ML20206U880
| ML20206U880 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 09/16/1986 |
| From: | TENNESSEE VALLEY AUTHORITY |
| To: | |
| Shared Package | |
| ML20206U867 | List: |
| References | |
| C011103-SQN, C11103-SQN, NUDOCS 8610080447 | |
| Download: ML20206U880 (5) | |
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.t TVA EMPLOYEE CONCERNS REPORT NUMBER: C011103-SPECIAL PROGRAM SQN REPORT TYPE: Sequoyah Nuclear Plant Element REVISION NUMBER:
1 TITLE: Methods Used During Installation PAGE 1 0F 5 REASON FOR REVISION:
To incorporate TAS and SRP conunents, o
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SIGNATURE DATE SIGNATURE DATE APPROVED BY:
ECSP MANAGER DATE MANAGER OF NUCLEAR POWER DATE CONCURRENCE (FINAL REPORT ONLY) 1435T 8610080447 860925 PDR ADOCK 05000327 P
TVA EMPLOYEE CONCERNS REPORT NUMBER: C011103-SPECIAL PROGRAM SQN REVISION NUMBER: 1 PAGE 2 0F 5 I. Introduction This element addresses three concerns. Two of these concerns (IN-85-288-001 and IN-86-116-001) were determined to be potentially generic to Sequoyah Nuclear Plant (SQN) by the Watts Bar Nuclear Plant (WBN) ECTG evaluation. The other concern (XX-85-070-007) was site specific to SQN.
d II. Summary of Perceived Problems The perceived problems of this element are:
A.
There are no procedures governing the handling of snubbers.
B.
Snubbers are not installed according to the design drawings.
lR1 C.
All vertical tube steel sections located in outside areas are not capped.
Perceived problems A and C are generic items resulting from the WBN i
evaluation. Perceived problem B is site specific to SQN.
III. Evaluation Methodology The evaluation methodology used for this element was:
A.
Reviewed Nuclear Safety Review Staff (NSRS) Report I-85-713-WBN, Generic Concern Task Force (GCIF) Report for Employee Concern IN-85-288-001, and WBN ECTG Element Report C011103 to determine if the findings are applicable to this evaluation and how much additional evaluation was required.
B.
Reviewed the 47A050 Hanger Drawing General Notes (050's) to determine if there was a requirement for adding cap plates to the tube steel.
C.
Talked with personnel knowledgeable of the aspects involved in this element.
D.
Field evaluated outside areas around the plant to determine if the vertical tube steelssections have been capped.
E.
Reviewed Engineering Change Notice (ECN) 6237 and Work Plan (WP) 11287 to determine the extent of the as-constructed snubber program that is currently in progress at SQN.
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TVA EMPLOYEE CONCERNS REPORT NUMBER: C011103 x
SPECIAL PROGRAN SQN REVISION NUMBER: 1 PAGE 3 0F 5 F.
Reviewed the following instructions to determine if the procedures exist at SQN for handling snubbers:
1.
Surveillance Instruction (SI) 162.1, R7, " Snubber Visual IR1 Inspection (Hydraulic and Nechanical)"
i 2.
SI-162.2, R4, " Snubber Functional Testing (Hydraulic and IR1 Hechanical)"
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3.
Maintenance Instruction (MI) 6.13A, R3, " Removal and lR1 Reinstallation of Hydraulic and Mechanical Snubbers" 4.
Administrative Instruction (AI) 36, R9, " Storage Handling, l Rl..
and Shipping of QA Material" IV. Summary of Findings Concern IN-85-288-001, dealing with the mishandling of snubbers, was evaluated by the GCTF to determine if this was a problem at SQN. This evaluation by the GCTF involved reviewing the in-place procedures dealing with snubbers, interviewing knowledstable personnel about how the procedures are applied, and reviewing a sample of the test documentation for installed snubbers.
(See attached GCTF report for details.)
The findings of the GCTF report concluded that there was a problem with snubbkrs being stored outdoors during the construction phase. However, the initial testing done according to Sequoyah Nuclear Plant Inspection Instruction A-3, as well as, periodic surveillance testing done according to SQN SI-162.2 for snubbers would have detected any damage. A
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subsequent review, as part of the WBN ECTG evaluation, of the insiructions listed in section F of the evaluation methodology revealed that the necessary procedures are in place at SQN to ensure that snubbers are handled properly.
Concern XX-85-070-007 was expressed addressing 115 anubbers in SQN Unit 2 that were not installed in accordance with the design drawings. After
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talking with a knowledgeable person in the Modifications Group, it was discover ~ed that the only instance where this might be a problem would be in the 47A053 series typical support drawings, which are the only typical drawings involving snubbers. These drawings were used in both units and it was often necessary to deviate from the typical configuration to a
achieve a constructible configuration. When this was done a support variance was issued by co'nstruction and approved by design. However, some s
of these variance sketches have been lost and the supports are not easily identified in the field. As a result, ECN 6237 was issued requiring all 47A053 typical snubber supports to be as-built and evaluated by design.
lR1 A discussion with the Mechanical Maintenance Unit personnel, responsible for as-building these supports, revealed that this work was being done lR1
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REVISION NUMBER: 1 l
PAGE 4 0F 5 according to WP 11287 and all drawings have been as-built and sent to IR1 design for their evaluation. A review of ECN 6237 and WP11287 revealed that this condition was identified in September 1984 and involved 128 supports for each unit. This timeframe and support quantity closely match that expressed in the concern.
The completion of the field work I
associated with this as-built program is required before the restart (R1 i
of SQN.
l The addition of cap plates to open-ended vertical tube steel sections located in outside areas was found to be a deficient item at WBN and was determined to be potentially generic to SQN.
a A review of the 050 notes, and a discussion with the responsible modifications person, failed to
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identify any requirements for adding cap plates to outside tube steel at l
SQN.
However, the absence of a requirement does not alleviate the need i
for the cap plates to be installed to prevent damage because of water
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collecting and freezing in the tubes. A field evaluation of the outside areas around the Intake Pumping Station revealed several vertical tube I
steel sections that were not capped and water was standing in all of them.
Conclusions et; A.
During the construction process, there were some problems dealing withi j
the storage and handling of snubbers. However, the initial testing l
according to SQN Inspection Instruction A-3, as well as periodic l
surveillance testing according to SQN SI-162.2 would have. detected lR1 any damage resulting from bad construction practices.
Currently, i
l SI-162.1, R7; SI-162.2, R4; NI-6.13A, R3; and AI-36, R9, provide the l
necessary requirements for handling snubbers at SQN.
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B.
The 47A053 anubber support typicals were not always followed.
However, this was documented during the construction phase on support variances. In September 1984 it was-determined to be necessary to as-built these typicals due to missing documentation IR1 (Reference ECN 6237). This work is currently in progress according to WP 11287 and all snubber rework, as determined by design, will be l
complete before restart.
lR1 C.
Not all vertical tube steel sections in outside areas have caps on them.
During this evaluation no damage to existing tubes was l
observed.
However, water was standing in all tubes and, based on 1
past occurrences at Bellefonte Nuclear Plant end Watt Bar Nuclear
'(R1 Plant, this water cap freeze causing the tube steel to balloon and crack.
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l V. Root Cause The root cause for the tube steel not being capped is a failure by design to realize the environmental effects on tube steel and a lack of communication between design projects.
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TVA EMPLOYEE CONCERNS REPORT NUMBER: C011103 SPECIAL PROGRAM SQN REVISION NUMBER: 1 PAGE 5 0F 5 VI.
Corrective Actions Corrective actions will be provided by SQN line management.
IR1 VII. Generic Applicability The problems with handling of snubbers and capping open-ended tube steel were determined potentially generic to all nuclear plants by the WBN evaluation.
VIII. Attachments IVA-SQN Generic Concerns Task Force report on Concern IN-85-288-001 l
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