IR 05000324/1989033
| ML19351A315 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 10/05/1989 |
| From: | Blake J, Economos N NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML19351A314 | List: |
| References | |
| 50-324-89-33, 50-325-89-33, GL-84-07, GL-84-7, NUDOCS 8910200021 | |
| Download: ML19351A315 (5) | |
Text
I i
t e,
i
[pm Dec UNITED $TAf t$ -
<
o NUCLEAR REGULATORY COMMISstON j
g At GlON il i
g 101 MARitTTA STREET. N.W.
l
'
ATLANTA.OtORot A 30323
%,
...+
[
Report Nos.: 50-325/89-33 and 50-324/89-33 licensee: Carolina Power and Light Company
,
'
P. O. Box 1551 Raleigh, NC 27602 l
Docket Non.:
50-325 and 50-324 License Nos.:
<
Facility Name: Brunswick 1 and 2
-
l
'
Inspection C ted-September 13-15, 1989 N
Inspect r:
-
y N.
s Date Signed i
I Appro ed by:
/c
'/
3. J.
lake Chief Da~te Signed
t ials and Process Section
'
ng neering Branch Division of Reactor Safety l
,
SUMMARY Scope:
This routine, unannounced inspection was performed to provide the inspector the opportunity to meet with the licensee and discuss planning and technical issues associated with the recirculation system safe-end/ riser replacement, scheduled
'
during the outage.
Results:
By document review, and through discussions with management and key technical personnel, the inspector ascertained that the licensee is moving forward in this project following guidance of Generic Letter 84-07.
Accordingly, the licensee has generated controlling documents which address organization structure / responsibilities, design, radiation protection, and engineering specification for procurement, pipe installation and testing activities.
In the areas inspected violation or deviations were not identified.
$$k ${fff1 r
gp
.
E
.
,
.
REPORT DETAILS 1.
Persons Contacted Licensee Employees
- C, F. Blackmon, Manager Operations
- K. E. Enzor, Director Regulatory Compliance
- J. L. Harness, General Manager
- J. R. Holder Manager, Outage Management and Modifications Other licensee employees contacted during this inspection included technical and administrative personnel.
Other Organizations G E Nuclear Energy G W. Rowe, Project Manager NRC Resident inspectors
- W. Rulard, Senior Resident Inspector
- Attended exit interview 2.
Replacement of BWR Recirculation Piping Unit -2 (2512/13)
By memorandum to the Comission dated June 28, 1989 the licensee comitted to replace the inlet risers and nozzle safo-ends of Unit-2 during the 1989 fall outage.
An March 14, 1984 the Comission issued Generic Letter 84-07 " Procedural Guidance for Pipe Replacement at BWRs". This letter provides guidance to licensees planning to replace recirculation system piping (or other reactor coolant system pressure boundary piping) with material that is less susceptible to intergranular stress corrosion cracking.
In particular, guidance is provided regarding NRC reviews and approvals that may be necessary.
Following this publication, the Comission issued Revision 2 to NUREG-0313 dated January 1988; with specific recomendations and guidance for flaw evaluation per Section XI of the ASME Code, repairs of cracked piping, and pipe replacement.
By reference the licensee has adopted the guidance and recomendations set-forth in the two Regulatory documents and is proceeding with plans to replace the subject components at this time.
Accordingly the licensee will replace existing intergranular stress corrosion cracking (IGSCC) susceptible material within the reactor coolant
,
-
".
,
.
.
recirculation piping system with low carbon, corrosion resistant,
,
austenitic stainless steel.
This project is essentially a direct replacement project with the exception of using seamless bent risers and an improved design safe-end which eliminates the thermal sleeve attachment weld.
A summar.w of welds being eliminated by the redesign of resers and safe-ends is as follows:
12" tircumferential butt welds - 14 risers)
10 safe-ends)
~
_2_4 Thermalsleeveattachmentwelds-10
Longitudinal seam welds
- 20 (Di se))
- 20 (elacw
Total welds eliminated
The work effort wili proceed under Plant Modification No.89-038 and related documents which include:
>
DBD #89-04, Rev. O Reactor Coolant Recirculation System Inlet Safe-End/ Riser Replacement Specification #248-155 Field Replacement of Reactor Coolant Recirculation System Inlet Safe-Ends and Piping By discussion with cognizant licensee personnel and through review of related documents / engineering specifications, the inspector ascertained that the primary objective of this modification is to upgrade material and thereby mitigate the intergranular stress corrosion cracking (IGSCC) of the replacement components.
Other design changes which will not impact the design intent of the reactor recirculation system but will require analysis include:
Redesign of the reactor recirculation system inlet safe-ends to
include integrally attached thermal sleeve extensions.
Renoval, by machining, of the existing weld overlay on nozzle N2E and
repair of the nozzle to remove rejectable indications.
l Removal, by machining, of the existing wel1 overlays on weld joints
- 2-B32-755, 777, and 778 and remov61/ repair of the rejectable indications Removal of differential pressure instrument taps on reactor
recirculation system discharge risers.
These taps are no longer functional and were abandoned-in-place and capped by a previous plant modification.
1,
-.
.,
,
,
i
-
,
f i
Following is a tabulation of upgraded materials with the scope of this
,
modification.
Cor,iponent Existino Material
_ Replacement Material Discharge Risers Type 304 Stainless Type 316 NG SS
<
Steel (SS)
l Sefe-ends Inconel 600 Type 316 NG SS
,
Thermal Sleeve Inconel 600 Type 316 NG SS Extensions N2 Nozzle Cladding Inconel 82 & 182 Type 308L and/or i
309L SS Weld Metal Inconnel 82 & 182 Type 308L SS
Type 308L SS
-
The scope of the work as described by the licensee is as follows:
Replace the reactor recirculation system inlet safe-ends.
- Replace the " riser" piping from the ring header up to the safe-ends.
l
Replace a portion of the thermal sleeve adapters.
- Remove, by machining, the inconel 182 cladding on the low alloy steel
reactor vessel N2 nozzles.
- Remove, by machining, the existing welds overlay on nozzle N2E and
repair the nozzle to remove the rejectable indication.
Cladding the reactor pressure vessel N2 nozzle inside diameter
surfaces with stainless steel weld metal including post weld heat treatment.
Remove the three (3) weld overlays on the ring header to riser welds
and removal / repair of the defects.
General Electric (GE) Nuclear Plant Services, under contract with the licensee, is responsible for fabrication, installation, and testing activities required by this modification.
Accordingly GE is the repair organization, and is therefore responsible for developing and qualifying welding procedures, qualification and the direct supervision of welders, generating work procedures etc.
The services of an independent (third party) inspection agency have been contracted for the modification.
By reference this modification will be performed under the requirements of V
'
,., _
I
'
-
s
!
.-
,
!
IWA 4000 IWA 7000, IWB 4000 and IWB 7000 of Section XI and related i
sections of Sections III and IX of the ASME Code.
Welding will be
>
performed using automatic orbital GTAW equipment operated with remote control.
The licensee expects to begin cutting out existing piping sometime during
the end of October 1989.
3.
Exit Interview The inspection scope and results were sumarized on September 15, 1989, with those persons indicated in paragraph 1.
The inspector described the
'
areas inspected and discussed in detail the inspection results.
Proprietary information is not contained in this report.
Dissenting
'
comments were not received from the licensee.
.
$
I
,