ML17291A976
| ML17291A976 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 08/23/1995 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML17291A975 | List: |
| References | |
| NUDOCS 9508250348 | |
| Download: ML17291A976 (13) | |
Text
p'~ RK00 c<
+
O C
O I
0
+~
~O
+>>*++
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON> O.C. 2055&4001 SAF TY EVA UATION B T
E OFF C
OF NUCLEAR REACTO R
GU ATION R
T TO T INS RVICE SP CTION OGRAH RE I F
RE U STS IS 003 AND S 011 WASH NGTON PUBLIC POW R SUPP Y
S ST NUCLE R
PROJ C
NO.
2 DOCKET NO. 50-397
1.0 INTRODUCTION
The Technical Specifications for WNP-2 state that the inservice inspection and testing of American Society of Hechanical Engineers (ASHE) Code Class 1, 2, and 3 components shall be performed in accordance with Section XI of the ASHE Boiler and Pressure Vessel 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).
Pursuant to 10 CFR 50.55a(g)(4),
ASHE Code Class 1, 2, and 3 components (including supports) shall meet the requirements, except the design and access provisions and the preservice examination requirements, set forth in the ASHE
- Code,Section XI, "Rules for Inservice Inspection (ISI) 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 each 10-year interval comply with the requirements in the latest edition and addenda of Section XI of the ASHE Code incorporated by reference in 10 CFR 50.55a(b) on the date 12 months prior to the start of the 120-month inspection interval, subject to the limitations and modifications listed therein.
The applicable edition of Section XI of the ASHE Code for the WNP-2 first 10-year ISI interval is the 1980 Edition, through Winter 1980 Addenda.
The components (including supports) may meet the requirements set forth in subsequent editions and addenda of the ASHE 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 ASHE Code is not practical for its facility,.information shall be submitted to the Commission in support of that determination.
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 licensee that could result if the requirements were imposed.
9508250348 950825 PDR ADQCK 05000397 P
PORE
By letter dated October 19,
- 1994, Washington Public Power Supply System (licensee) submitted Relief Requests ISI-02-003 and ISI-02-011.
The licensee had determined that the Code requirements discussed in the relief requests were impractical to perform at WNP-2.
- 2. 0 EVALUATION 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 first 10-year interval inservice inspection program plan Requests for Relief Nos.
003 and 011 for WNP-2.
The evaluation is included in the attached technical letter report.
- 3. 0 CONCLUSION Based on the information provided by the licensee in Relief Requests ISI-02-003 and ISI-02-011, the staff adopts the conclusions and recommendations presented in the attached INEL technical letter report.
The staff concludes that (1) the examinations performed provide reasonable assurance that operational readiness has been maintained, (2) the Code requirements discussed above are impractical and would be a burden on the licensee if imposed, and (3) granting relief from the Code requirements discussed above is authorized by law, will not endanger life or property or the common defense and security, and is otherwise in the public interest.
Therefore, relief is granted as requested pursuant to 10 CFR 50.55a(g)(6)(i).
Attachment:
Technical Letter Report Principal Contributor:
T. McLellan K. Thomas Date:
August 23, f995
ATTACHMENT TECHNICAL LETTER REPORT ON THE FIRST TEN-YEAR INTERVAL INSERVICE INSPECTION RE(UESTS FOR RELIEF 003 It Oll FOR WASHINGTON PUBLIC POWER SUPPLY SYSTEN MNP-2 OOCKET NUMBER:
50-397 I. F
~BIBB RC C
In a letter dated October '19, 1994, the licensee, Washington Public Power Supply System (WNP-2), submitted Requests for Relief ISI-2-003 and ISI-2-011.
These requests for'elief are applicable for the first 10-year inservice inspection (ISI) interval at WNP-2, which ended Oecember 13, 1994.
The Idaho National Engineering Laboratory (INEL) staff has evaluated the subject requests for relief in the following section.
2.0
~VALUAT OM The Code. of record for.WNR-2, first 10-year ISI interval, is the American Society of Mechanical Engineers Boiler and Pressure Vessel Code,Section XI, 1980 Edition, through Minter 1980 Addenda.
The information provided by the licensee in support of the requests for relief has been evaluated and the basis for granting relief is documented below.
A.
Re uest for Relief SI-2-003 Part 1
xamination Cate pries F-B and F-C Item F2. 10 F
0 and F3. 10 throu h F3.50 Class 2 and 3
Com onent
~Su overt
~dd:
T CI IIIF-Td -I, T
I I
C I
I-B d F-C, Iteas F2. 10, F2.20, and F3. 10 through F3.50 require a VT-3 or VT-4 visual exaaination of 100K of the Class 2 and 3 component supports as defined by Figures IMF-3410, -3420,
-3430 as applicable.
Licensee's Code Relief Re u
Relief is requested from the Code-required VT-3 and VT-4 visual examinations for the components listed below.
COMPONENT EXAM.
COMPONENT ID.DESCRIPTION SW-69 Rigid F-8 SW-67 Rigid F-8 SW-72 Rigid F-8 SW-317 Rigid F-8 SW-152 Rigid F-8 SW-431 Rigid F-8 SW-137 Rigid F-8 SW-438 Rigid F-8 SW-203 Rigid F-8 SW-77 Rigid F-8 SW-34 Rigid F-8 SW-142 Rigi d F-8 SW-60 Rigid F-8 SW-916N Rigid F-8 SW-75 Rigid F-8 RCIC-18 Rigid F-8 FPC-64 Box F-8 FPC-98 Rigid F-8 FPC-114 Rigid F-8 FPC-203 Box F-8 LPCS-19 Anchor F-8 RHR-99 Anchor F-8 RHR-174 Box F-8 RHR-605 Strut F-8 RHR'-606 'trut 'f-8 SLC-4453-57Rigid F-8 SW-90 Rigid F-8 SW-123 Rigid F-8 SW-439 Rigid F-8 SW-946N Rigid F-8 SW-951N Rigi d F-8 SW-950N Rigid F-8 RHR-53 SpringF-C CATEGORY icensee's Basis for Re u
s in Relief (as stated):
"The component supports and welded attachments are completely or partially inaccessible to examination.
The component supports and welded attachments are within or close to wall penetrations which are foam filled for fire protection barriers or enclosed in cubicles or pipe chases.
The support is covered by the foam.
A loss of function of the component support is expected to be identified at adjacent supports which are examined.
For supports within wall penetrations, it should also be noted that the pipe is completely surrounded by concrete with the metal support embedded in the concrete; the annulus between the pipe and concrete is foam filled. If any failure did occur, the concrete would perform a backup support function.
"There will be no adverse impact on plant quality and safety.
Failure of
these component supports or welded attachments will not prevent the reactor from, being shutdown.
During the first inspection period the following percent of items were examined:
xamination Cate or Percen 0-B
>97X 0-C
>90X F-B
>93X F-C
>99X "No unacceptable indications were found during these examinations.
"Later editions of ASHE Section XI define the sample size for category F-B (category F-A in later Code editions) as 10X of the Class 3 piping supports.
The percent of Class 3 component supports examined during the first interval
(>93X of rigid type supports for F-B) exceeds the minimum sample size of lOX required in later Code editions.
"Later editions of ASNE Section XI define the sample size for category F-C (category F-A in later Code editions) as 15X of the Class 2 piping supports.
The percent of Class 2 component supports examined during the first interval
(>93X of rigid type supports for F-B) exceeds the minimum sample size of 15X required in later Code editions.
"The Class 3 welded attachments in Categories 0-B and 0-C examined during the first inspection interval represent greater than 96X of the total welded attachments in these two categories.
"Th'e sample sizes'in these four categories are reasonably large and unrepresentative and assure continued plant quality and safety."
'censee's Pro osed lter n tive (as stated):
"The component supports and welded attachments are completely or partially inaccessible to all examination techniques.
No examinations are proposed."
I=valu Ltt,:
The Code of record requires 100X of the Class 2 and 3
component supports to be examined per their respective examination category each inspection interval.
The licensee examined 93X of Class 2
and 99X of Class 3 component supports.
The subject component supports are completely or partially inaccessible to examination.
The component supports are within or close to wall penetrations or enclosed in cubicles or pipe chases.
Supports within wall penetrations are embedded in concrete and the annulus between the pipe and concrete is foam filled.
Therefore, the subject component
support examinations are impractical to perform to the extent required by the Code.
To meet the Code requirements, the supports would have to be redesigned, modified, or replaced; imposition of the requirements would cause a considerable burden on the licensee.
A total of 93X of Class 2 and 99X of Class 3 component supports required by the Code to be examined, were examined.
Since a significant number of component supports were examined, it is reasonable to conclude that a
pattern of degradation, if present, would have been detected.
Therefore, reasonable assurance of operational readiness has been maintained by the examinations that were performed and, considering the impracticality of meeting the Code requirements, it is recommended that relief be granted pursuant to 10 CFR 50.55a(g)(6)(i).
B.
Re uest for Relief IS - -003 Part xamination Cate pries D-B and D-tems D2.20 and D3.20 Class 3 Melded Inte ral Attachments Code Re uirement:
Table IWD-2500-1, Examination.Categories D-B and D-C, Items D2.20 and D3.20 require a VT-3 visual examination of Class 3
integral attachments as defined by Figure IWD-2500-1.
Licensee's Code Relief Re uest:
Relief is requested from the Code-required VT-3 visual examinations for the components listed below.
COHPONENTESN.
CONPONENT ID.DESCRIPTION CATEGORY FPC-64(W)
SW-90(M)
SW-123 (M)
SW-439(M)
SW-946(M)
SW-951 (M)
Melded Attachment Melded Attachment Welded Attachment Melded Attachment Melded Attachment Welded Attachment D-C D-B D-B D-B D-B D-B se '
i for e
s i li f (as stated):
"The component supports and welded attachments are completely or partially inaccessible to examination.
The component supports and welded attachments are within or close to wall penetrations which are foam filled for fire protection barriers or enclosed in cubicles or pipe
chases.
The support is covered by the foam.
A loss of function of the component support is expected to be identified at adjacent supports which are examined.
For supports within wall penetrations, it should also be noted that the pipe is completely surrounded by concrete with the metal support embedded in the concrete; the annulus between the pipe and concrete's foam filled. If any failure did occur, the concrete would perform a backup support function.
"There will be no adverse impact on plant quality and safety.
Failure of these component supports or welded attachments will not prevent the reactor from being shutdown.
During the first inspection period the following percent of items were examined:
Examination Cate or Percent 0-8
>97X D-C
>90X "No unacceptable indications were found during these examinations.
"The Class 3 welded attachments in Categories 0-B and 0-C examined during the first inspection interval represent greater than 96X of the total welded attachments in these two categories.
icensee's Pro osed Alterna ve (as stated):
"The component supports and welded attachments are completely or partially inaccessible.to all examination techniques.
No alternate examihations are proposed."
Th Cd f
d qi lOII f h
Ci 3i 9
welded attachments be examined per their respective examination category each inspection interval.
The licensee examined 97X of Examination Category D-B and 90X of Examination Category 0-C integrally welded attachments.
The subject welded attachments are completely or partially inaccessible to examination.
These welded attachments are within or close to wall penetrations or enclosed in cubicles or pipe chases.
Attachments within wall penetrations are embedded in concrete and the annulus between the pipe and concrete is foam filled.
Therefore, the subject integrally welded attachment examinations are impractical to perform to the extent required by the Code.
To meet the Code requirements, the piping systems twould have to be redesigned and replaced; imposition of the requirements would cause a considerable burden on the licensee.
A total of 97X of Examination Category 0-B and 90X of Examination Category 0-C Class 3 integrally welded attachments required by the Code to be examined, were examined.
Since a significant number of attachments were examined, it is reasonable to conclude that a pattern of degradation, if present, would have been detected.
Therefore, reasonable assur ance of operational readiness has been maintained by the examinations that were performed and, considering the impracticality of meeting the Code requirements, it is recommended that relief be granted pursuant to 10 CFR 50.55a(g)(6)(i).
C.
R uest for Relief SI-2-011 xami ation Cate pries B-K-1 and C-C Items B10.10 and C3.40 Class 1
and 2 Welded Inte ral Attachments Code Re uirement:
Table IWD-2500-1, Examination Categories B-K-1 and C-C, Items 810. 10 and C3.40 require surface examination of Class 1 and 2
integral attachments as defined by Figures IWB-2500-13, -14, -15 and IWC-2500-5 as applicable.
Licensee's Code Relic Re uest:
Relief is requested
.from the Code-'equired surface examinations for the components listed below.
COMPONENTEXAM.
COMPONENT ID.DESCRIPTION CATEGORY RRC-HA-l(W)
Welded Attachment B-K-1 RRC-HB-1(W)
Welded Attachment B-K-1 RHR-77(W)
Welded Attachment C-C RHR-410(W)
Welded Attachment C-C License 's Basis for Re uestin Relief {as stated):
"Relief is required from ASME Section XI examination requirements for the two item B10.10 welds on the basis of partial inaccessibility of the weld due to plant design and high dose required to prepare for and perform the examinations.
The welds identified in this relief request require disassembly of a component support collar to gain access to perform a
IOOX Code examination.
~ "Relief is required from ASME Section XI examination requirements for the two C3.40 welds on the basis of inaccessibility of the welds due to their location in a pipe chase where access will place a hardship on the plant to gain access.
0
~5
~
~
"There will be no adverse impact on plant quality and safety by doing only a partial Code examination of the item B10. 10 welds.
- 1. The attachment welds have passed dye penetrant examination in accordance with Section III.
- 2. Seventy-five (75) percent of weld RRC-HA-l(M) and fifty (50) percent of weld RRC-HB-1(M) are accessible without removing the component support collar.
- 3. The percent of category 8-K-I welds examined during the first inspection interval exceeds 95X of total welds in this category.
During the first inspection interval no unacceptable indications were found in this sample.
- 4. Other similar welds in this system and in the area of the subject welds have or will receive full Code surface examination coverage.
The integrity of the pressure boundary can thus be verified by sampling.
"There will be no adverse impact on plant quality and safety by doing only a partial Code examination of the item C3.40 welds.
- 1. The attachment welds have passed magnetic particle examination in accordance with Section III.
2.
The percent of category C-C welds examined in the first inspection interval exceeds 96X of total welds in this category.
During the first inspection interval no unacceptable indications were found in this sample.
- 3. Other similar welds in this system and in the ar'ea of the subject welds have, or will:receive full Code surface ex'amihation coverage.
The integrity of the pressure boundary can thus be verified by sampling.
"The sample sizes in these two categories are reasonably large and representative and assure continued plant quality and safety."
icensee's Pro osed Alternative (as stated):
"The accessible portion of the item B10. 10 welds, without removing the component support, of each weld will be examined per Section XI requirements.
"No alternate examination is proposed for item C3.40 welds."
~v i~LqII:
The Code requires 100X of the Class 1 and 2 integrally welded attachments to be examined per their respective examination category each inspection interval.
The licensee examined 95X of the Class 1 and 96X of the Class 2 integrally welded attachments.
The subject B10. 10 welded attachments will have partial examinations due to,partial inaccessibility and the subject C3.40 welded attachments will
not be examined due to the inaccessibility of welds within a pipe chase.
Therefore, the subject integrally welded attachment examinations are impractical to perform to the extent required by the Code.
To meet the Code requirements, the piping systems would have to be redesigned and replaced; imposition of the requirements would cause a considerable burden on the licensee.
A total of 95X of Class 1 and 96X of Class 2 integrally welded attachments required by the Code to be examined, were examined.
Since a
significant number of attachments were examined, it is reasonable to conclude that a pattern of degradation, if present, would have been detected.
Therefore, reasonable assurance of operational readiness has been maintained by the examinations that were performed and, considering the impracticality of meeting the Code requirements, it is recommended that relief be granted pursuant to 10 CFR 50.55a(g)(6)(i).
- 3. 0 CONCLUSION Based on the above evaluation, the INEL staff concludes
.that. the Code'equirements addressed in Requests for Relief ISI-2-003 and ISI-2-011 are impractical for WNP-2, and recommends that relief be granted for these relief requests.
In these cases the licensee's examinations should provide reasonable assurance of continued structural integrity.
Therefore, it is recommended that relief be gr anted pursuant to 10 CFR 50.55a(g)(6)(i).