ML052270275
| ML052270275 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 08/24/2005 |
| From: | Marinos E NRC/NRR/DLPM/LPD2 |
| To: | Christian D Virginia Electric & Power Co (VEPCO) |
| Marinos E, NRR/DE/EEIB, 415-2911 | |
| References | |
| TAC MC5451, TAC MC5452 | |
| Download: ML052270275 (11) | |
Text
August 24, 2005 Mr. David A. Christian Sr. Vice President and Chief Nuclear Officer Virginia Electric and Power Company Innsbrook Technical Center 5000 Dominion Blvd.
Glen Allen, Virginia 23060-6711
SUBJECT:
NORTH ANNA POWER STATION, UNITS 1 AND 2 - RELIEF REQUEST FOR SNUBBER VISUAL EXAMINATION AND FUNCTIONAL TESTING (TAC NOS.
Dear Mr. Christian:
By letter dated December 21, 2004, Virginia Electric and Power Company (VEPCO) requested relief from certain requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code,Section XI, with regard to the visual examination and the functional testing of snubbers at North Anna Power Station, Units 1 and 2. In its submittal, VEPCO had requested approval of Revision 1 to previously approved Relief Request CS-3 for North Anna, Unit 1 and Revision 1 to previously approved Relief Request CS-1 for North Anna, Unit 2. The Nuclear Regulatory Commission (NRC) staff has completed its review of these revisions to the relief requests, and the NRC staffs evaluation and conclusions are contained in the enclosed Safety Evaluation.
The NRC staff concludes that the proposed alternatives in Relief Request CS-3, Revision 1 and Relief Request CS-1, Revision 1 provides an acceptable level of quality and safety and, thus, ensures the structural integrity of the related systems. Therefore, Relief Request CS-3, Revision 1 for North Anna, Unit 1 and Relief Request CS-1, Revision 1 for North Anna, Unit 2 are authorized pursuant to Title 10 of the Code of Federal Regulations Section 50.55a(a)(3)(I) for the snubber functional testing for the remainder of the third 10-year inservice inspection interval.
Sincerely,
/RA/
Evangelos A. Marinos, Chief, Section 1 Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-338 and 50-339
Enclosure:
As stated cc w/encl: See next page
August 24, 2005 Mr. David A. Christian Sr. Vice President and Chief Nuclear Officer Virginia Electric and Power Company Innsbrook Technical Center 5000 Dominion Blvd.
Glen Allen, Virginia 23060-6711
SUBJECT:
NORTH ANNA POWER STATION, UNITS 1 AND 2 - RELIEF REQUEST FOR SNUBBER VISUAL EXAMINATION AND FUNCTIONAL TESTING (TAC NOS.
Dear Mr. Christian:
By letter dated December 21, 2004, Virginia Electric and Power Company (VEPCO) requested relief from certain requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code,Section XI, with regard to the visual examination and the functional testing of snubbers at North Anna Power Station, Units 1 and 2. In its submittal, VEPCO had requested approval of Revision 1 to previously approved Relief Request CS-3 for North Anna, Unit 1 and Revision 1 to previously approved Relief Request CS-1 for North Anna, Unit 2. The Nuclear Regulatory Commission (NRC) staff has completed its review of these revisions to the relief requests, and the NRC staffs evaluation and conclusions are contained in the enclosed Safety Evaluation.
The NRC staff concludes that the proposed alternatives in Relief Request CS-3, Revision 1 and Relief Request CS-1, Revision 1 provides an acceptable level of quality and safety and, thus, ensures the structural integrity of the related systems. Therefore, Relief Request CS-3, Revision 1 for North Anna, Unit 1 and Relief Request CS-1, Revision 1 for North Anna, Unit 2 are authorized pursuant to Title 10 of the Code of Federal Regulations Section 50.55a(a)(3)(i) for the snubber functional testing for the remainder of the third 10-year inservice inspection interval.
Sincerely,
/RA/
Evangelos A. Marinos, Chief, Section 1 Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-338 and 50-339
Enclosure:
As stated cc w/encl: See next page Distribution PUBLIC RidsNrrLA (CHawes) JHoncharik PDII-1 R/F RidsRgn2MailCenter ALee RidsNrrDlpmLpdii1 (EMarinos) EHackett RidsAcrsAcnwMailCenter RidsNrrPMSMonarque RidsOgcRp GHill (2)
ADAMS ACCESSION NO. ML052270275 NRR-028 *No substantive changes OFFICE PDII-1/PM PDII-1/LA EMEB-A OGC PDII-1/SC NAME JHoncharik CHawes RKaras* KKannler EMarinos DATE 8/16/05 8/16/05q 7/21/05 8/24/05 8/24/05 OFFICIAL RECORD COPY
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELIEF REQUEST FOR SNUBBER VISUAL EXAMINATION AND FUNCTIONAL TESTING VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION, UNITS 1 & 2 DOCKET NO. 50-338/339
1.0 INTRODUCTION
By letter dated December 21, 2004, Virginia Electric and Power Company (VEPCO, the licensee) submitted a request for relief for the third 10-year inservice inspection interval of Title 10 of the Code of Federal Regulations (10 CFR) Section 50.55a(g) for North Anna Power Station, Units 1 & 2. The licensee requested approval to use an alternative to the inservice inspection requirements for examination and testing of snubbers in Article IWF-5000 of Section XI of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code) on preservice and inservice examinations and tests of Class 1, 2, and 3 Snubbers. The licensee requested approval to use the proposed alternative of a combination of the existing North Anna, Units 1 & 2 Technical Requirements Manual (TRM) Section 3.7.5 and other applicable ASME Code requirements.
2.0 BACKGROUND
Inservice inspection of the ASME Code Class 1, 2, and 3 components is to be performed in accordance with Section XI, "Rules for Inservice Inspection of Nuclear Power Plant Components," of the ASME Code and applicable addenda as required by 10 CFR 50.55a(g),
except where specific written relief has been granted by the Commission pursuant to 10 CFR 50.55a(g)(6)(i). Section 50.55a(a)(3) of 10 CFR Part 50 states in part that alternatives to the requirements of paragraph (g) may be used, when authorized by the Nuclear Regulatory Commission (NRC), if the licensee demonstrates that: (i) the proposed alternatives would provide an acceptable level of quality and safety or (ii) compliance with the specified requirements 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 pre-service examination requirements, set forth in the ASME Code,Section XI, to the extent practical within the limitations of design, geometry, and materials of construction of the components. The regulation requires that inservice examination of components and system pressure tests conducted during the first 10-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.
ATTACHMENT
Pursuant to 10 CFR 50.55a(g)(5), if the licensee determines that conformance with an examination requirement of Section XI of the ASME Code is not practical for its facility, information will be submitted to the Commission in support of that determination and a request must be made for relief from the ASME Code requirement. After evaluation of the determination, pursuant to 10 CFR 50.55a(g)(6)(i), the Commission may grant relief and/or may impose alternative requirements that are determined to be authorized by law, will not endanger life, property, or the common defense and security, and are otherwise in the public interest, giving due consideration to the burden upon the licensee that could result if the requirements were imposed.
The applicable edition of Section XI of the ASME Code for the North Anna, Unit 1 third 10-year interval is the 1989 Edition of ASME Section XI. The North Anna, Unit 2 code of reference is the 1995 Edition with addenda up to and including the 1996 Addenda.
Currently, North Anna tests snubbers in accordance with approved Relief Requests CS-3 for Unit 1 and CS-1 for Unit 2, which were approved by the NRC in letters dated September 7, 2001, and May 9, 2002, respectively. These relief requests addressed the use of Technical Specification requirements with regard to examination and functional testing of snubbers in lieu of the ASME Section XI Code requirements. In a subsequent letter to the NRC dated June 13, 2002, VEPCO notified the NRC that the testing requirements for snubbers had been relocated from the North Anna, Units 1 and 2 Technical Specifications to the North Anna TRM as part of the Improved Technical Specification implementation and that no change to these requirements had been made.
3.0 EVALUATION By letter dated December 21, 2004, the applicant stated that the historical performance of snubbers at North Anna has not exceeded one snubber surveillance failure per inspection cycle since 1992. In order to account for this historical performance, the applicant requests approval, pursuant to 10 CFR 50.55a (a)(3)(i), of the proposed revisions to CS-3 and CS-1 to permit use of a C value of C=1, in lieu of C=2, in the snubber sampling formula of the TRM. The C is the number of functional test failures required before expanded sampling begins. It establishes the initial sample size, and, when exceeded, it establishes the snubber functional test expansion requirement.
The information provided by the licensee in support of the requests for relief from the ASME Code requirements has been evaluated and the basis for disposition is documented below.
Relief Request CS-3 Revision 1, North Anna, Unit 1 The ASME Code,Section XI, 1989 Edition, paragraphs IWF-5200 (b) and IWF-5300 (b) require the use of the ASME/ANSI OM-1987 Code (ASME OM Code), Code for Operation and Maintenance of Nuclear Power Plants, Part 4, published in 1988, to perform the preservice and inservice tests of Class 1, 2, and 3 snubbers.
The licensee stated in its submittal dated December 21, 2004, that integration of Section XI of the ASME Code and Subsection ISTD, Preservice and Inservice Examination and Testing of
Dynamic Restraints (Snubbers) in Light-Water Reactor Nuclear Plants of the ASME OM Code into an effective, coherent testing program along with associated required changes to the TRM would require a significant amount of administrative activity (e.g., administrative procedure changes, reconciliation of ASME Code requirement differences, technical procedure changes, etc.). The licensee proposed an approach which provides a means to accomplish the examination and testing required by Section XI of the ASME Code and the ASME OM Code with minimum additional burden.
The current testing and examination requirements of TRM Section 3.7.5 formed the basis of the North Anna, Unit 1 inservice testing program for snubbers during the past (2nd) ISI interval.
The licensee stated that Revision 1 of this relief request permits a C value of one to be utilized in the sampling formula of the TRM. The licensee stated that the change from C=2 to C=1 is desirable to take advantage of the historically low number of snubber failures experienced at North Anna. There has not been more than one failure from the required surveillance test group during any inspection cycle since 1992. The C value establishes the initial size, and when exceeded, establishes the size for the expanded snubber functional test group.
To demonstrate that reducing the allowable number of small-bore snubber functional test failures from two to one would continue to provide an adequate degree of testing, the licensee has performed a comparison of the current TRM formula to that of the 1995 Edition with 1996 Addenda of the ASME OM Code, Subsection ISTD, Preservice and Inservice Examination and Testing of Dynamic Restraints (Snubbers) in Light-Water Reactor Power Plants (ASME OMa Code-1995 with 1996 Addenda), assuming similar failure rates.
The licensee stated that the current formula used in TRM Section 3.7.5 to determine the initial number of small bore snubbers to be functionally tested each cycle is as follows: At least once per 18 months during shutdown, a representative sample of small bore snubbers which follows the expression 35(1+C/2), where C=2 is the allowable number of small bore snubbers not meeting the acceptance criteria selected by the operator, shall be functionally tested either in-place or in a bench test. The equation used in the TRM to define expanded sample size is 35(1+C/2)(2/(C+1))2(A-C) where C is the allowable number of functional failures (currently equal to two), and A is the total number of functional test failures in the initial sample size.
This equation is used when A exceeds C. Three functional test failures are required before an expanded sampling happens with C=2. With C=1, the number of functional test failures required before expanded sampling begins will change to two. The TRM formula is based on guidance given in NUREG-0452, Standard Technical Specifications for Westinghouse Pressurized Water Reactors, Revision 3, issued in Fall 1980. NUREG-0452, Section 4.7.9 states in part The value C will be arbitrarily chosen by the applicant and incorporated into the expressions for the representative sample and for the resample prior to the issuance of the Technical Specifications. The TRM establishes a C to account for a certain number of failures before the testing population has to be expanded. This builds a failure rate into the group to be tested each outage before scope expansion would be required.
The ASME OMa Code-1995 with 1996 Addenda uses two different formulas for establishing the number of snubbers to be initially functionally tested. The licensees decision of which plan to use is determined by the number of snubbers installed in the station. North Anna, Unit 1 has less than 370 snubbers and therefore the 10% plan is the licensees preferred plan and will be used for comparison to the TRM formula. ASME OMa Code-1995 with 1996 Addenda (Subsection ISTD, paragraph 7.9.2) states that the additional sample size shall be at least one-half the size of the original sample. So the total number of snubbers to be tested, including initial test group, is N $ 0.1n + C(0.1n/2) where N is the total number of snubbers to be tested, n is the total number of snubbers in the defined test plan group, and C is the number of unacceptable snubbers found through functional testing.
It can be seen that the ASME OMa Code-1995 with 1996 Addenda formula does not define a pre-set number of allowable failures as does the TRM. It only requires that a minimum number of snubbers be tested based on the population [the 0.1n factor], and an additional number of snubbers be tested for scope expansion based on the number of snubber found inoperable by testing [the C(0.1n/2) factor]. Substituting the number of snubbers for North Anna, Unit 1, this formula is reduced to N $ 32.6 + 16.3C The licensee provided the initial sizes and expanded sample sizes, once the allowable number of functional test failures is exceeded, in the table below.
TRM formula ASME OMa Code (same values for both units) Values Functional C=2 C=1 North Anna, Unit 1 test failures (Current value) (Proposed value)
A=3 102 158 82 A=2 70 106 66 A=1 70 53 49 A=0 70 53 33 (Note: the value A or functional test failures as defined here by the TRM would be equivalent to the value C in the ASME OMa Code-1995 with 1996 Addenda formula.)
From the above table it can be seen that the TRM formula, with C=2 (current value) or C=1 (proposed value), will require testing of essentially the same or more snubbers than would be required by the ASME OMa Code-1995 with 1996 Addenda. The comparison in the table demonstrates that changing the value of C (from 2 to 1) in the TRM formula will continue to
provide an adequate degree of testing when compared to the ASME OMa Code-1995 with 1996 Addenda.
Based on the above snubber testing/sample size comparison, the staff finds that the proposed TRM Section 3.7.5 (C=1) functional testing requirements will continue to provide an equivalent level of quality and safety for inservice testing of snubbers. It is, therefore, acceptable to the NRC staff.
However, to comply with the preservice testing requirements of the ASME Code verbatim, the licensee stated that additional testing activity is required beyond the above proposal for inservice snubber testing activities. Therefore, the licensee proposes that the inclusion of the snubber testing requirements contained in ASME OMa Code-1995 with 1996 Addenda, subsection ISTD, paragraph 5, Preservice Operability Testing, into the current snubber surveillance program provides an alternative with an acceptable level of safety and quality for the preservice testing requirements. The licensee stated that the inclusion of these requirements into the snubber surveillance program achieves the preservice inspection requirements of the ASME Code with only small administrative impact. No other requirements of Subsection ISTD will be implemented as part of this alternative. Since Subsection ISTD, paragraph 5 has been accepted by the NRC for the snubber preservice testing, this is acceptable to the NRC staff.
In summary, the licensee proposed as an alternative to the Section XI of the ASME Code requirements a snubber surveillance program comprised of the following elements:
(1) The continued implementation of the surveillance requirements of TRM Section 3.7.5, Snubbers, with C=1, and (2) The preservice testing requirements of ASME OMa Code-1995 with 1996 Addenda, subsection ISTD, paragraph 5, Preservice Operability Testing.
The staff has reviewed the above information provided in the licensees submittal of December 21, 2004, and concludes that the licensees relief request meets the intent of the requirements of ASME Code,Section XI, and is, therefore, acceptable to the NRC staff.
Relief Request CS-1 Revision 1, North Anna, Unit 2 The ASME Code,Section XI, 1995 Edition with addenda up to and including the 1996 Addenda, paragraphs IWF-5200(a) and (b) and IWF-5300(a) and (b) require the use of the ASME/ANSI OM-1987 Code (ASME OM Code), Code for Operation and Maintenance of Nuclear Power Plants, Part 4, published in 1988, to perform the preservice and inservice examinations and functional testing of Class 1, 2, and 3 snubbers.
The licensee in its submittal dated December 21, 2004, proposed as an alternative to the requirements of ASME OM Code to use the existing North Anna, Unit 2, Technical Requirements Manual (TRM) Section 3.7.5 and specific paragraphs from ASME OM Code, Subsection ISTD, Inservice Testing of Dynamic Restraints (Snubbers) in Light-Water Reactor Power Plants. The snubber requirements were formerly in Technical Specifications.
The licensee stated that differences exist between the referenced ASME Code,Section XI requirements and North Anna, Unit 2 TRM Section 3.7.5, Snubbers. The ASME Code contains requirements which were removed from the plant Technical Specifications as recommended by Generic Letter (GL) 90-09, Alternative Requirements for Snubber Visual Inspection Intervals and Corrective Actions, dated December 11, 1990, which has been accepted by the NRC.
Section XI of the ASME Code continues to require the restrictive inspection schedule of ASME OM Code, for inservice examination of snubbers. A later revision of the ASME OM Code, the ASME OMa Code - 1995 with 1996 Addenda, Subsection ISTD, changed the inspection scheduling requirements to essentially agree with the recommendations of GL 90-09. The rulemaking of September 22, 1999, recognized this fact and included in the rule a provision to allow the use of Subsection ISTD provided the licensee revises the applicable Technical Specifications (now the TRM). Table 3.7.5-1 of the TRM provides the inspection scheduling requirements similar to GL 90-09 and Subsection ISTD .
The licensee stated, however, that the simple inclusion of Subsection ISTD of ASME OMa Code - 1995 with 1996 Addenda into the TRM does more than alter the excessive examination requirements of the ASME OM Code. Subsection ISTD of ASME OMa Code - 1995 with 1996 Addenda is written as a self-contained surveillance program for determining the continuing acceptability of snubbers. It is not designed to be used as a supplement to Section XI of the ASME Code. The integration of Section XI of the ASME Code and Subsection ISTD of the ASME OMa Code - 1995 with 1996 Addenda into an effective coherent examination and testing program along with the required change to the TRM would result in a significant amount of administrative activity without a compensating increase in safety. On this basis, the licensee proposed that the following alternative approach would avoid this unnecessary administrative impact and still provide a means to accomplish the examination and testing required by Section XI of the ASME Code and the Subsection ISTD of the ASME OMa Code - 1995 with 1996 Addenda.
The licensee stated that the current examination and testing requirements of TRM Section 3.7.5 and the additional visual examination requirements of the approved ASME Code,Section XI, 1995 Edition with addenda up to and including the 1996 Addenda, have formed the basis of the North Anna, Unit 2 inservice examination and testing program for snubbers for the past inservice inspection interval. The licensee stated that this program is essentially the same as the program for examination and testing described in Subsection ISTD for inservice inspection, and, therefore, will continue to provide an acceptable level of quality and safety for inservice examination and testing of snubbers.
The licensee stated that Revision 1 of this relief request permits a C value of one to be utilized in the sampling formula of the TRM. The licensee stated that the change from C=2 to C=1 is desirable to take advantage of the historically low number of snubber failures experienced at North Anna. There has not been more than one failure from the required surveillance test group during any inspection cycle since 1992. The C value establishes the initial size, and when exceeded, establishes the size for the expanded snubber functional test group.
To demonstrate that reducing the allowable number of small-bore snubber functional test failures from two to one would continue to provide an adequate degree of testing, the licensee has performed a comparison of the current TRM formula to the ASME OMa Code - 1995 with 1996 Addenda, Subsection ISTD formula, assuming similar failure rates.
The licensee stated that the current formula used in TRM Section 3.7.5 to determine the initial number of small bore snubbers to be functionally test each cycle is as follows: At least once per 18 months during shutdown, a representative sample of small bore snubbers which follows the expression 35[1+C/2], where C=2 is the allowable number of small bore snubbers not meeting the acceptance criteria selected by the operator, shall be functionally tested either in-place or in a bench test. The equation used in the TRM to define expanded sample size is 35(1+C/2)(2/(C+1))2(A-C) where C is the allowable number of functional failures (currently equal to two), and A is the total number of functional test failures in the initial sample size.
This equation is used when A exceeds C. Three functional test failures are required before an expanded sampling happens with C=2. With C=1, the number of functional test failures required before expanded sampling begins will change to two. The TRM formula is based on guidance given in NUREG 0452, Standard Technical Specifications for Westinghouse Pressurized Water Reactors, Revision 3, issued in Fall 1980. NUREG-0452, Section 4.7.9 states in part The value C will be arbitrarily chosen by the applicant and incorporated into the expressions for the representative sample and for the resample prior to the issuance of the Technical Specifications. The TRM establishes a C to account for a certain number of failures before the testing population has to be expanded. This builds a failure rate into the group to be tested each outage before scope expansion would be required.
The ASME OMa Code - 1995 with 1996 Addenda uses two different formulas for establishing the number of snubbers to be initially functionally tested. The licensees decision of which plan to use is determined by the number of snubbers installed in the station. North Anna, Unit 2 has less than 370 snubbers and, therefore, the 10 percent plan is the licensees preferred plan and will be used for comparison to the TRM formula. The ASME OMa Code - 1995 with 1996 Addenda (Subsection ISTD, paragraph 7.9.2) states that the additional sample size shall be at least one-half the size of the original sample. So the total number of snubbers to be tested, including initial test group, is N $ 0.1n + C(0.1n/2) where N is the total number of snubbers to be tested, n is the total number of snubbers in the defined test plan group, and C is the number of unacceptable snubbers found through functional testing.
It can be seen that the ASME OMa Code - 1995 with 1996 Addenda formula does not define a pre-set number of allowable failures as the TRM does. It only requires that a minimum number of snubbers be tested based on the population [the 0.1n factor] and an additional number of snubbers be tested for scope expansion based on the number found inoperable by testing [the C(0.1n/2) factor]. Substituting the number of snubbers for North Anna, Unit 2, this formula reduces to:
N $36.2 + 18.1C The licensee provided the initial sizes and expanded sample sizes once the allowable number of functional test failures is exceeded in the table below.
TRM formula ASME OMa Code (same values both units) Values Functional C=2 C=1 Unit 2 test failures (Current value) (Proposed value)
A=3 102 158 91 A=2 70 106 73 A=1 70 53 55 A=0 70 53 37 (Note: the value A or functional test failures as defined by the TRM would be equivalent to the value C in the ASME OMa Code - 1995 with 1996 Addenda formula.)
From the above table it can be seen that the TRM formula with C=2 (current value) or C=1 (proposed value) will require testing of essentially the same or more snubbers than the ASME OMa Code -1995 with 1996 Addenda, except in the case where A=1, but the difference in this case is considered insignificant. The comparison in the table demonstrates that changing the value of C (from 2 to 1) in the TRM formula will continue to provide an adequate degree of testing when compared to the ASME OMa Code - 1995 with 1996 Addenda .
Based on the above snubber testing/sample size comparison, the NRC staff finds that the proposed TRM Section 3.7.5 ©=1) functional testing requirements will continue to provide an acceptable level of quality and safety for inservice testing of snubbers. Therefore, it is acceptable to the NRC staff.
To satisfy the preservice examination and testing requirements intended by Section XI of the ASME Code, however, additional examination and testing activity is required beyond the above proposal for inservice snubber testing activities. Therefore, the licensee proposed to include the preservice examination and testing requirements contained in Subsection ISTD, paragraph 4, Preservice Examination (excluding Subsection ISTD, paragraph 4.3), and Subsection ISTD, paragraph 5, Preservice Operability Testing, respectively, into the current snubber surveillance program. The licensee stated that Subsection ISTD, paragraph 4.3 is not proposed as it addresses requirements best suited for the initial heatup and cooldown of the plant. It would be a burden to impose these requirements on an operating plant such as North Anna, Unit 2, which is constructed with a sub-atmospheric containment. As an alternative to the requirements of Subsection ISTD, paragraph 4.3, the licensee will follow the guidance of IWF-2220(b) to Section XI of the ASME Code for systems that operate at a temperature greater than 200EF. IWF-2220(b) to Section XI of the ASME Code requires the Owner to perform an additional preservice examination on the affected component supports during or following the subsequent system heatup and cooldown cycle unless determined unnecessary by evaluation.
The staff considers that the inclusion of these requirements into the snubber surveillance program provides an adequate alternative for the preservice examination and testing requirements of Section XI of the ASME Code. Since the proposed alternative provides an acceptable level of quality and safety for supports, it is acceptable to the NRC staff.
No other requirements of Subsection ISTD will be implemented as part of this alternative.
In summary, the licensee proposed as an alternative to Section XI of the ASME Code, requirements a snubber surveillance program comprised of the following elements:
(1) The continued implementation of the surveillance requirements of TRM Section 3.7.5, Snubbers, with C=1, (2) The implementation of the other applicable requirements of the ASME Code,Section XI, 1995 Edition with addenda up to and including the 1996 Addenda, unless specific approval has been obtained to do otherwise from the NRC, pursuant to the requirements of 10 CFR 50.55a and the plants TRM. This will include using the VT-3 visual examination method in IWA-2213 to Section XI of the ASME Code for preservice and inservice examinations, (3) The preservice examination requirements of Subsection ISTD, paragraph 4, Preservice Examination, excluding Subsection ISTD, paragraph 4.3; and Subsection ISTD, paragraph 5, Preservice Operability Testing, and (4) An additional preservice examination on the affected snubbers during or following the subsequent system heatup and cooldown cycle, in accordance with IWF-2200(b) to Section XI of the ASME Code, for systems that operate at a temperature greater than 200EF.
The staff has reviewed the information provided in the licensees submittal of December 21, 2004, and concludes that the licensees relief request meets the intent of the ASME Code,Section XI, requirements, and is, therefore, acceptable to the NRC staff.
3.0 CONCLUSION
Based on the information provided by the licensee, the NRC staff concluded that with respect to Relief Request CS-3, Revision 1, for North Anna, Unit 1, the licensee has presented an adequate justification for its relief from the requirements of ASME Code,Section XI, 1989 Edition, with regard to snubber functional testing of the North Anna, Unit 1 Class 1, 2, and 3 snubbers. The staff concurs with the licensee that the proposed alternative snubber testing program, based on TRM Section 3.7.5 ©=1), with the inclusion of the preservice operability testing requirements of Subsection ISTD, paragraph 5 of ASME OMa Code - 1995 with 1996 Addenda, provides an acceptable level of quality and safety, and thus ensures structural integrity of the related systems.
The staff also concludes that, with respect to Relief Request CS-1, Revision 1, for Unit 2, the licensee has presented an adequate justification for its relief from the requirements of ASME Code,Section XI, 1995 Edition with addenda up to and including the 1996 Addenda, with regard to visual examination and functional testing of the North Anna, Unit 2 Class 1, 2, and 3 snubbers. The staff concurs with the licensee that the proposed alternative, which includes requirements of the current TRM Section 3.7.5 ©=1), other applicable visual examination requirements of Section XI of the ASME Code (including VT-3 examination method), the preservice examination and testing requirements of Subsection ISTD, paragraph 4 (excluding
ISTD, paragraph 4.3) and Subsection ISTD, paragraph 5, respectively, in addition to the requirements of IWF-2200(b) to Section XI of the ASME Code, provides an acceptable level of quality and safety, and thus ensures structural integrity of the related systems.
Therefore, pursuant to 10 CFR 50.55a(a)(3)(I), the licensee's alternatives stated in its requests for relief, CS-3, Revision 1 and CS-1, Revision 1, relating to the third 10-year inservice inspection interval of the North Anna, Units 1 and 2, respectively, are authorized.
North Anna Power Station, Units 1 & 2 cc:
Mr. C. Lee Lintecum Mr. Jack M. Davis County Administrator Site Vice President Louisa County North Anna Power Station Post Office Box 160 Virginia Electric and Power Company Louisa, Virginia 23093 Post Office Box 402 Mineral, Virginia 23117-0402 Ms. Lillian M. Cuoco, Esq.
Senior Counsel Dr. Robert B. Stroube, MD, MPH Dominion Resources Services, Inc. State Health Commissioner Building 475, 5 th floor Office of the Commissioner Rope Ferry Road Virginia Department of Health Waterford, Connecticut 06385 Post Office Box 2448 Richmond, Virginia 23218 Dr. W. T. Lough Virginia State Corporation Commission Division of Energy Regulation Post Office Box 1197 Richmond, Virginia 23218 Old Dominion Electric Cooperative 4201 Dominion Blvd.
Glen Allen, Virginia 23060 Mr. Chris L. Funderburk, Director Nuclear Licensing & Operations Support Dominion Resources Services, Inc.
Innsbrook Technical Center 5000 Dominion Blvd.
Glen Allen, Virginia 23060-6711 Office of the Attorney General Commonwealth of Virginia 900 East Main Street Richmond, Virginia 23219 Senior Resident Inspector North Anna Power Station U. S. Nuclear Regulatory Commission 1024 Haley Drive Mineral, Virginia 23117