ML070810243
| ML070810243 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 04/04/2007 |
| From: | Chandu Patel NRC/NRR/ADRO/DORL/LPLII-2 |
| To: | Walt T Carolina Power & Light Co |
| Patel C, NRR/DORL/LPL2-2, 415-3025 | |
| Shared Package | |
| ML070810258 | List: |
| References | |
| TAC MD2180 | |
| Download: ML070810243 (13) | |
Text
April 4, 2007 Mr. Thomas D. Walt, Vice President Carolina Power & Light Company H. B. Robinson Steam Electric Plant Unit No. 2 3581 West Entrance Road Hartsville, South Carolina 29550
SUBJECT:
H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT NO. 2 ISSUANCE OF AN AMENDMENT ON TECHNICAL SPECIFICATIONS CHANGES TO SECTION 3.5.2 (TAC NO. MD2180 )
Dear Mr. Walt:
The Nuclear Regulatory Commission has issued the enclosed Amendment No. 213 to Renewed Facility Operating License No. DPR-23 for the H. B. Robinson Steam Electric Plant, Unit No. 2 (HBRSEP2). This amendment changes the HBRSEP2 Technical Specifications (TS) in response to your application dated June 1, 2006, as supplemented by letters dated November 20, 2006, and February 22, 2007.
The amendment revises Surveillance Requirement (SR) 3.5.2.6 in HBRSEP2 TS.
A copy of the related Safety Evaluation is enclosed. Notice of Issuance will be included in the Commission's biweekly Federal Register notice.
Sincerely,
/RA/
Chandu P. Patel, Project Manager Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-261
Enclosures:
- 1. Amendment No. 213 to DPR-23
- 2. Safety Evaluation cc w/encls: See next page
Mr. T. D. Walt H. B. Robinson Steam Electric Plant, Carolina Power & Light Company Unit No. 2 cc:
Mr. David T. Conley Associate General Counsel II - Legal Department Progress Energy Service Company, LLC Post Office Box 1551 Raleigh, North Carolina 27602-1551 Ms. Margaret A. Force Assistant Attorney General State of North Carolina Post Office Box 629 Raleigh, North Carolina 27602 U. S. Nuclear Regulatory Commission Resident Inspectors Office H. B. Robinson Steam Electric Plant 2112 Old Camden Road Hartsville, South Carolina 29550 Mr. Ernest J. Kapopoulos, Jr.
Plant General Manager H. B. Robinson Steam Electric Plant, Unit No. 2 Carolina Power & Light Company 3581 West Entrance Road Hartsville, South Carolina 29550 Mr. William G. Noll Director of Site Operations H. B. Robinson Steam Electric Plant, Unit No. 2 Carolina Power & Light Company 3581 West Entrance Road Hartsville, South Carolina 29550 Public Service Commission State of South Carolina Post Office Drawer 11649 Columbia, South Carolina 29211 Mr. J. F. Lucas Manager - Support Services - Nuclear H. B. Robinson Steam Electric Plant, Unit No. 2 Carolina Power & Light Company 3581 West Entrance Road Hartsville, South Carolina 29550 Mr. C. T. Baucom Supervisor, Licensing/Regulatory Programs H. B. Robinson Steam Electric Plant, Unit No. 2 Carolina Power & Light Company 3581 West Entrance Road Hartsville, South Carolina 29550 Ms. Beverly Hall, Section Chief N.C. Department of Environment and Natural Resources Division of Radiation Protection 3825 Barrett Dr.
Raleigh, North Carolina 27609-7721 Mr. Robert P. Gruber Executive Director Public Staff - NCUC 4326 Mail Service Center Raleigh, North Carolina 27699-4326 Mr. Henry H. Porter, Assistant Director South Carolina Department of Health Bureau of Land & Waste Management 2600 Bull Street Columbia, South Carolina 29201 Mr. J. Paul Fulford Manager, Performance Evaluation and Regulatory Affairs PEB 5 Carolina Power & Light Company Post Office Box 1551 Raleigh, North Carolina 27602-1551 Mr. John H. ONeill, Jr.
Shaw, Pittman, Potts, & Trowbridge 2300 N Street NW.
Washington, DC 20037-1128
ML070810243 Package: ML070810258 TS: ML070990023 OFFICE LPL2-2/PM LPL2-2/LA SSIB/BC EMCB/BC OGC LPL2-2/BC NAME CPatel CSola MScott (By memo dated)
KManoly SHamrick TBoyce DATE 3/26/07 3/26/07 12/07/06 3/26/07 4/2/07 4/4/07
CAROLINA POWER & LIGHT COMPANY DOCKET NO. 50-261 H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT NO. 2 AMENDMENT TO RENEWED FACILITY OPERATING LICENSE Amendment No. 213 Renewed License No. DPR-23 1.
The Nuclear Regulatory Commission (the Commission) has found that:
A.
The application for amendment by Carolina Power & Light Company (the licensee), dated June 1, 2006, as supplemented by letters dated November 20, 2006, and February 22, 2007, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commission's rules and regulations set forth in 10 CFR Chapter I; B.
The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C.
There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commission's regulations; D.
The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E.
The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.
2.
Accordingly, the license is amended by changes to the Technical Specifications, as indicated in the attachment to this license amendment; and paragraph 3.B. of Renewed Facility Operating License No. DPR-23 is hereby amended to read as follows:
B. Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 213, are hereby incorporated in the license. Carolina Power &
Light Company shall operate the facility in accordance with the Technical Specifications.
3.
This license amendment is effective as of the date of its issuance and shall be implemented within 60 days.
FOR THE NUCLEAR REGULATORY COMMISSION
/RA/
Thomas H. Boyce, Chief Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
Attachment:
Changes to Operating License No. DPR-23 and the Technical Specifications Date of Issuance: April 4, 2007
ATTACHMENT TO LICENSE AMENDMENT NO. 213 RENEWED FACILITY OPERATING LICENSE NO. DPR-23 DOCKET NO. 50-261 Replace page 3 of Operating License No. DPR-23 with the attached page 3.
Replace the following page of the Appendix A Technical Specifications with the attached revised page. The revised page is identified by amendment number and contains marginal lines indicating the areas of change.
Remove Page Insert Page 3.5-6 3.5-6
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 213 TO RENEWED FACILITY OPERATING LICENSE NO. DPR-23 CAROLINA POWER & LIGHT COMPANY H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT NO. 2 DOCKET NO. 50-261
1.0 INTRODUCTION
By letter dated June 1, 2006 (ML061560113 [Agencywide Documents Access and Management System Accession Number]), as supplemented by letters dated November 20, 2006 (ML063320521), and February 22, 2007 (ML070600152), the Carolina Power & Light Company (licensee) submitted a request for changes to the H. B. Robinson Steam Electric Plant, Unit No. 2 (HBRSEP2), Technical Specifications (TS). The requested changes involve revisions to Surveillance Requirement (SR) 3.5.2.6, with the objective of clarifying terminology associated with containment recirculation sump components to support a planned modification to replace the existing sump screen and trash racks with a single-stage replacement strainer assembly.
The first proposed revision is intended to clarify that both trains of the emergency core cooling system (ECCS) and containment spray system (CSS) take suction from a single, common sump.
The second proposed revision to SR 3.5.2.6 is intended to reflect the revised terminology associated with the Spring 2007 replacement of the existing sump screen and trash racks with a single-stage strainer assembly. To reflect the planned containment recirculation sump modifications, the licensee has proposed to revise SR 3.5.2.6 to replace the phrase trash racks and screens with the word strainers.
The licensees containment recirculation sump modifications were prompted by Generic Letter (GL) 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors," dated September 13, 2004.
The licensees letters dated November 20, 2006, and February 22, 2007, provided clarifying information that did not change the initial proposed no significant hazards consideration determination.
2.0 REGULATORY EVALUATION
The licensee has proposed a change to SR 3.5.2.6, which covers the periodic inspection of the containment sump screen assembly and trash racks relied upon by the ECCS and CSS for long-term functionality. The licensees September 1, 2005 (ML052490343), response to GL 2004-02 describes the Nuclear Regulatory Commission's (NRCs) requirements regarding the long-term functionality of the ECCS and CSS that are applicable to HBRSEP2. The regulatory requirements pertinent to the proposed TS change are summarized below. As the licensee noted, HBRSEP2 was originally licensed for operation based upon conformance with proposed General Design Criteria (GDC) published in the Federal Register on July 11, 1967.
Paragraph (b)(5) of 10 CFR 50.46, "Acceptance criteria for emergency core cooling systems for light-water nuclear power reactors, states that after any calculated successful initial operation of the emergency core cooling system, the calculated core temperature shall be maintained at an acceptably low value and decay heat shall be removed for the extended period of time required by the long-lived radioactivity remaining in the core.
Proposed GDC 44, Emergency Core Cooling System Capability, states that an emergency core cooling system with the capability for accomplishing adequate emergency core cooling shall be provided. This core cooling system and the core shall be designed to prevent fuel and clad damage that would interfere with the emergency core cooling function and to limit the clad metal-water reaction to acceptable amounts for all sizes of breaks in the reactor coolant piping up to the equivalent of a double-ended rupture of the largest pipe. The performance of such emergency core cooling system shall be evaluated conservatively in each area of uncertainty.
Proposed GDC 52, Containment Heat Removal System, states that where an active heat removal system is needed under accident conditions to prevent exceeding containment design pressure, this system shall perform its required function, assuming failure of any single active component.
The basis for pressurized-water reactor (PWR) licensees to demonstrate compliance with the above requirements is documented in GL 2004-02. The primary purpose of GL 2004-02 was to request that PWR licensees evaluate the performance of their containment recirculation sumps and implement any modifications necessary to ensure compliance with applicable regulatory requirements on a mechanistic basis in light of the technical issues associated with Generic Safety Issue 191 (GSI-191), Assessment of Debris Accumulation on PWR Sump Performance. The generic letter requested that PWR licensees complete actions necessary for compliance with applicable regulatory requirements using the updated information associated with GSI-191 by December 31, 2007. Prior to this date, GL 2004-02 concluded that licensees compliance with their current licensing bases was sufficient to support continued plant operation.
In light of the regulatory framework established by GL 2004-02, this safety evaluation reviews the licensees proposed TS change to ensure that consistency with the current licensing basis is maintained. Assurance that PWR licensees proposed sump modifications are adequate in light of the technical issues associated with GSI-191 will be provided separately through the NRC staffs review of GL 2004-02 supplemental responses, through selected sample audit reviews of PWR licensees sump performance calculations, and through reviews of standardized industry guidance and vendor practices.
3.0 TECHNICAL EVALUATION
3.1 Proposed TS Change Currently, SR 3.5.2.6 reads as follows:
Verify, by visual inspection, the ECCS train containment sump suction inlet is not restricted by debris and the suction inlet trash racks and screens show no evidence of structural distress or abnormal corrosion.
The licensee has proposed the following revisions to SR 3.5.2.6:
(1) to delete the word train from the first line, and (2) to replace the phrase trash racks and screens in the middle line with the word strainers.
The licensee indicated that the proposed revisions would not fundamentally alter the current inspection practice required by SR 3.5.2.6. Specifically, the licensee will continue to be required to visually inspect the containment sump suction inlet with an 18-month frequency to verify that it is not restricted by debris and that its debris filters show no evidence of structural distress or abnormal corrosion.
3.2 Deletion of the Word Train from SR 3.5.2.6 3.2.1 Licensee Justification The licensees submittal stated that the removal of the word train from SR 3.5.2.6 is a clarification of the current TS requirement, since the existing sump is a combined header for both ECCS trains. As a result, the licensee stated that inclusion of the word train is not necessary in SR 3.5.2.6.
3.2.2 NRC Staff Evaluation Although the containment recirculation sump provides suction to both trains of ECCS during the recirculation mode, it was not apparent to the staff that deletion of the word train from SR 3.5.2.6 clarifies this requirement. Specifically, while the two ECCS trains share a common sump, separate suction lines are provided for each train. The licensees submittal did not clearly define the phrase ECCS train containment sump suction inlet, which is used in SR 3.5.2.6 and the associated TS Basis. As a result, the staff could not determine the specific components and/or structures that the licensee considered to be within the scope of either the current TS SR or the proposed SR. Therefore, the staff requested that the licensee provide additional information concerning the scope of both the current and the proposed containment sump SRs.
In its November 20, 2006, letter the licensee stated that the current SR calls for an examination of the ECCS containment sump suction inlet, the coarse filtration screens (i.e., trash racks), and the ECCS sump hood. The licensee stated that the proposed SR would require an examination of the strainers and the strainer manifold (which will physically replace the sump components that are currently inspected following the planned strainer replacement modification). A diagram provided in the licensees response shows that the planned replacement strainers will be connected to a common header that is directly connected to both of the ECCS suction pipe inlets. The licensees response further stated that both the current and proposed surveillances are visual inspections of external surfaces.
Based upon the licensees statement that the proposed TS change would not alter the methodology for performing SR 3.5.2.6 (i.e., both the current and proposed surveillances are visual inspections of external surfaces), the staff concludes that deleting the word train from SR 3.5.2.6 would not change the intent of this TS SR. Although the specific components covered by the inspection would change, these changes are based upon the replacement of the existing screen assembly, trash racks, and sump hood with a single-stage strainer assembly connected directly to the ECCS suction pipe inlets. Therefore, the staff considers deletion of the word train from SR 3.5.2.6 to be acceptable.
3.3 Replacement of Trash Racks and Screens with Strainers in SR 3.5.2.6 3.3.1 Description of Existing Screens and Trash Racks The existing sump screen is a two-stage assembly constructed of a 1/2-inch square mesh pre-screen and a 7/32-inch square mesh fine screen. The total screen surface area is 116 ft2.
Section 6.3.2.2.2 of the updated final safety analysis report (UFSAR) states that the design function of the existing screen is to intercept neutrally and nearly neutrally buoyant debris that is greater than 7/32-inch in diameter.
Since a detailed description of the trash racks and their design functions was not available in the licensees original submittal, the staff requested additional information in these areas. In its November 20, 2006, letter the licensee stated that the trash racks are coarse screens with a mesh size of approximately 1 inch that are located at the inner base of the bioshield wall. The trash racks are mounted in three separate locations to provide filtration for a total of twenty 2 ft x 2 ft openings in the bioshield wall through which debris-laden water would flow on its way to the containment recirculation sump. The licensee stated that the total surface area provided by the trash racks is approximately 600 ft2.
The licensees response further stated that the design function of the trash racks is to serve as part of the existing strategy of performing a staged removal of debris from the water in the post-accident containment pool. Specifically, the trash racks are designed to interdict debris larger than 1-inch at the inner base of the bioshield wall. The licensee stated that the trash racks provide no other function in support of ECCS operability. The licensee also stated that, based upon the sump performance evaluation conducted in response to GL 2004-02, the design function of the trash racks is not considered necessary once the replacement sump strainers have been installed.
3.3.2 Licensee Justification for Proposed TS Change The licensees submittal indicated that the replacement of trash racks and screens with strainers in SR 3.5.2.6 provides a more appropriate description of the sump configuration after the planned installation of a larger strainer assembly to address GL 2004-02 is completed.
The licensee stated that the replacement strainer assembly is functionally equivalent to the existing trash racks and screen for meeting the requirements of 10 CFR 50.46(b)(5) for long-term reactor core cooling and for satisfying the HBRSEP2 plant-specific GDC 44.
The licensee also stated that the replacement strainer assembly will provide support for operation of the CSS if its operation is necessary for containment cooling during the sump recirculation phase of a loss-of-coolant accident.
3.3.3 NRC Staff Evaluation In determining the adequacy of the licensees proposed TS change, the staffs evaluation considered whether the planned replacement strainer assembly is capable of fulfilling the design functions of the existing screen and trash rack configuration under the current licensing basis.
The planned replacement strainer assembly is described in the licensees response to GL 2004-02, dated September 1, 2005. In this response, the licensee described the planned replacement strainers as having a minimum surface area of 3000 ft2 and perforations of 1/8 inch. The licensee further stated therein that the planned replacement strainers will have a complex geometry to reduce the potential for thin, uniform debris beds to cause high head losses.
The planned replacement strainer assembly is a single-stage debris filter that does not have a trash rack or pre-screen to intercept debris prior to its arrival on the strainer surfaces.
Nevertheless, the staff considers the replacement strainer configuration as meeting the intent of the current sump performance licensing basis because the filtration capacity associated with the replacement strainers large, complex surface is significantly in excess of the filtration capacity associated with the existing screen assembly and trash racks. Furthermore, the staff considers the replacement strainer design to be a significant enhancement as compared to the existing screen and trash racks with respect to reducing the potential for a loss of net positive suction head margin due to excessive head loss across a post-accident debris bed.
In addition to ensuring that the replacement strainer assembly adequately satisfies the current licensing basis for sump head loss performance, the planned modifications associated with the replacement strainers must address potential dynamic effects of pipe ruptures, such as impacts from whipping pipes, jet impingement, and missiles. The NRC staff particularly noted that the relocation of strainer modules and associated strainer suction piping inside the bioshield wall should be reviewed to ensure conformance with the licensees current licensing basis for dynamic effects. The NRC staff reviewed to determine whether the planned replacement strainer evaluation has adequately considered potential dynamic effects of jet impingement, missile impact, and pipe whip. The staff requested that the licensee provide additional information concerning the consideration of potential dynamic effects.
In its February 22, 2007, letter the licensee stated that the strainer assembly is adequately protected from the hazardous effects of missiles. The licensee stated that the evaluations for potential pipe whip and jet impingement sources, and consideration of potential dynamic effects are contained in its Engineering Change (EC) 63481 document. The design and construction of a jet impingement shield, to protect the strainer from a high energy jet due to a high energy line break in the normal letdown line upstream of the letdown isolation valves, is documented in its EC 61244 document. Based upon this input from the licensee, the NRC staff concludes that the proposed replacement of trash racks and screens with strainers in SR 3.5.2.6 is acceptable.
Based upon the above discussion, the NRC staff considers the replacement strainers to be functionally equivalent to the existing screen assembly and trash racks under the non-mechanistic current licensing basis for satisfying the requirements of 10 CFR 50.46(b)(5) for long-term reactor core cooling and the other regulatory requirements applicable to HBRSEP2 listed above in Section 2.0 of this evaluation. Consistent with the intent of GL 2004-02, current licensing basis compliance is sufficient until December 31, 2007. No later than this date, the NRC staff has requested that licensees complete modifications to their licensing bases for containment recirculation sump performance to ensure consistency with the mechanistic methodology associated with GSI-191. Assurance that the licensees replacement strainer design is adequate for satisfying the intent of GL 2004-02 will be provided by the staffs regulatory activities regarding GL 2004-02 and GSI-191, including reviews of licensees supplemental responses to GL 2004-02, sample audits of licensees sump performance calculations, and reviews of generic industry guidance and practices. Therefore, the NRC staff considers the licensees proposed replacement of trash racks and screens with strainers in SR 3.5.2.6 to be acceptable.
4.0
SUMMARY
The NRC staff has reviewed the licensees proposed revisions to SR 3.5.2.6 of the HBRSEP2 TS. As described above, the proposed revisions would clarify terminology associated with the replacement strainers and sump configuration. The licensee will continue to be required to visually inspect the containment sump suction inlet with an 18-month frequency to verify that it is not restricted by debris and that its debris filters show no evidence of structural distress or abnormal corrosion. The NRC staff further determined that, under the current licensing basis, the planned replacement strainers are functionally equivalent to the existing trash racks and screen assembly for satisfying 10 CFR 50.46(b)(5) for long-term reactor core cooling and the other regulatory requirements applicable to HBRSEP2 listed in Section 2.0 of this evaluation. In addition, the NRC staff noted that generic review activities associated with GL 2004-02 will provide assurance that PWR licensees replacement strainer designs are adequate to satisfy applicable regulatory guidance in accordance with the mechanistic criteria associated with GSI-191. Based upon these findings, the NRC staff concludes that the proposed revisions to SR 3.5.2.6 are acceptable.
4.0 STATE CONSULTATION
In accordance with the Commission's regulations, the State of South Carolina official was notified of the proposed issuance of the amendment. The State official had no comments.
5.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes the SRs. The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration, and there has been no public comment on such finding (71 FR 75992). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
6.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributors:
J. Lehning B. Chakrapani Date: April 4, 2007