ML20238F767
| ML20238F767 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 09/09/1987 |
| From: | Tiernan J BALTIMORE GAS & ELECTRIC CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| Shared Package | |
| ML20238F770 | List: |
| References | |
| IEB-87-001, IEB-87-1, NUDOCS 8709160334 | |
| Download: ML20238F767 (36) | |
Text
.
BALTIMORE GAS AND ELECTR!C CHARLES CENTER R O. BOX 1475 BALTIMORE, MARYLAND 21203 JOSEPH A.T4ERNAN wee PREslDENT
" " ^" '"*" '
September 9,1987 U. S. Nuclear Regulatory Commission Washington, DC 20555 ATTENTION:
Document Control Desk -
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit Nos.1 & 2; Docket Nos. 50-317 & 50-318 NRC Bulletin No. 87-01. Thinnine of Pine Walls in Nuclear Power Plants
REFERENCE:
(a) NRC Bulletin No. 87-01, Thinning of Pipe Walls in Nuclear Power Plants, dated July 9,1987 Gentlemen:
Reference (a) ' requested information concerning Calvert Cliffs' program to monitor the thickness of pipe walls in high-energy, single-phase and two-phase carbon steel piping systems. Our response is provided in Enclosures (1) through (6).
Should you have any further questions regarding this matter, we will be pleased to discuss them with you.
Very truly yours STATE OF MARYLAND :
TO WIT:
COUNTY OF CALVERT :
Joseph A. Tiernan, being duly sworn states that he is Vice President of the Baltimore Gas and Electric Company, a corporation of the State of Maryland; that he provides the l
foregoing ' response for ' the purposes therein set forth; that the statements made are l
true and correct to the best of his knowledge, information, and belief; and that he was l
authorized to provide the response on behalf of said Corporation.
WITNESS my lland and Notarial Seal:
T/A'/)
Notary Public
/
deY
/787
' My Commission Expires: 'N d4d,/990
/
Date JAT/LSL/dtm Enclosures gy Q9J6033497o999 v
0 ADocK 0500o337 i(3 PDR
Document Control Desk September 9,1987 Page 2 cc:
D. A. Brune, Esquire J. E.
Silberg, Esquire R. A.Capra, NRC C. E. Rossi, NRC S. A. McNeil, NRC W. T. Russell, NRC T. Foley/D. C. Trimble, NRC
ENCLOSURE (1)
CALVERT CLIFFS RESPONSE TO NRC BULLETIN 87-01 The following responds to your request for information concerning Calvert Cliffs' program' to monitor the wall thickness of pipes in condensate, feedwater, steam, and 0
connected high-energy (greater than 200 F and/or 275 psia) piping systems. Our response addresses both safety-related and non-safety-related carbon steel piping for
. these systems.
1.
Identify the codes or standards to which the piping was designed and fabricated.
RESPONSE.
With 1 the exception of those systems listed ' :in ' Table 1,
all carbon steel, high-energy piping systems 'within Calvert - Cliffs'. wall thickness monitoring program are designed and fabricated to ANSI B31.1 - 1967, with 1968 and 1969 Addenda.
2.
Describe the scope and extent of your programs for ensuring that pipe wall thick-nesses. are not reduced below the minimum allowable thickness. Include in the description the criteria - that you have established for:
a.
selecting points at which to make thickness measurements, b.
determining how frequently to make thickness measurements, c.
selecting the methods used to make thickness measurements, and d.
making replacement / repair decisions.
RESPONSE
A formal inspection program was established in 1984 primarily to address concerns regarding. the extent of erosion / corrosion. occurring in secondary plant two-phase systems; however, it included some single-phase high energy systems. The specific objectives of the program were to identify systems where erosion / corrosion existed, to quantify the extent of-identified problems, and to establish a systematic approach for assessing and correcting pressure boundary deterioration.
Currently, the program encompasses all, or portions of, the systems listed in Enclosure (2). Within the program, there are p total of 2325 possible areas to inspect on Unit One and 3085 areas on Unit Two. An area may consist of more than IThe primary reason for the difference in the number of Unit One and Unit Two areas is that Unit Two has four Moisture Separator Reheaters (MSRs) as opposed to two MSRs for Unit One.
ENCLOSURE (I)
CALVERT CLIFFS RESPONSE TO NRC BULLETIN 87-01 one fitting if ' they are in close proximity. Piping one inch and greater is included within the inspection program.
Initially, piping systems were classified as High, Medium or Low priority systems based on their - susceptibility to erosion / corrosion. High priority systems are noted in Enclosure -(2). The classification of High priority systems was ' based on the' high moisture content of the steam or flashing conditions within the system, and ' included the entire system even though only a portion of. it may have been highly susceptible to ~ erosion / corrosion.
As the program has progressed, priorities have been adjusted based on inspection results, ' piping replacements, or new concerns, identified within the industry.
. Following the initial classification of systems,' isometric drawings were reviewed and f system walkdowns were performed to select particular geometries which were likely to experience erosion / corrosion.
These areas were then planned for inspection.
The number of areas selected for the inidal and subsequent
. inspections ' are related to the priority of the system (i.e.,
High priority systems had more areas selected than Low priority systems), previous inspection results, and the extent of previous system replacements. Inspections are typically planned for scheduled refue!% outages. However, additional inspections are sometimes performed during unp.nned outages or when systems are isolated.
After each area is inspected, an erosion / corrosion rate is calculated based on the area's minimum measured thickness.
If the erosion / corrosion rate calculated predicts that the component will remain above the code minimum allowable wall thickness throughout the next operating cycle, the component can remain installed.
If the erosion / corrosion rate predicts that the code minimum allowable wall thickness will be reached sometime between the next refueling outage and the second following refueling outage, that area is classified as " red-alert" and is scheduled for re-inspection during the next refueling outage.
If the erosion / corrosion rate predicts that the code minimum allowable wall thickness will be reached sometime between the second and third following refueling outages, that area is classified as " yellow-alert" and is scheduled for re-inspection during the second (or possibly the next) refueling outage.
1 The majority of inspections for wall thinning utilize ultrasonic (UT) examination techniques. The inspections are done manually, but a data acquisition system is used for recording information when the examinations are performed during a planned outage. if a piping system is opened, a visual examination is often performed and a UT examination is completed if visual evidence of erosion /cor-rosion exists.
Piping components found to have wall thicknesses that are below, or will be below, the code minimum allowable in the next operating cycle are replaced with chromium-molybdenum steel components (or carbon steel components if chromium / molybdenum i
steel is unavailable). Piping systems which have several non-conforming or l
" red-alert" components are evaluated for complete replacement. Finally, if all l
other replacement possibilities have been exhausted, a weld build-up is done on the eroded / corroded area if all of the below conditions exist.
1
) l l
l I
L_ _u1__ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _. _
i i
l-ENCLOSURE (1)
CALVERTCLIFFS RESPONSE TO NRC DULLETIN 87-01 j
I o
The component is non-safety related, o
The replacement pipe / fitting is unavailable, and I
o The eroded / corroded area is localized.
1.
3.
For liquid-phase systems, state specifically whether the following factors have been considered in establishing your criteria for selecting points at which to monitor piping thickness (Item 2a):
i a.
piping material (e.g. chromium content),
b.
piping configuration (e.g.,
fittings less than 10 pipe diameters apart),
I c.
pH of water in the system (e.g., pH less than 10),
d.
system temperature (e.g., between 190 and 500 F),
e.
fluid bulk velocity (e.g.,
greater than !0 ft/s), and f.
oxygen content in the system (e.g., oxygen content less than 600 ppb).
RESPONSf4 The following factors are considered in the selection of liquid-phase water systems for the erosion / corrosion inspection program:
o fluid velocity, o
piping / component geometry, o
piping / component material, l
o operating conditions, o
temperature, and o
industry experience.
Liquid-phase systems included in the erosson/ corm:on program ' vere originally all j
carbon steel. If a component is subsequently replaced with a different material, j
such as chromium-molybdenum steel (or, in some instances, stainless steel), the i
component is retained within the program for any future inspections. No analyses for chromium content of carbon steel components are donc prior to inspections.
I i l
4 ENCLOSURE (1)
CALVERT CLIFFS RESPONSE TO NRC BULLETIN 87-01 l
Piping ' configuration has played a major role in Calvert Cliffs' overall selection criteria. Prior. to each outage, the system piping configuration is reviewed.
Areas. for inspection are -chosen based on complexity of flow paths (i.e., fittings in close _ proximity) and susceptibility to turbulent flow. Fluid bulk velocities have also been calculated and.used for the selection of areas to inspect within the feedwater system. Because of the increased velocities of fluids as they go through control valves and/or reducers, inspections downstream of such components are given a higher priority.
Neither 'the pH nor the oxygen content of water within a system is specifically measured for erosion / corrosion inspection purposes. These have not been used as a selection criteria. While there are no specific temperature band or temperature cut-off criteria. used, ' low temperature carbon steel systems included within the program: are given a lower priority.
4.
Chronologically list and summarize the results of all inspections that have been performed, which were specifically conducted for the purpose of identifying pipe.
wall thinning, whether or not pipe wall thinning was discovered, and ' any other inspections where pipe wall thinning was discovered even though that was not the purpose of that inspection.
RESPONSli A chronological summary of inspections performed under the present program is provided in Enclosure (3), Prior to the establishment of the formal inspection p'rogram in 1984, other inspections to detect wall thinning were performed. A summary of these is provided in Enclosure (4).
5.
Briefly describe the inspection program and indicate whether it was specifically
. intended to measure wall thickness or whether wall thickness measurements were an incidental determination. Describe what piping was examined and how (e.g.,
describe the inspection instrument (s), test method, reference thickness, locations examined, means for locating measurement point (s) in subsequent inspections).
Report thickness. measurement results and note those that were identified as unacceptable and why.
RESPONSE
- i..
Calvert Cliffs' current inspection program was specifically implemented tc address pipe wall thinning. Each area selected for inspection is gridded prP to inspection and UT measurements are recorded at every grid inte-section. Ti are i
i 4
['
ENCLOSURE (1)
CA LVERT CLIFFS RESPONSE TO NRC BULLETIN 87-01 o
2 of the grid' is' dependent upon the pipe size. Both the actual fitting and at~
least one pipe diameter downstream of the fitting are gridded.
~
' Examinations are usually performed using standard UT equipment with a scope and a digital read-out (i.e.,
Sonics Mark I).' The starting point for each. examination is recorded'on the data' sheet. for future reference. No permanent markings or stamps are placed on the pipe; however, the grid markings have been found to still-
' exist during subsequent inspections.
Unacceptability ; is' based - on the code minimum allowable wall thickness.. If. the area examined is either below ~ the allowable minimum, or is estimated to go below
. the, allowable minimum during the next opcrating cycle, it is unacceptable. Areas found to be..in 'such a category are listed in Enclosure (3).
For ' further information on Calvert Cliffs' current inspection program or techniques, refer to Enclosures (5) and (6).
' 6.
Describe actions already taken or planned for piping that has been found to have a nonconforming wall thickness. If you have performed a failure analysis, include the results of that analysis. Indicate whether the actions involve repair or replacement, including any change of materials.
RESPONSD Three options are available and have. been used in t past to address pipe wall thicknesses that. have been found to be non-conforming 1.
Replace sections of pipe with conforming pipe. Typically the replace-ment pipe material and/or fittings is of a more crosion-resistant material such as chromium-molybdenum steel.
2.
Furtherf evaluate the non-conforming section of pipe per the j
construction ' code. The analysis may indicate that the non-conforming pipe may be acceptable for continued service by de-rating the pipe design pressure.
l.]
2A 1"xl" grid is used on < 6" diameter pipe. A 3"x3" grid is used on
> 18" diameter pipe. For pipe between 6" and 18" diameter, a 2"x2" grid is used.
3The term "non-conforming" is defined as pipe wall thickness that is below the minimum wall thickness as defined (calculated) by the original construction code.
1 1
Y ENCLOSURE (II r-CALVERT CLIFFS RESPONSE TO NRC BULLETIN 87-01 L
-u 3.
. Perform repairs to the 'non-conforming pipe to bring the wall thickness -
[
into a conforming configuration.
- 7.
Describe any plans either for. revising the present ; or for developing new or
- additional. programs for. monitoring pipe wall thickness.
l RESPONSE.
As new areas of concern develop throughout the nuclearfindustry, they are reviewed-for - applicability to Calvert Cliffs.
If ' necessary new systems, or portions '
thereof - are added to the inspection program. In s lition, programs such as the EPRI CHEC computer model will be reviewed for. possible future use.
4 l 1
l t.
ENCLOSURE (1)-
CALVERTCLIFFS RESPONSE TO NRC BULLETIN 87-01 o
TABLE 1, l
CARBON STEEL - HIGH ENERGY PIPING SYSTEM DESIGN AND FABRICATION CODE
. A.
kiain Feedwater. Penetration' Piping ANSI B31.7 - 1969 with 1970 and 1971 Addenda - Class 11 B.
Main Steam Piping Between Containment ANSI B31.7 - 1969 with 1979 Liner Plate and Isolation. Valves and 1971 Addenda - Class II-C.' ' Auxiliary Feedwater Penetration ANSI B31.7. - 1969 with 1970
. Piping and 1971 Addenda - Class II D.
Steam Generator Blowdown -
ANSI B31.7 - 1969 with 1970 Containment Penetration Piping and 1971 Addenda - Class II l
i I
i ENCLOSURE (2) i i
CALVERT CLIFFS RESPONSE TO NRC DULLETIN 87-01
{
SYSTEMS INCLUDED IN THE EROSION / CORROSION INSPECTION PROGRAM 4
k I
l 1.
Main steam to high pressure turbine stop valves 2.
Main steam to second stage reheater j
1 3.
Main steam turbine bypass to condenser 4.
Main steam to main feedwater (MFW) pump turbine 5.
Main steam to auxiliary feed pump turbine 6.
High Pressure turbine exhaust to Moisture Separator Reheaters (MSRs) (High Priority) 7.
Reheated steam to low pressure turbines 8.
Reheated steam to MFW pump turbine & auxiliary boiler 9.
Condensate booster pump discharge to MFW pump suction 10.
Feedwater pump discharge to steam generator 11.
Feedwater pump recirculation to condenser (High Priority) 12.
Auxiliary Feedwater from the Auxiliary Feedwater pumps 13.
Steam generator blowdown (Iligh Priority) 14.
Heater 6A & 6B extractions, vents, dumps, and drains, excluding atmospheric vents & drains (High Priority) 15.
Ileater SA & SB extractions, vents, dumps, and drains, excluding atmospheric vents & drains (High Priority) 16.
Heater 4A & 4B extractions, vents, dumps, and drains, excluding atmospheric I
dumps and drains 17.
Heater 3A & 3B extractions, vents, dumps, and drains, excluding atmospheric dumps and drains 18.
MSR second stage reheater drains to reheater drain tank and to heaters 6A &
6B and condenser 19.
MSR first stage reheater drains to reheater drain tank and to heater 5A & 5B and condenser (High Priority) 20.
Moisture separator drains to reheater drain tank and to heater drain tanks and condenser (High Priority) 21.
Heater drain pump discharge 22.
High Pressure extraction steam drains (High Priority) 23.
Miscellaneous steam line drains
b d
ENCLOSUR E (3) 3 CALVERT CLIFFS RESPONSE TO NRC BULLETIN 87-01
~
CHRONOLOGICAL
SUMMARY
OF INSPECTIONS A..~ chronological. summary of inspections performed to identify pipe wall thinning is provided. below..The' numbers ' represent areas inspected and/or replaced. Scheduled
. refueling : outages 'are. designated
. ith an asterisk. A system 'is. listed 'under. the w
" replaced" heading. if, in addition to any " unsatisfactory" areas, further ~ replacements were done within that system without first performing ultrasonic examinations.
19M Unit Two April 22 to June 1
- 339 in:;pected 233'
. satisfactory E
yellow alert 28-red alert 49 unsatisfactory 3 steam generator blowdown system 5 main steam system 27 extraction steam system to sixth stage. feedwater heaters (FWHs) 6 extraction steam system to fifth stage FWHs 7 2" or less drains system i extraction steam system to fourth stage FWHs 53 replaced 19B Unit One Nov. 20 to Dec. 20 108 inspected 67 satisfactory 7
yellow alert 11 red alert 23 unsatisfactory 6 Steam Generator Feed Pump (SGFP) recirculation to condenser system 11 extraction steam system to sixth stage FWHs
-6 extraction steam system to fifth stage FWils 10-replaced 12 pad welded :___._
ENCLOSURE (3) 1 CALVERT CLIFFS RESPONSE TO NRC BULLETIN 87-01
- CHRONOLOGICAL
SUMMARY
OFINSPECTIONS I-M' Unit One Jan.18-28 '
March 7-11 230 inspected
" April 6-30
- 163 satisfactory Sept. 28 15 yellow alert j
17 red alert 35
'. unsatisfactory
'2'SGFP recirculation.to condenser ' system 8 steam generator blowdown : system
.1 ' Moisture Separator Reheater (MSR) second stage reheater drain system 11 -. extraction. steam system. to sixth stage FWHs 5, extraction steam system to fifth stage FHWs 5 MSR first stage reheatu drain system 2 MSR shell drain system 1
2" or less drains system 47 replaced l
.M Unit Two April 25-29 July 24 176 inspected Oct. 23 to Nov. 20
- 77 satisfactory 27' yellow alert 39 red alert 33 unsatisfactory
~ 12 High Pressure (HP) - turbine exhaust system 4 SGFP recirculation to. condenser system 1 main ' steam system
- 1. MSR second.. stage reheater system 3 extraction steam. system to sixth stage FWHs i
J 5 extraction. steam system to fifth stage FWHs 1 heater drain pump system 6
2" or less drains system 27 replaced j
extraction steam to sixth stage FWHs j
12 encapsulated (HP turbine exhaust) l 1
1 l
6 ;
1
-: s Z
ENCLOSURE (3)
- CALVERTCLIFFS RESPONSE TO NRC BULLETIN 87-01 i
CIIRONOLOGICAL
SUMMARY
OF INSPECTIONS
{
.)
l
.jlgd Unit One March 27. to. April 7
)
April 18-21 j
255 inspected July 9 & 23 l
-151 satisfactory Oct. 23 to Dec.19
- 39-yellow alert 31 red alert -
-34 unsatisfactory -
1 3 main feedwater system (discharge of main feedwater pumps) 4 SGFP recirculation to condenser system 1 main steam system l
.1 MSR second stage reheater system i extraction steam system to fifth stage FWH j
1 heater drain pump system 3 MSR first stage reheater drain system 13 MSR shell drain system 7
2" or less dr'ain system.
143 replaced MSR first stage drain system MSR shell drain system extraction steam to fifth stage FWH extraction steam to sixth stage FWII jl82 Unit Two March 17 to April 12
- 275 inspected 172 satisfactory 33 yellow alert 26 red alert 44 unsatisfactory 7 main feedwater system (discharge of main feed pump) 2 extraction steam system to sixth stage FWils 2 main feedwater system (suction of main feed pump) 2 heater drain pump system 12 MSR first stage reheater drain system 11 MSR shell drain system 8
2" or less drain systems 295 replaced IIP turbine exhaust SGFP recirculation to condenser system l
extraction steam to fifth stage FWH 2" MSR vent lines to extraction system steam generator blowdown system.
- r ENCLOSURE (3)
CA LVERT CLIFFS RESPONSE TO NRC B ULLETIN 87-01 CIIRONOLOGICAL
SUMMARY
OF INSPECTIONS.
Totals to Date.
Unit One Unit Two -
527
- inspected 2, at D least 'once -
679 inspected-at least once 131 unsatisfactory 191 unsatisfactory
[
.191 --
replaced
'359 rep!sced l
L-l l-i 4
ENCLOSURE (4) c
\\
CALVERT CLIFFS RESPONSE TO NRC BULLETIN 87-01 INSPECTIONS PRIOR TO 1984 Prior to the establishment of ' the. formal inspection program. in 1984, other inspections.
to detect wall. thinning' were performed. A summary of those inspections follows.
- Qqtober 1979 '(Unit Oneh Wall. thinning was. found at a weld. joint in the extraction steam line which - provides steam from the' High Pressure (HP) turbine exhaust to a #15 feedwater heater (FWH). The
' extent of the. thinning was : determined - by ultrasonics, but was actually discovered because of a steam leak.
Scotember 1981 (Unit Twoh i
Wall thinning caused the failure of a feedwater normal level control line between #26A l
and #25A.FWHs, downstream of the flow control valve where the piping expands from 6" to 14".
. After. ultrasonic. inspections, three other drain line sections - were found ~
to require replacement in the area between the outlet of a control valve and the inlet to an expander. Approximately 90 additional locations, on Unit One and Unit - Two, were examined and.no excessive wall thinning was identifiec'.
November 1981 (Unit Oneh After a 5" long by: 1/4" wide break in the third stage extraction steam line to a #16 FWH necessitated a shutdown, wall thinning.was ultrasonically found in a 64" long section below the two turbine nozzles which required replacement of those sections.
Additional inspections were performed on other portions of the extraction steam line, but no other immediate repairs were necessary.
February 1982 (Unit Twok
)
Ultrasonic thickness measurements were taken 'on Unit Two's third stage extraction steem j
piping to the #26 FWHs and to the first stage of the Moisture Separator Reheaters
)
(MSRs). Some measurements were below the code minimum allowable wall thickness.
Measurements.wcre also taken on the HP turbine exhaust extraction steam lines to the
- 25 FV/Hs.
May.1982 (Unit Onet i
i Darmg a shutdown, thickness readings were taken on the steam generator feed pump j
recirculation lines. A total of eighteen elbows and twelve straight sections were replaced with chromium-molybdenum steel. _ _ - - - _ _ _ _ _ _ - _ _ _ _ _ _ -
pjy i
~
. 4e p.
1
' ENCLOSURE (4)
CALVERT CLIFFS RESPONSE TO NRC BULLETIN 87 INSPECTIONS PRIOR TO 1984 -
a Scotember 1982 (Unit Oneh
' The' steam ' generator blow'down - tank inlet nozzles, small-bore steam drain lines, portions
'of the MSR drains system and the main steam system were ultrasonically examined. No unacceptable - wall thinning - was found.
~
May 1983 (Unit Oneh The main 'steami lines to the second stage of MSRs #11 an'd' 12 were ultrasonically; examined.1 No' wall thinning was found.'
1 November / December 1983 (Unit Oneh Portions of the main steam ' lines to the second stage of #11 and.12 MSRs, third stage extraction ~ steam to the #16 FWHs, normal leul centrol drain from #16 to #15 FWHs, and normal level control drain from #15 FWHs to the heater drain tanks were ultrasonically examined. Thinning was found in two places, dov*nstream of the ' normal ' level control valve to a heater drain tank 'and on the extraction steam line to #16B FWH.
The MSR first stage drain tank drain-lines to the #15 FWHs were also examined Wall
' thinning was found on two elbows which. required replacement. The HP turbine exhaust extraction steam lines to - #15 FWHs were also inspected and no _ unacceptable wall thinning was found.
1
. o
l ENCLOSURE 5 i
SECONDARY PIPING SYSTEMS INSPECTION I.
PURPOSE SECTION 1
This inspection program will provide guidelines for the
)
inspection of secondary piping for erosion /corrosien.
q Ultrasonic inspection techniques will be used to detect wall thinning and visual inspections will be performed wherever practicable.
II.
REFERENCE SECTION A.
Nondestructive Examination Procedure NDE 5.400 Ultrasonic Thickness Measurement B.
M-600 Piping Class Sheets C.
M-601 Piping Class Summary D.
Site Safety Manual E.
CCI-107 (Area Cleanliness Requirements)
G.
CCI-206 (Personnel and Material Accountability)
III.
ADMINISTRATIVE REQUIREMENTS i
A.
Qualification Requirements of Personnel I
1 1.
Personnel certified as a Level IT may operate the ultrasonic instruments that are used for thickness measurement only and record data provided they have been instructed in the use of the equipment.
2.
Personnel certified to operate ultrasonic I
instruments, Level 1 or better, may use j
i instruments th7t utilize a CRT without a digital readout.
However, it is recommended that I
instruments with digital readouts be used if possible.
3.
A D-meter may be used for thickness measurements by anyone who has been instructed in its use.
However, it is preferred that an ultrasonic instrument with a CRT and digital readout be used.
B.
Initial Conditions Verify insulation has been removed and scaffolding has been installed where necessary.
I C.
Precautions and Limitations When entering the piping system to perform a visual inspection, follow the requirements of the Site Safety l
Manual for tank and void entries, CCI-107 (Area l
Cleanliness Requirements), CCI-206 (Personnel and Material Accountability), and CCI-ll2 (Safety Tagging) 1 IV.
SELECTION CRITERIA A.
The responsible supervisor shall generate a list of inspection points for each line number in the inspection program using Attachment (1).
1 i
- -a
r-3,-
B.-
The list of inspection points (Attachment (1)) should include all poss'ible inspections for a given system.
Systems subject to inspection should be selected based on susceptibility to erosion / corrosion (1.e., moisture content), consequence of failure and any past-history of problems.
Components scheduled for inspection should also be prioritized by the same factors.
V.
SCHEDULING REQUIREMENTS
.A.
A list'of inspections is to.be created prior to each refueling outage.
1.
This list shall include all " Red Alert" components from previous inspections.
2.
Examinations may be added, deleted or postponed at the discretion of the engineer implementing j
i the program.
.B.
During a " mini-outage", inspections may be performed
(
as necessary.
VI.
INSPECTION RESPONSIBILITIES A.
The inspection engineer shall fill in the required information on Attachment (2) for each inspection j
point scheduled for inspection.
i l
1 1
4
- j s
i 1.
Inspection point identification number example:
EB-04-2023-05 where:
EB = Pipe class OA = System 2 = Unit 023 = Line number 21 = Inspection point number
- NOTE -
g TIhe inspection point nummer is de'ter-s mined by counting each geometric point (listed under Section 3.3.B) starting w
at.,the beginning of the line number w
counting in the direction of flow.
2.
Inspection point geometry a
a.
CV - control valve b.
MV - motor operated valve c.
GV - gate valve' d.
TV - globe valve e.
BV - butterfly or check valve f.
TE - tee l=
g.
EL - elbow h.
RD - reducer i.
FO - flow orifice l
j.
TP - pipe taps (pressure, temperature, drains, etc.)
k.
EJ - expansion joint u _ _ _ _ _ _ _.----_ ---
1 i
' J i
3.
Isometric drawing number that inspection point is j
located on.
]
- Y 4.
Pipe diameter j
5.
Piping and instrument drawing number that i
inspection point is located on.
6.
Area:
Location number, example: X-YYY-ZZ X = Erosion / corrosion priority A, B, or C 1
(A being the highest priority)
YYY r Area location between columns in Turbine I
Building.
Auxiliary Building and Containment will be used when pipe is located there. (Reference Attachment (4)).
ZZ = Floor elevation Examples: A-A01-12 i
C-AUX-27 I
B-J08-45 I
7.
Description of the line number function 8.
Give location of inspection point using columns, pumps, large equipment, etc., as landmarks l
9.
Height above floor i
10.
Insulation type (i.e., Pad, Asbestos, Metal) 11.
Access (scaffolding or ladder required or N/A if none required) e.
.l 1
-_- _u
ep.
y
..a..
L:
12.
Pipe nominal wall (M-600 gives pipe schedule,
'then reference standardized. tables, i.e.,
)
Technical Data Handbook) 13.
Minimum
- fall (reference Step 3.8)
.14.
Examination results a.
Date examined b.
c.
Folder number d.
Smallest thickness'found e.
Results'(UNSAT, SAT, RED ALERT, YELLOW l
ALERT)
B.
.The examiner is responsible.for filling out an Ultrasonic Thickncas Measurement Record, see
' Attachment (3)..
(Use form with appropriate geometric shape.)
1.
The Ultrasonic Thickness Measurement Record shall provide the following:
a.
ID #
'I b.
Pipe diameter j
c.
Inspection node grid spacing (1)
Use a 1" x 1" grid on 6" pipe or less (2)
Use a 2" x 2" grid on pipe greater than 6" up to 18" (3)
Use a 3" x 3" grid on pipe greater than 18" d.
Minimum wall thickness found
_ - _ _ _ 2.
The examiner vill also be responsible for marking
\\
the following on the geometric sketch provided on the bottom of the Ultrasonic Thickness l
Measurement Record.
a.
Inspection starting point I
b.
Number sequence of inspection points c.
Component orientation (i.e., looking up, down, north, south, etc.) to establish a frame of reference d.
Attach printout of pipe wall thickness measurements C.
The inspection engineer shall determine the disposition of those components found to be under the accept / reject criteria.
Keeping in mind that components close to this value may not last until the next inspection.
D.
When requestqd, a Level II or III Examiner shall evaluate the results of examination.
VII.
INSPECTION PROCEDURE A.
Surface Preparation 1.
The examination surface shall be free from all foreign materials that would interfere with the examination, i.e.,
dirt, weld splatter, loose paint, et:.
-,, - _ - -_ 1 L.
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2 '.
The area to be examined may be cleaned by:
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a.
scraping, hand sanding or wire brushing b.
detergents, approved solvent or paint removers.
The cleaning agent shall not be detrimental to the surface c.
grinding, if done under a Maintenance Request B.
Standard Calibration 1.
The instrument shall be calibrated on a reference block of the same basic material as the component (s) to be examined.
The reference block shall be designed to provide approximately 0.1 inch over the anticipated thickness range of the material to be tested.
Calibration procedure will vary depending on the type of instrument.
See manufacturer's instructions.
2.
The instrument calibration shall be checked before and after each examination.
3.
Any change of operator, instrument, cable, transducer, shoe, couplant, etc., shall require recalibration.
C.
Calibration Chance Perform the followi g if the distance calibration 1.
n 1
has changed on the digital display more than O.005 inch.
a.
Void all measurements referring to the 1
calibration in question.
l
,,.. - - ~, -.. -., - - -
lb.
Adjust the calibration to meet the specified;
. limits or conduct a new calibration.
c.
- Remeasure the areas for wh.Ich measurements have been voided.
D.
Examination Secuqjlge.
1.
Prior to starting the examination, an Ultrasonic Thickness: Measurement Record (Attachment (3))
should be completed showing the Inspection starting point, number sequencing in respect to this. point,, grid size, pipe diameter, etc.
2.
Any pulse-echo type instrument may be used.
This includes a'CRT with or without a digital readout, and a "D-meter", provided the user is qualified.
The preferred instrument is a CRT with a digital readout.
- 3.
Any contact-type transducer having a minimum diameter of.250"~and a minimum frequency of 1 MHZ.
4.
The couplant may be oil, grease, glycerin, etc.
Material used shall be in accordance with ASME Section V and shall not be detrimental to surface being examined.
1 5.
The transducer shall be placed in contact with the component and manipulated in such a way as to l
ensure maximum response.
I-
- _ _ 6.
Record the Identification Number.
Verify the calibration as required by Paragraph VII.B. and document each verification.
7.
The search unit shall be placed at each of the selected positions on the component.
Obtain a clean (no baseline noise) backwall response without any intermediate signals.
Normalize this amplitude to 80 - 100% of FSH.
Read the digital display and confirm the measurement by observing its screen position on the instrument screen.
Couple the search unit as firmly to the location on the component as was done on the reference block during the calibration and record the thickness.
E.
Visual Exam Requirements 1.
An internal visual inspection should be used wherever practical.
2.
If the internal visual inspection shows signs of erosion / corrosion, a UT examination should be performed to determine whether the component needs to be repaired or replaced.
Such signs may include:
smooth, shiny, black surface, indentations or grooves, or ripples.
_. VIII.
ACCEPTABLE / REJECTION CRITERIA A.
Minimum allowable thickness should be in accordance with the following equation from B31.1, 1967:
TM = 2(SE PY) + A WHERE:
TM = Minimum wall thickness (inches)
P = Dc;ign pressure (PSIG) (From M-601)
Do = outside diameter of pipe (incher)
SE = Maximum allowable stress due to internal pressure and joint efficieny.
(From App. A of B31.1) (PSI)
Y =.4 from code (all our piping is the same)
A=.0625 instr. error plus tolerance Minimum wall thickness values approaching the TM value should be compared to its erosion / corrosion rate to determine how much longer it may operate until repair / replacement of the component is required.
Erosion / corrosion rate may be calculated via:
E/C Rate = Nominal Wall (in) - As-found Wall (in) time in service (months)
B.
Post Examination Requirements 1.
The responsible supervisor should review the data recorded on Attachment (3) to determine if the
_ _ _ _ _ _ - - _ _ - _ _ - _ component is acceptable or rejectable by the following criteria.
T i
T
= Unsat.
g m
T T
= Unsat.
1 m
T T
= R/A 2
m T3 Tm " Y/A T3 T,= Sat.
WHERE:
Tg= Tactual (smallest thickness found)
T
=Tminimum (calculated in Sect.
m VIII.A.)
E/C Rate = Erosion / Corrosion Rate (inches /
month)(calculated in Section VIII.A.)
T
=Tg-(months in one fuel cycle) (E/C 1
Rate) approx. thickness after one fuel cycle T
"TA-(months in two fuel cycles) (E/C 2
Rate) approx. thickness after two fuel cycles T3 g-(months in three fuel cycles)
=T (E/C Rate) approx. thickness after three fuel cycles 2.
If the component is Unsat., the appropriate System Engineer shall be notified that the piping should be repaired / replaced or an engineering evaluation should be made to accept the component.
l-f e 3.
If the component is R/A.(Rei Alert), itl should: be inspected.the next refuelint outage, and if time permits.during any mini out age.
4.
If the component is Y/A (Yellow Alert), it should be-inspected ~the.next refueling outage, but no later than two outages from when it entered the
'Y/A code.
5.
If the component is acceptable, the couplant should be cleaned off, the insulation reinstalled and the. scaffolding removed, if applicable.
IX.
RECORDS & REPORTS A.
A copy of the inspection results for each system should be-sent to the appropriate system engineer within 3 months of the completion of each refueling outage..
B.
A status report on the condition of the secondary
. plant piping should be made to POSRC within 3 months
.I of each refueling outage's completion.
C.
Inspection results should be transferred to Plant History within one year of inspection.
D.
Until transfer to Plant History, records should be controlled by the Performance Engineering Unit.
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ATTACHMENTS (1)' -Line' Number Inspection Data Sheet
-(2)' Inspection Point Data Sheet (3)
Ultrasonic Thickness Measurement Record (4)' Turbine Building Layout j
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1 ATTACHMENT (1)
SECONDARY WALL THICKNESS INSPECTION PROGRAM-u ID#~
GEOMETRY ISOf EXAMINE i
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L ATTACHMENT (2)
SECONDARY WALL THICKNESS INSPECTION PROGRAM DATA SHEET A.
ID#:-
B.
GEOMETRY:
C.
ISO # :.
D.
PIPE SIZE:
E.
'P&ID #:
F.
AREA:
G.
SYSTEM DESCRIPTION:
H.
' LOCATION:
I.
FLOOR ELEVATION:
J.
HEIGHT ABOVE FLOOR:
K.
INSULATION TYPE:
L.
ACCESS:
M. : NOMINAL WALL:-
N.
MINIMUM WALL:
O.
EXAMINATION RESULTS DATE TYPE OF SMALLEST RESULTS EXAMINED EXAM FOLDER #
THICKNESS CODE REMARKS:
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ATTACHMENT (3)'
ULTRASONIC THICKNESS MEASUREMEN? RECORD
- EgIng -
I
.f A.. ID #:
1.-
Show Starting Point-for Inspection Points.-
B.
PIPE DIAMETER:
2.
Show Numbering Sequence-for Inspection Points..
C.
' GRID SPACING:
3.
Show' Component Orientation-
'(e.g.,
Looking Up, Down, D.
MIN THICKNESS FOUND:
North, South,.etc.).To Esta-lish a Frame of Reference.
4.
Attach Printout of Pipe Wall?
Thickness. Measurements
.i
)
r EXAMINER:
DATE:
REPORT REVIEW ~rn:
DATE:
ACCEPT / REJECT:
ALERT (R/Y)
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