ML072920290
| ML072920290 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 10/18/2007 |
| From: | Cowan P AmerGen Energy Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 2130-07-20510 | |
| Download: ML072920290 (12) | |
Text
10 CFR 50.90 October 18, 2007 2130-07-20510 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001
Subject:
Oyster Creek Generating Station Facility Operating License No. DPR-16 NRC Docket No. 50-219 Technical Specification Change Request No. 374 - Revision to Mechanical Snubber Functional Testing Requirements Pursuant to 10 CFR 50.90, ArnerGen Energy Company, LLC (AmerGen) hereby requests a change to the Technical Specifications included in Oyster Creek Operating License No.
DPR-16. The proposed change modifies Technical Specifications (TS) Section 4.5.M.1 .e.l concerning Mechanical Snubbers Functional Test Acceptance Criteria, specifically, replacement of the snubber breakaway test with the drag force test.
AmerGen requests approval of the proposed change by October 18,2008 in support of the Oyster Creek Fall 2008 refueling outage. Once approved, the amendment shall be implemented within 60 days. The proposed change has been reviewed by the Plant Operations Review Committee and approved by the Nuclear Safety Review Board. No new regulatory commitments are established by this submittal.
We are notifying the State of New Jersey of this application for changes to the Technical Specifications by transmitting a copy of this letter and its attachments to the designated State Official.
If any additional information is needed, please contact Tom Loomis at (610) 765-5510.
2130-07-20510 October 18, 2007 Page 2 I declare under penalty of perjury that the foregoing is true and correct. Executed on the 18thof October, 2007.
Respectfully, Director - Licensing & Regulatory Affairs AmerGen Energy Company, LLC
Enclosures:
(1) Evaluation of Proposed Change (2) Markup of Proposed Technical Specification Page Change cc: S. J. Collins, Administrator, USNRC Region I G. E. Miller, USNRC Project Manager, Oyster Creek M. Ferdas, USNRC Senior Resident Inspector, Oyster Creek Director, Bureau of Nuclear Engineering, New Jersey Department of Environmental Protection File No. 07044
ENCLOSURE 1 Oyster Creek Technical Specification Change Request No. 374 Evaluation of Proposed Change 2130-07-20510 Page 1 of 7 ENCLOSURE 1 CONTENTS
SUBJECT:
Revision to Mechanical Snubber Functional Testing Requirements 1.o DESCRIPTION
2.0 PROPOSED CHANGE
3.0 BACKGROUND
4.0 TECHNICAL ANALYSIS
5.0 REGULATORY ANALYSIS
5.1 No Significant Hazards Consideration 5.2 Applicable Regulatory RequirernentsEriteria
6.0 ENVIRONMENTAL CONSIDERATION
7.0 PRECEDENT
8.0 REFERENCES
Enclosure 1 2 130-07-20510 Page 2 of 7 1.O DESCRIPTION This letter is a request to amend Operating License No. DPR-16 for Oyster Creek Generating Station (OCGS).
The proposed change modifies Technical Specifications (TS) Section 4.5.M.1 .e.l concerning Mechanical Snubbers Functional Test Acceptance Criteria, specifically, replacement of the snubber breakaway test with the drag force test.
2.0 PROPOSED CHANGE
The current TS Section 4.5.M.1 .e.l states (bold text added):
The mechanical snubber functional test shall verify that:
- 1. The force that initiated free movement of the snubber rod in either tension or compression is less than the specified maximum drag force.
The proposed change modifies the wording as follows:
The mechanical snubber functional test shall verify that:
- 1. The drag force to maintain movement of the snubber rod in either tension or compression is less than the specified maximum drag force.
3.0 BACKGROUND
Current TS Section 4.5 (Containment System) provides specific methodology for snubber testing. A representative sample of snubbers is functionally tested at least once every 24 months in accordance with TS Section 4.5.M.1 .c. Snubber TS contain requirements for Visual Inspections (4.5.M.1 .a), Visual Inspection Acceptance Criteria (4.5.M.1 .b), Functional Tests (4.5.M.1 .c), Hydraulic Snubbers Functional Test Acceptance Criteria (4.5.M.1 .d), and Mechanical Snubbers Functional Test Acceptance Criteria (4.5.M.1 .e). A test contained in the Mechanical Snubbers Functional Test Acceptance Criteria is referred to as the breakaway test. Fundamentally, the breakaway test (i.e., force that initiated free movement) measures the force necessary to initiate snubber motion. The breakaway test was intended to prevent the introduction of higher stresses to the component.
Technical Specifications for snubber testing were added to the OCGS TS in Amendment No.
100, dated March 31 1986 (Reference 1). This amendment incorporated model TS surveillance requirements for snubbers as provided in a letter from the NRC dated March 23, 1981 (Reference 2).
The current 10 CFR 50.55a(b)(3)(v) permits the use of ASME OM Code, Subsection ISTD, in lieu of ASME Code,Section XI, for the inservice testing of snubbers. Subsection ISTD of the ASME OM-Code, Preservice and lnservice Examination and Testing of Dynamic Restraints
Enclosure 1 2130-07-20510 Page 3 of 7 (Snubbers) in Light-Water Reactor Nuclear Power Plants, provides the requirements for snubber testing. 10 CFR 50.55a currently endorses the 2001 Edition through the 2003 Addenda of the ASME OM Code.
ASME OM Code-2001 through 2003 Addenda (Reference 3), Section ISTD-5210, Test Parameters, states that snubber operational readiness tests shall verify the following:
(c) for mechanical snubbers, drag force is within specified limits in tension and in compression.
Accordingly, the currently approved edition of the ASME OM Code does not require a breakaway test; instead, the snubber is to be tested for drag force in tension and in compression. Therefore, OCGS requests that the breakaway test be deleted from the OCGS TS and replaced with a drag force test.
4.0 TECHNICAL ANALYSIS
Current ASME OM Code requirements require a drag force test (not a breakaway test). The breakaway force test is a measurement of the force required to initiate free motion of the snubber and is generally measured at one location along its stroke. The drag force test is a measurement of the force that will sustain low-velocity motion of the snubber and is measured over the working range of the snubber stroke. The drag force test is a more encompassing representation of overall snubber resistance to thermal movement because it is performed over the entire working range of the snubber stroke. Therefore, a drag force test is the preferred test rather than the breakaway or force that initiated free movement as currently worded in the OCGS TS.
The likelihood that the breakaway force will be measured for a snubber in the exact hot or cold position setting from the field or that the breakaway force will be measured at the point of maximum resistance within a snubbers range of motion is remote. In addition to the above, the breakaway test is intended to be performed prior to any movement of the snubber. This is an impractical test situation, because the snubber has typically moved while the unit is cooling down, and the piping experiences thermal cycles.
The INPO Engineering Program Guide for snubbers (EPG-07, July 2006) (Reference 4) provides an integrated snubber inspection and testing program, including appropriate evaluation and assessment attributes. The INPO guide recommends drag force testing as part of the functional testing. The breakaway test is not included as part of the functional testing.
Specific snubber testing methodology is typically no longer contained in the plant Technical Specifications, and when available, relocated to a plants Technical Requirements Manual, which is a licensee controlled document. NUREG-1433, Standard Technical Specifications for General Electric Plants, BW W4, Revision 3, does not contain specific snubber testing methodology.
2130-07-20510 Page 4 of 7
5.0 REGULATORY ANALYSIS
5.1 No Significant Hazards Consideration AmerGen has evaluated whether or not a significant hazards consideration is involved with the proposed amendment by focusing on the three standards set forth in 10 CFR 50.92, Issuance of amendment, as discussed below:
- 1. Does the proposed amendment involve a significant increase in the probability or consequences of an accident previously evaluated?
Response: No The proposed change modifies Technical Specifications (TS) Section 4.5.M.1 .e.l concerning the Mechanical Snubbers Functional Test Acceptance Criteria, specifically, replacement of the snubber breakaway test with the drag force test. 10 CFR 50.55a(b)(3)(v) permits the use of ASME OM Code, Subsection ISTD, in lieu of the ASME Code,Section XI, for the inservice testing of snubbers. Subsection ISTD of the ASME OM-Code, Preservice and lnservice Examination and Testing of Dynamic Restraints (Snubbers) in Light-Water Reactor Nuclear Power Plants, provides the requirements for snubber testing. A requirement to perform the breakaway test no longer exists in the ASME OM Code. Current ASME OM Code requirements require a drag force test. The drag force test is a more encompassing representation of overall snubber resistance to thermal movement because it is performed over the entire working range of the snubber stroke. Therefore, a drag force test should be used rather than the breakaway or force that initiated free movement as currently worded in the OCGS TS. In addition to the above, the breakaway test is intended to be performed prior to any movement of the snubber.
This is an impractical test situation, because the snubber has typically moved while the unit is cooling down, and the piping experiences thermal cycles.
The percentage of snubbers sampled and the period between inspections has not changed. Also, the way the snubber functions has not changed, only the method of testing that ensures continued functionality of it. Elimination of the breakaway test will not reduce the ability of snubbers to perform their intended design function. Drag force testing as defined in the TS will ensure adequate demonstration of snubber performance. Also, this change will not increase the probability of malfunction of plant equipment, or the failure of plant structures, systems, or components. Piping systems that include snubbers in their configuration will still be capable of performing their safety function.
Therefore, the proposed change does not affect the probability or consequences of an accident previously evaluated.
- 2. Does the proposed amendment create the possibility of a new or different kind of accident from any accident previously evaluated?
2130-07-20510 Page 5 of 7 Response: No The proposed change does not affect the assumed accident performance of the Reactor Coolant Pressure Boundary, nor any plant structure, system, or component previously evaluated. The proposed change does not involve the installation of new equipment, and installed equipment is not being operated in a new or different manner. The change deletes the breakaway test for snubbers, which is no longer required by the ASME OM Code, and replaces it with a drag force test to ensure snubber functionality consistent with the ASME OM Code. No set points are being changed which would alter the dynamic response of plant equipment, and the design function of systems associated with snubbers will not be altered. Accordingly, no new failure modes or accident initiators are introduced.
Therefore, the proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.
- 3. Does the proposed amendment involve a significant reduction in a margin of safety?
Response: No The proposed change does not affect the function of any safety systems or response during plant transients. There are no changes proposed which alter the set points at which protective actions are initiated, and there is no change to the operability requirements for equipment assumed to operate for accident mitigation. The snubbers will continue to perform their design function. This change deletes the breakaway test for snubbers, which is no longer required by the ASME OM Code, and replaces it with a drag force test.
Therefore, the proposed change does not involve a significant reduction in a margin of safety.
Based upon the above, AmerGen concludes that the proposed amendment presents no significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and, accordingly, a finding of no significant hazards consideration is justified.
5.2 Applicable Regulatory RequirementdCriteria 10 CFR 50.55a(b)(3)(v) permits the use of ASME OM Code, Subsection ISTD, in lieu of ASME Code,Section XI, for the inservice testing of snubbers. Subsection ISTD of the ASME OM-Code, Preservice and Inservice Examination and Testing of Dynamic Restraints (Snubbers) in Light-Water Reactor Nuclear Power Plants, provides the requirements for snubber testing. 10 CFR 50.55a currently endorses the 2001 Edition through the 2003 Addenda of the ASME OM Code.
ASME OM Code-2001 through 2003 Addenda, Section ISTD-5210, Test Parameters, states that snubber operational readiness tests shall verify the following:
2130-07-20510 Page 6 of 7 (c) for mechanical snubbers, drag force is within specified limits in tension and in compression.
Accordingly, the currently approved edition of the ASME OM Code does not require a breakaway test; instead, the snubber is to be tested for drag force in tension and in compression.
Specific snubber testing methodology is typically no longer contained in the plant Technical Specifications, and when available, relocated to a plants Technical Requirements Manual, which is a licensee controlled document. NUREG-1433, Standard Technical Specifications for General Electric Plants, BW R/4, Revision 3, does not contain specific snubber testing methodology.
In conclusion, based on the considerations discussed above, (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 Commissions 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.
6.0 ENVIRONMENTAL CONSIDERATION
A review has determined that the proposed amendment would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR 20, or would change an inspection or surveillance requirement. However, the proposed amendment does not involve: (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any effluent that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure. Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(~)(9).Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed amendment.
7.0 PRECEDENT Specific snubber testing methodology is typically no longer contained in the plant Technical Specifications, and when available, relocated to a plants Technical Requirements Manual, which is a licensee controlled document.
8.0 REFERENCES
- 1. Letter from J. Zwolinski (NRC) to P. Fiedler (Oyster Creek Nuclear Generating Station),
Mechanical and Hydraulic Snubbers Technical Specifications (TAC 8439, 8440, TSCR loo), dated March 31, 1986.
- 2. Letter from D. Eisenhut (NRC) to All SEP Plants, Technical Specification Revisions for Snubber Surveillance, dated March 23, 1981.
2130-07-20510 Page 7 of 7
- 3. ASME OM Code-2001 through 2003 Addenda, Code for Operation and Maintenance of Nuclear Power Plants.
ENCLOSURE 2 MARKUP OF PROPOSED TECHNICAL SPECIFICATION PAGE CHANGE Revised TS Page 4.5-8
In addition to the regular sample, snubbers which failed a previous functional test shall be retested during the next test period. If a spare snubber has been installed in place of a failed snubber, then both the failed (if it is repaired and installed in another position) and the replacement snubber shall be retested. The results from testing of these snubbers are not included for determining additional sampling requirements. .
For any snubber that fails to lockup or fails to move, i.e., frozen in place, the cause will be evaluated. If caused by manufacturer or design deficiency, actions shall be taken to ensure that all-snubbersof the same design are not subject to the same defcct.
- d. Hydraulic Snubbers Functional Test Acceptance Criteria The hydraulic snubber functional test shall verify that:
- 1. Activation (resuaining action) is achieved within the specified range of velocity or acceleration in both tension and compression.
- 2. Snubber bleed, or release rate, where required, is within the specified range in compression or tension. For snubbers .
specifically required to not displace under continuous load, the ability of the snubbers to withstand load without displacement shall be verified.
- e. Mechanical Snubbers Functional Test Acceptance Criteria movement of the snubber rod in n is less than the specified maximum drag force. -
- 2. Activation (restraining action} is achieved within the specified range of velocity or acceleration in both tension and compression.
- 3. Snubber release rate, when required, is within the specified range in cornpression or tension. For snubbers specifidly required not to displace under continuous load, the ability of the snubber to withstand load without displacement shall be verified.
OYSTER CREEK 4.5-8 Amendment No.: d&?, 186