ML072950275
| ML072950275 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 10/24/2007 |
| From: | Michael Scott NRC/NRR/ADES/DSS/SSIB |
| To: | Chernoff H NRC/NRR/ADRO/DORL/LPLI-2 |
| Whitney L, NRR/DSS/SSIB, 415-3081 | |
| References | |
| GL-04-002, TAC MC4712, TAC MC4713 | |
| Download: ML072950275 (6) | |
Text
October 24, 2007 MEMORANDUM TO: Harold Chernoff, Chief, Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation FROM:
Michael L. Scott, Chief
/RA/
Safety Issue Resolution Branch Division of Safety Systems Office of Nuclear Reactor Regulation
SUBJECT:
SALEM UNITS 1 AND 2 DRAFT OPEN ITEMS FROM STAFF AUDIT OF CORRECTIVE ACTIONS TO ADDRESS GENERIC LETTER 2004-02 (TAC NOS. MC4712 AND MC4713)
Generic Letter (GL) 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors" (GL 2004-02), requested that all pressurized-water reactor (PWR) licensees (1) evaluate the adequacy of the emergency sump recirculation function with respect to potentially adverse effects associated with post-accident debris, and (2) implement any plant modifications determined to be necessary. PSEG Nuclear LLC (PSEG), the licensee, has conducted an evaluation of recirculation sump performance for the Salem Nuclear Generating Stations Unit No. 1 and Unit No. 2, and is conducting significant modifications, including installation of new recirculation sump strainers.
The staff conducted a detailed audit of the new sump design and associated analyses, evaluations, testing and modifications for Salem Unit 1 and Unit 2 the week of October 1, 2007. This audit was an in-process "snapshot" of PSEGs GL 2004-02 corrective actions, which are to be completed by December 31, 2007. This is one of several audits to be conducted over an approximate two-year period to establish a sample basis to assist in verifying the adequacy of PWR licensee corrective actions to address GL 2004-02.
This memorandum transmits the draft open items from the audit. These draft open items are subject to change as the audit report is developed, finalized and issued. Please note that the audit report will contain no conclusion as to the overall adequacy of PSEG GL 2004-02 corrective actions. That conclusion will be reached when the licensees final CONTACT:
Leon Whitney, DSS/ SSIB (301) 415-3081 Joe Golla, PGCB/DPR (301) 415-1002 GL 2004-02 response (expected by December 31, 2007) is reviewed. That response will address the audit report open items and generic requests for additional information issued to the licensee in 2006. Further, PSEG will describe the finalized GL 2004-02 corrective actions for Salem Unit 1 and Unit 2, and in doing so may follow the format of the NRCs Content Guide for Generic Letter 2004-02 Supplemental Responses dated August 15, 2007 (ADAMS Accession No. ML071060091).
Docket No:
50-272, 50-311
Enclosure:
As stated
Docket No:
50-272, 50-311
Enclosure:
As stated DISTRIBUTION: SSIB R/F JGolla ADAMS Accession Number: ML072950275 NRR-106 OFFICE NRR/DSS/SSIB NRR/DSS/SSIB:BC NAME LWhitney MScott DATE 10/23/07 10/24/07
DRAFT OPEN ITEMS FOR OCTOBER 2007 AUDIT OF SALEM UNT I 1 AND UNIT 2 CORRECTIVE ACTIONS FOR GENERIC LETTER 2004-02 (TAC NOS. MC4712 AND MC4713).
October ##, 2007 Open Item: Aluminum Paint The licensees chemical effects analysis does not address the presence of large amounts of aluminum paint on the Unit 2 steam generators. The licensee should address this material in its evaluations and/or testing.
Open Item:
Chemical Effects Resolution Because plant-specific chemical effects evaluations were in progress at the time of the onsite audit, chemical effects resolution in general was designated as an open item.
The licensee needs to complete plant-specific chemical effects evaluations and integrated head loss tests.
Open Item:
Downstream Effects for Components and Systems Incomplete The downstream effects analysis for components and systems was in progress but incomplete. Examples of specific items which were incomplete were evaluation of the charging pump start/stop operations and charging system evaluation, validation of safety injection pump and charging pump mission times, and general validation of critical inputs to the downstream effects analyses. The licensee needs to complete the analysis for downstream effects for components and systems.
Open Item:
Downstream Effects for Fuel and Vessel The licensee analysis of downstream effects for the fuel and vessel was in draft and will be re-evaluated in accordance with WCAP 16793 Evaluation of Long-term Cooling Considering Particulate, Fibrous and Chemical Debris in the Recirculating Fluid, Revision 0. The licensee needs to complete the analysis for downstream effects for the fuel and vessel.
Open Item:
Use of an 8 Pipe Diameter (8D) Zone of Influence (ZOI) for Steel Jacketed Nukon The licensee used an 8D ZOI for steel jacketed Nukon fibrous insulation based on a Westinghouse (WCAP) test report which the licensee did not possess and therefore was unavailable for audit team review. The licensee needs to provide the NRC an opportunity to review this test report.
Open item:
Preparation of Fibrous Debris for Head Loss Tests Not Prototypical In the head loss tests conducted by the licensee before the onsite audit week, the fibrous debris was prepared in such a significantly coarse manner that a major fraction of it settled in front of the test strainers and loaded the strainer test pockets in a gravitationally-skewed manner. However, licensee documentation showed that the fibrous debris accumulating on the sump strainer would consist mainly of readily transported suspended and generally independent fibers. Therefore, the preparation of fibrous debris for the head loss tests was not prototypical and, as a result, tended to preclude the formation of a fibrous debris thin bed in the test strainers. The licensees conclusion that a thin bed would not form on the sump strainer may therefore be in error.
The licensee should evaluate this issue for its impact on plant testing.
Open Item:
Certain Water Holdup Calculation Omitted from Latest Revision to the Minimum Sump Water Level Calculation The technical evaluation for steam generator nozzle break loss-of-coolant accidents (LOCAs) capable of filling the lower refueling cavity by blocking the drain line with debris and preventing the lower refueling cavity from draining (and thereby decreasing sump water volume) was omitted from the licensees latest revision to the minimum sump water level calculation. This evaluation explained that although significant from a hold-up perspective, LOCAs from this set of breaks are mutually exclusive from, and less severe than, reactor vessel nozzle breaks that directly fill the reactor pit but have no potential to block the lower refueling cavity drain line nor fill the lower refueling cavity.
The licensee should revise the latest minimum sump water level calculation to include the previous technical evaluation from an earlier version of the minimum sump water level calculation.
Open Item:
Final Chemical and Non-chemical Integrated Head Loss Testing Not Performed The licensee needs to perform the final chemical and non-chemical head loss testing and then calculate strainer head loss. Net-positive suction head (NPSH) margin for the emergency core cooling systems (ECCS) pumps can then be calculated.
Open Item:
Licensee NPSH Calculations Credit Containment Partial Air Pressure Without an Approved License Amendment Request (LAR)
Licensee calculations include credit for the contribution of partial containment air pressure to NPSH, but the NRC has not yet approved the licensees LAR requesting approval for this credit. The licensee needs to receive the NRC-approved LAR or remove the credit for air pressure-difference contribution to NPSH.
Open Item:
Spray Droplet Water Holdup Calculation Omitted from Latest Revision to the Minimum Sump Water Level Calculation The technical evaluation for the spray droplet holdup mechanism was omitted from the licensees latest revision to the minimum sump water level calculation. The licensee needs to revise the minimum sump water level calculation to include the technical evaluation of spray droplet holdup in the containment atmosphere.
Open Item:
Inadequate Technical Basis for Maximum Flow Rates for RHR Pumps The licensee needs to develop an adequate technical basis for the maximum flow rates for the RHR pumps for cold leg and hot leg injection, and spray operation in limiting single-pump operation.