ML16342C318
| ML16342C318 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 10/15/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML16342A540 | List: |
| References | |
| NUDOCS 9810210175 | |
| Download: ML16342C318 (66) | |
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UNITED STATES NUCLEAR REGULATORYCOMMISSION WASHINGTON, D.C. 20555-0001 AFETY NB F
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D N E R
-27 ND 1.C ~C The technical specifications (TS) for Diablo Canyon Power Plant, Units 1 and 2, state 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 Section XI of the ASME Boiler and Pressure Vessel (B8PV) 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 Title 10 of the Code of Federal Regulations 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 difficultywithout 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, "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 ten-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) twelve 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 ASME Code for the Diablo Canyon Power Plant, Unit 1 and 2, second ten-year inservice inspection (ISI) interval is the 1989 Edition.
By letter dated November 19, 1996, the licensee submitted its second 10-year interval inservice inspection program plan and associated requests for relief for Diablo Canyon Power Plant, Units 1 and 2. The licensee provided additional information in its letters dated May 2, 1997, August 13, 1997, December 24, 1997, January 30, 1998, and April 10, 1998.
98i02iOi75 98iOi5 PDR ADOCK 05000275 8
2.0 EVALU 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 the licensee's second ten-year inservice inspection program plan and associated requests for relief for Diablo Canyon Power Plant, Units 1 and 2.
Based on the results of the review, the staff adopts the contractor's conclusions and,recommendations presented in the attached Technical Evaluation Report (TER).
Request for Relief NDE-01: ASME Code,Section XI, Table IWB-2500-1, Examination Category B-A, Item B1.11 requires 100 percent volumetric examination of the shell-to-bottom-head weld as defined by Figure IWB-2500-1. Pursuant to 10 CFR 50.55a(g)(5)(iii), the licensee requested relief from examining the shell-to-bottom-head weld to the extent required by the Code.
The staff determined that it is impractical to examine the subject weld to the extent required by the Code.
However, six longitudinal welds in each unit have not been examined to the extent required by the regulations.
In accordance with 10 CFR 50.55a(g)(6)(ii)(A), examination of essentially 100 percent of each Item B1.10 wetds is required.
Essentially 100 percent, as defined by the regulations, means more than 90 percent of the examination volume of each weld.
The staff determined that the requirements of 10 CFR 50.55a(g)(6)(ii)(A), were not met and, the licensee must propose an alternative that provides an acceptable level of quality and safety.
In the April 10, 1998, submittal, the licensee stated that it has met and willcontinue to meet the augmented requirement.
However, no alternative to augmented RPV examination has been proposed and until the licensee satisfies the augmented examination requirements of the Regulations, reliefs from these Code requirements cannot be evaluated. Section 50.55a(g)(6)(ii)(A)(1) revokes all previous requests for relief for Item B1
~ 10 welds, and relief cannot be granted from Code requirements until the augmented rule is satisfied.
Request for Relief NDE-02:
ASME Code,Section XI, Table IWB-2500-1, Examination Category B-A, Item B1.21 requires 100 percent volumetric examination of the reactor pressure vessel circumferential head welds as defined by Figure IWB-2500-3.
Pursuant to 10 CFR 50.55a(g)(5)(iii), the licensee requested relief from the Code requirement to examine the reactor pressure vessel circumferential head welds (Unit 1 bottom head Weld 4-443 and closure head Weld 6446B; Unit 2 bottom head Weld 4-202 and closure head Weld 6-205B).
The Code requires that the accessible lengths of the subject circumferential reactor pressure vessel head welds be 100 percent volumetrically examined during each inspection interval. The licensee has requested relief from the Code required 100 percent volumetric coverage due to inaccessibility, resulting from the instrumentation tubes on the lower head, the control rod drive penetrations, and the cooling duct shroud on the closure head.
Because these items restrict scanning, it is impractical to perform the examinations to the extent required by the Code. To obtain access for volumetric examination, design modifications would be necessary.
Imposition of this requirement would cause a considerable burden on the licensee.
The subject head circumferential welds are the farthest from the "beltline" region of the shell and therefore see the least neutron fluence.
In addition, the bottom head weld area is visually examined as required by Code Category B-N-1 and all welds are subject to visual examination conducted during pressure test per Code Category B-P. These visual examinations and the volumetric examination of all other accessible weld areas on the reactor vessel provide continued assurance of weld integrity.
Based on the above evaluation, the staff concluded that performing the Code-required volumetric examination of the reactor pressure vessel circumferential head welds at Diablo Canyon Power Station, Units 1 and 2, is impractical and the licensee's proposed alternative provides reasonable assurance of structural integrity of the reactor vessel.
Therefore, pursuant to 10 CFR 50.55a(g)(6)(i), relief is granted.
Request for Relief NDE-03, R1: The ASME Code,Section XI, Table IWB-2500-1, Examination Category B-A, Item B1.22 requires 100 percent volumetric coverage of the accessible portions of the reactor pressure vessel (RPV) head welds as defined by Figure IWB-2500-3.
Pursuant to 10 CFR 50.55a(g)(5)(iii), the licensee requested relief from the Code coverage requirements for RPV bottom head meridional Welds 1~3A through F (Unit 1) and 1-202A through F (Unit 2), and closure head Weld 1-446 through F (Unit 1) and 1-205A through F (Unit 2).
The Code requires 100 percent volumetric examination of the accessible lengths of the subject RPV bottom head and closure head meridional welds. The licensee has requested relief from the Code-required 100 percent volumetric coverage due to physical limitations that restrict scanning.
Examination of the bottom head meridional welds was partially obstructed by the bottom head instrument penetrations and examination of the closure head welds is limited by the closure head CRDM penetrations, cooling duct shroud, and closure head lifting lugs. These restrictions make volumetric examination impractical to perform to the extent required by the Code. To meet the Code requirements, the RPV heads would have to be redesigned and modified. Imposition of this requirement would result in a burden on the licensee.
The licensee proposed to perform the volumetric examinations to the extent practical on the subject welds and estimates that 39 percent volumetric coverage of the bottom head meridional welds, 68 percent of three closure head welds, and 29 percent of the remaining three closure head welds can be obtained.
In addition, accessible portions of the vessel interior receive a VT-3 visual examination in accordance with Examination Category B-N-1. Therefore, the partial volumetric examinations, in conjunction with the visual examination, willdetect any existing patterns of.inservice degradation and provide reasonable assurance of continued structural integrity of the bottom head and closure head meridional welds.
Based on the above evaluation, the staff concluded that obtaining the Code. coverage requirements are impractical to meet for the bottom-head and closure-head meridional welds at
. Diablo Canyon Power Plant.
Furthermore, it is concluded that the volumetric examinations completed, in conjunction with the VT-3 visual examination provide reasonable assurance of the continued structural integrity. Therefore, relief is granted pursuant to 10 CFR 50.55a(g)(6)(i).
e
-4 Request for Relief NDE4 The ASME Code, Table IWB-2500-1, Examination Category B-A, Item B1.30 requires 100 percent volumetric examination of the reactor pressure vessel shell-to-flange weld as defined by Figure IWB-2500-4.
Pursuant to 10 CFR 50.55a(g)(5)(iii), the licensee requested relief from the Code required 100 percent volumetric coverage of the reactor pressure vessel shell-to-flange weld.
The Code requires that the subject reactor pressure vessel shell-to-flange weld be 100 percent volumetrically examined during the inspection interval. The licensee has requested relief because the flange taper limits scanning.
Based on this review, the staff has determined that it is impractical to examine the subject welds to the extent required by the Code. To obtain complete volumetric coverage, design modification would be necessary to eliminate scanning limitations. Imposition of this requirement would cause a burden on the licensee.
The licensee proposed to perform the volumetric examinations to the extent practical. The licensee estimates a combined coverage of 66 percent of the required examination volume.
In addition, the licensee can scan from the flange seal surface.
Based on the percent of volumetric coverage obtainable from the shell side in combination with 100 percent scanning coverage from the flange seal surface, it is reasonable to conclude that a pattern of degradation, ifpresent, willbe detected.
As a result, the staff determined that reasonable assurance of continued structural integrity is provided.
Based on the above evaluation; the staff concluded that obtaining the Code-required volumetric coverage is impractical for the reactor pressure vessel shell-to-flange welds at Diablo Canyon Power Plant, Units 1 and 2. Also the staff concluded that the licensee's proposed alternative provides reasonable assurance continued structural integrity of the subject components.
Therefore, relief is granted pursuant to 10 CFR 50.55a(g)(6)(i).
Request for Relief NDE-5: The ASME IWB-2500-1, Examination Category B-A, Item B1.40 requires 100 percent volumetric and surface examination of the reactor pressure vessel head-to-flange weld as defined by Figure IWB-2500-5.
Pursuant to 10 CFR 50.55a(g)(5)(iii), the licensee requested relief from the Code required 100 percent volumetric coverage of the reactor pressure vessel head-to-flange weld.
The Code requires 100 percent volumetric and surface examination for the subject reactor pressure vessel head-to-flange weld. However, complete volumetric examination is restricted by the flange blend radius and lifting lugs. Therefore, it is impractical to examine the subject welds to the extent required by the Code.
To obtain complete volumetric coverage, design modifications would be necessary to eliminate scanning limitations. Imposition of this requirement would cause a considerable burden on the licensee.
The licensee proposed to perform the volumetric examinations to the extent practical. The licensee estimates a combined coverage of 68 percent of the required examination volume.
In addition, the licensee willperform 100 percent of the required surface examination.
Based on the percent of volumetric coverage obtainable in combination with the 100 percent surface examination, it is reasonable to conclude that a pattern of degradation, ifpresent, will be detected.
As a result, reasonable assurance of continued structural integrity willbe provided.
Based on the above evaluation, the staff concluded that obtaining the Code-required volumetric coverage is impractical for the reactor pressure vessel head-to-flange welds at Diablo Canyon Power Plant, Units 1 and 2. Also the staff concluded that the licensee's proposed alternative provides reasonable assurance continued structural integrity of the subject components Therefore, relief is granted pursuant to 10 CFR 50.55a(g)(6)(i).
Request for Relief NDE-6:
Request for Relief NDE-6 was withdrawri by the licensee in its letter dated August 13, 1997.
Request for Relief NDE-6A: ASME Code,Section XI, Table IWB-2500-1, Examination Category B-D, Items B3.90 and B3.100 require 100 percent volumetric examination of reactor pressure vessel nozzle-to-vessel and nozzle inner radius sections.
For reactor pressure vessel nozzle welds and inner radius sections, at least 25 percent but not more than 50 percent (credited) of the nozzles shall be examined by the e'nd of the first inspection period and the remainder by the end of the inspection interval. Complete nozzle examination may be deferred ifpartial examinations are completed from the nozzle bore using a straight beam ultrasonic method.
Pursuant to 10 CFR 50.55a(a)(3)(i) the licensee proposed an alternative essentially equivalent to Code Case N-521. Pursuant to 10 CFR 50.55a(a)(3)(ii), the licensee stated that repeating the examinations such that no more that 10 years elapses between examinations is a burden.
The licensee stated:
"Allaccessible areas of,the outlet nozzle-to vessel welds willbe completely examined as required at or near the end of the inspection interval, coincident with the remainder of the RV examinations.
This one time deferral willresult in an increase of 6 years in the nominal 10 year examination cycle for these particular welds.
Future examinations will be repeated on a nominal 10 year frequency.
This alternative schedule provides an acceptable level of quality and safety in accordance with 10 CFR 50.55a(a)(3)(i)."
"Relief is requested from performing Period one examinations, including the deferral conditions of the shell side exam required by Code footnotes 2 and 3 and coincident nozzle-to-safe end examinations, for the 4 outlet nozzles in Unit 1 and 2 of the outlet nozzles in Unit 2."
The Code requires examination of all RPV nozzle-to-vessel welds during the course of the 10-year ISI interval.
In accordance with Table IWB-2500-1, Examination Category B-D, Note (2), a portion (at least 25 percent of the nozzle-to-vessel welds and inner radius sections) of the nozztes must be examined by the end of the first inspection period. As an alternative to the Code scheduling requirements, the licensee has proposed an alternative similar to Code Case N-521, Alternative Rules for Deferral of Inspection of Nozzle-to-Vessel Welds, Inside Radius Sections, and Nozzle-to-Safe End Welds of Pressurized Water Reactor (PWR) Vessel.
Code Case N-521 has been found acceptable for use at other plants providing licensees meet all the conditions of the Code Case, and ensure that no more than 10 Code years elapse between examinations.
This essentially requires that nozzle examinations must be repeated at
e the end of the previous interval. The licensee stated that they cannot meet this latter requirement and that performing the examination of two (or four) nozzies in the first period constitutes an extreme burden.
However, the licensee has not provided adequate justification to support that burden, or provided an alternative that would provide an acceptable level of quality and safety.
Therefore, the licensee's proposed alternative is denied.
Request for Relief NDE-6B: Table IWB-2500-1, Examination Category B-D, item B3.90 requires 100 percent volumetric examination of reactor pressure vessel nozzle-to-vessel welds.
Pursuant to 10 CFR 50.55a(g)(5)(iii), the licensee requested relief from the volumetric examination of the RPV inlet and outlet nozzle-to-vessel welds to the extent required by the Code.
The Code requires 100 percent volumetric examination of the subject nozzle-to-vessel weids.
However, examination of these welds is restricted by nozzle configuration, vessel configuration, and adjacent nozzles, which limitscan travel ~ These physical limitations make the Code coverage requirements impractical to meet for the nozzle-to-vessel welds at Diablo Canyon Power Plant. To meet the Code requirements, the vessel and nozzles would have to be redesigned and modified. Imposition of this requirement would cause a burden on the. licensee.
The licensee can obtain 86 percent coverage for each inlet nozzle and 66 percent coverage on each outlet nozzle.
This represents a significant percentage of the Code-required volumetric examinations.
Therefore, existing patterns of degradation willbe detected and reasonable assurance of the continued structural integrity provided.
Considering the impracticality of meeting the Code requirements, and the reasonable assurance of the structural integrity provided by the volumetric examinations that can be performed, relief is granted pursuant to 10 CFR 50.55a(g)(6)(i).
Request for Relief NDE-7:
ASME Code,Section XI, Table IWB-2500-1, Examination Category B-D, Item B3.100 requires 100 percent volumetric examination of reactor pressure vessel nozzle inner radius sections of least 25 percent but not more than 50 percent (credited) of the nozzles shall be examined by the end of the first inspection period and the remainder by the end of the inspection interval. Pursuant to 10 CFR 50.55a(a)(3)(i), the licensee proposed an alternative to the Code scheduling requirements for the RPV nozzle inside radius sections.
The licensee stated:
"Allof the required nozzles inside radius section willbe completely examined at or near the end of the inspection interval, concurrently with the examination of the rest of the reactor vessel."
The Code requires examination of all RPV nozzle-to-vessel welds and nozzle inner radius sections during the course of the 10-year ISI interval.
In accordance with Table IWB-2500-1, Examination Category B-D, Note (2), a portion (at least 25 percent of the nozzle-to-vessel welds and inner radius sections) of the nozzles must be examined by the end of the first inspection period. As an alternative to the Code scheduling requirements, the licensee has proposed an alternative similar to Code Case N-521, Alternative Rules for Deferral of Inspection
of Nozzle-to-Vessel Welds, Inside Radius Sections, and Nozzle-to-Safe End Welds of Pressurized Water Reactor (PWR) Vessel.
Code Case N-521 has been found acceptable at other plants providing licensees meet all the conditions of the Code Case, and ensure that no more than ten years elapses between examinations.
This essentially requires that nozzle examinations must be repeated at the end of the previous interval. The licensee states that they cannot meet this latter provision and states that performing the examination of two nozzles in the first period constitutes an'extreme burden.
However, the licensee has not provided adequate justification to support that burden, or provided an alternative that would provide an acceptable level of quality and safety.
Therefore, the licensee's proposed alternative is denied.
Request for Relief NDE-10:
Request for Relief NDE-10 was withdrawn by the licensee in its letter dated August 13, 1997.
Request for Relief NDE-27: The ASME Code,Section XI, Table IWB-2500-1, Examination Category B-A, Item B1.30, requires 100 percent volumetric examination of the reactor pressure vessel shell-to-flange weld as defined by Figure IWB-2500-4. Examinations can be performed in conjunction with the examination of the nozzle-to-vessel welds.
In accordance with Note (3),
ifpartial examinations are conducted from the flange face, the remaining volumetric examinations required to be conducted from the vessel wail may be performed at or near the end of each inspection interval. Examination Category B-G-1, Item B6.40, requires 100 percent volumetric examination of the threads in the reactor pressure vessel flange as defined by Figure IWB-2500-12.
The Code requires 100 percent volumetric examination of the vessel-to-flange weld and threads in the flange each period. Deferral to the end of the interval for examination of the vessel-to-flange weld is permissible when a partial examination is performed from the flange face.
'I The licensee has proposed to defer the examination of these areas until the end of the interval.
However, the licensee has not demonstrated that compliance would result in an undue hardship without a compensating increase in the level of quality and safety. Therefore, the licensee's proposed alternative is denied, because the burden associated with performing the subject examinations has not been adequately provided.
Request for Relief NDE-S, R1: ASME Code,Section XI, Table IWB-2500-1, Examination Category B-D, Item B3.120 requires 100 percent volumetric examination of pressurizer nozzle inner radius sections as defined by Figure IWB-2500-7. Pursuant to 10 CFR 50.55a(g)(5)(iii),
the licensee requested relief from performing the volumetric examination to the extent required by the Code for the pressurizer surge line nozzle inner radius sections.
The Code requires 100 percent volumetric examination of the pressurizer surge line nozzle inner radius sections.
However, examination of subject inner radius sections is restricted by adjacent heater penetrations that preclude performance of the Code-required volumetric examination.
Therefore, the Code examination requirements are impractical for these areas at Diablo Canyon Power Plant. To meet the Code requirements, the pressurizer would have to be
redesigned and modified to allbw access for examination.
Imposition of this requirement would result in a considerable burden on the licensee.
Although the surge line nozzle inner radius sections are inaccessible for examination, the licensee can perform the inner radius examinations on the top head nozzles and can examine approximately 50 percent of the surge line nozzle-to-vessel weld in the Unit 2 pressurizer (the Unit 1 pressurizer is integrally cast and has no nozzle-to-vessel weld). These examinations will
'detect any significant patterns of inservice degradation occurring at the pressurizer nozzles and provide reasonable assurance of the continued structural integrity.
The staff concluded that considering the impracticality of meeting the Code examination requirements for the surge line nozzle inner radius sections and the reasonable assurance of the structural integrity provided by the examination of other pressurizer nozzles and the Unit 2 surge line nozzle-to-vessel weld, relief is granted pursuant to 10 CFR 50.55a(g)(6)(i).
Request for Relief NDE-11:
Request for Relief NDE-11 was withdrawn by the licensee in its letter dated August 13, 1997.
Request for Relief NDE-25, (Unit 2 Only):
The Code,Section XI, Table IWB-2500-1, Examination Category B-D, Item B3.110 requires 100 percent volumetric examination of pressurizer nozzle-to-vessel welds as defined by Figure IWB-2500-7(b). Pursuant to 10 CFR 50.55a(g)(5)(iii), the licensee requested relief from performing the volumetric examination of the Unit 2 pressurizer surge line nozzle-to-vessel weld to the extent required by the Code.
The Code requires that the subject pressurizer surge nozzle-to-shell weld receive 100 percent volumetric examination.
However, the design of the pressurizer surge line nozzle-to-vessel configuration and the pressurizer heater penetrations adjacent to the weld preclude complete volumetric examination.
As a result, Code volumetric coverage is impractical. To obtain complete volumetric coverage, design modifications or replacement of the nozzle-to-safe-end design with one of a design providing for complete examination would be required.
Imposition of this requirement would cause a considerable burden on the licensee.
The licensee can. obtain 50 percent coverage by performing the Code-required volumetric examination in the circumferential direction.
In addition, the Code-required volumetric examinations. can be completed on the other pressurizer nozzle-to-vessel welds. Therefore, significant patterns of degradation would be detected by the pressurizer examinations that can be performed and reasonable assurance of continued structural integrity willbe provided.
The staff determined that considering the impracticality of meeting the Code coverage requirements for the subject welds, and the reasonable assurance of the structural integrity provided by the examinations that can be completed, relief is granted pursuant to 10 CFR 50.55a(g)(6)(i).
Request for Relief NDE-26, R1 (Unit 2): The Code,Section XI, Table IWB-2500-1, Examination'Category B-H, Item B8.20 requires 100 percent volumetric or surface examination of the pressurizer support skirt weld as defined by Figure IWB-2500-1 3, -14, or -15, as applicable.
Pursuant to 10 CFR 50.55a(a)(3)(i), the licensee proposed an alternative volumetric.
examination in lieu of the Code-required surface examination of the interior surface of the pressurizer support skirt weld. The licensee stated:
"The weld is accessible for volumetric examination, which was the Code requirement in the first inspection interval, and is still the requirement for the Unit 1 weld configuration.
Volumetric examination provides an equivalent level of quality and safety in accordance with 10 CFR 50.55a(a)(3)(i)."
In its April 10, 1998, letter, the licensee confirmed that the Unit 2 pressurizer skirt weld would receive a volumetric examination of the internal surface and a surface examination of the external surface.
The Code requires surface examination of both the interior and exterior surfaces of the subject pressurizer support skirt weld. However, access to the interior surface (surface examination Area C-D on Figure IWB-2500-13), is limited by component geometry.
As an alternative, the licensee proposed to supplement the Code required surface examination of the exterior surface with volumetric examination of the interior surface.
Based on review of the support skirt design, the staff concludes that the alternative volumetric examination, in conjunction with the Code required surface examination, should detect any significant patterns of degradation that may occur. Therefore, the licensee's proposed alternative provides an acceptable level of quality and safety.
The staff concluded, based on the evaluation above, that the proposed volumetric examination, in conjunction with the Code required surface examination, will provide an acceptable level of quality and safety. Therefore, the licensee's proposed alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(i).
Request for Relief NDE-9:
ASME Code,Section XI, Table IWB-2500-1, Examination Category B-D, Item B3.140 requires 100 percent volumetric examination of steam generator (primary side) nozzle inner radius sections.
Pursuant to 10 CFR 50.55a(g)(5)(iii), the licensee
'requested relief from the Code required 100 percent volumetric examination of steam generator (primary side) nozzle inside radius sections.
The Code requires 100 percent volumetric examination of the subject steam generator nozzle inside radius sections.
However, component configuration and surface conditions prevent volumetric examination from the outside surface.
In addition, access to the inside surface for volumetric examination or an alterriative visual examination is obstructed by the nozzles dam retaining rings that are welded to the nozzle at the inside radius. Therefore, the staff concluded that the Code required volumetric examination is impractical to perform'for the subject nozzle inside radius sections at Diablo Canyon.
To meet the Code requirements, the licensee would have to make design modifications to allow access for examination.
Imposition of the Code requirements would result in a significant burden on the licensee.
The licensee cannot examine the subject steam generator nozzles for the reasons stated above.
However, there are other Class 1 nozztes and nozzle inside radius sections on the reactor pressure vessel that can be examined.
The examination of these other nozzles will
detect any significant patterns of degradation occurring at the nozzle inside radius sections and will provide reasonable assurance of the structural integrity of the Class 1 steam generator nozzles.
The staff concluded that based on the impracticality of meeting the Code requirements and the reasonable assurance of structural integrity of the subject components provided by the examination of other similar nozzle inside radius sections, relief is granted pursuant to 10 CFR 50.55a(g)(6)(i).
Request for Relief NDE-12: Request for Relief NDE-12 was withdrawn by the licensee in its letter dated August 13, 1997.
Request for Relief NDE-13.1, R8:
ASME Code,Section XI, Table IWB-2500-1, Examination Category B-J, Items B9.11 and B9.12 requires 100 percent volumetric and surface examination as defined by Figure IWB-2500-8. Pursuant to 10 CFR 50.55a(g)(5)(iii), the licensee requested relief from the Code coverage requirements for the welds listed in the section below.
lJgjt 1 W~l WIB-RC-1-11.5A WIB-RC-1-11.5B WIB-RC-2-13.5A WIB-RC-2-13.5B WIB-334, WIB-334 (Surface)
WIB-64 WIB433A
~in itgttig 5
31 Abrupt contour chg elbow pp seam 5
31 Abrupt contour chg elbow pp seam 6
31 Abrupt contour chg elbow pp seam 6
31 Abrupt contour chg elbow pp seam 727 6
Code ID band welded around pipe
~
727 6
Code ID band welded around pipe 13 4
Abrupt contour chg at valve body 14 4
Abrupt contour chg at valve body 70 70 70 70 60 50 surface 64 56 The Code requires 100 percent volumetric and surface examinations for the subject circumferential and longitudinal piping welds.
However, complete examination of these welds was restricted due to joint configuration or welded Code nameplates that restrict access and make the Code coverage requirements impractical to meet. To meet the Code coverage requirements, the subject piping systems would have to be redesigned and modified to allow access for complete examination.
Imposition of this requirement would result in a burden on the licensee.
The licensee completed a significant portion (>56 percent) of the volumetric examination for these welds.
In addition, with one exception, all the welds received the Code required surface examination.
For Weld WIB-334, volumetric examination coverage was limited to 60 percent with only 50 percent surface examination coverage.
However, this weld is only one weld in a much larger population of Class 1 welds that are receiving the Code-required examinations.
Therefore, the staff concluded that any significant patterns of degradation would have been detected and reasonable assurance of the structural integrity has been provided by the examinations that were performed.
The staff concludes that meeting the Code coverage requirements for the subject welds is impractical, and the licensee's proposed alternatives provide reasonable assurance of the structural integrity of the subject components.
Therefore, the staff concludes that pursuant to 10 CFR 50.55a(g)(6)(i) relief is granted.
Request for Relief NDE-14, R1: Request for Relief NDE-14, Revision 1 was withdrawn by the licensee in its letter dated August 13, 1997.
Request for Relief NDE-15, (Unit 1):
ASME Code,Section XI, Table IWB-2500-1, Examination Category B-J, Item B9.40 requires 100 percent surface examination of Class 1
socket welds as defined by Figure IWB-2500-8.
Pursuant to 10 CFR 50.55a(g)(5)(iii), the licensee requested relief from the Code required surface examination of certain Class 1 socket welds.
Design of certain socket welds limits access for surface examination due to the presence of physical obstructions such as welded supports, Code nameplates, adjacent piping, or structures.
These conditions or combination of conditions may physically prevent access to portions of the required examination area.
The Code requires that the subject pipe branch connection weld receive 100 percent volumetric and surface examinations.
However, due to the weld joint configuration, complete volumetric and/or surface coverage is impractical. To obtain complete Code coverage, design modifications or replacement of the subject areas with one of a design providing for complete examination would be required.
Imposition of this requirement would cause a burden on the licensee.
The licensee proposed to perform the volumetric examinations to the extent practical, resulting in estimated coverage of 75 percent.
Based on the percent of coverage obtainable, in combination with the other examination areas receiving complete Code coverage, it is reasonable to conclude that significant degradation, ifpresent, will be detected.
The staff determined that the licensee's proposed alternative provides reasonable assurance of structural integrity of the subject components.
The staff concluded that based on the above evaluation, performing the Code required volumetric examination of the subject pipe welds is impractical for Diablo Canyon Power Plant. Therefore, relief is granted pursuant to 10 CFR 50.55a(g)(6)(i).
Request for Relief NDE-16: ASME Code,Section XI, Table IWB-2500-1, Examination Category B-K-1, Item B10.20 requires 100 percent volumetric or surface (as applicable) examinations of pump integrally welded attachments as defined by Figure IWB-2500-13, -14, and -15. Pursuant to 10 CFR 50.55a(g)(5)(iii), the licensee requested relief from the Code required 100 percent examination of the reactor coolant pump (RCP) integrally welded attachments.
The Code requires that the integral attachment welds to the RCP receive 100 percent surface examination.
However,,due to the support structure design, access for complete surface coverage is restricted.
As a result, it is impractical to perform the surface examination to the extent required by the Code.
To obtain complete Code coverage, design modifications or replacement of the subject areas with one of a design providing for complete examination would be required.
Imposition of this requirement would cause a considerable burden on the licensee.
The licensee proposed to perform the volumetric examinations to the extent practical, resulting in estimated 70 percent coverage.
Based on the percent of coverage obtainable, it is reasonable to conclude that significant degradation, ifpresent, willbe detected.
The staff determined that the licensee's proposed alternative provides reasonable assurance of structural integrity of the subject components and performing the Code required volumetric examination of the subject RCP integral attachment welds is impractical for Diablo Canyon Power Plant.
Therefore, relief is granted pursuant to 10 CFR 50.55a(g)(6)(i).
Request for Relief NDE-17 (Part 1):
ASME Code,Section XI, Table IWB-2500'-1, Examination Category C-A, Items C1.10, C1.20, and C1.30 require 100 percent volumetric examination of Class 2 vessel shell circumferential, head, and tubesheet-to-shell welds as defined by Figures IWC-2500-1, and -2. Pursuant to 10 CFR 50.55a(g)(5)(iii), the licensee requested relief from the volumetric examination to the extent required by the Code for the following welds:
Unit 152 Component Steam Generator (Figure 2.1-1)
RHRHX (Figure 2.1-6)
Welds Girth Weld W1-3 Girth Weld W2-4 Girth Weld W3-5 Girth Weld W4-7 Shell-to-flange Weld ¹1 Head-to-shell Weld ¹2 Limitation Permanent insulation Component configuration The Code requires 100 percent volumetric examination of the subject welds.
- However, examination of these welds is restricted by either permanent insulation or by component configuration. Therefore, the Code coverage requirements are impractical to meet.
To examine these welds to the extent required by the Code, the steam generator permanent insulation would have to be redesigned and replaced, and the RHR heat exchangers would require design modification to allow access for examination.
Imposition of these requirements would result in a considerable burden on the licensee.
The licensee can examine 20 percent of each of the subject steam generator wetds in Unit 1 and can examine the equivalent welds in Unit 2 to the extent required by the Code.
For the RHR heat exchangers, the licensee has proposed to perform an alternative surface examination on approximately 80 percent of the shell-to-flange weld and shell-to-head welds.
The performance of these examinations should detect any significant patterns of degradation that may occur and provide reasonable assurance of the structural integrity of the subject steam generator and RHR heat exchanger welds.
The staff concluded that based on its evaluation, the Code coverage requirements are impractical, and the licensee's proposed alternative provides reasonable assurance of the structural integrity of the subject components.
Therefore, relief is granted pursuant to 10 CFR 50.55a(g)(6)(i).
Request for Relief NDE-17, R1 (Part 2): ASME Code,Section XI, Table IWB-2500-1, Examination Category C-A, Items C1
~ 10 and C1.20 require 100 percent volumetric examination of Class 2 vessel shell and head circumferential welds as defined by Figure IWC-2500-1.
Pursuant to 10 CFR 50.55a(a)(3)(ii),
the licensee proposed an alternative to the Code-required examinations for welds listed below. The subject welds willreceive pressure testing as required by the Code.
Unit Component Seal Injection Filters (Figure 2.1-3)
Welds Shell-to-flange Weld GA Head-to-shell Weld GB Limitation Access, ALARA The Code requires 100 percent volumetric examination of the subject seal injection filterwelds.
However, the filters are contained in a filter bank with limited access and with radiation exposure expected to exceed 10 rad/hour.
Therefore, the radiation hazard associated with examining these welds would create a burden on the licensee ifthe Code required examinations were imposed.
In lieu of the volumetric examination, the licensee willperform the Code required pressure testing to assess the operational readiness of the vessels.
This testing, along with the volumetric examination of other Class 2 vessels, willprovide reasonable assurance of the continued structural integrity of the seal injection filters.
The staff concluded that based on its evaluation imposition of the Code requirements would cause an undue hardship on the licensee without a compensating increase in the level of quality and safety. Therefore, the licensee's proposed alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(ii).
Request for Relief NDE-18, R1 (Part 1): ASME Code,Section XI, Table IWC-2500-1, Examination Category C-B, Item C2.21 requires 100 percent volumetric and surface examination of Class 2 nozzle welds (without reinforcing plates in vessels
>Y~ inch nominal thickness) as defined by Figure IWC-25004(a) or (b) as applicable.
Pursuant to 10 CFR 50.55a(g)(5)(iii), the licensee requested relief from the Code required volumetric coverage for the steam generator main feedwater nozzles and the RHR heat exchanger nozzle-to-shell inlet and outlet nozzle welds.
The Code requires 100 percent volumetric and surface examination for each of the subject welds. However, access to these welds for examination is restricted by component configuration and adjacent obstructions.
Therefore, the Code coverage requirements are impractical to meet. To examine these welds to the extent required by the Code, the components would require design modification to allow access for examination.
Imposition of these requirements would result in a considerable burden on the licensee.
The licensee can obtain 70 percent volumetric examination coverage and complete surface examination coverage for the steam generator feedwater nozzle welds.
For the RHR heat exchangers welds, the licensee willperform an alternative surface examination.
The performance of these examinations should detect any significant patterns of degradation that may occur. Therefore, the staff determined that the licensee's proposed alternative provides reasonable assurance of the structural integrity of the subject steam generator and RHR heat exchanger welds. The staff concludes that based on its evaluation, the Code coverage requirements are impractical, and reasonable assurance of the structural integrity is provided by the proposed examinations.
Therefore, relief is granted pursuant to 10 CFR 50.55a(g)(6)(i).
Request for Relief NDE-18, R1 (Part 2): ASME Code,Section XI, Table IWC-2500-1, Examination Category C-B, Item C2.21 requires 100 percent volumetric and surface examination of Class 2 nozzle welds (without reinforcing plates in vessels >/~ inch nominal thickness) as defined by Figure IWC-2500-4(a) or (b) as applicable.
Pursuant to 10 CFR 50.55a(a)(3)(ii), the licensee proposed an alternative to the Code-required examinations for the seal injection filter inlet and outlet nozzle-to-vessel welds. The subject wetds will receive pressure testing as required by the Code.
The Code requires 100 percent volumetric and surface examination of the subject seal injection filternozzle-to-vessel welds. However, the filters are contained in a filter bank with limited access with radiation exposure expected to exceed 10 rad/hour. Therefore, the radiation hazard associated with examining these welds would create a burden on the licensee ifthe Code required examinations were imposed.
In lieu of the volumetric examination, the licensee willperform the Code required pressure testing to assess the operational readiness of the vessels.
This testing, along with the volumetric examination of other Class 2 vessels, will provide reasonable assurance of the continued structural integrity of the seal injection filters.
The staff concluded that based on its evaluation imposition of the Code requirements would cause an undue hardship on the licensee without a compensating increase in the level of quality and safety. Therefore, the licensee's proposed alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(ii).
Request for Relief NDE-19, R1: ASME Code,Section XI, Table IWC-2500-1, Examination Category C-B, Item C2.22 requires 100 percent volumetric examination of nozzle inside radius sections as defined by Figures IWC-2500M(a) or (b) as applicable, in nozzles without reinforcing plates in vessels greater than Y~inch nominal wall thickness.
Pursuant to 10 CFR 50.55a(g)(5)(iii), the licensee requested relief from the Code-required volumetric examination of nozzle inside radius sections in the RHR heat exchanger and seal injection filter.
The Code requires 100 percent volumetric examination of the subject nozzle inner radius sections.
For the RHR heat exchanger nozzle inner radius, nozzle configuration and adjacent obstructions completely restrict access to the examination area.
The seal injection filter nozzles have no inner radius due to the configuration. Therefore, the staff concluded that the Code requirements are impractical for both of these examination areas.
To meet the Code
examination requirements, design modifications would be necessary to provide access for examination, or in the case of the seal injection filter nozzles, provide an inner radius to examine.
Imposition of this requirement would cause a burden on the licensee.
The licensee willperform a surface examination on the adjacent nozzle-to-vessel welds in the RHR heat exchanger.
It is reasonable to conclude that a pattern of degradation, ifpresent, will be detected.
Therefore, the licensee's proposed alternative provides reasonable assurance of structural integrity of the subject components.
The staff concluded that based on the nozzle configuration or lack of an inner radius, the Code require'ments are impractical for the subject nozzle inner radius sections, and the examinations performed provide reasonable assurance of the continued operation readiness of the subject components.
Therefore, relief is granted pursuant to 10 CFR 50.55a(g)(6)(i).
Request for Relief NDE-21.1, R8: ASME Code,Section XI, Table IWC-2500-1, Examination Category C-F-1, Item C5.20 requires 100 percent surface and volumetric examination, as defined by IWC-2500-7, for piping welds greater than 1/5-Inch nominal wall thickness in piping greater than or equal to 2-inch nominal pipe size (NPS) but less than or equal to 4-inch NPS.
Pursuant to 10 CFR 50.55a(g)(5)(iii), the licensee requested relief from the volumetric examination to the extent required by the Code for Unit 1 Welds WIC-189A and WIC48A.
Design of certain pipe welds limits access for volumetric examination due to various geometric conditions on or adjacent to the welds, or due to the presence of physical obstructions such as welded supports, Code nameplates, adjacent piping, structures, or penetrations.
These conditions or combination of conditions may physically prevent access to portions of the required examination volume. Approximate accessible portions of each weld volume and the specific limitations are described below:
~i) ~
~ii~tti in WIC-189A 111 14 Abrupt surface contours flange-pp WIC-48A 48 3
Abrupt surface contour chg at tee 23 60 The Code requires 100 percent surface and volumetric examination for the subject Class 2 welds. However, volumetric examination of these welds is limited by component configuration that precludes complete volumetric examination.
Therefore, the Code coverage requirements are impractical to meet for these welds. To meet the Code requirements, the weld joints would have to be redesigned and modified to allow access for examination.
Imposition of this
'requirement would result in a burden on the licensee.
The licensee can volumetrically examine a portion of each weld (23 percent and 60 percent) in addition to the Code required surface examination.
Furthermore, these welds are part of a larger population of welds that are being completely examined.
Therefore, any significant patterns of degradation will be detected by the examinations performed and reasonable assurance of the structural integrity provided.
The staff concludes that based on the impracticality of meeting the Code coverage requirements and the reasonable assurance of the structural integrity provided by the examinations performed on these and other Class 2 welds, relief is granted pursuant to 10 CFR 50.55a(g)(6)(i).
Request for Relief NDE-22: ASME Code,Section XI, Table IWC-2500-1, Examination Category C-F-2, Item C5.51 requires 100 percent volumetric and surface examination of Class 2 carbon and low alloy,pipe welds as defined by Figure IWC-2500-7. Pursuant to 10 CFR 50.55a(g)(5)(iii), the licensee requested relief from the Code required 100 percent volumetric coverage of the Class 2 pipe welds listed in the section below.
Design of certain pipe welds limits access for volumetric examination due to various geometric conditions on or adjacent to the welds, or due to the presence of physical obstructions such as welded supports, Code namepiates, adjacent piping, structures, or penetrations.
These conditions or combination of conditions may physically prevent access to portions of the required examination volume. Approximate accessible portions of each weld volume and the specific limitations are described below:
~Unit1Wel
!Jr'28 None Qgjt ~tio c
i I
JJ~~WI
~i
~P L.imit~ti WIC-1357B 1357 6
Ventilation duct across pipe WIC-1357C 1357 6
Ventilation duct across pipe 75 80 The Code requires that the subject Class 2 pipe welds receive 100 percent volumetric and surface examination.
However, due to the surface configuration of the weld and ventilation duct across the pipe, scanning for complete volumetric examination is restricted.
As a result, it is impractical to perform the volumetric examination to the extent required by Code. To obtain complete Code coverage, design modifications or replacement of the subject areas with one of a design providing for complete examination would be required.
Imposition of this requirement would cause a considerable burden on the licensee.
The licensee proposed to perform the volumetric examinations to the extent practical, resulting in estimated 75 percent and 80 percent coverage.
Based on the percent of coverage obtainable, it is reasonable to conclude that degradation, ifpresent, willbe detected.
As a result, reasonable assurance of structural integrity will be provided.
The staff concluded that based on its evaluation, performing the Code required volumetric examination of the subject Class 2 pipe welds is impractical for Diablo Canyon Power Plant, Units 1 and 2, and the licensee's proposed alternative provides reasonable assurance of structural integrity of the subject components.
Therefore, relief is granted pursuant to 10 CFR 50.55a(g)(6)(i).
Request for Relief NDE-29 (Unit 2): ASME Code,Section XI, Table IWC-2500-1, Examination Categories C-F-1 and C-F-2 require that a number of welds equal to 7.5% of all
nonexempt welds in Class 2 piping systems be selected for examination.
Examinations shall be distributed among Class 2 systems prorated to the degree practicable on the number of welds within each system.
Within a system, examinations are to be distributed among terminal ends and structural discontinuities prorated to the degree practicable on the number of nonexempt terminal ends and structural discontinuities.
Pursuant to 10 CFR 50.55a(a)(3)(i), the licensee proposed an alternative to the Code requirements for Class 2 piping welds. The licensee noted:
One hundred percent of the Code required total of Class 2 pipe welds will be examined.
The apportionment of Class 2 pipe welds in Unit 2 will be to a single stream in those systems having multiple streams.
No other examination requirement will be limited as a result of having the single stream distribution. Should the examination of one stream reveal unacceptable indications, additional examinations willbe conducted on another. stream in accordance with IWC-2430(a) and (b). Alllines are scheduled for periodic pressure test.
The Code requires the examination of 7.5 percent of nonexempt welds in Class 2 piping systems.
Examinations are prorated and distributed among systems based on the number of wetds within each system.
The licensee proposed to apply a single stream approach that would limitexaminations to one stream in multiple stream systems.
Examinations performed during preservice and the first interval used the same approach.
Therefore, the welds selected for examination during the first interval willbe reexamined during the second interval in accordance with the Code. The examinations performed willbe distributed within a single stream to provide a representative sample of the condition of Class 2 piping welds. Ifthe examination of one stream reveals an unacceptable indication, additional examinations willbe conducted on another stream in accordance with the Code.
Furthermore, examinations performed in Unit 1 willbe distributed among multiple streams as required by the Code.
Therefore, any significant patterns of degradation should be detected and the licensee's proposed alternative provides reasonable assurance of the structural integrity of the subject components.
The staff concluded that the licensee's proposed alternative to use a single stream approach, in
'onjunction with the distribution of examinations in Unit 1 in accordance with the Code, should detect any patterns of degradation that could occur. Therefore, the staff concludes that the proposed alternative provides an acceptable level of quality and safety, and the licensee's proposed alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(i).
Request for Relief NDE-20, R1: ASME Code,Section XI, Table IWC-2500-1, Examination Category C-C, Items C3.10, C3.20, and C3.30 require 100 percent surface examination of integrally welded attachments as defined by Figure IWC-2500-5. Pursuant to 10 CFR 50.55a(g)(5)(iii), the licensee requested relief from the Code-required surface examination of the Class 2 integrally welded attachments listed in the section below.
0
~Uit 1 weId Lii ~
JJQlltRthB Cent'I Charging Support structure Pp Legs under legs 77.
gone 2~WI I
~ ~
Limital Cent'I Charging Support structure Pp Legs under legs 77 The Code requires that the integral attachment welds receive 100 percent surface examination.
However, due to the surface configuration and limited access, complete surface coverage is restricted.
As a'result, it is impractical to perform the surface examination to the extent required by Code. To obtain complete Code coverage, design modifications or replacement of the subject areas with one of a design providing for complete examination would be required.
Imposition of this requirement would cause a considerable burden on the licensee.
The licensee proposed to perform the surface examinations to the extent practical, resulting in an estimated 77 percent coverage.
Based on the percent of coverage obtainable, it is reasonable to conclude that significant degradation, ifpresent, willbe detected.
Therefore, the licensee's proposed alternative provides reasonable assurance of structural integrity of the subject components. The staff concluded that based on its evaluation, performing the Code required volumetric examination of the subject integral attachment welds is impractical for Diablo Canyon Power Plant, and the licensee's proposed alternative provides reasonable assurance of structural integrity of the subject components.
Therefore, relief is granted pursuant to 10 CFR 50.55a(g)(6)(i).
Request for Relief PRS-2, R1: ASME Code,Section XI, Table IWC-2500-1, Examination Category C-H, Items C7.30 through C7.80 require a system pressure test, inservice or functional test (IWC-5221), and a system hydrostatic test (IWC-5222) in conjunction with a VT-2 visual examination of pressure-retaining components, piping, and valves.
Pursuant to 10 CFR 50.55a(a)(3)(i), the licensee proposed an alternative to the Code pressure testing requirements for the piping listed below that penetrates the containment and is attached to non-Code Class piping. The nonsafety related lines detailed below are classified as Class 2 solely for the containment integrity function:
j ine 1163 2572 2518 1459 2999 2998 2061 2004 2003 3851 Qg~r'i Pzr Quench Tk Gas Analyzer'l Pp 1-2 Disch Line RV Cnt Spray Pps Disch RV Out PRT Chg Pps Suet RV Disch SIS RV Outlet Hdr to PRT SIS RV Outlet Hdr to PRT Sl Pps Suet RV Out RHR Ht Exchr 2 Out RV RHR HT Exchr 1 Out RV SIS P 1-1 Disch Line RV 3/8 1
1 4
4 1
3 3
1 I
r ure 20 0
3 0
3 3
0 0
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Qg~rIPtigg e
re Lire 3852 SIS Pps Recirc Disch Line RV 525 React Cool Dm Tk Vent 526 React Cool Drn Tk Gas Anal 4382 CHPS AirSup Fans 1 8 2 Disch 4386 CHPS AirSup Fans 1 & 2 Disch 4388 CHPS AirSup Fans 1 & 2 Disch 4389 CHPS AirSup Fans 1 8 2 Disch 4387 CHPS AirSup Fans 1 & 2 Disch 4390 CHPS Exh AirFilt 2 Inlet 4395 CHPS Exh AirFilt 2 Inlet 647 Containment Vacuum Relief K2-Containment Purge Out K2-Containment Purge In 3936 Incore Chiller Water Rtn 3937 Incore Chiller Water Supply 3837 Containment AirSample Inlet 3838 Containment AirSample Return 5190 Post-LOCA Samp Cnt AirRtn S-Post-LOCA Samp Cnt AirRtn 4633 Hyd Mon Cel 82 Cnt AirSup 4634 Hyd Mon Cel 82 Cnt AirSup 4635 Hyd Mon Cel 82 Cnt AirSup 4636 Hyd Mon Cel 82 Cnt AirSup 749 Cont Str Sump Pps Disch 2993 Refueling Canal Water Return 4663 Post LOCA Sample & R 8 Cavity Pene 83 In Pene 83 In Pene 83 In Pene 83 In Pene 83 In Sump 1
3/4 1/2 4
4 4
4 4
4 4
12 48 48 2
2 1
1 3/8 3/8 3/8 3/8 3/8 3/8 2
4 1/4 0
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, 3 3
3 3
3 5
5 0
<50
<50 25 25 3
0
<50
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<50 27 7
<50 The Code requires that a VT-2 visual examination be performed during system pressure testing for Class 2 pressure-retaining piping. As an alternative, the licensee proposed to implement ASME Code Case N-522, which has previously been found acceptable for use at other facilities with certain conditions.
Code Case N-522 allows the use of an Appendix J pressure test in lieu of the Code pressure test requirements for Class 2 containment penetrations when the balance of the piping is non-Code class.
The subject piping is classified as Class 2 because it penetrates primary reactor containment and is considered an extension of the containment vessel.
Since the piping on either side of these penetrations is non-classed, the requirements of Appendix J are more appropriate than those of Examination Category C-H. Appendix J pressure tests verify the leak-tight integrity of the primary reactor containment and of systems and components that penetrate containment by local leak rate and integrated leak rate tests.
In Appendix J pressure tests, containment isolation valves and connecting pipe segments must withstand the peak calculated containment internal pressure related to the maximum design containment.
In addition, the NRC staff has determined that the Appendix J test frequencies are acceptable for assuring containment
0 integrity. Therefore, use of Appendix J should be considered acceptable for the subject penetration piping.
The licensee has committed to perform the Appendix J testing at no less than the peak calculated containment pressure and willuse test procedures that provide for the detection and location of through-wall leakage.
Therefore, the staff concludes that an acceptable level of quality and safety is provided by the licensee's proposed alternative since it willtest the subject penetrations for their intended function.
The staff concludes, based on the evaluation above, that the proposed alternative willprovide an acceptable level of quality and safety. Therefore, the licensee's proposed alternative pressure test is authorized pursuant to 10 CFR 50.55a(a)(3)(i).
The use of this Code Case is authorized for the second 10-year interval at Diablo Canyon Power Plant or until the Code Case is approved for general use by reference in Regulatory Guide 1.147. After that time, the licensee may continue to use Code Case N-522 with the limitations, ifany, listed in Regulatory Guide 1.147.
Request for Relief PRS4, R1: ASME Code,Section XI, Table IWC-2500-1, Examination Category C-H. Item C7.30, and Code Case N498-1 required a VT-2 visual examination during system pressure testing for Class 2 piping., Pursuant to 10 CFR 50.55a(a)(3)(i), the licensee requested relief from the Code pressure test requirements for the fuel transfer tube to refueling canal. The licensee, stated:
"The flange 0-ring seal willbe inspected for integrity under the program being developed to comply with Section XI, Subsection IWE. The penetration is also part of Class MC that is tested under 10 CFR 50, Appendix J. Code Case N-522 allows the 10 CFR 50, Appendix J test to'be credited as the Code examination."
In the licensee's submittal dated April 10, 1998, it confirmed that Code Case N-522, Pressure Testing ofContainment Penefrafion Piping, willbe used in its entirety.
In addition, the licensee included the condition that the leak test would be performed at the peak calculated containment pressure and that test procedures would be used that provide for detection and location of through-wall leakage.
The Code requires that a VT-2 visual examination be performed during system pressure testing for Class 2 pressure-retaining piping. As an alternative, the licensee proposed to implement ASME Code Case N-522, which has previously been found acceptable for use at other facilities with certain conditions.
Code Case N-522 allows the use of an Appendix J pressure test in lieu of the Code pressure test requirements for Class 2 containment penetrations when the balance of the piping is non-Code class.
The subject piping is classified as Class 2 because it penetrates primary reactor containment and is considered an extension of the containment vessel.
Since the piping on either side of these penetrations is non-classed, the requirements of Appendix J are more appropriate than those of Examination Category C-H. Appendix J pressure tests verify the leak-tight integrity of the primary reactor containment and of systems and components that penetrate containment by
/
tf e
local leak rate and integrated leak rate tests.
In Appendix J pressure tests, containment isolation valves and connecting pipe segments must withstand the peak calculated containment internal pressure related to the maximum design containment pressure.
In addition, the NRC staff has determined that the Appendix J test frequencies are acceptable for assuring containment integrity. Therefore, use of Appendix J is considered acceptable for the subject penetration piping.
The licensee has committed to perform the Appendix J testing at no less than the peak calculated containment pressure and willuse test procedures that provide for the detection and location of through-wall leakage.
Therefore, the staff concludes that an acceptable level of quality and safety is provided by the licensee's proposed alternative since it willtest the subject penetrations for their intended function. In addition, the staff concludes that based on the evaluation above, the proposed alternative provides an acceptable level of quality and safety.
Therefore, the licensee's proposed alternative pressure test is authorized pursuant to 10 CFR 50.55a(a)(3)(i).
The use of this Code Case is authorized for the second 10-year interval at Diablo Canyon Nuclear Plant or until the Code Case is approved for general use by reference in Regulatory Guide 1
~ 147. After that time, the licensee may continue to use Code Case N-522 with the limitations, ifany, listed in Regulatory Guide 1
~ 147.
Request for Relief PRS-5:
ASME Code,Section XI, Table IWC-2500-1, Examination Category C-H, Item C7.30 requires a system pressure test once each inspection period. For open ended portions of discharge lines beyond the last shut-off valve in nonclosed systems,
'WC-5222(d) requires a demonstration of an open flow path test in lieu of the system hydrostatic test.
Pursuant to 10 CFR 50.55a(a)(3)(ii), the licensee proposed to perform the required demonstration on the subject piping once each inspection interval. The examination would be performed using system engineers, not certified VT-2 examiners.
The Code requires a system pressure test once each inspection interval in accordance with IWC-5221
~ The Code also requires a system hydrostatic test once each inspection interval for the subject piping in accordance with IWC-5222. For open ended portions of discharge lines beyond the last shut-off valve in non-closed systems, IWC-5222(d) requires a demonstration of an open flow path test in lieu of the system hydrostatic test. Although specified for the 10-year hydrostatic test, this approach should also be considered acceptable to satisfy the periodic pressure test requirement for the subject piping.
In lieu of the periodic pressure tests, the licensee has proposed to perform a demonstration of an open flow path once during the 10-year interval using non-certiflied personnel.
However, the licensee has not presented the burden associated with performing the demonstration using certified personnel or with meeting the periodic frequency specified by the Code. As stated by the licensee, plant technical specifications require the demonstrations at least once during the 10-year interval. There is no discussion precluding performance on a more frequent schedule.
The staff concluded that based on its evaluation that the proposed alternative has not been adequately justified. Therefore, the licensee's proposed alternative is denied.
1
'I F
Request for Relief PRS-3: ASME Code,Section XI, Table IWB-2500-1, Examination Category B-P, Item B15.51 and Table IWC-2500-1, Examination Category C-H, Item C7.40 require a system hydrostatic pressure test once per interval in accordance with IWB-5222 and IWC-5222, respectively.
Pursuant to 10 CFR 50.55a(a)(3)(ii), the licensee proposed an alternative to the Code required pressure tests for smail diameter Class 1 pipe segments between isolation valves. The licensee stated:
"Each line segment below will be visually inspected once during the 10-year system test; however, the line segments willnot be pressurized to full system pressure.
Pressure may exist due to first offvalve leakby and thermal affects. The Class 1 line segments are also observed each refueling outage during the system leakage test and the Class 2 line segments are also observed once each inspection period during the system inservice test.
es r'llss
~Siz 1
3/4 1
3/4 1
3/4 1
3/4 1
3/4 1
2 1
2 2
1 3/4 1
2 1
3/4 1
3/4 1
3/4 1
3/4 1
3/4 1
3/4 3/4
~
1 3/4 1
3/4 3/4 1
3/4 1
3/4 1
3/4 1
3/4 1
3/4 1
3/4 1
3/4 1
3/4 1
3/4 line 2527 betwn vlvs 8364A & 283 RCP Lp 1 Seal Inj Dm RCDT line 2534 betwn vlvs 8364B & 294 RCP Lp 2 Seal Inj Dm RCDT line 2536 betwn vlvs 8364C & 303 'CP Lp 3 Seal Inj Drn RCDT line 2541 betwn vlvs 8364D & 308 RCP Lp 4 Seal Inj Drn RCDT segment betwn vlvs 513 & 514 Pzr Spray Drn to RCDT segment betwn vlvs 8057A & 8058A RCP Lp 1 Cld Lg Dm RCDT segment betwn vlvs 8057B & 8058B RCP Lp 2 Cld Lg Drn RCDT segment betwn vlvs 8057C & 8058C RCP Lp 3 Cld Lg Dm RCDT line 109 betwn vlvs 579 & 570 Hot Leg Recirc Vent
.line 961 betwn vlvs 8057D&8066,8058D Lp 4 Cld Lg Drn (to 3/4")
RVRLIS connection between valve 8070 & blind flange line 14 Loop 2 spray line vent between valve 517 & 518 line 14 Loop 2 spray line drain to RCDT between valve 515 & 516 line 14 Loop 2 spray line drain to RCDT between valve 519 & 520 line 13 Loop 1 spray line vent between valve 521 & 522 line 13 Loop 1 spray line drain between valve 523 & 524 line 1195 Pressurizer PORV vent betwn valve 8056 & blind flange line 1469 Pzr Ip seal vent betwn valve 8052 & 8064A, 8064B, 8064C line 1495 RCP 1 seal bypass vent betwn valve 8362A & blind flange line 1496 RCP 2 seal bypass vent betwn valve 8362B & blind flange line 1497 RCP 3 seal bypass vent betwn valve 8362C & blind flange line 1498 RCP 4 seal bypass vent betwn valve 8362D & blind flange U2 In 246 Charging line loop 4 vent between valve 100 & 572 U2 In 253 Accumulator inject loop 1 vent between valve 138 & 139 U2 In 254 Accumulator inject loop 2 vent between valve 140 & 141 U2 In 256 Accumulator inject loop 4 vent between valve 144 & 145 line 235 Safety inject loop 1 hot leg vent between valve 50 & 51 U2 In 236 Safety inject loop 2 hot leg vent between valve 54 & 55 line 237 Safe in'ect loo 3 hot le vent between valve 58 & 59 "Note: Line numbers given refer to main line that the subject segment is joined to. The small segments do not have individual line numbers.
Qasa Sm 1
3/4 1
3/4 1
3/4 2
1 2
1 2
3/4 2
3/4 U2 In 238 Safety inject loop 4 leg vent between valve 62 & 63 line 109 Hot leg recirc vent between valve 6 & 935 line 109 RHR loop 4 vlv 8702 thermal expn drain betwn vlv 3,4, & 7 Reactor vessel head vent between valve 8078B & 8078A Reactor vessel head vent between valve 8078C & 8078D RVRLIS hot leg instrument connection between valve 617 & 616 React vessel head vent valve test conn between test conn & valve 661" The Code requires a system hydrostatic test to be performed once per interval in accordance with IWA-5000 for Class 1 components and IWC-5000 for Class 2 items.
However, pressure testing of the subject piping segments would result in excess radiation exposure to plant personnel and, in some cases, may subject certain plant safety systems to be compromised.
Imposition of the Code pressure test requirements would result in a considerable burden on the licensee.
In lieu of the Code requirements, the licensee willvisually examine each of the segments during system pressure testing at less than full system pressure.
This willoccur once per refueling outage for Class 1 segments and once per inspection period for Class 2 segments.
The staff concluded that this visual examination willdetect any leakage that may occur and the licensee's alternative provides reasonable assurance of the continued operation readiness of the subject segments.
Furthermore, the staff concludes that based on the burden associated with meeting the Code pressure testing requirements, and the reasonable assurance provided by the visual examination during system pressure testing, imposition of the Code requirements would result in a hardship without a compensating increase in quality and safety. Therefore, the licensee's proposed alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(ii)
~
Request for Relief NDE-23: ASME Code,Section XI, IWA-2430(d), requires that for components inspected under Program B, each inspection interval may be extended or decreased by as much as one year. Adjustments shall not cause successive intervals to be altered by more than one year from the original pattern of intervals.
Paragraph IWB-2412(b) requires that the inspection period may be decreased or extended by as much as one. year to enable an inspection to coincide with a plant outage, within the limitations of IWA-2430(d).
Table IWB-2412-1 requires that the maximum examinations credited in the first period be 34 percent and in the second period be 67 percent of the requirement for the interval.
Pursuant to 10 CFR 50.55a(a)(3)(i), the licensee proposed an alternative.
The licensee stated:
"The second and subsequent ISI interval may be extended or decreased by as much as two years.
Adjustments shall not cause successive'intervals to be altered by more than two years from the original pattern of intervals. The specified inspection period may be decreased or extended by as much as two years to enable an inspection to coincide with a plant outage, within these limits. The percentage of examinations completed in the first period may be up to 40 percent, and in the second period up to 80 percent of the examinations required for the interval."
e The Code allows the length of an inspection interval or period to be increased or decreased by as much as one year so that inspections can coincide with a refueling outage.
The licensee has proposed to alter that requirement such that the interval or period can be extended (or decreased) as much as two years.
The basis for the licensee's proposal appears to be so that there are an equal number of refueling outages in each period. The licensee contends that since they are on a 24-month refueling cycle, there are an odd number of outages during the 10-year interval and that examinations will be unequally distributed because of this.
This request appears to be administrative in nature and there is no real basis to support the request.
It is agreed that examinations may be unequally distributed among outages, but that does not mean the periodic examination samples cannot be met. This may require a larger sample selected during one outage this should be reflected in the ISI Program.
Ifthe examination of a specific component cannot be completed within the existing allowances of the Code, specific relief should be requested.
These reliefs will be evaluated on a case-by-case basis.
The staff concluded that considering that the licensee's proposed alternative is administrative in nature and that the licensee has not provided a basis for the impracticality or the associated burden, relief is denied.
Request for Relief NDE-24:
Request for Relief NDE-24 was withdrawn by the licensee in its letter dated April 10, 1998.
Request for Relief PRS-1, R1: Request for Relief PRS-1, R1 was withdrawn by the licensee in its letter dated April 10, 1998.
Request for Relief PRS-1A: The ASME Code requires that for systems borated for the purpose of controlling reactivity, Subparagraph IWA-5242(a) requires removal of insulation from pressure-retaining bolted connections for VT-2 visual examination during system pressure testing.
In accordance with 10 CFR 50.55a(a)(3)(ii), the licensee proposed an alternative to the requirements of the Code for the reactor pressure closure flange joint. The licensee stated:
"The system leakage test (or system hydrostatic test) willbe performed with a 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> hold time to assure that any leakage willbe detectable, but the reactor vessel closure flange joint insulation willnot be removed for performance of VT-2 visual examination.
Instead, the reactor vessel flange leakage monitoring system willbe used to assure that there is no leakage past the inner 0-ring seal.
VT-2 visual examination willalso be conducted around the flange joint from the top of the reactor cavity with the insulation left in place."
The Code requires the removal of all insulation from pressure-retaining bolted connections in systems borated for the purpose of controlling reactivity when performing VT-2 visual examinations during system pressure tests.
However, removal of the insulation for direct VT-2 visual examination of the RPV closure head flange joint would require an unnecessary thermal cycle of the primary system and unnecessary radiation exposure for plant personnel.
Therefore, imposition of the Code requirements would cause a burden on the licensee.
As an alternative, the licensee has proposed to perform the leakage test with the insulation in place with a 4-hour hold time, and with the reactor vessel flange leakage monitoring system to assure that there is no leakage past the inner 0-ring seal.
This approach willallow leakage to be detected without removal of the insulation; therefore, it provides reasonable assurance. of the op'erational readiness of the RPV closure flange joint.
The staff concluded that considering the burden associated with removal of the insulation from the RPV closure head, and the reasonable assurance provided by the licensee's proposed alternative, imposition of the Code requirements would result in hardship without a compensating increase in quality and safety. Therefore, the licensee's proposed alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(ii).
Request for Relief PRS-1C:
ASME Code,Section XI, IWA-5242(a)(2), Insulation Removal For VT-2 Visual Examination Of Bolting In Class 1 and 2, Borated Systems.
Request for Relief PRS-1C was evaluated and authorized in an NRC SE dated May 1, 1998.
Request for Relief PRS-1D:
Use of Code Case N-533, Alternative Requirements for VT-2 Visual Examination of Class 1 Insulated Pressure-Retaining Bolted Connections,Section XI, Division 1, for Class 2 Systems.
Request for Relief PRS-1D was evaluated and authorized in an NRC SE dated May 1, 1998.
Request for Relief PRS-1E:
ASME Code,Section XI, Paragraph IWA-5250(a)(2), Corrective Measures for Bolted Connections.
Request for Relief PRS-1E was evaluated and authorized in an NRC SE dated May 1, 1998.
Request for Relief CNT-1:
ASME Code,Section XI, Examination Categories IWE and IWL, Examination of the Containment Structure, Including the Concrete Shell and Metal Liner.
Pursuant to 10 CFR 50.55a(b)(2)(vi), licensees shall implement Subsections IWE and IWLof the 1992 Edition with the 1992 Addenda of ASME Section XI when performing containment examination.
Subsection IWE contains requirements for Class MC and metallic liners of Class CC components.
Subsection IWLcontains requirements for Class CC concrete components.
Pursuant to 10 CFR 50.55a(a)(3)(ii), the licensee proposed an alternative to the repair and, replacement provisions, VT-1, VT-3, and visual examiner definitions, ANIIqualiTications and surface examinations for dissimilar metal welds as specified in subsections IWE and IWLof the 1992 Edition with the 1992 Addenda.
The licensee stated:
"The VT-1 and VT-3 examination rules in subsection IWA, including examiner qualification details, willconform to the 1989 Edition. These are the same requirements that apply for all other components in the ISI program.
Examination extent and all other requirements will conform to the 1992 Edition except for surface examination of dissimilar metal welds, which may instead be included ln the general surface visual.
The regulations require that licensees implement the provisions of Subsections IWE and IWLof the 1992 Edition, with the 1992 Addenda of ASME Section XI. The licensee stated that some of the imposed requirements were a burden without a compensating increase in the level of
e 0
0 quality and safety and proposed an alternative to the qualification requirements for VT-1 and VT-3 examiners and the qualifications for authorized inspectors.
The licensee also proposed an alternative to the surface examination of dissimilar metal welds. However, the licensee has not provided adequate justification su'pporting their determination that the Code requirements are a burden.
Review of Subsection IWLindicates that some new qualification/examination levels (VT-1C and VT-3C) are imposed to address relevant conditions in concrete structures that were not considered by previous VT-1 and VT-3 examinations.
Consequently, it appears that additional qualifications are necessary to provide for effective examinations for concrete.
Likewise, authorized inspectors should get additional training to meet new requirements as needed.
Regarding the alternative visual for examination of dissimilar metal welds, the licensee has not provided adequate justification supporting their determination that the Code-required surface examination is a hardship.
The staff concludes that the licensee has not adequately justified the burden associated with meeting the requirements of IWE and IWL. Therefore, the licensee's proposed alternative is denied.
Request for Relief DOC-1: Implementation of Alternatives to Code Recording and Reporting Requirements.
Request for Relief DOC-1 was withdrawn by the licensee in its letter dated April 10, 1998.
Request for Relief NDE-28:
ASME Code,Section XI, Examination Category F-A, Items F1.20 and F1.30, Examination of Component Supports.
Request for Relief NDE-28 was withdrawn by the licensee in its letter dated April 10, 1998.
Request for Relief NDE-30:
ASME Code,Section XI, Examination Category F-A, Item F1.10 requires a VT-3 visual examination each inspection interval, as defined by Figure IWF-1300-1, Paragraph IWF-1300 and IWF-2510. Figure IWF-1300-1(d) defines the support boundary as the pressure retaining component surface to the building structure surface.
Pursuant to 10 CFR 50.55a(a)(3)(ii), the licensee proposed the following alternative to the requirements of the Code:
"The examination willbe completed with the SG insulation left in place. The exposed portions of'the clamp attachment will be examined and the insulation willbe observed for signs of damage that could indicate loosening of the attachment."
The Code requires the visual examination of the subject component support from the vessel surface to the building surface.
However, direct access to the entire support is restricted by permanent insulation that limits the visual examination.
To gain access for examination, the
0
27 insulation would have to be re'moved and disposed of, and then replaced.
This would require a significant work effort and unnecessary radiation exposure to plant personnel.
Therefore, imposition of this requirement on the licensee would result in a considerable burden.
The licensee's proposed alternative is to perform the visual examination on the exposed portions of the support with the insulation in place. Any significant degradation of the support willbe indicated by deformation of the support and damage to the surrounding insulation.
Therefore, the licensee's proposed alternative provides reasonable assurance of the structural integrity of the subject support.
The staff concluded that based on its evaluation, imposition of the Code requirements would result in a hardship without a compensating increase in quality and safety. Therefore, the
'icensee's proposed alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(ii).
Proposed Alternative to use Code Case N-524, Alternative Examination Requirements for Longitudinal Welds in Class 1 and 2 Piping,Section XI, Division 1 (NDE-31):
The ASME Code,Section XI, Examination Category B-J, requires 100 percent volumetric and/or surface examination of longitudinal piping welds as defined by Figure IWB-2500-8. The examination shall include at least one pipe diameter, but not more than 12 inches of each longitudinal weld intersecting circumferential welds required to be examined by Examination Categories B-J and B-F. Examination Categories C-F-1 and C-F-2 require 100 percent volumetric and/or surface examination, as defined by Figure IWC-2500-7, -1 2 and -1 3, for 2.5t of each longitudinal weld intersecting circumferential welds examined.
In accordance with 10 CFR 50.55a(a)(3)(i), the licensee proposed to use Code Case N-524 as
'lternative requirements for the examination of Class 1 and 2 longitudinal piping welds. The licensee stated:
"Code Case N-524 has been issued to address extent of examination for longitudinal welds in piping systems.
DCPP seam welds willbe examined as required by Code Case N-524 when the intersecting circumferential welds is examined.
For stainless steel welds, the extent of examination required by Code Case N-524 assures that the areas subject to sensitization will be examined."
ASME Section XI requires the examination of one pipe diameter, but not more than 12 inches, of Class 1 longitudinal piping welds.
For Class 2 piping welds, the length of longitudinal weld required to be examined is 2.5 times the pipe thickness.
These lengths are measu'red from the intersection with the circumferential weld. The licensee's proposed alternative is to examine only the portions of longitudinal weld within the examination area of the intersecting circumferential weld in accordance with Code Case N-524, Alternative Examination Requirements for Longitudinal Welds in Class 1 and Class 2 Piping.
Longitudinal welds are produced during the manufacture of the piping, not in the field as is the case for circumferential welds. Consequently, longitudinal welds are fabricated under strict manufacturing standards, which provide assurance of structural integrity. These welds have also been subjected to the preservice and initial inservice examinations, which provide additional assurance of structural integrity.
No significant loading conditions or material degradation mechanisms have been identified to date that specifically relate to longitudinal seam welds in Class 1 and 2 nuclear plant piping.
The most critical region of the longitudinal weld is the portion that intersects the circumferential weld. Ifdegradation associated with a longitudinal weld were to occur, it is expected that it would be located at the intersection with a circumferential weld. Since this region willbe examined during the examination of the circumferential weld, the licensee's alternative provides reasonable assurance of the continued structural integrity.
The staff concluded that, based on its evaluation the use of Code Case N-524 provides an acceptable level of quality and safety. Therefore, the licensee's proposed alternative, to use Code Case N-524, is authorized pursuant to 10 CFR 50.55a(a)(3)(i).
The use of this Code Case is authorized for the second 10-year interval at Diablo Canyon Power Plant, or until the Code Case is approved for general use by reference in Regulatory Guide 1.147. After that time, the licensee must followthe conditions, ifany, specified in the regulatory guide.
~CO CL The staff concluded that based on the review of the Diablo Canyon Power Plant, units 1 and 2, Second 10-Year Interval Inservice Inspection Program Plan, Revision 0, the licensee's response to the NRC's request for additional information, and the recommendations for granting
~ relief from the ISI examinations that cannot be performed to the extent required by Section XI of the ASME Code, no deviations from regulatory requirements or commitments have been identiTied except as noted below.
Pursuant to 10 CFR 50.55a(g)(6)((A)(1), the staff has concluded that certain inservice examinations cannot be performed to the extent required by Section XI of the ASME Code.
In the case of Requests for Relief NDE-02, NDE-03 R1, NDE4, NDE-5, NDE-6B, NDE-8 R1, NDE-9, NDE-1 3.1 R8, NDE-1 5 (Unit 1), NDE-16, NDE-17 R1 (Part 1), NDE-18 R1 (Part 1),
NDE-1 9 R1, NDE-20 R1, NDE-21.1 R8, NDE-22 and NDE-25 (Unit 2), the licensee has demonstrated that specific Section XI requirements are impractical. Therefore, relief is granted as requested pursuant to 10 CFR 50.55a(g)(6)(i). The granting of relief will not endanger life, property, or the common defense and security and is otherwise in the public interest, giving.due consideration to the burden upon the licensee that could result ifthe requirements were imposed on the facility.
The staff concluded that the licensee's proposed alternatives contained in Requests for Relief NDE-26 R1 (Unit 2), NDE-29 (Unit 2), PRS-2 R1, PRS-4 R1 and PA N-524 (NDE-31), provide an acceptable level of quality and safety. Therefore, the licensee's proposed alternatives contained in Requests for Relief NDE-26 R1(Unit 2), NDE-29 (Unit 2), PRS-2 R1, PRSA R1 and PA N-524 (NDE-31), are authorized pursuant to 10 CFR 50.55a(a)(3)(i).
0 The staff concluded that the Gode requirements contained in Requests for Relief NDE-17 R1 (Part 2), NDE-1 8 R1 (Part 2), NDE-30, PRS-1A and PRS-3, would result in hardship without a compensating increase in the level of quality and safety.
The alternatives contained in Requests for Relief NDE-17 R1 (Part 2), NDE-18 R1 (Part 2), NDE-30, PRS-1A and PRS-3 are authorized pursuant to 10 CFR 50.55a(a)(3)(ii).
The staff determined that the requirements of 10 CFR 50.55a(g)(6)(ii)(A) were not met for Request for Relief NDE-01, and that the licensee must propose an alternative that provides an acceptable level of quality and safety.
In the April 10, 1998, submittal, the licensee stated that it has met and willcontinue to meet the augmented requirement.
However, no alternative to augmented RPV examination has been proposed and until the licensee satisfies the augmented examination requirements of the regulations, reliefs to Code requirements cannot be evaluated.
Section 50.55a(g)(6)(ii)(A)(1) revokes all previous requests for relief for Item 81.10 welds and relief cannot be granted to Code requirements until the augmented rule is satisfied.
Requests for Relief NDE-6, NDE-10, NDE-11, NDE-12, and NDE-14 R1 were withdrawn by the
. licensee's letter dated August 13, 1997.
Requests for Relief NDE-24, NDE-28, PRS-1 R1, and DOC-1 were withdrawn by the licensee's letter dated April 10, 1998. Requests for Relief PRS-1C, PRS-1D, and PRS-1E were evaluated and authorized by the staffs safety evaluation dated May 1, 1998.
Requests for Relief NDE-6A, NDE-7, NDE-23, NDE-27, PRS-5, and CNT-1 are denied b the staff.
Attachment:
Table 1 - Summary of Relief Requests Principal Contributor: T. McLellan Date:
October 15, 1998
DIABLOCANYON POWER PlANT, UNITS 1 AND2 Second 10-Year ISI Interval TABLE 1
SUMMARY
OF RELIEF REQUESTS Page 1 of
-""":'.":.Number.,'i:"'.:;'Comporie'rit".',Citegory,'
- Item.'-..:
.','-",'.No;":,'-',". :;:.'-::;-,'.':.Volum'a:or'A'res.,to'be;.Examined".~-."'::; M'ethod'","',:::::"".-.":.,:,:"',,i::;::,:.",:,"'g:"AItematlv'e'.,"',.':.-:X:,"";:i:-':, ":Relief Re'quest':Statui,',:":'.:;
NDE1 NDE-02 NDE-03, R1 NDE-4 NDE-5 NDE-6 NDE-6A NDE-68 NDE-7 NDE-B, R1 NDE-9 RPV RPV RPV RPV RPV RPV RPV RPV RPV Pressurizer Steam Generator 8-A 8-A 8-A 8-A 8-A 8-D 8-D 8-D B-D 8-D 8-D 81.11 81.22 81.22 81.30 81.40 83.90 83.100 83.90 83.100 83;90 83.100 83.120 83.140 Shell-to-head weld Circumferential head weld Meridional Weld Shell-to-flange weld Head-to-flange weld Nozzle-to-vessel welds and IR sections Nozzle-to-vessel welds and IR sections Nozzle-to-vessel welds Nozzle IR sections Nozzle IR sections Primary Nozzle IR sections Volumetric Volumetric Volumetric Volumetric Volumetric Volumetric Volumetric Volumetric Volumetric Volumetric Volumetric Volumetric exam to extent practical Volumetric exam to extent practical Volumetric exam to extent practical Volumetric exam to extent practical Volumetric exam to extent practical Code Case N-521 (equivalent)
Volumetric exam to extent practical Code Case N-521 (equivalent)
Volumetric exam to extent practical Volumetnc exam to extent practical Not grarited Granted Granted Granted Granted Withdrawn Not authorized Granted Not Authorized Granted Granted NDE-10 NDE-11 NDE-12 RPV Pressurizer Steam Generator 8-F 8-F 8-F 85.10 85.40 85.70 Nozzle-to-safe end weids Nozzle-to-safe end welds Nozzle-to-safe end welds Volumetric Volumetric Volumetric Withdrawn Withdrawn Withdrawn
I
DIABL ANYON POWER PLANT, UNITS 1 AND 2 Second 10-Year ISI Interval TABLE 1
SUMMARY
OF RELIEF REQUESTS Page 2 of
!,'"::~@i:~Rel(ef F,";;>j;.:
~".". Re'quest'.
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,';.;'-,".;;Number<:.,-.
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NDE-13.1RB Class 1
Piping 8-J 81.11 81.12 Circ and longitudinal welds Volumetric and Surface Volumetric and surface exams to extent practical Granted NDE-14, R1 NDE-15 (Unit 1)
NDE-16 Class 1
Piping Class 1
Piping Class 1
Pump 8-J 89.31 8-J 89AO 8-K-1 810.20 Branch Connections Socket Welds Integral Attachments Surface Volumetric or Surface Surface exam to extent practical Volumetric or surface to extent practical Withdrawn Granted Gfanted NDE-17 (Part 1)
NDE-17 (Part 2)
Class 2 Class 2 C-A C-A C1.10 C1.20 C1.30 C1.10 C1.20 Vessel Welds Seal Injection Filter Volumetric Volumetric Volumetric exam to extent practical Code-required pressure testing granted Authorized NDE-18, R1 (Part 1)
NDE-18, R1 (Part 2)
NDE-19, R1 Class 2 Vessels Class 2 Class 2 C-8 C2.21 C-8 C2.21 C-8 C2.22 Nozzle-to-Vessel Welds Nozzle-to-Vessel Welds RHRHX and Seal Injection Filter IR Sections Volumetric and surface Volumetric and surface Volumetric Volumetric and surface to extent practical Code-required pressure testing Volumetric exam to extent practical Granted Authorized Granted NDE-20, R1 Class 2 C-C C3.10 C3.20 C3.30 Integral attachments to vessels, pumps and piping Surface Surface exams to extent practical Granted NDE-21.1 RB Class 2 C-F-1 C5.20 Piping Welds Volumetric and surface Volumetric and surface exams to extent practical Granted NDE-22 Class 2 C-F-2 C5.51 Piping Welds Volumetric and surface Volumetric and surface exams to extent practical Granted NDE-23 Class 1,2 and 3 Scheduling Requirements IWB-2412-1 Denied
0
DIABL NYON POWER PLANT, UNITS 1 AND 2 Second 10-Year ISI Interval TABLE 1
SUMMARY
OF RELIEF REQUESTS Page 3 of
)'.:.,':.:,i+Relief':~'.;.;.,
','!"".Requei't:,:."',,'j5
- "'
- ;'(Numbe'r'<g.;-.;
NDE 24
- Componerit "'Ca'teg'or'y'",~'No.",'"'"
Class 1,2 and 3
- ,";.i,'.Vofume,'or.,"Ar'e'e.to,'be". Examined;,".i, Successive Examinations per IWB-2420, IWC-2420 and IWD-2420
',';;:;;Meth'od,.';;::.':-.".,"
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Withdrawn NDE-25 (Unit 2)
Pressurizer B-D B3.110 Nozzie-to-vessel welds Volumetric Volumetric exam to extent practical Granted NDE-26, R1 (Unit 2)
Pressurizer B-H B8.20 Support Skirt Volumetric or surface Volumetric and surface Authorized NDE-27 NDE-28 RPV Supports B-A B-G-1 F-A B1.30 86.40 F1.20 F1.30 Shell-to-flange welds and threads in flange Volumetric Deferral to end of interval Not Authorized Withdrawn NDE-29 (Unit 2)
Class 2 C-F-1 C-F-2 Piping Welds Volumetric and/or surface Exams on single stream Authorized NDE-30 Supports F-A F1.10 Mechanical Connections to Pressure Retaining Components and Structures VT-3 Visual Visual exam with insulation in place Authorized PRS-1, R1 Successive Examinations per IWB-2420, IWC-2420 and IWF-2420 Withdrawn PRS-1A, R1 PRS-1C Insulated bolted connections Insulation Removal IWA-5242(a)(2)
Authorized in SER dated 5/1/98 IWA-5242(a).
VT-2 with insulation in place Authorized PRS-1D Insulation Removal Code Case N-533 Evaluated in SER dated 5/1/98 PRS-1E Corrective Measures for Bolted Connections IWA-5250(a)(2)
Authorized in SER dated 5/1/98 PRS-2 Class 2 C-H C7.30 C7.40 Containment Penetrations VT-2 Visual Code Case N-522 Authorized
DIABL NYON POWER PLANT, UNITS 1 AND2 Second 10-Year ISI Interval TABLE 1
SUMMARY
OF RELIEF REQUESTS Page 4 of
'~;'j,ReHef,.,"',:!;-.;;.":
,,:,:;,'<" Reques'tv':,":<
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ReHef;.Reqruelt,Statue'<.'".'RS-3 Class 1 &2 B-P C-H B15.51 Piping Segments C7.40 System Hydrostatic Test Pressure test at reduced pressure Authorized PRSC, R1 Class 2 C-H C7.30 Fuel Transfer Tube to Refueling Canal VT-2 Visual Code Case N-522 Authorized PRS-5 Oass 2 C-H Open Ended portions of discharge lines Demonstration each period Demonstrations once per interval with noncertified engineers Not Authorized CNT-1 Containment IWE IWL Dissimilar Metal Weids, Personnel Qua!ifications 1992 Addenda VT-1 and VT-3 per 1989 Code Not Authorized DOC-1 Alternative to Code Recording and Reporting Requirements Withdrawn N-524 Class 1 and 2
8-J C-F-1 C-F-2 Longitudinal Welds Surface and/or Volumetric Code Case N-524 Authorized
0