ML091470432

Request for Additional Information Regarding TSTF-514 on Reactor Coolant System Leakage Detection

ML091470432
Person / Time
Site:	Technical Specifications Task Force
Issue date:	06/11/2009
From:	Williams J NRC/NRR/DPR/PSPB
To:	Technical Specifications Task Force
Williams J, NRR/DPR, 415-1470
References
TAC ME0989, TSTF-514
Download: ML091470432 (5)

Text

June 11, 2009 Technical Specification Task Force 11921 Rockville Pike, Suite 100 Rockville, MD 20852

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION REGARDING TSTF-514 ON REACTOR COOLANT SYSTEM (RCS) LEAKAGE DETECTION (TAC NO.

ME0989)

Dear Members:

By letter dated February 18, 2009, the Technical Specifications Task Force (TSTF) submitted TSTF-514, Revision 0, "Revise BWR Operability Requirements and Actions for RCS Leakage Instrumentation" for NRC review. The staff has determined that additional information is needed to complete the review. Enclosure 1 is the NRC staffs request for additional information. Please contact me at (301)415-1470 or by electronic mail at joseph.williams@nrc.gov if you have any questions on this topic.

Sincerely,

/RA/

Joseph F. Williams, Senior Project Manager Special Projects Branch Division of Policy and Rulemaking Office of Nuclear Reactor Regulation

Enclosure:

Request for Additional Information cc: See next page

ML091470432 NRR-106 OFFICE PSPB:PM PSPB:PM PSPB: LA PSPB:BC NAME RSubbaratnam JWilliams DBaxley SRosenberg (CMH For)

DATE 06/10/09 06/10/09 06/10/09 06/11/09 Technical Specifications Task Force Mailing List cc:

Technical Specifications Task Force Brian Mann 11921 Rockville Pike EXCEL Services Corporation Suite 100 11921 Rockville Pike, Suite 100 Rockville, MD 20852 Rockville, MD 20852 Attention: Donald Hoffman Telephone: 301-984-4400 Telephone: 301-984-4400 E-mail: brianm@excelservices.com E-mail: donaldh@excelservices.com Kenneth Schrader Diablo Canyon Power Plant Building 104/5/21A P.O. Box 56 Avila Beach, CA 93424 Telephone: 805-545-4328 E-mail: kjse@pge.com John Messina First Energy Nuclear Operating Company 76 South Main Street Mail Stop: Akron-GO-14 Akron, OH 44308 Telephone: 330-384-5878 E-mail: jmessina@firstenergycorp.com Thomas Raidy Southern California Edison Mail Stop D-3-E P.O. Box 128 San Clemente, CA 92672 Telephone: (949) 368-7582 E-mail: Tom.Raidy@sce.com Reene' V. Gambrell Duke Energy Mailcode: ON03RC 7800 Rochester Highway Seneca, SC 29672 Telephone: 864-885-3364 E-mail: RVGambrell@duke-energy.com

U.S. NUCLEAR REGULATORY COMMISSION OFFICE OF NUCLEAR REACTOR REGULATION REQUEST FOR ADDITIONAL INFORMATION REGARDING TSTF-514 ON REACTOR COOLANT SYSTEM LEAKAGE DETECTION The proposed change to the boiling water reactor (BWR) Improved Standard Technical Specification (ISTS) for reactor coolant system (RCS) leakage detection instrumentation revises the Bases to more clearly define the RCS leakage detection instrumentation operability requirements, modifies the actions to be taken when the containment atmosphere gaseous radioactivity monitor is the only operable monitor, and modifies the actions taken when there are no operable RCS leakage detection monitors. However, the staff determined that the following additional information is necessary to more clearly define the attributes of an operable RCS leakage detection system and the necessary actions under certain conditions:

1) As described in Section 4.0 of the ISTS Change Traveler, Technical Analysis, RCS leakage monitoring instrumentation is typically set to provide the most sensitive response without distracting the reactor operators with unnecessary alarms. This capability is consistent with the discussion in Section B of Regulatory Guide 1.45, Rev.

0, which states that it is essential that leakage detection systems have the capability to detect significant reactor coolant pressure boundary degradation as soon after occurrence as practical to minimize the potential for a gross boundary failure.

Information regarding monitoring instrumentation alarm setpoint establishment, particularly for the containment gaseous and particulate monitors, is often described in the safety analysis report or other licensing basis document. However, the proposed limiting condition for operation (LCO) Bases information does not include a provision to describe plant-specific RCS leakage alarm setpoint establishment information. Please provide revised LCO Bases that include provisions for this plant-specific information or justify its exclusion.

2) Surveillance Requirement (SR) 3.4.4.1 and SR 3.4.5.1 of NUREG-1433 and NUREG-1434, respectively, require that operators verify RCS unidentified leakage and total leakage [and unidentified leakage increase] are within limits on a frequency of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. The associated bases indicate that sump level and flow rate would typically be used to determine actual leakage rates. However, the bases also state that any method within the guidelines of Regulatory Guide 1.45, Rev. 0, may be used to quantify leakage.

Alternative Staff Position 3 of Supplement 1 to NRC Generic Letter (GL) 88-01, "NRC Position on IGSCC [Intergranular Stress Corrosion Cracking] in BWR Austenitic Stainless Steel Piping," describes that manual pumping of the containment sump or measurement of the differences in sump level over time may be used to quantify RCS leakage rate when the sump monitoring instrumentation is inoperable.

Proposed Condition F would require obtaining and analyzing a grab sample of the primary containment (BWR/4) or drywell (BWR/6) atmosphere, monitoring RCS leakage using administrative means every 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and restoring at least one RCS leakage detection monitor to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />; otherwise, a plant shutdown would ENCLOSURE

be required. From the proposed bases, it is not clear that the proposed required actions would reasonably quantify RCS leakage. The precedent amendment (ADAMS Accession No.: ML082261529) cited in Section 4.0 of TSTF-514 required performance of a specific surveillance at an increased frequency to quantify RCS leakage when all leakage monitoring systems were inoperable. This surveillance used instruments that were independent of the inoperable leakage monitoring systems. Accordingly, please revise the required actions for proposed Condition F to specify performance of a method to quantify RCS leakage at an increased frequency that would demonstrate RCS unidentified leakage and total leakage [and unidentified leakage increase] are within limits during the period that all automatic RCS leakage monitoring systems are inoperable.

3) In part, the LCO section of the proposed bases states:

The drywell floor drain sump monitoring system is required to quantify the unidentified LEAKAGE from the RCS. Thus, for the system to be considered OPERABLE, either the flow monitoring or the sump level monitoring portion of the system must be OPERABLE.

This statement does not clearly indicate the required capabilities for the drywell floor drain sump monitoring system to quantify the leakage rate. Clarify the statement to indicate that both a means of quantifying the volume of leakage and a means of determining the time for the volume to accumulate in the sump must be available for the monitoring system to be operable.