ML20247B852
| ML20247B852 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 07/14/1989 |
| From: | Sieber J DUQUESNE LIGHT CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEB-88-008, IEB-88-8, NUDOCS 8907240226 | |
| Download: ML20247B852 (4) | |
Text
__
^ >
L
- s..
K 1 D"-me Li@t Company pg;,;e-soa h*'
Shippingport. PA 15077-0004
$15.,* ens!"wse.., on..on.
July 14, 1989 U.
S. Nuclear Regulatory Commission Attn:. Document Control Desk Washington, DC 20555
Reference:
Beaver Valley Power Station, Unit No. 2 Docket No. 50-412, License No. NPF-73 NRC Bulletin 88-08 Gentlemen:
Attached
- is a
follow-up report for NRC Bulletin 88-08,
" Thermal Stresses in Piping Connected to Reactor Coolant Systems".
This report is required by Reporting Requirement 2 of the Bulletin and provides the results of actions taken at Beaver Valley Unit 2 during the first refueling outage.
If there are any questions concerning this matter, please contact my office.
Very truly yours, lv.
L.
C.
D. Sieber Vice President Fuclear Group Attachment cc:
Mr. J.
Beall, Sr. Resident Inspector Mr. W. T. Russell, NRC Region I Administrator Mr.
P. Tam, Sr. Project Manager Director, Safety Evaluation & Control (VEPCO) 8907240226 890714 gDR ADOCK 05000412 PDC
r;... ~
s.
i,
.y e.
r
'j.,
. COMMONWEALTH OF: PENNSYLVANIA).
)' -SS:.
i COUNTY OF BEAVER
).
':L s
..i -
E On this
_. day of M7
, 1989,
///
[dDLI, a
No ry Public in and:for said before. me_, g,
-Commonwealth and ' County, personally appeared J. D. Sieber, who being duly ' s w o r n,' ' deposed, and; said that (1)- he: 'is Vice President of h
.Duquesne Light,..(2) he. is' duly, authorized to execute and file the
- foregoing-Submittal on~ behalf.of said
- Company, and'(3).the statements set forth in the Submittal are true and correct to the best of his-
. knowledge, information and belief.
p
/
WWSeal She4s M. Fallore, Notary Pubic Shippirgp3r1 be.Seever County My Commesen Epires Od. 23,1989
, Member,Pennsyhere Assomatonof Notaries
S, l
DUQUESNE. LIGHT COMPANY Nuclear Group L
Beaver Valley Power Station Unit 2 l'
Attachment l
Follow-up Report for NRC Bulletin 88-01 Action Items 2 and 3 For any unisolable sections of piping connected to the RCS that may have been subjected to excessive thermal
- stresses, examine nondestructively the
- welds, heat-affected zones and high stress locations, including geometric. discontinuation, in that piping to provide assurance that there are no existing flaws.
Plan and implement a
program to provide continuing assurance that
.unisoluble sections of all piping connected to the RCS will not be subjected to combined cyclic and static thermal and other-stresses that could cause fatigue failure during the remaining life of the unit.
This assurance may be provided by (1)-
redesigning and modifying these sections of piping to withstand combined stresses caused by various loads including temporal and spatial distributions of temperature resulting from leakage across valve
- seats, (2)'
instrumenting this piping to detect adverse temperature distributions and establishing appropriate limits on temperature distributions, or (3) providing means for ensuring that pressure upstream from block valves which might leak is monitored and does not exceed RCS pressure.
Response
In our september 20, 1988 response to Action Item 1 we identified the-follow 3:sg Beaver Valley Unit 2
(BV-2) piping lines which could be sub3ected to stresses from thermal stratification or temperature oscillations assuming that all normally closed valves would Icak by.
Beaver Vallev Unit 2 Pipina Lines 2-SIS-006-26-1(A)
SAFETY INJECTION TO "A" HOT LEG 2-SIS-006-12-1(A)
SAFETY INJECTION TO "A" COLD LEG 2-SIS-006-24-1(B)
SAFETY INJECTION TO "B" HOT LEG 2-SIS-006-15-1(B)
SAFETY INJECTION TO "B" COLD LEG 2-SIS-006-25-1(C)
SAFETY INJECTION TO "C" HOT LEG 2-SIS-006-16-1(C)
SAFETY INJECTION TO "C" COLD LEG 2-CHS-002-140-1(A)
CHARGING FILL TO "A" LOOP 2-CHS-002-141-1(B)
CHARGING FILL TO "B" LOOP 2-CHS-002-142-1(C)
CHARGING FILL TO "C"
LOOP 2-CHS-006-490-1(2)
NORMAL CHARGING TO PRESSURIZER SPRAY LINE In addition to the above lines, an additional location on the BV-2 Residual Heat Removal System was identified for examination and instru?aentation.
This
- line, 2-RHS-012-1-1, RHR suction to "A" hot leg was identified based on our review of the Genkai Plant RHR suction line cracking problem, which was the subject of NRC Bulletin 88-08, Supplement 3.
4. Attachm:nt l
Foll'ow-up Report for NRC Bulletin 88-08 Page 2 l
During the BV-2 first refueling
- outage, these lines were nondestructively examined at selected locations which included welds, heat-affected zones and high stress locations, including geometric discontinuation.
The nondestructive examination locations and tecanique took into account the guidance provided by Bulletin 88-08, Supplements 1
and 2.
The ultrasonic examinations of the selected locations covered the fitting, fitting-to-pipe or fitting-to-fitting welds and a
minimum of one (1) inch of adjacent base material, and was covered to the maximum extent possible as permitted by accessibility and component geometry.
Ultrasonic scans were conducted at beam angles of 45 and 60 degrees.
Liquid penetrant examinations supplemented the ultrasonic examinations.
No recordable indications were found during the ultrasonic examinations.
Two (2) rejectable indications were found during.the liquid penetrant examinations, one on a fitting on the charging fill to "A"
loop
- line, the other on a fitting on the RHR suction to "A" hot leg line.
These fittings were reexamined following surface conditioning and the results of the reexamination were satisfactory for both fittings.
During the first refueling outage, the above lines were instrumented with thermocouple at strategic locations.
Data collection began at startup from the first refueling outage and is continuing.
The recorded data has been evaluated against established acceptance criteria and has shown that:
1)
Stratification does exist in the majority of the lines.
However stratification
- itself, as in this
- case, is ccno' ant and has a c
negligible effect on stresses in the line.
2)
The temperature distributions recorded in the pipes do not fluctuate to any major degree that would cause additional fatigue cycling.
Monitoring of these lines will continue during the second fuel cycle at BV-2.
If the stratification conditions exceed the acceptance criteria, appropriate corrective action will be taken.
We will use the results of the temperature monitoring program in our consideration of a
long-term solution to Action Item 3
of the Bulletin.
We will provide a letter describing our plans to resolve this concern by June 30, 1990.
Temperature monitoring will continue until a long term solution is implemented.
l l
I
_ _ -