NRC 2005-0037, Clarification to Information Regarding the Point Beach Nuclear Plant License Renewal Application

Clarification to Information Regarding the Point Beach Nuclear Plant License Renewal Application

ML051090337
Person / Time
Site:	Point Beach
Issue date:	04/08/2005
From:	Koehl D Nuclear Management Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NRC 2005-0037, TAC MC2099, TAC MC2100
Download: ML051090337 (12)

Text

NMCh Committed to Nuclear Excellence Point Beach Nuclear Plant Operated by Nuclear Management Company, LLC April 8, 2005 NRC 2005-0037 10 CFR 54 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 Point Beach Nuclear Plant, Units 1 and 2 Dockets 50-266 and 50-301 License Nos. DPR-24 and DPR-27 Clarification to Information Regarding the Point Beach Nuclear Plant License Renewal Application (TAC Nos. MC2099 and MC2100)

By letter dated February 25, 2004, Nuclear Management Company, LLC (NIMC),

submitted the Point Beach Nuclear Plant (PBNP) Units 1 and 2 License Renewal Application (LRA). As a result of an Inspection conducted during the weeks of March 7, and March 21, 2005, the Nuclear Regulatory Commission (NRC) staff requested clarifications regarding information contained in the PBNP LRA. The enclosure to this letter contains NMC's clarifications to that information.

Should you have any questions concerning this submittal, please contact Mr. James E. Knorr at (920) 755-6863.

Summary of Commitments New commitments made as part of this clarification to be implemented prior to the period of extended operation are as follows:

1. NMC will conduct eddy current inspections under the One-Time Inspection Program of the tubing of one RHR heat exchanger or replace the RHR heat exchanger tube bundles prior to the period of extended operation if eddy current testing of the tubing of at least one RHR heat exchanger is not completed.

2. As part of the Bolting Integrity program, maintenance instructions will be revised as necessary to clearly state that lubricants containing molybdenum disulfide should not be used unless evaluated on a case-by-case basis with consideration given for the potential of stress corrosion cracking (SCC).

6590 Nuclear Road

• Two Rivers, Wisconsin 54241 4Q t Telephone: 920.755.2321

Document Control Desk Page 2 NMC will continue to use locking devices per the design codes, standards and specifications applicable to PBNP.

NMC will continue to follow the requirements of 10 CFR 50.55a or request relief, as necessary, regarding the qualification and certification of NDE personnel.

NMC will clarify that the prohibition against reuse of any bolt or nut tightened by the turn-of-nut method only applies to component support bolting installed in accordance with American Institute of Steel Construction (AISC) or similar design specifications in which the turn-of-nut method may result in the bolting material being stressed beyond yield.

3. NMC will provide the One-Time Inspection Program methodology for NRC review to detail the sample size selection criteria and specific component identification criteria within that sample.

4. All systems within the scope of license renewal containing components requiring an aging management review and that credit the Systems Monitoring Program for managing the effects of aging on the external surfaces of the components will be walked down at a minimum frequency of once per operating cycle, within the limits of accessibility.

A supervisory review will be performed and documented to ensure that the accessible portions of each system are walked down at a minimum frequency of once per operating cycle.

Those portions of a system that are considered inaccessible will be evaluated to ensure that accessible portions of the system that are walked down contain the same material(s) and the same or more severe environment(s) as those portions that are considered inaccessible.

When an unacceptable condition or situation is identified in an accessible portion of a system, an extent of condition evaluation will be performed to determine whether the same condition or situation is applicable to other accessible or inaccessible portions of the system.

5. If degradation is detected by the Flow Accelerated Corrosion Program such that wall thickness is less than or equal to 87.5% of nominal wall thickness for safety related piping or 60% of nominal wall thickness for non-safety related piping, additional examinations will be performed in adjacent areas to bound the thinning. The sample size will also be expanded when inspection results indicate that a component has a remaining service life less than one operating cycle.

This covers situations where the code minimum allowable wall thickness may be greater than 60% of nominal wall thickness.

Document Control Desk Page 3

6. As part of the Periodic Surveillance and Preventive Maintenance Program, records of deferrals, cancellations, and frequency changes for callups credited for License Renewal as aging management or replacement activities will be retained in an auditable and retrievable form.

I declare under penalty of perjury that the forgoing is true and correct. Executed on April 8, 2005.

Dennis L. Koehl Site Vice-President, Point Beach Nuclear Plant Nuclear Management Company, LLC Enclosure cc:

Administrator, Region 111, USNRC Project Manager, Point Beach Nuclear Plant, USNRC Resident Inspector, Point Beach Nuclear Plant, USNRC PSCW

ENCLOSURE CLARIFICATION TO INFORMATION REGARDING POINT BEACH NUCLEAR PLANT, UNITS 1 AND 2 LICENSE RENEWAL APPLICATION The following information is provided in response to the Nuclear Regulatory Commission (NRC) staff's request during a March 2005 Region III inspection of the Point Beach Nuclear Plant (PBNP) License Renewal Application (LRA) related information.

LRA Section B2.1.13: One-Time Inspection Program:

PBNP LRA Table 3.2.2-3, "Engineered Safety Features - Residual Heat Removal System - Summary of Aging Management Evaluation," indicates that the aging management programs that apply to Component Type "Heat Exchanger," that cover the Residual Heat Removal (RHR) heat exchanger tubing pressure boundary are Water Chemistry Control Program, Closed-Cycle Cooling Water System Surveillance Program, and One-Time Inspection Program. LRA Section B2.1.13, "One-Time Inspection Program," provides for a visual inspection of the tubing in the RHR heat exchanger.

NRC inspection staff requested justification for the proposed visual inspection of the RHR heat exchanger tubes under the One-Time Inspection Program. An alternative would be to conduct an eddy-current test of the tubes of at least one RHR heat exchanger prior to the period of extended operation or the replacement of the heat exchanger tubing prior to the period of extended operation.

One RHR heat exchanger from each unit has had an eddy current inspection performed of the tube bundle.

1. The Unit 1 "B" heat exchanger was inspected in December of 1983. The results of this inspection indicated the following: The overall tube condition is excellent and there was no severe or extensive tube damage recorded. Only five tubes recorded internal damage most likely small internal pits or inconsistencies. Wall losses are estimated at 0 to 15%. The signals are not characteristic of corrosion pits, and may be inherent to the tubes.

2. The Unit 2 "B" heat exchanger was inspected in October of 1990. The results of this inspection indicated the following: The overall tube condition, after 20 years of service is excellent. No severe or extensive tube damage was recorded. Only two tubes recorded internal damage most likely small internal pits or inconsistencies. Wall losses are estimated at 5 to 20%. The signals are not characteristic of corrosion pits, and may be inherent to the tubes.

The Aging Effect Requiring Management of concern here for the RHR heat exchanger tubing pressure boundary is "Loss of Material." This aging effect is being managed Page 1 of 9

using the Water Chemistry Control Program and Closed-Cycle Cooling Water System Surveillance Program by controlling water chemistry to mitigate the aging effect, with confirmation of its effectiveness by visual inspections under the One-Time Inspection Program.

Nonetheless, to ensure adequate aging management, NMC will conduct eddy current inspections under the One-Time Inspection Program of the tubing of one RHR heat exchanger prior to the period of extended operation. This sample will be expanded to another RHR heat exchanger if indications requiring plugging of a tube are identified.

The alternative to this testing regimen will be to replace the RHR heat exchanger tube bundles prior to the period of extended operation if eddy current testing of at least one RHR heat exchanger is not completed.

LRA Section B2.1.4: Bolting Integrity Program PBNP LRA Section B2.1.4, "Bolting Integrity Program," includes an exception to NUREG-1801,Section XI.M18, "Bolting Integrity," regarding conformance with the recommendations of NUREG-1 339, EPRI NP-5769, and EPRI TR-104213. Due to the broad scope of these documents, the Bolting Integrity Program uses them as reference information and guidance only. The Bolting Integrity Program further states that "Enhancements to existing plant implementing documents dealing with bolted joints will be made to incorporate recommendations as deemed appropriate from the review of NUREG-1339, EPRI NP-5769, and EPRI TR-104213." NMC was requested to review these documents and provide additional detail with regards to the specific exceptions taken during the March 2005 NRC Region IlIl License Renewal Inspection of the PBNP LRA. The following discussion provides the information requested.

PBNP will use EPRI TR-1 04213 as a guidance document for the development of practices and procedures for non-safety related bolting as described in Section 1.4 of that document.

NMC understands that the industry recommendations discussed in NUREG-1 801 as being delineated in EPRI NP-5769 are contained within Section 1 of Volume II of EPRI NP-5769. The page numbers below are from Section 1 of Volume II of EPRI NP-5769. NMC will comply with these recommendations with the exceptions noted in NUREG-1339 for safety related bolting, except as described below:

1.

Thread Lubrication - Page 1-12 NMC does not utilize a single lubricant for all bolting material on site because of multiple needs and vendor recommendations. The use of thread lubricants is controlled via the use of Maintenance Instructions Ml 32.1, "Flange and Closure Bolting"" and Ml 29.1, "Use of Thread Lubricants and Sealants."

These documents have been reviewed and will be revised as necessary to more clearly state that lubricants containing molybdenum disulfide should not be used unless evaluated on a case-by-case basis with consideration given for the potential of stress corrosion cracking (SCC).

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2.

Locking Devices for Component Supports - Page 1-13 This section describes design requirements for component support threaded fastener locking devices and specifically precludes the use of disk or helical spring locking devices. These requirements were derived from ASME Section 1I1, Subsection NF. PBNP is not an ASME Section III code of record plant and will not apply these specific requirements but will continue to use locking devices per the design codes, standards and specifications applicable to PBNP.

The code of record for PBNP piping is ASA B31.1 - 1955 for the RCS piping and USAS B31.1 - 1967 for other piping. B31.1 - 1967, Section 121.1.3, "Hanger Adjustments," and B31.1 - 1955, Section 605(f) contain a specific requirement for suitable locking devices on hanger screw thread (and equivalent) adjustments. NMC will continue to comply with these code requirements for PBNP.

Bolt preload, as a technique for a locking device for threaded fasteners, is employed at PBNP in certain applications. High strength bolting design and installation was in accordance with AlSC-Specification for the Design, Fabrication, and Erection of Structural Steel for Buildings, (April 1963).

Section 1.23, "Fabrication," and specifically Section 1.23.5, "Riveted and High Strength Bolted Construction-Assembling," details the requirements for bolt tensioning and hence fastener locking. Note, high strength structural bolting at PBNP is in accordance with ASTM A325 and A490.

ASME Section 1I1, Subsection NF - Supports, incorporates the requirements of high strength bolting from the AISC specification. Even though PBNP is not an ASME Section III designed plant for piping, PBNP meets the design requirements for preloading for high strength fasteners as used in component support design and installation.

3.

Torquing Requirements for Quenched and Tempered Bolting - Table 1-2 The recommended torque values specified in Table 1-2 of the EPRI document were derived from page 383 of Crane Co. Catalogue No. 60 published in 1960, and applies a +/- 10% tolerance on the torque values.

NMC currently uses the guidance provided in Ml 32.1 and Form PBF-9142 which contains information that is derived from a more recent Crane Co catalog and applies a +/- 5% tolerance on the torque values. The torque values in the more recent guidance differ slightly from the earlier information for the larger diameter bolting-material. The torque values in Ml 32.1 and Form PBF-9142 are used by maintenance personnel for flange and closure bolting unless torque values are imposed by other documents such as drawings, applicable specifications, or instruction manuals.

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4.

Flanged Joints with Flexitallic Gaskets or Soft. Rubber, or Other Pliable Gaskets - Page 1-13 and 1-14 The first paragraph in this section of NP-5769 states that the torque values specified in Table 1-2 are also recommended for soft, rubber and other pliable gaskets. At PBNP, NMC does not normally use'bolt torque values as the controlling factor for pressure retaining joints that use rubber gasket material over the full face of the joint (i.e., do not have a metal-to-metal interface to control compression) unless specifically evaluated or recommended for the application. Use of the torque values specified in Table 1-2 of Volume II of EPRI NP-5769 may result in over compression of rubber gasket material.

Appropriate tightening of closure bolts for pressure retaining joints that use full face rubber gasket material is controlled by verifying the evenness of the gasket compression without over compressing the gasket material. This is similar to the "skill-of-the-craft" guidance provided in Section 3.7.1 of EPRI TR-1 04213.

5.

Procedures and Personnel - Page 1-17 NP-5769 states that NDE personnel performing or interpreting NDE, including visual examinations specified by codes, are qualified to SNT-TC-1 A-1 975.

PBNP uses NDE personnel qualified and certified to latter revisions of SNT-TC-1A or ANSI/ASNT CP-1 89, which is more restrictive than SNT-TC-1A. This is discussed in the 1998 edition through 2000 Addenda of ASME Section Xl, IWA-2310. NMC will continue to follow the requirements of 10 CFR 50.55a or request relief, as necessary for PBNP. Note that the reference section of Volume II, Section 1 of EPRI -5769 invokes the application of latter editions of various ASME codes, including Section Xl.

6.

Re-Use of Bolting Material - Page 1-18 This section of NP-5769 states that any bolt or nut tightened by the turn-of-nut method shall not be reused. NMC will clarify this requirement to apply only to component support bolting installed in accordance with AISC or similar design specifications in which the turn-of-nut method may result in the bolting material being stressed beyond yield.

7.

Non-ASME Section III Bolting Material - Page 1-3 PBNP is a B 31.1 plant and does not specify ASME Class IlIl requirements for non-ASME Class IlIl bolting. NMC does however require a Certified Material Test Report (CMTR) or a Certificate of Conformance (COC) for the procurement of all QA bolting material. Augmented Quality (AQ) bolting is procured to catalog description/part number or material specification and is verified to meet those standards through generation of a Purchase Order to Page 4 of 9

an approved vendor; reviewing the vendor supplied packing lists, labeling and supplemental documents; and by performing a visual examination consisting of part number verification, marking verification and dimensional verification as applicable.

8.

Hardness Test - Page 1-7 NMC does not perform hardness tests of random samples of bolting material during receipt inspection at PBNP. With few exceptions, (e.g., Hilti Quickbolts), safety related bolting used at PBNP is provided with a CMTR.

NMC reviews the CMTR and confirms that either the hardness or actual tensile or proof load test falls within the acceptable range for the material.

Hardness, tensile strength, and proof load information is not provided if the material is procured only with a COC. NMC would only perform hardness tests if the provided information was suspect based on site or industry operating experience.

LRA Section B2.1.20: Structures Monitoring Program PBNP LRA Section B2.1.20, "Structures Monitoring Program," discusses the ten program elements in the section Aging Management Program Elements. Under the element Acceptance Criteria (Page B-205), the following passage has been extracted and revised as follows (additions are double-underlined; deletions are strikethrough):

"If a structure or component does not meet the acceptance criteria stated in the inspection procedure, the structure/component will be evaluated to determine if it can meet its design basis -still porform its function as defined by the Maintenance Rule (i.e., support and/or protect maintenance rule systems and equipment during normal operation and design basis events). If the structure is found unable to meet its design basis porform its function, it will be reclassified under the Maintenance Rule as (a)(1)."

The incorporation of this wording makes the LRA consistent with Regulatory Guide 1.160, "Monitoring The Effectiveness Of Maintenance At Nuclear Power Plants," Revision 2, and NUREG-1 801, Section XL.S6, "Structures Monitoring Program."

LRA Section 3.2.2.2.2.2: Loss of Material Due to General Corrosion PBNP LRA Section 3.2.2.2.2.2, "Loss of Material Due to General Corrosion," has been revised (deletions are strikethrough) to state that the "Water Chemistry Control Program and/GF One-Time Inspection Program are credited." This revision was made to clarify the use of the combination of the Water Chemistry Control Program and One-Time Inspection Program.

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LRA Section 3.2.2.2.4: Local Loss of Material Due to Microbiologically Influenced Corrosion PBNP LRA Section 3.2.2.2.4, "Local Loss of Material Due to Microbiologically Influenced Corrosion," has been revised (deletions are strikethrough) to state that the "Water Chemistry Control Program andlo One-Time Inspection Program are credited."

This revision was made to clarify the use of the combination of the Water Chemistry Control Program and One-Time Inspection Program.

LRA Section B2.1.13: One-Time Inspection Program The One-Time Inspection Program (LRA Section B2.1.13) provides for follow-up examinations if unacceptable conditions are discovered on passive systems, structures and components (SSCs), thus expanding the sample size and locations of inspections.

NMC will provide the One-Time Inspection Program methodology for NRC review that will detail the sample size selection criteria and specific component identification criteria within that sample.

LRA Section B2.1.21: System Monitoring Program All systems within the scope of license renewal that contain components requiring an aging management review and that credit the Systems Monitoring Program for managing the effects of aging on the external surfaces of the components will be walked down at a minimum frequency of once per operating cycle, within the limits of accessibility. This may be accomplished via one comprehensive walkdown or a series of routine walkdowns, as long as the entire system is walked down within the limits of accessibility. A supervisory review will be performed and documented to ensure that the accessible portions of each system are walked down at a minimum frequency of once per operating cycle. The inspection frequency may be increased based on the safety significance, production significance, and/or operating experience of each system.

Those portions of a system that are considered inaccessible will be evaluated to ensure that accessible portions of the system that are walked down contain the same material(s) and the same or worse environment(s) as those portions that are considered inaccessible. The intent of this evaluation is to ensure that the aging effects on the accessible portions of the system bound those portions that are considered inaccessible. When an unacceptable condition or situation is identified in an accessible portion of a system, an extent of condition evaluation will be performed to determine whether the same condition or situation is applicable to other accessible or inaccessible portions of the system.

LRA Section B2.1.11: Flow-Accelerated Corrosion Program PBNP LRA Section B2.1.1 1, " Flow-Accelerated Corrosion Program," discusses the ten program elements in the section Aging Management Program Elements. Under the Page 6 of 9

elements Monitoring and Trending (Page B-123) and Acceptance Criteria (Page B-123 and B-1 24), the following passages have been extracted and revised as follows (additions are double-underlined; deletions are strikethrough):

Monitoring and Trending CHECWORKS code is used to predict component degradation in systems susceptible to flow-accelerated corrosion (FAC). Plant data, including material composition, system flow characteristics, and operating conditions are also important in determining the remaining service life, which is recalculated after each inspection.

CHECWORKS is acceptable because it provides a bounding analysis for FAC.

The inspection schedule developed on the basis of the results of this predictive code provides reasonable assurance that adequate wall thickness will be maintained between inspections.

If degradation is detected such that the wall thickness is less than or equal to 87.5 % of nominal wall thickness for safety related piping or 60 % of nominal wall thickness for non-safety related piping, additional examinations will be performed in adiacent areas to bound the thinning. The sample size will also be expanded when inspection results indicate that a component has a remaining service life less than one operating cycle.

This covers situations where the code minimum allowable wall thickness may be greater than 60 'o of nominal wall thickness. The expansion of the sample size should include a minimum of the next two most susceptible components in that CHECWORKS line.

any component within two pipe diameters downstream (upstream if expander), or like components in parallel trains. If the initial expansion finds additional components with significant loss of material due to FAG, the examination scope is expanded further.

This element includes exceptions to the corresponding NUREG-1801 aging management program element. NUREG-1801 states: "If degradation is detected such that the wall thickness is less than the minimum predicted thickness, additional examinations are performed in adiacent areas to bound the thinning." Literal interpretation of this sample expansion criteria is not practical in many cases. If very little degradation is predicted, measured wall thickness may be less than the predicted thickness even though the calculated life of the affected component may exceed the operating life of the plant. In this case, sample expansion would not be warranted.

The FAC program at PBNP implements the EPRI guidelines in NSAC-202L-R2. which recommends increasing the sample size when inspections of the sample detect significant FAC wear. In the PBNP FAC program, significant FAC wear is defined as FAC resulting in a wall thickness of less than or equal to 87.5 % of nominal wall thickness for safety related piping or 60 % of nominal wall thickness for non-safety related piping. In addition, the sample size will be expanded when inspection results indicate that a component has a remaining service life less than one operating cycle.

This covers situations where the code minimum allowable wall thickness may be greater than 60 % of nominal wall thickness. This criterion for sample expansion is acceptable Page 7 of 9

because it specifies a wall thickness criterion and requires projection of inspection results to the next inspection opportunity consistent with industry guidance. Therefore, PBNP meets the intent of this NUREG-1801 aging management program element.

Acceptance Criteria Inspection results are used to calculate the number of operating cycles remaining before the component reaches code minimum allowable wall thickness. If calculations indicate that an area will reach code minimum allowable wall thickness before the next inspection interval, the component must be replaced, repaired, or re-evaluated.

The acceptance criteria are well defined in plant pFroedures. For example, if minimum measured thickness is lees than 700% of pipe nominal wall thickness the sample size must be expanded. The expansion must include a minimum of the next two most 6ur.,Gptible rempanents in that GHEGWORKS line, any component within two diameter downstream (up stream if expander), or like omponents in parallel trains. If the initial expansion finds additional comAponents With significant loss6 of material due to FAC, the examination scope is expanded further. If the measured wall thickness is less than :F-mn (the code minimum allowable wall thickness), a local thinning evaluation is performed using the methodology of an approved ASME Section Xl Code Case. If the component cannot satisfy the local thinning evaluation, it must be replaced or repaired.

Procedures will be enhanced to require a local thinning evaluation if the measured wall thickness is less than T-min (the code minimum allowable wall thickness)

This element is consistent with the corresponding NUREG-1 801 aging management program element.

LRA Section B2.1.15: Periodic Surveillance and Preventive Maintenance Program Records of deferrals, cancellations, and frequency changes for callups credited for License Renewal as aging management or replacement activities will be retained in an auditable and retrievable form prior to entering the period of extended operation.

LRA Section 4.5: Loss of Preload In NMC letter to the NRC dated February 23, 2005, the confirmatory Pre-Stressed Concrete Containment Tendon Surveillance Program (LRA Section B3.3) was deleted since the analyses associated with containment tendon loss of pre-stress have been projected to the end of the period of extended operation, in accordance with the requirements of 10 CFR 54.21 (c)(1)(ii) (LRA Section 4.5.1).

LRA Section B2.1.1 0: Fire Protection Program The following revision is being made in response to the March 2005 NRC Region IlIl License Renewal Inspection. This change is being made to indicate that periodic full Page 8 of 9

flow flushing of the main fire system underground piping is being conducted to ensure that the system function is being maintained and that no credit is being taken for corrosion control by the flushing. This text is located on page B-1 15 of the PBNP LRA (deletions are strikethrough).

Monitoring and Trending The fire protection system pressure is continuously monitored. Test results from the various surveillance tests are evaluated. Periodic full flow flushing of the main fire system underground piping is performed to assure that corrosion is not occurring and the system function is maintained. Any degradation identified either by visual inspections or as a result of testing is evaluated and corrected.

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