ML20153A930
| ML20153A930 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 03/11/1988 |
| From: | NRC OFFICE OF SPECIAL PROJECTS |
| To: | |
| Shared Package | |
| ML20127A683 | List:
|
| References | |
| NUDOCS 8803210298 | |
| Download: ML20153A930 (6) | |
Text
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SAFETY EVALUATION BY THE OFFICE OF SPECIAL PROJECTS EMPLOYEE CONCERNS ELEMENT REPORT C0 11301-SON, REVISION 8 "DESIGN OF PLATES TENNESSEE VALLEY AIITHORITY SE000YAH NUCLEAR POWER PLANT UNITS 1 AND 2 DOCKET NOS. 50-327 AND 50-328 I.
SUBJECT Construction (10000)
Subcategory:
Hangers / Supports (11100)
Element:
Design of Plates (11301).
Concerns:
IN-85-031-001, IN-85-033-001, IN-85-103-001, IN-85-109-X04, OE-QMS-8 The bases for element Report CO 11301-SQN Revision 8, dated July 8,1987 are five employee concerns which question TVA's design of plates.
II.
SUFMARY OF ISSUES The Employee Concerns Task Group (ECTG) report identified the followirg four issues from the employee concerns:
Errors, omissions, and incorrect assurptions were not corrected in design a.
calculations, b.
EnDes Procedure 4.03, Appendix 4, which addresses visual acceptance of load additions to embedded plates (embeds), is not adequate, TVA is not in compliance with Nuclear Regulatory Comission (NRC) IE c.
Bulletin 79-02 in that base plate flexibility is not a desirn consideration.
d.
Concrete anchor bolt load allowables 'er wedae brit anchors are craater for Unit I than for Unit 2.
!!I. EVALUATION A technical review of Employee Cnrcerns Element Report To 11301-SQN, Revisinn 2 was performed by an NRC cor. tractor under NRC Contract No. 05-86-156.
The results of this review are surrarized in the attached contractor technical evaluation report dated January 21. 1900 on Employee Concerns Element Report CO 11301-SON, Revision 8.
8803210298 880311 DR ADOCK 050 8
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, Element Report CO 11301-SQN, Revision 8 found that all of the employea concerns were verified as being true for Watts Barr and that three of the employee concerns were applicable 'to Sequoyah.
The ECTG report found that one additional concern, IN-85-033-001, was indirectly applicable to Sequoyah.
The element report further found that these concerns were being adequately addressed by sampling plans that had been initiated at Sequoyah.
The element report identified rine corrective actions associated with these concerns.
These corrective actions involved disposition and closure various of SCR's, NCR's and Potential Generic Cordition Reports as well es the development of procedural controls for attachments.
The resolution of these corrective actions were not considered restart items in the ECTG report.
The contractor review of Element Report C011301-SQN, Revision 8 found that TVA's evaluaticn cf the employee concerns was adeouate.
The staff concurs with the conclusinns 1
presented in the contractor technical evaluation report.
The contractor technical eva'.uation report reconvended that TVA's corrective actions associated with base plate flexibility analysis and structural steel attachments be reviewed when they are completed.
These areas will ba reviewed as part of the NRC's review of TVA's calculation program.
IV.
CONCLUSIONS Based on the review of Employee Concerns Element Report CO 11301-SQN, Revision E the staff concludes that Employee Concerns IN-85-031-001, IN-85-033-001, IN-85-103-001, IN-85-109-X04 and OE-QMS-8 have beer ccequately addressed at Sequoyah.
The staff will review TVA's calculations en structural steel connections and pipe supports as part of the review of TVA's calculation program.
-6 Report 4 CO 11301 SON SEQUOYAH UUCLEAR POWER PLANT, UNITS 1& 2 TECHNICAL EVALUATION REPORT FOR EMPLOYEE CONCERNS ELEMENT REPORT CO 11301-SON "DESIGN OF PLATES" 1.
Subject Construction (10000)
Sub Category:
Hangers / Supports (11100)
Element:
Design of Plates (11301).
Design did not consider all loads, plate flexibility (79-02) and contained errors and incorrect assumptions.
Concerns: IN-85-031-001, IN-85-033-001, IN-85-103-001, IN-85-109-XO4, & OE-QMS-8 The basis for element Report CO 11301 SON REV.48 dated 7/8/87 are the following concerns:
o I.9 031 - 001 "IN REVIEWING PREVIOUSLY APPROVED DESIGN CALCULATIONS FOR STRUCTURAL STEEL ACCESS PLATFORMS LOCATED IN THE REACTOR BUILDINGS UNITS 1 & 2.
CI HAS AT TIMES FOUND ERRORS, OMISSIONS OR INCORRECT ASSUMPTIONS WHICH COULD HAVE AN AFFECT ON QUALITY / SAFETY.
WHEN CI MADE REQUEST TO SUPERVISOR (NAME KNOWN) TO CORRECT ERRORS, CI WAS TOLD THAT THERE WAS NO TIME OR MAN-HOURS AVAILABLE TO MAKE I
CORRECTIONS.
CI STATED THAT SOME CALCULATION WENT UNCORRECTED.
THIS OCCURRED DURING ALL OF 1984.
CI COULD NOT PROVIDE ANY SPECIFICS / DETAILS."
o IN 033 - 001 "EN DES PROCEDURE EP 4.03 APP. 4 IS INADEQUATE.
EP 4.03 APP. 4 ALLOWS ACCEPTANCE OF MINOR LOADS TO EMBEDDED PLATES BY PERFORMING VISUAL INSPECTIONS OF ATTACHMENTS TO EMBEDDED PLATES.
SINCE PROCEDURE EP 4.03 APP.4 DOES NOT DEFINE WHAT A MINOR LOAD IS, THERE IS NO-LIMIT TO WHAT CAN BE ACCEPTED BY VISUAL INSPECTION.
EXAMPLE:
FCR EP03784 ILLUSTRATES PROBLEM WITH PROGRAM OF VISUAL INSPECTION.
NO FOLLOW-UP REQUIRED."
o IN 103 - 001 "TVA IS NOT IN COMPLIANCE WITH NRC BULLETIN 79-02 (SUPPORT OF RIGID PLATE ASSUMPTIONS IN ANALYSIS) IN THAT BASE PLATE FLEX IS NOT A DESIGN CONSIDERATION.
NO ADDITIONAL CONTACT REQUIRED."
a o
IN 109 - XO4 "CONCRETE ANCHOR BOLT (NEDGE BOLTS) IN UNIT 1 & 2.
THE ALLOWABLE BOLT LOADS FOR UNIT 1 ARE GREATER THAN UNIT 2.
THE DESIGN PHILOSOPHY TO DETERMINE THE ACTUAL ALLOWABLES ON ANCHOR BOLTS HAS CHANGED.
FOR UNIT 1, THE DESIGN GROUP DID NOT CONSIDER FLEXIBLE PLATE THEORY, INSTEAD THEY CONSIDERED THE BASE PLATE AS RIGID.
CI QUESTIONS THESE TWO DIFFERENT ALLOWABLES."
o OE - QM3 - 8 "TWO AREAS REGARDING DESIGN METHODS FOR PIPE SUPPORTS ARE NOT RECEIVING PROPER CONSIDERATION.
- 1) EFFECT OF BASEPLATE FLEXIBILITY ON ANCHOR LOADS.
- 2) DETAILING METHODS FOR WELDS."
These concerns were_ evaluated by TVA to be potentially nuclear safety-related and safety significant.
II.
Summary of Issues The problem as defined by TVA is as follows:
a)
Errors, omissions and incorrect assumptions were not corrected in design calculations.
b)
EnDes Procedure 4.03 Appendix allows for visual acceptance of load additions to embedded plates, c)
Plate Flexibility as required by IE Bulletin 79-02 was not adequately considered in the design.
d)
Concrete anchor bolt load allowables for wedge bolt are greater for Unit #1 than for Unit 42.
III. Evaluatian The TVA Employee Concern Task Group (ECTG) evaluators reviewed applicable documents and interviewed cognizant Sequoyah engineering personnel to determine if the above concerns are valid.
Concern !N-85-031-001 will be addressed directly at SQN by the Potential Generic Condition evaluation (PGCE) for SCR WBN CEB-8650.
This SCR will address structural steel attachments and will also serve to identify errors, omissions and incorrect assumptions in the design calculations.
Concern IN-85-031-001 was verified 3s being true at WBN and that is is applicable to SCN.
a.
Concern IN-85-033-001 was verified as being true at WBN and that portion of the concern which addressed minor loads attached to embeds is indirectly applicable to SQN.
SQN has a program in place which will evaluate minor loads attached to embeds.
However, this program has been in place for approximately 6 months and only recent attachments will be evaluated.
All other existing embeds will not be evaluated as part of this program.
Also min 7r-loads are not defined.
The TVA ECTG concluded that the program for evaluating minor load attached to embeds are adequate with the following comments:
J a)
Guidelines should be established-to define minor loads t
b.'
Existing programs should be axpanded to inc3pde all attachments to embedded plates Concern IN-85-103-001 and OE-QmS-8 will be answe.ed by the evaluation NCR-SON CEB-8404.
This NCR addresses tho irsue of base plate flexibility which was a repairepent of 7g-02.
TVA has committed to recalculate the loads on the concrete anchorages for the approximately 5600 pipe suppc'.ts which afe presently being generated.
These calculttionr Vill take into account plate flexibility.
Also T\\'A' hat committed that the factors of safety of all expansion anchors installed in' SQN unit #2 wil. be in acco2dahce wi+p I&E bulletin 79-02 prior to the next refueling obtage and will meet interim criteria (factor of safety of 2) during the period between start up and the next 96fue2ing outage.
All factors of safety will be based on actual e'agansion anchor tests.
Concern IN-85-109-X04 was verified to be true at WBN but was not applicable to SQN.
IV. Conclusions Element report #CO ll301-SQN Rev. 58-Design of Plates, General Construction specification AG-32 Rev ll-Bolt, j
Anchors Set in Hardened Concrete, Modification and j
Additions Instruction - M&AI -09 Rev 37, Modification ard Additions Instruction M&AI Rev 415 and TVA design standard DS-C1.7.1 wars reviewed.
TVA's investigation of these concerns are adequate, and i
TVA's conclusions, resolutions and commitments to resolve the concerns described in this element report are satisfactory.
It is recommended that the results of the PGCE for SCR WBN CEB-8650 (Errors, omissions and incorrect assumptions were e
not corrected in design calculation), the resolution of NCR-SQn CEB-8404 (Base Plate Flexibility) and the proposed procedure changes which address minor load be reviewed after these items are completed.
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