ML092290862
| ML092290862 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 08/25/2009 |
| From: | Nancy Salgado Plant Licensing Branch 1 |
| To: | Sena P FirstEnergy Nuclear Operating Co |
| Morgan M | |
| References | |
| TAC ME0211, TAC ME0212 | |
| Download: ML092290862 (8) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555*0001 August 25, 2009 Mr. Peter P. Sena III Site Vice President FirstEnergy Nuclear Operating Company Beaver Valley Power Station Mail Stop A-BV-SEB1 P.O. Box 4, Route 168 Shippingport, PA 15077
SUBJECT:
BEAVER VALLEY POWER STATION, UNIT NOS. 1 AND 2 - RELIEF REQUEST NO. BV3-IWA-5244-1 REGARDING THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS BOILER AND PRESSURE VESSEL CODE SECTION XI, PARAGRAPH IWA-5244 EXAMINATION REQUIREMENTS (TAC NOS. ME0211 AND ME0212)
Dear Mr. Sena:
By letter dated December 2, 2008, FirstEnergy Nuclear Operating Company (licensee) submitted a request for authorization of a proposed alternative to American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code)Section XI, paragraph IWA-5244(b)(1) for buried portions of ASME Code Class 3 river water, service water, and auxiliary feedwater system piping. Specifically, the licensee requested the use of system full flow tests for Beaver Valley Power Station, Unit NO.1 (BVPS-1) river water system buried piping, BVPS-2 service water system buried piping, and the use of demineralized water storage tank level indication for BVPS-1 auxiliary feedwater system buried piping.
The Nuclear Regulatory Commission (NRC) staff has concluded that compliance with the inservice inspection (lSI) Code of Record would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety, and that the proposed alternative provides reasonable assurance of structural integrity. Therefore, pursuant to Section 50.55a(a)(3)(ii) of Part 50 of Title 10 of the Code of Federal Regulations (10 CFR), the NRC staff authorizes the proposed alternative for the remainder of the BVPS-1 and BVPS-2, fourth and third 10-year lSI intervals, respectively.
All other ASME Code,Section XI requirements for which relief was not specifically requested and approved in this relief request remain applicable, including third party review by the Authorized Nuclear Inservice Inspector.
P.Sena -2 If you have any questions, please contact the Beaver Valley Project Manager, Nadiyah Morgan, at (301) 415-1016.
Sincerely,
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Plant Licensing Branch 1-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-334 and 50-412
Enclosure:
As stated cc w/encl: Distribution via Listserv
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- SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION REGARDING THE 10-YEAR INSERVICE INSPECTION PLAN INTERVAL FOR RELIEF REQUEST NO. BV3-IWA-5244-1 FIRSTENERGY NUCLEAR OPERATING COMPANY FIRSTENERGY NUCLEAR GENERATION CORP.
OHIO EDISON COMPANY THE TOLEDO EDISON COMPANY BEAVER VALLEY POWER STATION, UNIT NOS. 1 AND 2 DOCKET NOS. 50-334 AND 50-412
1.0 INTRODUCTION
By letter dated December 2, 2008 (Agencywide Document Access and Management System (ADAMS) accession number ML083430003), FirstEnergy Nuclear Operating Company (licensee) submitted a request for authorization of a proposed alternative to American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code)Section XI, paragraph IWA-5244(b)( 1) for buried portions of ASME Code Class 3 river water, service water, and auxiliary feedwater system piping. Specifically, the licensee requested the use of system full flow tests for Beaver Valley Power Station, Unit NO.1 (BVPS-1) river water system buried piping, BVPS-2 service water system buried piping, and the use of demineralized water storage tank level indication for BVPS-1 auxiliary feedwater system buried piping.
Paragraph IWA-5244(b)(1) of ASME Code,Section XI requires that system pressure tests of isolable buried components be conducted to determine either the rate of pressure loss or change in flow between the ends of the buried components. Alternatively, the licensee proposed a test that will confirm that adequate flow to all of the safety-related loads is available during the routine operating surveillance test conducted once every 18 months for the remainder of the BVPS-1 and BVPS-2, fourth and third 1O-year inservice inspection (lSI) intervals, respectively.
2.0 REGULATORY EVALUATION
Section 50.55a(a)(g) of Part 50 of Title 10 of the Code of Federal Regulations (10 CFR) requires that lSI of ASME Code Class 1, 2, and 3 components be performed in accordance with Section XI of the ASME Code and applicable addenda, except where specific written relief has been granted by the Commission pursuant to 10 CFR 50.55a(g)(6)(i). According to 10 CFR 50.55a Enclosure
-2 (a)(3), alternatives to the requirements of paragraph 50.55a(g) may be used, when authorized by the Nuclear Regulatory Commission (NRC), if an applicant demonstrates that the proposed alternatives would provide an acceptable level of quality and safety or if the specified requirement would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
Pursuant to 10 CFR 50.55a(g)(4), ASME Code Class 1,2, and 3 components (including supports) shall meet the requirements, except the design and access provisions and the preservice examination requirements, set forth in the ASME Code,Section XI, "Rules for Inservice Inspection of Nuclear Power Plant Components," to the extent practical within the limitations of design, geometry, and materials of construction of the components.
The regulations require that lSI of components and system pressure tests conducted during the first 1O-year interval and subsequent intervals comply with the requirements in the latest edition and addenda of Section XI of the ASME Code incorporated by reference in 10 CFR 50.55a(b) 12 months prior to the start of the 120-month interval, subject to the limitations and modifications listed therein. The lSI Code of Record for the fourth 1O-year inspection interval of the BVPS-1 and the third 10-year interval of the BVPS-2 is the 2001 Edition through the 2003 Addenda of the ASME Code,Section XI.
3.0 TECHNICAL EVALUATION
3.1 System/Component(s)
Buried Class 3 Components in the river water, service water, and auxiliary feedwater piping.
BVPS-1 24"-WR-101-301 6"-WR-90-301 6"-WR-91-301 24"-WR-102-301 6"-WR-674-157W 6"-WR-675-157W 8"-WO-22-151 6"-WO-23-151 6"-WO-24-151 BVPS-2 2-SWS-030-41 2-SWS-030-82 2-SWS-012-162 2-SWS-030-81 2-SWS-024-63 2-SWS-012-161 2-SWS-030-40 2-SWS-024-62 3.2 Applicable Code Requirements The 200'1 Edition through the 2003 Addenda of ASME Code,Section XI, Table IWO-2500-1, Examination Category O-B, Item No. 02.10 requires a system leakage test and a VT-2 visual examination. For buried components where a VT-2 visual examination cannot be performed, the examination requirement of Item No. 02.10 is satisfied by the following:
The system pressure test for buried components that are isolable by means of valves shall consist of a test that determines the rate of pressure loss. Alternatively, the test may determine the change in flow between the ends of the buried components.
The acceptable rate of pressure loss or flow shall be established by the Owner.
-3 3.3 Licensee's Basis for Request Paragraph IWA-5244(b)(1) of ASME Code,Section XI requires that system pressure tests of isolable buried components be conducted to determine either the rate of pressure loss or change in flow between the ends of the buried components. This requirement is applicable to the buried portions of the affected river and service water system piping at BVPS-1 and 2. At BVPS-1, the affected piping includes both 24-inch river water system supply headers and the 6-inch supply lines to the diesel generator cooling system heat exchangers. The requirement is also applicable to the two 6-inch and one 8-inch supply lines from the primary plant demineralized water storage tank to the three auxiliary feedwater pumps. At BVPS-2, the affected piping includes both 30 inch service water system supply headers and also the two 24-inch supply lines to the recirculation spray heat exchangers, and two 12-inch supply lines to rod control and diesel generator cooling system heat exchangers.
The affected pipe lines utilize butterfly valves for isolation. While suitable to provide isolation between equipment trains and/or other components, these valves are not capable of maintaining the leak-tight isolation function required to conduct the pressure loss test required by paragraph IWA-5244(b)(1) of the ASME Code,Section XI.
The licensee also stated, "As an alternative to a test that determines system pressure loss, paragraph IWA-5244(b)(1) states that the test may determine the change in flow between the ends of the buried components. However, the affected pipe lines lack the plant instrumentation necessary to determine a flow rate between the ends of the buried pipe via direct measurement, or lack sufficient length of accessible straight pipe by which flow could be determined using an ultrasonic flow measurement device."
The pressure loss test would require hardware changes, and determining the flow rate between the ends of the buried components would require installation of upstream flow monitoring instrumentation. Performing either of the Code-required tests described in paragraph IWA-5244(b)(1), therefore, would require hardware changes and would cause hardship.
3.4 Licensee's Proposed Alternative In lieu of performing a system pressure test in accordance with the requirements of IWA-5244(b)(1), the licensee proposed the use of plant surveillances and flow acceptance criteria appropriate to the locations being tested. Specifically, the licensee proposed to use the system full flow test for the BVPS-1 river water and BVPS-2 service water system buried piping, and use primary plant demineralized water storage level indication in the control room for the BVPS-1 auxiliary feedwater system buried piping.
- BVPS-1 River Water System and BVPS Unit 2 Service Water System Operating surveillance tests will be performed once every 18 months on the river water and service water systems to verify adequate flow to all of the safety-related loads. These BVPS-1 and 2 operating surveillance tests would require full flow through each train of equipment. The flow acceptance criteria (adjusted to river water level) for all of the downstream safety-related loads including the diesel generator cooling system heat exchangers and recirculation spray
-4 heat exchangers which are supplied through buried supply lines will meet the requirement of the system full flow test procedure under the 1ST program. If, during an operating surveillance test, the minimum flow could not be achieved through either the main header or one or more of the downstream loads, and the cause of the deviation could not be attributed to the test instruments being used, the system would be declared inoperable and a condition report would be generated in accordance with the FirstEnergy Nuclear Operating Company (FENOC) Corrective Action Program as required by the existing operating surveillance test. Further corrective actions, such as, maintenance on the associated pump, system walk-downs etc. would be initiated as necessary to restore the system to an operable status.
- BVPS-1 Auxiliary Feedwater System Buried Piping The three auxiliary feedwater system pumps at BVPS-1 are supplied through buried pipe lines from the primary plant demineralized water storage tank (PPDWST) through three normally open valves between the PPDWST and their respective buried lines. Operability of PPDWST is defined as the water level greater than or equal to 130,000 gallons which is verified by Operations surveillance every 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br />. A significant drop in PPDWST level which could be evidence of a gross leakage in one or more of the buried lines, would be annunciated in the control room and identified during the required Operations surveillance. This would result in declaring the PPDWST inoperable and identifying the condition in the FENOC Corrective Action Program. Corrective actions would be initiated as necessary to determine the cause of the decrease in PPDWST level and to restore the PPDWST to operable status.
The above proposed alternatives to the testing requirements of paragraph IWA-5244(b)(1) of the applicable ASME Code,Section XI would only detect significant leakage in the buried piping identified in the relief request.
3.5 Staff Evaluation The Code of Record requires a system pressure test for the buried portion of Class 3 river water, service water, and auxiliary feedwater piping that will determine either a rate of pressure loss or a change in flow at the ends of the buried piping. The buried piping at BVPS-1 and 2 uses butterfly valves at the ends which were not designed for pressure isolation and, therefore, are unsuitable to determine meaningful rate of pressure loss. One end of buried piping is not instrumented for flow measurement which does not permit measurement of change in flow.
Therefore, the ASME Code-required test cannot be performed. The ASME Code, however, allows for nonisolable buried components to confirm that flow during operation is not impaired.
In lieu of performing a system pressure test in accordance with the requirements of IWA 5244(b)(1), the licensee proposed the use of plant surveillances, and flow acceptance criteria appropriate to the locations being tested. Specifically, the licensee proposed to use the system full flow test for the BVPS-1 river water and BVPS-2 service water system buried piping, and use primary plant demineralized water storage tank level indication in the control room for the BVPS-1 auxiliary feedwater system buried piping.
Operating surveillance tests will be performed once every 18 months on the river water and service water systems to verify adequate flow to all of the safety-related loads. These operating surveillance tests would require full flow through each train of equipment. The flow acceptance criteria (adjusted to river water level) for all of the downstream safety-related loads including the diesel generator cooling system heat exchangers and recirculation spray heat exchangers
-5 which are supplied through buried supply lines will meet the requirement of the system full flow test procedure under the licensee's inservice testing program. Operating personnel will monitor PPDWST level and perform routine surveillance of the tank water level to verify operability of PPDWST by ensuring no significant leakage in the buried piping. The NRC staff has noted that if acceptable flow could not be achieved in the downstream loads or a significant drop in PPDWST level, the licensee would initiate corrective action under FENOC Corrective Action Program as required by the existing operating surveillance test. Further corrective actions (e.g.,
maintenance on the pump and system walk downs) would be initiated as required to restore the pump and/or the system to an operable status.
The NRC staff finds the licensee's proposed alternative acceptable, since unimpaired flow in the buried piping can be qualitatively assessed by performance of operating surveillance test and measurement PPDWST level, thus, detecting significant leakage through buried piping.
Compliance with the Code requirement would require installation of additional flow measuring device at the inlet end of buried piping, which would result in hardship without a compensating increase in the level of quality and safety.
4.0 CONCLUSION
Based on the above discussion, the NRC staff has concluded that compliance with the applicable ASME Code requirement to perform a test that determines the rate of pressure loss or the change in flow for the buried portion of Class 3 river water, service water, and auxiliary feedwater piping would result in hardship without a compensating increase in the level of quality and safety. The licensee's proposed alternative provides reasonable assurance of detecting any gross leakage in the buried portion of piping and restoring the system to an operable status.
Therefore, pursuant to 10 CFR 50.55a(a)(3)(ii), the NRC staff authorizes the proposed alternative for the remainder of BVPS-1 and 2, fourth and the third inspection intervals, respectively.
All other requirements of the ASME Code,Section XI for which relief has not been specifically requested remain applicable, including a third party review by the Authorized Nuclear Inservice Inspector.
Principle Contributor: P. Patnaik Date: August 25, 2009
P. Sena -2 If you have any questions, please contact the Beaver Valley Project Manager, Nadiyah Morgan, at (301) 415-1016.
Sincerely, IRA!
Nancy L. Salgado, Chief Plant Licensing Branch 1-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-334 and 50-412
Enclosure:
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