ML20155E847
| ML20155E847 | |
| Person / Time | |
|---|---|
| Site: | Perry  |
| Issue date: | 04/15/1986 |
| From: | Edelman M CLEVELAND ELECTRIC ILLUMINATING CO. |
| To: | |
| Shared Package | |
| ML20155E826 | List: |
| References | |
| PROC-860415, NUDOCS 8604180147 | |
| Download: ML20155E847 (22) | |
Text
,,
e a
e SNUBBER AUGMENTED INSERVICE INSPECTION / EXAMINATION AND FUNCTIONAL TESTING PROGRAM FOR PERRY NUCLEAR POWER PLANT UNIT 1 PREPARED BY CLEVELAND ELECTRIC ILLUMINATING COMPANY PERRY, OHIO l
1 8604180147 860415
~
PDR ADOCK 05000440 G
TABLE OF CONTENTS SECTION I - AUGMENTED SNUBBER PROGRAM ARTICLE PAGE INTRODUCTION 1.0 1-1 DEFINITIONS 2.0 1-1 CATEGORIZATION 3.0 1-1 TESTING PERSONNEL QUALIFICATION 4.0 1-2 TABLE l-1, SAMPLE SAFETY-RELATED SNUBBER LISTING FIGURE l-1, SAFETY-RELATED SNUBBER CATEGORIZATION SECTION II - AUGMENTED VISUAL INSPECTION / EXAMINATION INTRODUCTION 1.0 2-1 PROGRAM PLAN INTERVAL 2.0 2-1 DEFINITIONS 3.0 2-2 EXEMPTION CRITERIA 4.0 2-2 INSPECTION / EXAMINATION BOUNDARIES 5.0 2-3 INSPECTION / EXAMINATION REQUIREMENTS 6.0 2-3 INSPECTION / EXAMINATION ACCEPTANCE CRITERIA 7.0 2-3 FIGURES 2-1, 2-2, 2-3 AND 2-4 SECTION III - AUGMENTED FUNCTIONAL TESTING INTRODUCTION 1.0 3-1 PROGRAM PLAN INTERVAL 2.0 3-1 DEFINITIONS 3.0 3-1 PROGRAM SAMPLE PLAN 4.0 3-2 EXEMPTION CRITERIA 5.0 3-3 FUNCTIONAL TEST REQUIREMENTS 6.0 3-3 FUNCTIONAL TEST FAILURE ANALYSIS 7.0 3-3 REPAIR, REPLACEMENT AND MAINTENANCE 8.0 3-4 SNUBBER RELIEF REQUEST SR-1 PERRY UNIT I TECHNICAL SPECIFICATION FIGURE 4.7.4-1 o
l
'g
- .s 9
ION I - AUGMENTED SNUBBER PROGRAM l
I
t L.
1.0 INTRODUCTION
The Perry Nuclear Power Plant (PNPP) Unit 1 Augmented Inservice Snubber Inspection / Examination and Testing Program has been developed to implement both the proposed PNPP Unit 1 Technical Specifications and the ASME Boiler t
and Pressure Vessel Code, 1980 Edition through Winter 1981 Addenda,Section XI Article IWF-5000.
j.
The implementing documents to support this program shall be PNPP approved procedures and instructions. This program description provides the guidelines used to develop these procedures and instructions. The listing of safety-related snubbers (Section I Article.3.0) shall require a 10CFR50.59 applicability check.
2.0 DEFINITIONS AUGMENTED INSERVICE INSPECTION / EXAMINATION AND FUNCTIONAL TESTING PROGRAM (AUGMENTED PROGRAM)
An inservice inspection / examination and testing program which meets additional requirements beyond those of the ASME Boiler and Pressure Vessel Code,- Section XI.
Augmented inspection / examination requirements are established by regulatory authority or other agencies and do not require complete compliance with the ASME Boiler and Pressure Vessel Code,Section XI.
Augmented testing requirements are also established by regulatory or other agencies; these testing requirements shall comply with the ASME Code,Section XI Article IWF-5000, Inservice Test Requirements.
SNUBBER A device (component) which provides restraint to a component or system during a sudden application of force but allows essentially free motion during thermal movement.
TYPE Snubbers of the same design (i.e., mechanical or hydraulic) and manufacturer (e.g. Montek or Pacific Scientific Co.), irrespective of capacity (e.g., 20 kips, 30 kips).
3.0 CATEGORIZATION 4
1 The categorization of PNPP Unit I safety-related snubbers includes conditions and parameters to identify failure analysis groups and develop a representative sampling for visual inspection / examination and functional testing.
Table 1-1 shows a sample from the listing of safety-related snubbers included in the Augmented Program. The information tabulated allows for ease of type indentification and failure mode categorization.
Figure 1-1 provides the snubber classification numbers which identify type, accessibility, capacity, service, environment and vibration.
1-1
-s -
Table 1-1 Format 1.
Mark Number - identifies the Unit, System, and unique hanger number.
EXAMPLE:
1821-H0005 (Unit 1, Nuclear Boiler System, Hanger No.5) 2.
Class - identifies the ASME code classification associated with the snubber.
i EXAMPLE:
1 (ASME Class 1 Hanger)
NOTE: Class 5 represents nonsafety-related snubbers used to support a safety-related system.
3.
Size - Provides the type and capacity of snubber.
EXAMPLE: PSA10 (Mechanical, 15 kip).
4.
Location - provides the building, elevation and column or azimuth.
i EXAMPLE:
D, 609, 61 (Drywell, 609 Feet, 61 Degrees).
5.
Accessibility - identifies if the snubber is accessible during normal plant operation.
i d
EXAMPLE: N (NO).
I 6.
Categorization - provides a unique set of integers for grouping l
snubbers ( see Figure 1-1).
i 4.0 TESTING PERSONNEL QUALIFICATION Personnel making the observations, measurements, and recording the results 7
required by Article IWF-5000 Inservice Test Requirements shall be qualified in accordance with the owner's (CEI) Quality Assurance Program 4
for training and qualification of plant and contractor personnel. The Quality Assurance Program shall require routine surveillances to be performed by quality control personnel, who should be certified VT-3/VT-4, during snubber testing.
Personnel qualification / certification for performance of ASME Code,Section XI examinations (i.e., visual, surf ace, and volumetric) shall be in accordance with the ASME Code Section XI, Article IWA-2000 Examination and Inspection.
NOTE: ASME Code Section XI, Interpretation: XI-1-82-06R was used for the I
snubber testing program divelopment: "The qualification of 3-individuals making the observations and. measurements and recording the results required by Subsections IWP and IWV shall be in accordance with the Owner's Quality Assurance program for training and qualification of plant and contractor personnel." 2
TABLE I Sample Safety-Related Snubber Listing (Approximately 1800 Total)
Location Y/N Mark Number Class Size Bldg.
Elev.
Col /Az Access. Categor.
IB21-H0002 3
PSA35 D
615 53 N
226221 IB21-H0004 3
PSA35 D
612 65 N
226221 1821-H0005 3
PSA10 D
609 61 N
225221 IB21-H0006 3
PSA35 D
611 65 N
226221 IB21-H0007*
3 PSA10 D
605 58 N
225221 IB21-H0009*
3 PSA3 D
620 67 N
224221 IB21-HC010*
3 PSA35 D
620 70 N
226221
)
IB21-H0012 3
PSA10 D
617 76 N
225221 IB21-H0013 3
PSA35 D
615 76 N
226221 IB21-H0014 3
PSA10 D
607 76 N
225221 IB21-H0015 3
PSA10 D
625 247 N
225221 IB21-H0020*
3 PSA35 D
602 98 N
226221 1B21-H0021 3
PSA10 D
615 90 N
225221 IB21-H0022 3
PSA35 D
610 98 N
226221 1B21-H0023 3
PSA10 D
615 98 N
225221 l
PSA10 D
615 98 N
225221 IB21-H0025*
3 PSA10 D
625 244 N
225221 IB21-H0029*
3 PSA35 D
605 274 N
226221
~~
IB21-H0031 3
PSA10 D
615 274 N
225221 IB21-H0032 3
PSA35 D
611 265 N
226221 IB21-H0033 3
PSA10 D
613 265 N
225221 IB21-H0038 3
PSA35 D
620 306 N
226221 IB21-H0039 3
PSA35 D
615 286 N
226221 IB21-H0040 3
PSA35 D
613 283 N
226221 IB21-H0041 3
PSA35 D
610 283 N
226221 1B21-H0042*
3 PSA10 D
605 292 N
225221 IB21-H0043 3
PSA10 D
616 259 N
225221 IB21-H0045 3
PSA10 D
621 274 N
225221 1B21-H0046 3
PSA10 D
620 266 N
225221 IB21-H0047 3
PSA35 D
620 263 N
226221 IB21-H0048 3
PSA35 D
614 256 N
226221
)-
IB21-H0049*
3 PSA35 D
608 256 N
226221 IB21-H0051*
3 PSA10 D
625 220 N
225221
~
IB21-H0054*
3 PSA10 D
604 21 N
225221 i
PSA10 D
615 22 N
225221 1B21-H0057 3
PSA35 D
615 13 N
226221 IB21-H0058 3
PSA35 D
612 13 N
226221 IB21-H0059 3
PSA10 D
612 13 N
225221 IB21-H0060 3
PSA3 D
618 202 N
224221 IB21-H0063*
3 PSA10 D
604 346 N
225221 IB21-H0064 3
PSA35 D
615 340 N
226221
- Denotes: Multiple snubbers on the support 1-3 i
!I 1l l
lI
'llll l
Ill ll l'
c i
lua r
d y
0
/
10
/
H
/ 0 E
l
/0 a
la 5
2 L
L A
c 1
5 1
E B L
n 5 6 7 L
I C A o
E l
S S C
B i
i S
C r
I l
IL I
O n S
L I
t L
1 V
I a 0 0 0 0
$E U N c
e W F
F f
R T h 2 3 5 7 S C A A n
t u
C c /f((
O C
E E C R H f
0 0 O 0 S N e 5
C A D C 2
2 2 2 N U M 3 6 5 6 C N Y E s
F 0 0 A.
H.
M.
p
< 2
< 1
. S 1
l I
i 2 3 4 2
2 2
2 P 2
I 1
l f
1 1
k I
K 0
5 H
N T
e O
6 e
l I
b T
i DA s
EZ H
s 1
TI e
AR T
l c
LO 5
gg$ 2 e c
4 E EG a
1 R RE wm$* z5 hm n
U - T i
G YA H
I TC F E T
c 4
ehmE ozy$ySZm5 Ti i
FR AE l
SB u
B as U
D rl N
R di S
ym 3
eh h
0 s2 na<
en 2
> >s*
F 1
- 20 20 32 T
2 1
S wj I
ELP M
AXE
6 9
6 e
SECTION II - AUGMENTED VISUAL INSPECTION / EXAMINATION h
3 l
N l
1.0 INTRODUCTION
This section provides the augmented visual inspection / examination requirements to comply with PNPP Unit 1 Technical Specification 4.7.4.
The portions of Technical Specification 4.7.4 covered are:
a.
Inspection Types b.
Visual Inspections c.
Visual Inspection Acceptance Criteria d.
Transient Event Inspection i
h.
Functional Testing of Repaired and Replaced Snubbers 2.0 PROGRAM PLAN INTERVAL The Snubber Visual Inspection / Examination Interval must comply with the 9*
following frequencies:
1.
All safety-related snubbers shall be inspected / examined after four months but within ten months of commencing power operation.
2.
Inspections / examinations shall be conducted prior to (as-found) and after (as-left) performance of repairs, replacement or testing of a safety-related snubber.
3.
A sample of 10% of snubbers shall be inspected / examined during the first refueling outage and at the frequencies provided within these guidelines:
NO. INOPERABLE SNUBBERS SUBSEQUENT VISUAL OF EACH TYPE INSPECTION PERIOD 0
18 months.+ 25%
1 12 months][25%
2 6 months + 25%
3,4 124 days][25%
5,6,7 62 days + 25%
j 8 or more 31 days + 25%
NOTE:
The inspection interval for each type of snubber shall I
not be lengthened more than one step at a time unless a generic problem has been identified and corrected; in that event the inspection interval may be lengthened one step the first time and two steps thereaf ter if no inoperable snubbers of that type are found.
When performing increased frequency inspection /
)
examinations consideration shall be given to failure location (i.e., accessible or inaccessible).
4.
All snubbers attached to sections of systems that have experienced unexpected or potentially damaging transients shall be inspected /
examined (accessible systems within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or inaccessible systems within six months).
2-1
.,e r
p-9 y
i i
s e
i 3.0 DEFINITIONS
)
AS-FOUND The condition of a snubber as it exists is the sytem prior to any preventive maintenance, corrective maintenance, or disassembly to perform
)
testing.
AS-LEFT The condition of a snubber as it exists in the system after any preventive maintenance, corrective maintenance, or disassembly to perform testing.
EXAMINATION Denotes the performance of a visual observation in which the examiner shall be qualified by the owner or his agent in accordance with the comparable levels of competency as defined in ANSI N45.2.6-1973 and/or 1978.
FUNCTIONAL ADEQUACY A visual examination to confirm operability by verification of the settings or freedom of motion.
INACCESSIBLE SNUBBERS Those snubbers that are in a high radiation area or other conditions that would render it impractical for the snubbers to be examined during reactor operation without endangering perscnnel.
INSPECTION Denotes the performance of a visual observation in which the inspector shall be qualified by the owner or his agent in accordance with the competency levels of SNT-TC-1A or ANSI N45.2.6-1978.
SNUBBER DEVICE (FASTENERS)
A device used to secure the snubber to the component or structure (i.e.,
bolting, nuts, rtuds, and cotter pins).
TRANSIENT EVENT An unexpected or potentially damaging occurence which was determined from review of operation data or during a visual inspection / examination.
4.0 EXEMPTION CRITERIA Only snubbers not attached to safety class syster.s (ASME 1, 2, or 3) or not considered in the design as supporting a safety class system are exempt from the visual inspection / examination requirements.
2-2 e
-e,
,.w,-y--
o-.,~
n,-,,,
---r--
e-,,
's 5.0 INSPECTION / EXAMINATION BOUNDARIES The visual inspection / examination boundaries shall include the snubber and the attachment snubber devices (reference Figures 2-1,2-2,2-3,' and 2-4).
J 6.0 INSPECTION / EXAMINATION REQUIREMENTS i
i 1.
To verify the general mechanical and structural condition of the j
snubber and snubber attachment devices.
Conditions can be verified by checking for loose parts, debris, or abnormal corrosion products, wear, erosion, corrosion, and the loss of integrity a' bolted or welded connections.
1 2.
To ensure operability of the snubber by confirming functional adequacy, verification of settings, or freedom of motion.
7.0 INSPECTION / EXAMINATION ACCEPTANCE CRITERIA During the visual inspection / examinations, recorded indications can be placed into three categories of which one category is rejectable and the other two are acceptable. The categories are: inoperable (rejectable),
operable relevant (acceptable) and operable nonrelevant (acceptable).
1.
Icoperable indications:
- b. ARC strikes, weld spatter, roughness, general corrosion, paint, scoring on close-tolerance machined or sliding surfaces.
- d. Improper hot or cold settings (causing the snubber to top or bottom out during service).
- e. Lack of fluid indication (hydraulic snubber only).
2.
Operable Relevant:
- a. Detached, loosened, or missing locking devices.
- b. Incorrect or missing identification tags.
- c. Damaged or bound spherical bearings.
- d. Thread engagement less than flush.
j
- e. Fluid loss below 70% (hydraulic snubber only).
3.
Operable Nonrelevant:
- a. Weld spatter, scratches, or surf ace abrasion marks on other than close tolerance machined or sliding surfaces.
- b. Roughness or general corrosion showing no visible evidence of snubber or snubber attachment device weakening.
- c. Fabrication marks.
- d. Chipped or discolored paint resulting from other than actual snubber degradation.
- e. Others - as the visual inspector / examiner feels are necessary to record.
2-3
/
IWF supponT sxau antiwnAQY
.g A
A A
/
A B::::=.:3 u
e ny 3
cr2 m Zr 00 i.e..
oyg
's
^-
E h
a r
(:..-.-.:.0 SNUBBER g
o A
g i
-- {
O w
B IWB,1WC,1WD A-A-SNUB 8ER ATTACHMENT EXAM BOUNDARY DEVICE
/
8-LOCKING DEVICE AUGMENTFD EXAM BOUNDARY 1
\\
?"
EGYR RN UI A SND SA N s
I ET U j
REO g
'ii
/
j
's 8
1 '
l
's Ag YRADN T
U N
O B
E b
M h
M H
E l'
A C
C X
A R
I E
M T
V E
T E
B A
T A
D B
XY R
E R
G U
R O
EE N N
DA P
P S
D U
BC I
E BI K
TN S
U V C NU NE O EO F
SD L MB W
G A
B U
I A
A
[
B, A/.
~:
=
/
j ySQ2$
eES 5D
, A gg" e
e
){
g" T
EG N E
RN I
N UNO SISAP ETM s
,'l A
YR A
AD T
N N
U E
O M
B H
E M
C C
A M
s A
X A
e I
t T
V E
X
\\
T E
y A
D p
E
\\
\\
h T
R G
R O
E E NI ER 8 C K P
6I B %
P UV C B
U NE O U
S SD L N
8 S
A F
A 8 A
-M
]_*-
W I
l A
(-
B
/
b,D3$4 GBab
? h 8-e O
i i i
~A
${a[5o w$yw@
'v e
- .o l
Ak' '
t DW YR 1,M A
~
A C A D
~
WXN l,E U B O M
~
W B
A X
I YD E
YR A
R n A D
E F D N
B T N l
B N U l
O U
F O R
N M B S
G M
B U
A A
A M
g XF T
J Y(
R
~
O
~
P E
6
)E P
T R
J t
I R
N W
E
(
M F
E H
C W
C I
A V
T E
I T
D A
R G
EE N
0C I
BI K
UV C
NE O
SD L
A B
_._~ A
/
_ W3o3sw.L l
J
$oda 7"ygE pe 4
I e
e 4
SECTION III - AUGMENTED FUNCTIONAL TESTING t
u
1.0 INTRODUCTION
This section provides the augmented functional test requirements to comply with ASME Boiler Pressure Vessel Code,Section XI, Article IWF-5000 and the augmented tests of PNPP Unit 1 Technical Specification 4.7.4.
The portions of Technical Specification 4.7.4 covered are:
e - Functional Tests
)
f - Functional Test Acceptance Criteria g - Functional Test Failure Analysis h - Functional Testing of Repaired and Replaced Snubbers 2.0 PROGRAM PLAN INTERVAL The snubber testing interval must comply with the following f requencies:
1.
During the first refueling shutdown and at least once per 18 months thereafter during shutdown a representative sample of snubbers shall be tested. Additional snubbers shall be tested as necessary to comply with the sample plan selected.
~
2.
A snubber installed in place of a failed snubber shall be retested at the time of the next functional test.
3.
Snubbers being used as a replacement shall have been tested prior to installation (manufacturer / vendor test data is acceptable for initial service).
?
4.
Snubbers identified as inoperable during the augmented visual inspection / examination may be tested to verify operability.
5.
Repaired snubbers shall be tested prior to installati'on.
3.0 DEFINITIONS ACTIVATION ACCELERATION A distinct acceleration for mechanical snubbers which is usually characterized by an abrupt increase in resistive force or reduction in displacement.
ACTIVATION VELOCITY A distinct velocity for hydraulic snubbers which is usually characterized by an abrupt increase in resistive force or reduction in displacement BREAKWAY FORCE The minimum applied force required to initiate extension or retraction of the snubber.
\\
3-1
i i
DRAG FORCE The force required to maintain the snubber movement at a constant velocity prior to activation.
FUNCTIONAL TESTING An inplace or bench test exercising of a snubber while measuring and observing the required parameters in Article 6.0.
i HYDRAULIC SNUBBER A device which provides restraint to a component or system during a sudden application of force in which the load is transmitted through a hydraulic fluid. The device shall allow essentially free motion during thermal movement.
MECHANICAL SNUBBER A device which provides restraint to a component or system during a sudden application of force in which the load is transmitted entirely through mechanical parts. The device shall allow essentially free motion during thermal movement.
RELEASE RATE 1
The velocity of snubber movement under load after activation takes place.
ZERO DISPLACEMENT Snubber having a required rigid lockup upon activiation velocity.
4.0 PROGRAM SAMPLE PLAN A representative sample of snubbers shall be tested using one of the following sample plans for each type of snubber.
1.
At least 10% of the total of each type of snubber is functionally tested either in place or on a bench tester. For each snubber of,e type that fails the acceptance criteria, an additional sample of 1GI-of the total number of that type of snubber is tested until no more i
failures are found or until all snubbers of that type have been tested.
2.
A representative sample of each type of snubber is tested in accordance with Technical Specification Section 4.7.4e(2) and Figure 4.7.4-1.
When test results lie within the " continue testing" region, additional snubbers of that type are tested until the point f alls in the " accept" region or the " reject" region, or all the snubbers of that type have been tested.
3.
An initial representative sample of 55 snubbers of each type is tested. For each snubber type which does not meet the acceptance 3-2
criteria, another sample of at least one-half the size of the initial sample is tested until test results fall on or below the " accept" line generated by the equation N=55(1+C/2) or all the snubbers of that type have been tested.
5.0 EXEMPTION CRITERIA I
Only snubbers not attached to safety class sytems (ASME 1, 2 or 3) or not j
considered in the design as supporting a safety class system are exempt from the functional testing reqirements.
6.0 FUNCTIONAL TEST REQUIREMENTS l
Testing requirements shall -xercise the snubber while measuring or observing the following parameters important to operability.
1.
Mechanical Snubber PNPP UNIT 1 ASME CODE PARAMETER TECH. SPEC.
ARTICLE IWF-5000 Breakway/ Drag Force 4.7.4.f.3)
IWF-5400(b)(1)
Activation Acceleration 4.7.4.f.1)
IWF-5400(b)(2)
Release Rate N/A IWF-5400(b)(3)
!l 2.
Hydraulic Snubber PNPP UNIT 1 ASME CODE PARAMETER TECH. SPEC ARTICLE IWF-5000 Activatica Velocity 4.7.4.f.1)
IWF-5400(b)(2)
Ble:d/ Release Rates 4.7.4.f.2)
IWF-5400(b)(3)
'Zero Displacement 4.7.4.f.4)
IWF-5400(b)(3)
(if applicable) 7.0 FUNCTIONAL TEST FAILURE ANALYSIS 1.
An analysis shall be performed for all snubbers not meeting the acceptance criteria to determine the cause of failure. The analysis shall include a comparison of f ailure rate to categorization group.
2.
Data gained from previous visual inspection / examination of snubbers may be used when performing the functional test f ailure anlaysis.
t 3.
Based on the results of an anlaysis failure mode groups sha?. be developed. The groups used at PNPP are; isolated, design / manufacturing, application induced and unexplained.
- a. Isolated-Failure: Failures resulting from damage caused during installation or maintenance (e.g., dropping tools or equipment on the snubber, using the snubber as a hoist point). This type of failure can be directly attributed to a known single event and is not an indicator of possible generic snubber problems.
j
- b. Design / Manufacturing Failure - Failures resulting from a potential defect in manufacturing and/or design that gives cause to suspect other similar components (e.g., mechanical seal failure, clamp ring 3-3
)
j l
I degradation). This includes failures of any snubber that fails to withstand the environment or application for which it was designed.
- c. Application Induced Failures - Failures resulting from environ-mental conditions for which the snubber has not been designed or qualified. These failures may occur because of repetitive j
excessive cyleing which was not anticipated (e.g., water hammer, flow induced vibrations, valves being rapidly cycled).
- d. Unexplained Failures - Failures that cannot be categorized as isolated, design /manuf acturing or application induced. This i
includes all failures for which the cause of f ailure cannot be determined.
4.
After the f ailure mode has been determined a course of action will be established. The additional sampling tor other than design /
manuf acturing failures must include a sample of the same category that has failed.
5.
For a snubber found inoperable, an evaluation shall be performed on i
the component to which the inoperable snubber is attached. The l
evaluation shall determine if the component (e.g., vessel, pump, valve, or piping system) to which the inoperable snubber is attached-was adversely affected by the inoperability of the snubber.
6.
A snubber that fails to lock up or fails to move (i.e.,
frozen-in place) shall have the cause determined.
If caused by manuf acturer or design deficiency all snubbers of the same type and subject to the same defect (NOTE: Reference PNPP categorization for type and capacity) shall be functionally tested. This testing requirement shall be independent of the requirement for additional j
testing by sample plan.
i 8.0 REPAIR, REPLACEMENT AND MAINTENANCE 1.
Snubbers may require preventive maintenance (e.g., replace seals or 4
spring at service life), repairs, or replacement upon failure to meet the functional testing acceptance criteria. Replacement snubbers or snubbers which have undergone repair or maintenance which might have affected the functional test results shall be tested to meet the
-)
functional test criteria before installation. Mechanical snubbers
)
shall have met the acceptance criteria subsequent to their most recent service, and the f reedom-of-motion test must have been performed within 12 months before being installed.
2.
Service life of all snubbers shall be monitored to ensure that the service life is not exceeded between surveillance inspections. The maximum expected service life for various seals, springs, and other l
critical parts shall be extended or shortened based on monitored test results and failure history. Critical parts shall be replaced so that j
the maximum service life will not be exceeded during a period when the i
snubber is required to be operable.
3-4 i
.. -.. I
'e RELIEF REQUEST # SR-1 SYSTEM: All COMPONENTS: Hydraulic and Mechanical Snubbers 4
CLASS: All
)
FUNCTION:
To provide a restraint to a component or system during a sudden application of force but allow essentially f ree motion during thermal movement.
TEST REQUIREMENT:
IWF-5400(b) Inservice tests for snubbers less than 50 kips-a representative sample of 10% of the total number of nonexempt (IWF-1230) anubbers whose load rating is less than 50 kips shall be tested each inspection period.
IWF-5400(c) - An additional sample of 10% of the total number of snubbers shall also be tested at that time.
BASIS FOR RELIEF: The PNPP Unit 1 Technical Specification Bases 3/4.7.4 and Section 4.7.4.e prescribe one of three sampling methods to select snubbers for functional testing. The methods used and stated acceptance criteria are:
1.
Functionally test 10% of each type of snubber with an additional 10% tested for each functional testing failure, or, l
2.
Functionally test a sample size and determine sample acceptance or rejection using Technical Specification Figure 4.7.4.-1, or 3.
Functionally test a representative sample size and determine sample acceptance or rejection using the stated equation.
PNPP Unit 1 Technical Specification Figure 4.7.4-1 was developed using "Wald's Sequential Probability Ratio Plan" as described in " Quality Control and Industrial Statistics" by Acheson J. Duncan.
ALTERNATE TESTING: During the first refueling shutdown and at least once per i8 p
months thereafter during refueling, a representative sample of snubbers shall be tested using one of the Technical Specification sample plans for each type of snubber. The rample plan shall be selected prior to the test period and cannot be changed during the test period. The NRC Regional Administrator shall be notified in writing of the sample plan selected prior to the test period, or the sample plan used in the prior test period shall be implemented.
LT
9 PERRY UNIT 1 TECHNICAL SPECIFICATIONS 10 9
8 REJECT
/
e l
e ' / /.o
/
e.
/
4
[
CONTINUE
/
TESTING -
/
/
01 /
/
1 ',/
\\
ACCEPT cf 1
e
/
j 0
10 20 30 40
.0 60 70 80 90 100 N
.i SAMPLE PLAll 2) FOR SNUBBER FUNCTIONAL TEST Figure 4.7.4-1 i
.._ _ ___ _ _ _.,__. _ ____.._._ __. _ _ _ _ _. _ _ __ _