ML20077G173
| ML20077G173 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Quad Cities, 05000000 |
| Issue date: | 07/26/1983 |
| From: | Rybak B COMMONWEALTH EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| REF-SSINS-6820, REF-SSINS-SSINS-6 7033N, IEB-79-14, NUDOCS 8308030401 | |
| Download: ML20077G173 (5) | |
Text
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h Commonwealth Edison O / ons First N tional Pl:za, Chicago. Illinois 1
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~ Address Reply to: Post Office Box 767 Chicago, lilinois 60690 July 26, 1983 e
Mr. James G. Keppler, Regional Administrator
- Region III' U.S. Nuclear Regulatory Commission 799 Roosevelt Road
-Glen Ellyn, IL 60137'
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Subject:
Dresden Station Units 2 and 4 Quad-Cities Station Units 1 and 2 IE Bulletin 79-14, Blume Criteria Pipe Supports NRC Docket Nos. 50-237,50.-249,
.50-254, and'50-265
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Dear Mr. Keppler:
The purpose of this letter is to provide an explanation.of'thes scope of work planned to document certain' safety related pipe cupports.
These supports exist on piping systems which were originally analyzed by a " cookbook" method.
This letter discusses the work performed to satisfy IE Bulletin 79-14 and the. scope of our planned activities.
79-14 COMPLIANCE As'yo'u know, CECO lias an cxtensive program to implecient the requirements of NRC IE Bulletin 79-14., The bulletin requires thra following:
s walkdown safety relateo piping 2-1/2" and'largel' evaluate and reconcile nonconformances e
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evaluate operability reconcile as-built versus as designed
- restore system to FSAR limits Under these requirements all piping systems have bebn.andlyzed using the original desianLcriteria.
Operability evaluations were perfogmed which document system functionality using operabi14ty stres; limits.' All reauired pipe support evaluations are compl @ ' Design modifications to pipe supports-resulting from these evaluationelncluding addition of new supports has been completed and these support ( sr0 being installed in accordance with committed ' schedules.
This represents a%significant.
effort' involving approximately 4450 supports.
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J. G. Keppler July 26, 1983 i
! EVALUATION TECHNIQUE The final piping evaluation was performed using two methods of analysis.
In the first, large borg' systems which were originally analyzed by computer, were reanalyzed by computer.
In the second, smaller diameter piping systems were analyzed by a combination of " cookbook" (Blume criteria) methods and computer analysis.
For these systems the original design was based upon the " cookbook" method.
This Blume Criteria is an accepted industry method of qualifying smaller diameter piping systems.
For the first method, documentation existed and a detailed evaluation of as-built to as-designed loads was made by comparing computer generated loads. -Necessary modifications were then made.
For the second method only the criteria existed as documentation.
The attached flow chart (Attachment 1) illustrates the steps which were taken to evaluate piping using this method.
The as-built condition was evaluated against the criteria used to develope the design.
Where pipe support span violations occurred, a more detailed evaluation was performed.
This involved use of a computer analysis to evaluate the supports bounding the' span.
Support loads were compared to the typical Blume criteria loads.
If the computer loads wrre less than the Blume loads the support was considered qualified and no further action was taken.
If the loads exceeded the Blume " cookbook" loads, modifications or new supports were added to satisfy FSAR criteria.
Implementation of " cookbook" criteria described above in the attached flow chart leads to varying levels of documentation for the pipe supports.
APPRGVED METHOD This method for documenting the IE 79-14 review of piping systems was developed by CECO /EDS and reviewed and commented upon by NRC Region III.
The program fully satisfies IE Bulletin 79-14 and incorporates specific L
e concerns raised by Region III such as maintaining rigid piping spans.
NEW PROGRAM SCOPE
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The scope of this program can be summarized as follows.
It is estimated
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that detailed documentation will be provided on 240 Blume system supports s
per unit ~.
This represents approximately 20% of the supports evaluated under.the IE 79-14 scope.
Based on our 79-14 experience, it is expected that approximately 120 supports per unit will be upgraded.
These upgra,es are anticipated primarily because the criteria to be used for d
do'cumentation purposes is considered more stringent than the original design criteria.
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J. G. Keppler July 26, 1983 CECO'sdecisionwdsbasedonthefollowingitems.
The design work on 79-14 was completed in May, 1983.
Until then the actual number of supports in the Blume qualified category was unknown.
In reviewing the final documentation packages, CECO decided to initiate the documentation upgraue of these supports since they are a relatively small percentage of
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thr/ total 79-14 ef fort.
This program will provide a uniform level of documentation for all supports originally evaluated under 79-14. provides a list of piping systems that contain these supports.
Of all the systems defined only two systems fall into the safe shutdown category.
These are the Diesel Generator Service Water and Residual Heat Removal systems.
98 of these 240 supports per unit are located on these two safe shutdown path systems.
The schedule for completing this documentation effort is provided under.
SUMMARY
CECO has satisfied all requirements of Bulletin 79-14.
After reviewing the design results CECO has decided to initiate a program to upgrade the documentation on a small percentage of the 79-14 supports.
The estimated number of supports for this effort is expected to be 960 with total nroiect comoletion echeduled for 1985.
This should not be misunderstood Us M continuation oY the original 79-14 requirements.
If you have any questions regarding this matter, please contact this office.
Very truly you s, B. Rybak Nuclear Licensing Administrator 1m Attachments cc:
NRC Resident Inspector - Dresden NRC Resident Inspector - Quad Cities 7033N
BLUME CRITERIA SUPPORT EVALUATION FLOW PATH SPAN CHECK NO PIPE STRESS VALIFIE OPERABILITY
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EVALUATION YES NO PERABL FIX FOR
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OPERABILITY YES l
,r NANALYSIS[
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C0 ISON LESS NO THAN ORIGI r EVALUATE
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SUPPORT YES
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SU RT YES MODIFY SUPPORT y
3, NO ACTION QUALIFIED BY QUALIFIED SUPPORT e
CALCULATION 33840*
s ATTACHMENT 2 SYSTEMS WITH "NO-ACTION" SUPPORTS puad 1 and 2 Clean and Contaminated Condensate Control Rod Drive
- Diesel Generator Service Water High Pressure Coolant Injection Main Steam Reactor Building Equipment Drain Reactor Building Coolant Water Reactor Core Isolation Cooling Reactor Water Cleanup
- Residual Heat Removal Standby Liquid Control Standby Gas Treatment Dresden 2 and 3 Core Spray Control Rod Drive
- Diesel Generator Service Water Headspray High Pressure Coolant Injection Isolation Condenser Low Pressure Coolant Injection Pressure Suppression Reactor Building Cooling Water Reactor Building Equipment Drain Reactor Water Cleanup Shutdown Cooling Standby Liquid Control Standby Gas Turbine Building Equipment Drain Well Water
- Safe Shutdown 33550*