ML18153A051
| ML18153A051 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 08/30/1996 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML18153A050 | List: |
| References | |
| NUDOCS 9609040313 | |
| Download: ML18153A051 (13) | |
Text
(
I I
ENCLOSURE 1 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION OF THE THIRD TEN YEAR INTERVAL INSERVICE INSPECTION PROGRAM PLAN REQUESTS FOR RELIEF NOS. SR-009 THROUGH SR-017
1.0 INTRODUCTION
FOR VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION, UNIT 1 DOCKET NUMBER:
50-280 The Technical Specifications for Surry Power Station, Unit 1 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 Code and applicable Addenda as required by 10 CFR 50.SSa(g), except where specific written relief has been granted by the Commission pursuant to 10 CFR 50.55a(g)(6)(i).
10 CFR 50.55a{a){3) states that alternatives to the requirements of paragraph
{g) may be used, when authorized by the NRC, if (i) the proposed alternatives would provide an acceptable level of quality and safety or (ii) compliance with the specified requirements would result in hardship or unusual difficulties without a compensating increase in the level of quality and safety.
Pursuant to 10 CFR 50.55a(g)(4), ASME Code Class 1, 2, and 3 components (including supports) shall meet the requirements, except the design-and access provisions and-the preservice examination requirem~nts, set forth in _the ASME Code,Section XI, "Rules for Inservice Inspection of Nucle~r Power Plant Components,-" to the extent practical within the l i mitat i ans 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.SSa(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 Surry Power* Station, Unit 1 third 10-year inservice inspection (ISi) interval is the 1989 Edition. The components (including.
supports) may meet the requirements set forth in subsequent editions and addenda of the ASME Code incorporated by reference in 10 CFR 50.55a(b) subject to the limitations and modifications listed therein and subject to Commission approval.
Pursuant to 10 CFR 50.55a(g)(5), if the licensee determines that conformance with an examination requirement of Section XI of the ASME Code is not practical for its facility, information shall be submitted to the Commission in support of that determination and a request made for relief from the ASME Code requirement. After evaluation of the determination, pursuant to 10 CFR 50.55a(g)(6)(i), the Commission may grant relief and may impose alternative requirements that are determined to be authorized by law, will not endanger life, property, or the common defense and security, and are otherwise in the public interest, giving due consideration to the burden upon the**.
9609040313 960830 PDR ADOCK 05000280 P
e 2
licensee that could result if the requirements were imposed.
In a letter dated April 23, 1996, Virginia Electric and Power Company submitted to the NRC its Third Ten-Year Interval Inservice Inspection Program Plan Requests for Relief Nos. SR-009 through SR-017 for the Surry Power Station, Unit};
2.0 EVALUATION AND CONCLUSIONS The staff, with technical assistance from its contractor, the Idaho National Engineering Laboratory (INEL), has evaluated the information provided by the licensee in support of its Third Ten-Year Interval Inservice Inspection Program Plan Requests for Relief Nos. SR-009 through SR-017 for the Surry Power Station, Unit 1.
Based on the information submitted, the staff adopts the contractor's conclusions *and recommendations presented in the Technical Letter Report attached.
For Requests for Relief Nos. SR-009, SR-010, SR-011, SR-012, SR-013, SR-014, SR-015, SR-016, and SR-017 the staff concluded that the Code requirements are impractical because the weld configurations prevent full examination coverage.
Imposition of this requirement would cause a considerable burden on the licensee as design modifications would be necessary.
The licensee's proposed alternatives provide reasonable assurance*
of operational readiness of the subject systems.
Therefore, Requests for Relief Nos. SR-009, SR-010, SR-011, SR-012, SR-013, SR-014, SR~Ol5, SR-016, and SR-017 are granted pursuant to I0CFR50.55a(g)(6)(i) with a provision for Request for Relief No. SR-014.
Request for Relief No. SR-014 is granted provided that when the reactor coolant pumps are disassembled, the licensee performs the Code required examinations.
e TECHNICAL LETTER REPORT THIRD 10-YEAR INTERVAL INSERVICE INSPECTION RELIEF REQUESTS SR-009 THROUGH SR-017 VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION, UNIT 1 DOCKET NUMBER 50-280 ENCLOSURE 2
- 1. 0 INTRODUCTION The licensee, Virginia Electric and.Power Company, submitted Relief-Requests SR-009 through SR-017 for the third 10-year interval inservice inspection {ISi} at the Surry Power Station, Unit 1, in a letter dated April 23, 1996.
The INEL staff has evaluated the subject relief requests in the following section.
2.0 EVALUATION The Code of record for.the third 10-year ISi interval at the Surry Power Station, Unit 1, is the American Society of Mechanical Engineers {ASME}
Boiler and Pressure Vessel Code,Section XI, 1989 Edition.* The information provided by the licensee in support of the relief requests has been evaluated and the bases for disposition are documented below.
A.
Relief Requests SR-009, SR-010. and SR-011, Examination Category B-J, Items B9.ll and B9.12. Piping Welds Code Requirement:
Items B9.ll and B9.12 of Examination Category B-J require 100% volumetric and surface examinations of Class 1 circumferential and longitudinal piping welds NPS 4 or larger, as defined by Figure IWB-2500-8.
Licensee's Code Relief Request:
The licensee requested relief from the Code-required examination of inaccessible areas of the following piping welds.
No.
Line No.
Drawing No.
Relief SR-009 1-12 27lz"-RC-9-2501R ll448-WMKS-0102AZ-1 Volumetric SR-010 1-11 31 11-RC-f;3-2501R 11448-WMKS-0102AZ-1 Volumetric Volumetric SR-011 1-20 31 "-RC-8-2501R 11448-WMKS-0102AZ-l and Surface Licensee's Basis for Requesting Relief (as stated):
(SR-009):
uThe component listed above has been examined to the extent practical as required by the Code.
However, full examination coverage could not be achieved due to the configuration of the ~eld (pipe to reactor codlant pump} and a 1 11 by 5" identification tag. Coverage of the volumetric examinations are detailed in Table SR-009-1*.
Figure SR-009-1* is provided as graphic detail of the limitations experienced. This weld is a terminal end weld and, as such, all welds of this type are scheduled for examination.* Therefore, substitution with another weld is not feasible."
(SR-010):
uThe component listed above has been examined to the extent practical as required by the Code.
However, full examination coverage could not be* achieved due to the configuration of the weld (pipe to reactor coolant pump} and a support. Coverage of the examinations are detailed -in Table SR-Olo-1*.
Figure SR-010-1* is provided as graphic detail of the limitations experienced, where the weld could not be examined.
Figure SR-010-2* is provide to show the closeness of the support in relation to weld 1-11.
The support is a massive welded and bolted structure that supports the reactor coolant pump and, as such, cannot be removed to allow access to weld 1-11. This weld is a terminal end weld and, as such, all welds of this type are scheduled for examination. Therefore, substitution with another weld is not feasible."
(SR-011) uThe component listed above is inaccessible for both surface and volumetric examination. Examination could not be achieved due to the configuration of the support. A reactor coolant pump support/pipe support completely covers this longitudinal weld.
The circumferential weld {1-11} that intersects with this longitudinal weld is a terminal end weld and, as such, all welds of this type are scheduled for examination.
Therefore, substitution with another weld is not feasible.
The adjacent longitudfnal weld 1-21 (shown of drawing
'Not included in this evaluation.
e 3
11448~WMKS-0102AZ-1 and Figure SR-011-1*) was examined 100%, at weld.1-11, per Code Case N-524, with *no reportable indications (NRI)."
Licensee's Proposed Alternative (As stated):
(SR-009 and SR-010):
ult is proposed that the examination already completed at the red~ced coverage be counted as meeting the Code requirements."
(SR-011) ult is proposed that the system leakage test be substituted for the Code surface and volumetric examination."
Evaluation:
The Code requires 100% surface and volumetric examinations of the subject Code Items B9.ll and B9.12 circumferential and longitudinal piping welds.
From review of the supporting information, it has been determined that the weld configurations prevent full examination coverage and make the examinations impractical to perform to the extent required _by the Code.
Design modifications woul.d be necessary to sufficiently improve the access to and geometry of the subject piping terminal end joints to allow complete examinations.
Imposition of this requirement would cause a considerable burden on.the licensee..
From review of the information submitted by the licensee, and based on (1) the examinations performed to the extent practical for Relief Requests SR-009 and SR-010, which provided 76% and 50%
volumetric examination coverages, respectively, and 100% surface examination coverages; (2) the examinations performed on longitudinal welds similar to the weld addressed in Relief Request SR-011; and (3) the system leakage tests that are conducted following each refueling outage, it is concluded that significant degradation, if present, would be detected.
As a result, reasonable assurance of structural integrity is provided.
Therefore, it is recommended that relief be granted pursuant to 10 CFR 50.55a(g}(6}(i}.
- Not included in this evaluation.
B.
e e
4 Relief Request SR-012, Examination Category 8-F, Item 85.70, Piping-to-Steam Generator Safe End Welds Code Requirement:
Examination Category 8-F, Item 85.70, requires 100% volumetric and surface examinations of Class 1 nozzle-to-safe end piping welds NPS 4 or larger, as defined by Figure IWB-2500-8.
Licensee's Code Relief Request:
The licensee requested relief from the Code-required volumetric examination of inaccessible areas of the following dissimilar metal safe end welds.
Weld No.
Line No.
Drawing No.
l-05DM 29"-RC-l-2501R 11448-WMKS-OlOOAZ-1 1-06DM 31"-RC-2-2501R 11448-WMKS-OlOOAZ-1 Licensee's Basis for Requesting Relief (as stated):
uThe components listed above have been examined to the extent practical as required by the Code.
However, due to configuration of the weld (pipe to steam generator nozzle safe end butt weld),
full volumetric examination coverage could not be achieved.
Coverage of the volumetric examinations are detailed in Table SR-012-1*.
Figure SR-012-1* is provided as graphic detail of the limitations experienced. All the welds of this type are scheduled for examination.
Therefore, substitution with other welds is not feasible."
Licensee's Proposed Alternative (As stated):
ult is proposed that the examination already completed at the reduced coverage be counted as meeting the Code requirements."
Evaluation:
The Code requires that steam generator nozzle-to-safe end welds be 100% volumetrically examined.
The sketches provided show that the subject nozzle safe-end welds have limited scan areas as the result of the nozzle configurations and weld joiht geometry.
Therefore,.it is impractical to examine the steam generator nozzle safe end welds at Surry Unit 1 to the extent "Not included in this evaluation.
C.
e e
5 required by the Code.
To obtain-complete volumetric coverage, design modification of the subject nozzles would be required.
Imposition of this requirement would cause a considerable burden on the licensee.
The licensee performed the subject volumetric examinations to the extent practical, obtaining approximately 50% coverage, as determined from analysis of the licensee's submitted data.
Based on the coverage.obtained and examinations performed on other Category 8-F welds, it is reasonable to conclude that significant degradation, if present, would be detected. Thus, reasonable assurance of structural integrity is provided. Therefore, it is recommended that relief be granted pursuant to 10 CFR 50.55a{g){6){i).
Relief Request SR-013, Examination Category C-F-1, Item CS.21, Piping Welds Code Requirement:
Examination Category C-F-1, Item CS.21, requires 100% volumetric and surface examinations of Class 2 piping welds, as defined by Figure IWC-2500-7.
Licensee's Code Relief Request:
The licensee requested relief from the Code-required volumetric examination of inaccessible areas of the following piping weld.
Weld No.
Line No.
Drawing No.
0-07 3"-CH-113-1503 11448-WMKS-1105B3 Licensee's Basis for Requesting Relief {as stated):
uThe component listed above has been examined to the ~xtent practical as required by the Code.
However, full volumetric examination coverage could not be achieved due to the configuration of the weld (pipe to valve) and a welded pipe support.
Coverage of the volumetric examinations are detailed in
D.
e e
6 Table SR-013-1*.
Figure SR-013-1* is provided as graphic detail of the limitations experienced. Substitution with another weld of the same size would not necessarily improve the examination coverage since similar geometric conditions are expected."
Licensee's Proposed Alternative {As stated}:
Mlt is proposed that the examination already completed at the reduced coverage be counted as meeting the Code requirements."
Evaluation:
The Code requires that the subject piping weld b~
100% volumetrically examined.
The sketches provided show that the weld has limited scan areas as the result of the valve configuration in the~ipe-to-valve joint and a welded support on the pipe side of the joint. Therefore, it is impractical to examine this piping weld at Surry Unit I to the extent required by the Code.
To obtain complete volumetric coverage, design modification of the joint would be required.
Imposition of this requirement would cause a considerable burden on the licensee.
The licensee performed the subject volumetric examinations t9 the extent practical, obtaining approximately 59% coverage, as determined from analysis of the licensee's submitted data.
Based on the coverage obtained and examinations performed on other Category C-F-1 welds, it is reasonable to conclude that significant degradation, if present, would be detected.
- Thus, reasonable assurance of structural integrity is provided.
Therefore, it is recommended that relief be granted pursuant to 10 CFR 50.55a{g}{6){i).
Relief Reque~t SR-014, Examination Category B-J, Selection of Piping Welds for Examination Piping Selection Requirement:
Relief Request SR-008, as authorized in a Safety Evaluation Report {SER} dated July 7, 1995, "Not included in this evaluation.
e 7
was used for selection of piping welds to be examined in lieu of ASME Section XI.
The SER requires that all terminal ends of piping runs connected to vessels and pumps be examined in accordance with the ASME Code requirements.
The subject welds are 1% inch pipe-to-pump welds and require a surface examination.
Licensee's Relief Request:
The licensee requested relief from the piping selection requirements previously approved in Relief Request SR-008 and Code-required surface examinations for the following terminal end piping welds.
Weld No.
Line No.
Drawing No.
1-01 l\\
11-CH-97-1502 11448-WMKS-OlOOAlZ 1-01 1~"-CH-95-1502 11448-WMKS-OlOlAlZ 1-01 1~"-CH-93-1502 11448-WMKS-0102A1Z Licensee's Basis for Requesting Relief (as stated):
uThe components listed above are terminal ends on seal injection piping connected to the reactor coolant pumps.
The welds are completely inaccessible due to their closeness to the pump flange.
i.e., they are underneath the flange.
The attached picture* shows the configuration on the uA" loop.
However, when the reactor coolant pump main flange is disassembled, the weld is accessible for examination. All terminal end welds are scheduled for examination. Therefore, substitution with another weld is not feasible.
However, another weld will be selected for examination in order to ensure that 25% of examination Category B-J welds will be examined."
Licensee's Proposed Alternative (As stated):
ult is proposed that the system leakage test and the primary loop monitoring performed by the station be substituted for the Code surface examination.
If a reactor coolant pump main flange is disassembled, thereby making the weld accessible for examination, the weld will be examined consistent with Code requirements."
'Not included in this evaluation.
E.
8 Evaluation:
The sampling plan approved under Relief Request SR-008 required all t~rminal ends of piping connected to* vessels and pumps to be in the examination sample.
The photograph provided by the licensee shows that the subject terminal end welds are not accessible as a result of the pump flange configuration.
Therefore, it is impractical to perform Code-required surface examinations on these terminal ends.
To provide access for examination, 9esign modification of the reactor coolant pumps would be required.
Imposition of this requirement would cause a considerable burden on the licensee.
The licensee proposes to substitute other welds to make up the required 25% sample and to also perform examinations of the subject welds if the pump main flange is disassembled and access is thereby provided.
Based on the sampling of other Category B-J welds, including terminal ends, the system leakage tests that are performed every refueling outage, and the primary loop leakage monitoring, it is reasonable to conclude that significant degradation, if present, would be detected.
Thus~ reasonable assurance of structural integrity is provided.
Therefore, it is recommended that relief be granted pursuant to 10 CFR 50.55a{g){6){i), provided that when the reactor coolant pumps are disassembled, the required examinations will be performed.
Relief Requests SR-015 and SR-016, Examination Category C-G, Item C6.10, Pump Casing Welds Code Requirement:
Examination Category C-G, Item CG.IO requires 100% surface examinations of Class 2 pump casing welds, as defined by Figure IWC-2500-8.
e 9
Licensee's Code Relief Request:
.The licensee requested relief from the Code-required surface examination of inaccessible areas of the following pump casing welds.
RR No.
Weld No.
Line No.
Drawing No.
SR-015
- 2-05 1-RS-P-2A 11448-WMKS-RS-P-2A SR-016 2-05 1-SI-P-IA 11448-WMKS-SI-P-IA Licensee's Basis for Requesting Relief (as stated):
(SR-015):
uThe component listed above has been examined to the extent practical as required by the Code.
However, full surface coverage could not be achieved due to interferences from a pump casing support.
The reduction in coverage is forty (40) percent.
Figure SR-015-1* is provided as graphic detail of the limitations experienced. Substitution with another weld is not feasible because the uB" pump has the same limitation."
(SR-016}:
uThe component listed above has been examined to the extent practical as required by the Code.
However, full surface coverage could not be achieved due to interferences from a pump casing support.
The reduction in coverage is thirty-seven (37) percent.
Figure SR-016-1* is provided as graphic detail of the limitations experienced. Substitution with another weld is not feasibl~ because the uB" pump has the same limitation."
Licensee's Proposed Alternative (As stated):
ult is proposed that the examination already completed at the reduced coverage be counted as meeting the Code requirements."
Evaluation:
The Code requires 100% surface examinations of the subject Code Item C6.10 pump casing welds.. From review of the supporting information, it has been determined that supports attached to the pump casings prevent full examination coverage and make the examinations impractical to perform to the extent required by the Code.
Design modifications would be necessary to sufficiently improve the access to the subject joints to allow complete examinations~
Imposition of this requirement would cause a considerable burden on the licensee.
'Not included in this evaluation.
F.
e 10 Based on the examinations performed to the extent practical (60%
and 63% coverages) and the system leakage tests performed each inspection period, it is concluded that significant degradation, if present, would be detected.
As a result, reasonable assurance of structural integrity is provided.
Therefore, it is recommended that relief be granted pursuant to 10 CFR 50.55a(g}(6}(i}.
Relief Request SR-017, Examination Category B-J, Item B9.32, Piping Branch Connection Weld Code Requirement:
Examination Category B-J, Item B9.32 requires 100% surface examinations of Class 1 branch connection piping welds less than NPS 4, as defined by Figures IWB-2500-9, -10, and -11.
Licensee's Code Relief Request:
The licensee requested relief from the Code-required examination of the inaccessible area of the following branch connection piping weld.
Weld No.
Line No.
Drawing No.
. 3-07BC 3"-RC-35-1502 11448-WMKS-0124Al-1 Licensee's Basis for Requesting Relief (as stated}:
uThe weld listed above is covered by a reinforcement pad/saddle weld, which totally covers the examination area described in the Code.
Therefore, examination coverage cannot be achieved due to the configuration of the piping. This weld is a branch connection and, as such, all welds of this type are scheduled for examination.
Therefore, substitution with another weld is not feasible. "
Licensee's Proposed Alternative (As stated}:
ult is proposed that a surface examination performed on the fillet weld of the reinforcement pad and the system leakage test be substituted for the Code surface examination."
Evaluation:
The Code requires 100% surface examination of the subject Code Item B9.32. branch connection piping weld.. From
. 11 review of the supporting information, it has been determined that the reinforcement design prevents access and makes the Code-required examination of the subject weld impractical. Design modifications would be necessary to provide access to this branch connection for examination.
- Imposition of thi~ requirement would cause a considerable burden on the licensee.
Based.on the proposed surface examination of the reinforcement fillet weld, which is an important part of the structure of the branch connection, and the system leakage test conducted following each refueling outage, it is concluded that significant degradation, if present, would be detected.
As a result, reasonable assurance of structural integrity is provided.
Therefore, it is recommended that relief be granted pursuant to 10 CFR 50.55a{g){6){i).
3. 0 CONCLUSION The INEL staff has reviewed the licensee's relief requests and determined that certain of the Code requirements are impractical for the Surry Power Station, Unit 1. Therefore, it is recommended that relief be granted pursuant to 10 CFR 50.55a(g){6){i) for Relief Requests SR-009 through SR-017.
It is also recommended that the condition noted in the above evaluation be included in the approval of Relief Request SR-014.
- ! \\
i