is determined by subsequent evaluation that the

[system] is not rendered inoperable by the accumulated gas (i.e.,

the system is sufficiently full of water), the Surveillance may be declared met. Accumulated gas should be eliminated or brought within the acceptance criteria limits."

15 Technical Specifications Task Force TSTF A Joint Owners Group Activity Draft Revision

  • Discussion of Monitoring (very similar to NEI 0910):

[System]

[System] locations susceptible to gas accumulation are monitored and, if gas is found, the gas volume is compared to the acceptance criteria for the location. Susceptible locations in the same system flow path which are subject to the same gas intrusion mechanisms may be verified by monitoring a representative subset of susceptible locations. Monitoring may not be practical for locations that are inaccessible due to radiological or environmental conditions the plant configuration, conditions, configuration or personnel safety.

safety For these locations alternative methods (e.g., operating parameters, remote monitoring) may be used to monitor the susceptible location. "

(continued on next slide) 16 8

11/17/2011 Technical Specifications Task Force TSTF A Joint Owners Group Activity Draft Revision

  • Discussion of Monitoring (very similar to NEI 0910):

"Monitoring Monitoring is not required for susceptible locations where the maximum potential accumulated gas void volume has been evaluated and determined to not challenge system OPERABILITY.

The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY during the Surveillance interval. "

17 Technical Specifications Task Force TSTF A Joint Owners Group Activity Draft Revision

  • Discussion of Frequency:

For plants without a Surveillance Frequency Control Program:

"The 31 day Frequency takes into consideration the gradual nature of gas accumulation in the [system] piping and the procedural controls governing system operation."

For plants with a Surveillance Frequency Control Program:

"The Surveillance Frequency is controlled under the Surveillance ill Frequency Controll Program. The h Surveillance ill Frequency may vary by location susceptible to gas accumulation."

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11/17/2011 Technical Specifications Task Force TSTF A Joint Owners Group Activity Schedule

  • The TSTF will create a revision to TSTF523 for industry review and submittal to the NRC NRC.
  • The Traveler should be submitted in March 2012.

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