ML20239A253
| ML20239A253 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 09/03/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20239A247 | List: |
| References | |
| NUDOCS 9809080342 | |
| Download: ML20239A253 (10) | |
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t UNITED STATES g
j NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 3004H001 e%
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.....p SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION
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REQUESTS FOR RELIEF NUMBERS RR-17 AND RR-18 EDWIN l. HATCH NUCLEAR PLANT. UNITS 1 AND 2 DOCKET NOS: 50-321 AND 50-366
1.0 INTRODUCTION
i The Technical Specifications (TS) for Edwin I. Hatch Nuclear Plant (Hatch), Units 1 and 2, state j
that the inservice inspection of the American Society of Mechanical Engineers (ASME) Code Class 1,2, and 3 components shall be performed in accordance with Title 10 of the Code of Federal Reoufations (10 CFR)Section XI of the ASME Boiler and Pressure Vessel Code (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) states that alternatives to the requirements of paragraph (g) may be used, when authorized by the NRC, if (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 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 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. The applicable edition of Section XI of the l
ASME Code for Hatch, Units 1 and 2, third 10-year inservice inspection (ISI) interval is the 1989 Edition.
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By letter dated February 27,1998, Southern Nuclear Operating Company, Inc. (the licensee),
j submitted Requests for Relief Numbers RR-17 and RR-18, seeking relief from the ASME Code,Section XI requirements for Hatch, Units 1 and 2.
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9809080342 900903 I
PDR ADOCK 05000321 G
. 2.0 EVALUATION The staff, with technical assistance from its contractor, the Idaho National Engineering and Environmental Laboratory (INEEL), has evaluated the information provided by the licensee in support of its Requests for Relief Numbers RR-17 and RR-18, for Hatch, Units 1 and 2.
j Based on the results of the review, the staff adopts the contractor's conclusions and recommendations presented in the Technical Letter Report (Enclosure 2).
The Code requires that all Class 1 components within the reactor coolant system (RCS) boundary undergo a system hydrostatic test once per interval. The licensee has proposed an attemative to the hydrostatic test requirements of the Code for some line segments as i
' described in RR-17. The line segments, as stated by the licensee, include two manually l
operated valves separated by a short pipe nipple that is connected to the RCS via another short pipe nipple and half coupling. The line configuration, as outlined, provides double isolation of the RCS system..Under normal plant operating conditions, the subject line segments would see RCS temperatures' and pressures only if leakage through the inboard valve occurs. For the i
licensee to perform the Code-required test, it would be necessary to manually open the inboard
. valves to pressurize the line segments. Pressurization by this method would defeat the RCS double isolation and may cause safety concems for the personnel performing the examination.
Typical line/ valve configurations are in close proximity to the primary and secondary RCS piping. Manual actuation (opening and closing) of these valves is ectimated to expose plant personnel to 1.6 man-rem per test. Therefore, the Code requirement to perform the system hydrostatic test on these isolated line segments presents a substantial hardship for the licensee. The licensee proposed to visually examine the isolation valves in the normally closed position for leaks and evidence of past leakage during the system leakage test each refueling outage. Also, the RCS vent and drain connections will be visually examined with the isolation valves in the normally closed position during the 10-year inservice inspection pressure test.
The licensee's proposed attemative will provide reasonable assurance that operational readiness is maintained for the subject line segments. Imposition of the Code requirement on Hatch would cause a burden that would not be compensated by an increase in quality and safety.' Therefore, the licensee's proposed alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(ii).
9 With respect to RR-18, the Code requires that vehicular technology (VT)-2 visual examination personnel be qualified and certified in accordance with SNT-TC-1 A. The Code also requires that the examination personnel be qualified for near and far distance vision acuity. In lieu of the Code requirements, the licensee proposed to implement Code Case N-546 for personnel
- performing VT-2 visual examinations. The qualification requirements in Code Case N-546 are
- not significantly different from those for VT-2 visual examiner certification. Licensed and nonficensed operators, local kak rate personnel, system engineers, and inspection and l-nondestructive examination personnel typically have a sound working knowledge of plant components and piping layouts. This knowledge makes them acceptable candidates for l
performing VT-2 visual examinations and, thus, an acceptable level of quality and safety will be I
maintained. Therefore, the licensee's request to implement Code Case N-546 with the additional commitments made in RR-18 to maintain personnel certification records is authorized pursuant to 10 CFR 50.55a(s)(3)(i). Use of this Code Case is authorized for the current interval
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- or until such time as the Code Case is published in a future revision of Regulatory Guide 1.147.
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i At that time, if the licensee intends to continue to implement this Code Case, the licensee is to i
follow all provisions in Code Case N-546 with limitations issued in Regulatory Guide 1.147, if
- any, l
3.0 CONCLUSION
The staff has reviewed the licensee's submittal requesting relief from the ASME Code,Section XI requirements and the proposed alternatives to hydrostatic test requirements and personnel qualifications as stated in RR-17 and RR-18. With respect to RR-17, the staff has concluded that compliance with the Code would result in hardship without a compensating increase in the level of quality and safety. With respect to RR-18, tha staff has concluded that the alternative proposed will provide an acceptable level of quality and safety. Therefore, the proposed alternatives are authorized.
1 Principal Contributor: T. McLellan 1
Date: September 3, 1998
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O TECHNICAL LETTER REPORT ON THE THIRD 10-YEAR INTERVAL INSERVICE INSPECTION REQUESTS FOR RELIEF NOS. RR-17 AND RR-18 FOR GEORGIA POWER COMPANY l
EDWIN 1. HATCH NUCLEAR PLANT, UNITS 1 AND 2 DOCKET NUMBERS: 50-321 AND 50-366 l
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1.0 INTRODUCTION
By letter dated February 27,1998, Southern Nuclear Operating Company submitted Relief Requests RR-17 and RR-18 for the Edwin 1. Hatch Nuclear Plant, Units 1 and 2, seeking relief from the requirements of the ASME Code,Section XI, for the third 10-year l
inservice inspection (ISI) interval examinations. By letter dated June 17,1998, the licensee responded to the NRC Request for Additional information regarding Request for Relief RR-18. The Idaho National Engineering and Environmental Laboratory (INEEL) staff has evaluated the subject requests for relief in the following section.
2.0 EVALUATION The information provided by the licensee in support of these requests for relief from Code requirements has been evaluated and the bases for disposition are documented below.
The Code of record for the Hatch Nuclear Plant, Units 1 and 2, third 10-year ISI interval is the 1989 Edition of Section XI of the ASME Boiler and Pressure Vessel Code.
2.1 Reauest for Relief No. RR-17 (Rev. OL Examination Cateaorv B-P. Item Numbers B15.51 and B15.71. System Hydrostatic Testina of Small Diameter Pioina and Valves Code Requirement: Section XI, Examination Category B-P, items B15.51 and B15.71 require system hydrostatic testing and associated VT-2 visual examination of all Class 1 pressure retaining pioing and valves.
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Licensee's Pronosed Alternative: Pursuant to 10 CFR 55.55a(a)(3)(ii), the licensee -
proposed an alternative to the Code-required hydrostatic test of small diameter (s1 inch)
Class 1 reactor coolant system pressure boundary vent and drain connections.
Authorization is requested to perform the' Class 1 System Hydrostatic Test with these vent and drain valves in the closed position. The licensee stated:
"The RCS vent and drain connections will be visually examined, for leakage and any evidence of past leakage, with the isolation valves in the normally closed position each refueling outage during the ASME XI Class 1 System Leakage Test (lWB-5221).'
"The RCS vent and drain connections will also be visually examined with the isolation valves in the normally closed position during the 10-year ISI pressure test (lWB-5222 and Code Case N-498-1). This examination will be performed with the RCS at nominal operating pressure and at near operating temperature after satisfying the required 4-hour hold time._
Licensee's Basis for the Prooosed Alternative (as stated):
"These connections are equipped with manual valves which provide for double isolation of the reactor coolant system (RCS) pressure boundary. These valves are generally maintained closed during normal operation and the piping outboard of the first isolation valve is, therefore, not normally pressurized. The proposed attemative provides an acceptable level of safety and quality based on the following:
"1.
ASME Section XI Code, paragraph IWA-4400, provides the requirements for hydrostatic pressure testing of piping and components after repairs by welding to the pressure boundary. IWA-4700(b)(5) excludes component connections, piping, j
and associated valves that are 1 inch nominal pipe size and smaller from the hydrostatic test und visual examination of these si inch diameter RCS vent / drain connections once each 10-year interval is unwarranted considering that a repair
. weld on the same connections is exemoted by the ASME XI Code.
"2.
The non-isolable portion of the RCS vent and drain connections will be pressurized and visually examined as required. Only the isolable portion of these small diameter vent and drain connections will not pressurized.
"3.
A typical vent / drain connection includes two manual valves separated by a short j
pipe nipple which is connected to the RCS via another short pipe nipple and a half coupling. All connections are typically socket-welded and the welds received a surface examination after installation. The piping and valves are nominally heavy wall (sch.160 pipe and 6000# valve bodies). The vents and drains are not subjected to high stresses or cyclic loads, and the design ratings are significantly greater than RCS operating or design pressure.
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"The Technical Specifications (TS) require RCS leakage monitoring (TS 3A4 and 3.4.5) during normal operation. Should any of the TS limits be exceeded, then appropriate corrective actions, which may include shutting the plant down, are required to identity the source of the leakage and restore the RCS boundary integrity. Additionally, SNC believes that there are also potential personnel safety and Al. ARA issues assuciated with pressurizing these connections. These issues are as follows-l 1
1.
ASME Code Case N-498-1 is curre'ntly used at Hatch to perform this test.
Pressure testing these connections to the outboard valve requires the inboard isolation valves to be opened and subjects the valves and piping to RCS nominal operating pressure and near operating temperature. Opening the inboard valve at l
these conditions is contradictory to the requirement for double isolation of the RCS and thus creates the possibility for safety concerns for personnel performing visual i
examination of the connections.
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Performing the test with the inboard valves open requires several man-hours to
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position the valves for the test and then to restore them after the test is complete.
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l All of these valves are located in close proximity of the RCS main loop piping thus requiring personnel entry into high radiation areas within the containment. Based on estimates from Operations Department and Health Physics department personnel and previous outage data, it is estimated that dose associated with valve alignment and realignment would be approximately 1.6 man-Rem per test.
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Since this test would be performed near the end of an outage, when all RCS work l
has been completed, the time required to open and then close these vent / drain i
valves could impact the outage schedule."-
Evaluation The Code requires that all Class 1 components within the RCS system L
boundary undergo a system hydrostatic test once per interval. The licensee has proposed an attemative to the hydrostatic test requirements for the subject line segments. The line segments, as stated by the licensee, include two manually operated valves separated by a short pipe nipple that is connected to the RCS via another short pipe nipple and half coupling. The line configuration, as outlined, provides double isolation of the RCS system. Under normal plant operating conditions the subject line segments would see RCS temperatures and pressures only if leakage through the inboard valve occurs. For the licensee to perform the Code required test, it would be necessary to manually open the inboard valves to pressurize the line segments.
Pressurization by this method would defeat the RCS double isolation and may cause
.. safety concerns for the personnel performing the examination. Typical line/ valve configurations are in close proximity to the primary and secondary RCS piping. Manual actuation (opening and closing) of these valves is estimated to expose plant personnel to 3-a________________-_--__-____--__-_-____-_.
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1.6 man-Rem per test. Therefore, the Code requirement to perform the system hydrostatic test on these isolated line segments presents a substantial hardship for the licensee.
The licensee proposed to visually examine the isolation valves in the normally closed I
position for leaks and evidence of past lehksge during the system leakage test each refueling outage. Also, the RCS vent and drain connections will be visually examined with the isolation valves in the normally closed position during the 10-year ISI pressure test. The licensee's proposed attemative will provide reasonable assurance that operational readiness is maintained for the subject line segments. Imposition of the i
Code requirement on Georgia Power Company would cause a burden that would not be compensated by a significant increase in quality and safety. Therefore, it is recommended that the licensee's proposed attemative be authorized pursuant to 10CFR50.55a(a)(3)(ii).
2.2 Reauest for Relief No. RR-18 (Rev. OL Authorization to Imolement Code Case N-546.
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Altemative Rules for Qualification of VT-2 Examination Personnel.Section XI. Division 1 Code Requirement: ASME Code,Section XI, IWA-2313 requires personnel performing examinations to be qualified by examination and certified in accordance with SNT-TC-1 A.
Level I and ll personnel shall be decertified by qualification examination every 3 years.
Level 111 personnel shall be decertified by qualification examinations every 5 years.
Licensee's Prooosed Alternative: Pursuant to 10 CFR 55.55a(a)(3)(l), the licensee requested authorization to implement Code Case N-546, Altomative Rules for I
l Qualification of VT-2 Examination Personnel, as an altemative to the Code requirements.
The licensee stated:
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" Plant Hatch will implement a training program that satisfies the requirements of ASME XI Code Case N-546 for personnel to perform VT-2 leakage examinations. Personnel that are qualified and certified in accordance with ASME XI IWA-2300 requirements may also be utilized to perform VT-2 leakage examinations, however personnel that meet the requirements of the (.Nmer's training requirements in accordance with Code Case N-546 1
will also be considerec qualified to perform VT-2 examinations."
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Licensee's Basis for the Pronaamd Alternative (as stated):
"The ASME Section XI Code Committee recognized that personnel that are perfcrming examinations for evidence of leakage (VT-2) should not be required to satisfy the same i
stringent requirements for qualification and certification as personnel performing other types of visual examinations. Personnel performing leakage examinations should be familiar with the plant's specific configuration, systems, and procedures for VT-2 visual examination and Owner should be able t6 develop an acceptable program for training personnel to perform VT-2 leakage examinations."
l In the licensee's response to the NRC's Request for Additional Information dated June 17,1998, the licensee provided additional discussion and committed to 1) develop l'
procedural guidelines for obtaining consistent, quality VT-2 visual examinations; 2) document and maintain records to verify the qualification of persons selected to perform VT-2 visual examinations and; 3) implement independent review and evaluation of l.
detected leakage by persons other than those that performed the VT-2 visual j
examination.
L Evaluation The Code requires that VT-2 visual examination personnel be qualified and certified in accordance with SNT-TC-1A. The Code also requires that the examination '
personnel be qualified for near and far distance vision acuity, in lieu of the Code j
l-requirements, the licensee proposed to implement Code Case N-546 for personnel l
l performing VT-2 visual examinations. This Code Case includes the following l
requirements:
1.
At least 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> plant walkdown experience, such as that gained by licensed and non-licensed operators, local leak rate personnel, system engineers, and inspection and nondestructive examination personnel.
2.
At least four hours of training on Section XI requirements and plant specific procedures for VT-2 visual examination.
3.
Vision test requirements of IWA-2321,1995 Edition.,
The qualification requirements in Code Case N-546 are not significantly different from those for VT-2 visual examiner certification. Licensed and non-licensed operators, local leak rate personnel, system engineers, and inspection and nondestructive examination f
personnel typically have a sound working knowledge of plant components and piping layouts. This knowledge makes them acceptable candidates for performing VT-2 visual l
examinations.
In addition to meeting the requirements contained in Code Case N-546, the licensee has committed to use procedural guidelines for consistent, quality VT-2 visual examinations, verify and maintain records of the qualification of persons selected to perform VT-2 visual examinations, and perform independent reviews and evaluations of leakage by a 1
person (s) other than those that performed the VT-2 visual examination. Based on a review of Code Case N-546 and the additional commitments made by the licensee, the INEEL staff believes that the proposed alternative to the Code requirements will provide an acceptable level of quality and safety. Therefore, it is recommended that the
~ licensee's request to implement Code Case N-546 with the additional commitments be authorized pursuant to 10 CFR 50.55a(a)(3)(l). Use of this Code Case should be authorized for the current interval or until such time as the Code Case is published in a future revision of Regulatory Guide 1.147. At that time, if the licensee intends to continue to implement this Code Case, the licensee is to follow all provisions in Code Case N-546 with limitations issued in Regulatory Guide 1.147, if any.
3.0 CONCLUSION
l The INEEL staff has reviewed the licensee's submittal and concludes that for Request for Relief No RR-17, the Code requirements would result in a burden without a compensating increase in the level of quality and safety. It is further concluded that the licensee's proposed attemative
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- will provide reasonable assurance that operational readiness is maintained on the subject line segments. Therefore, it is recommended that the licensee's proposed attemative be authorized l
pursuant to 10CFR50.55a(a)(3)(ii). For Request for Relief No. RR-18, the licensee's proposed l.
alternative regarding the use of Code Case N-546 provides an acceptable level of quality and i
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safety. Therefore, it is recommended that the use of Code Case N-546, as proposed by the licensee, be authorized pursuant to 10 CFR 50.55a(a)(3)(1).
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