ML19319E128
| ML19319E128 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 10/06/1976 |
| From: | SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | |
| Shared Package | |
| ML19319E125 | List: |
| References | |
| NUDOCS 8003310635 | |
| Download: ML19319E128 (6) | |
Text
..
.~
n.
RAf1CHO SECO UNIT I TECHNICAL SPECIFICATl0llS Limiting Conditions for Operation 3.12 SAFETY SYSTEMS HYDP,AULIC SNUBBERS ApplicabiIity This specification applies to the operability of safety systems hydraulic shock suppressors during power operation.
Obj ect Ive To assure that safety related snubbers are operable to protect. the nuclear system during seismic transients when the reactor is operating.
Snecification 1.
During power operation all safety-related snubbers listed in Table h.14-1 shall be operable, except as noted in 3.12.2 through 3.12.4 below.
2.
If the requirements of 3.12.1 cannot be met, maintenance shall be allowed during power operation on any safety related snubber listed on Table 4.14-1.
If the snubber being repaired is not restored to meet the requirements of Specification 4.14 within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, the reactor shall be placed in a hot shutdown condition within 12 hotirs.
If the requirements of Specification 4.14 are not met within an additional 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, the reactor shall be placed in a cold shutdown condition within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
3 If a snubber is determined to be Inoperable while the reactor is in the cold shutdown, hot shutdown or refueling shutdown mode, the snubber shall be made operable or replaced prior to reactor startup.
4.
Snubbers may be added to safety related systems without prior NRC License Amendments to Table 4.14-1 provided that a revision to Table 4.14-1 is included with the subsequent License Amendment request.
Bases Snubbers are designed to prevent unrestrained pipe motion under dynamic loads as might occur during an carthquake or severe transient, while allowing normal thermal motion during startup and shutdown.
The consequence of an inoperable snubber is an increase in the probability of structural damage to piping as a result of a seismic or other event initiating dynamic loads.
It is therefore required that all hydraulic 38 snubbers requi.ed to protect the primary coolant system or any other safety system or component be operable within a limited time interval during reactor operation.
8003310 [ [
Proposed Amendment No. 38 3-50
r' RANCHO SECO UNIT I TECHNICAL SPECIFICATIONS Surveillance Standards 4.14.
SAFETY SYSTEMS' HYDRAULIC SNUBBERS 3
Applicability k
i The following surveillance requirements apply as applicable to hydraulic snubbers i
listed in Table 4.14-1.
Objective To verify that the hydraulic snubbers will perform their design function.
i l, -
Specification i
l'
.l.
All hydraulic snubbers'whose seal material has been demonstrated by operating experience, laboratory testing or analysis to be compatible with the operating environment shall be visually inspected.
This inspection s'.11 include inspection of the hydraulic fluid reservoir l
level, fluid connections and linkage connections to the piping and anchor for integrity in accordance with the following re.hedule:
Number of Snubbers Found Inoperable During inspection Next Required Or.During inspection interval Inspection Interval 0
18 months + 25%
1 12 months i 25%
2 6 months 17 25%
3,4 4 months IF 25%
5,6,7 2 months 17 25%
_,8 1 month [25%
The required inspection interval shall not be lengthened more than one step.at a time.
Snubbers may be categorized in two groups, " accessible" or " inaccessible" based on their accessibility.for inspection during reactor operation.
These two groups may be inspected independently according to the above
- schedule, f
2.
All hydraulic snubbers whose seal materials are other than ethylene propylene.or material that has been demonstrated to be compatible with the operating environment, shall be visually inspected for. operability monthly'.
1
~3
.The-initial inspection shall.be performed within 6 months from the dato.
of issuance of-these specifications.
For the-purpose of entering the
~
sche'dule.in Specification 4.14.1, it shall be assumed that the facility
.had been on a 6' month' inspection interval.
Proposed Amendment No. 38 A-h3
.c RANCHO SECO UNIT 1 TECHNICAL SPECIFICATIONS Surveillance Standards 4.
Once each refueling cycle, a representative sample of 10 bydraulic snubbers or approximately 10% of the hydraulic snubbers, whichever is less, shall be functionally tested for operability including verification of proper piston movement, lock up and bleed.
For each unit and subsequent unit found in-operable, an additional 10% or ten hydraulic snubbers of the same brand make as the' failed snubber shall be so tested until no more failures are found or all units of that brand have been tested.
Snubbers of rated capacity greater than 50,000 lbs. and snubbers designated in Table 4.14-1 as especially difficult to remove or in high radiation area during shutdown need not be functionally tested.
5 If, during the functional testing required by 4.14-4, defects are disclosed which cannot clearly be attributed to assembly errors or workmanship, the functional testing will continue. Otherwise, af ter all snubbers of the given brand required to be functionally tested by 4.14-4 have been tested two times without failure, the requirements of Paragraph 4.14-4 will be discontinued.
BASES:
Hydraulic Snubbers All safety related hydraulic snubbers are visually inspected for overall integrity and operability. The inspection will include verification of proper orientation, 38 adequate hydraulic fluid level and proper attachment of snubber to piping and structures.
The inspection frequency is based upon maintaining a constant level of snubber protection. Thus thu required inspection interval varies inversely with the observed snubber failures.
The number of iroperable snubbers found during a required inspection determines the time interval for the next required inspection.
Inspections performed before that interval has elapsed may be used as a new reference point to determine the next inspection.
However, the resul ts of such early inspections performed before the original required time interval has elapsed (nominal time less 25%) may not be used to lengthen the required inspec-tion interval.
Any inspection whose results require a shorter inspection interval will override the previous schedule.
Experience at operating facilities has shown that the required surveillance program should assure an acceptable level of snubber performance provided that the seal roterials are compatible with the operating environment.
Snubbers containing seal material which has not been demonstrated by operating experience, lab' tests, or analysis to be compatible with the operating environm2nt should be inspected more frequently (every month) until material compatibility is confirmed or an appropriate changeout is completed.
\\
Proposed Amendment No. 38 4-47a
RANCHO SECO UNIT I TECHNICAL SPECIFICATIONS Surveillance Standards Enamination of defective snubbers at reactor facilities and material tests performed at several laboratories have shown that millable gum polyurethane deteriorates rapidly under the temperature and moisture conditions present in many snubber locations. Although molded polyurethane exhibits greater resistance to these conditions, it also may be unsuitable for application in the higher temperature environments.
Data are not currently nvailable to precisely define an upper temperature limit for the molded polyurethane.
Lab tests and in plant experience indicate that seal materials are available, primarily ethylene propylene compounds, which should give satisfactory performance-under the most severe conditions expected in reactor installations.
To further increase the assurance of snubber reliability, functional tests should be performed once cach refueling cycle. These tests will include stroking of the snubbers to verify proper piston movement, lock-up and bleed.
Ten percent or ten 38 snubbers, whichever is less, represents an adequate sample for such tests.
Observed failures on these samples should require testing of additional units.
Those snubbers that have a rated capacity of greater than 50,000 lbs. and snubbers designated in Table 4.14-1 as being in high radiation areas or especially difficult to remove need not be selected for functional tests provided operability was previously verified.
Since the type of snubber failures observed in recent functional test programs relate to assembly errors or poor workmanship at time of assembly, the functional test program will serve no useful purpose once the adequacy of this work for a given brand of snubber has been verified. Therefore, the functional test program may be discontinued after two successful test cycles of all eligible snubbers provided no other failure modes are disclosed.
Proposed Amendment No. 38 m
l s.
.r.
RANCHO SECO UNIT I l
TECHNICAL SPECIFICATIONS surveillance standards TABLE 4.14-1 snubbers Accessible During Power Operations List No.
l.D. No.
List No.
l.0. No.
I xx Ms 20528 sW I 30 xx 4 sw 20024-3A 2 xx Ms 20521 sw 11 31 xx 4 su 26101-2 3x Ms 20520 su 3 32 xx 4 SW 26101-6 4x Ms 20521 SW 13 33 xx 4 sW 25023-5A 5 xx Ms 20520 SW 5 34 xx 4.sw 26101-8A 6x Ms 20521 SW 14 35 xx 4 SW 25023-8A 7x Ms 20520 SW 13A 36 xx 4 SW 26100-3 8x Ms 20520 sw 6 37 xx 4 sW 26100-1A 9 xx Ms 20526 sW 9 38 x 4 SW 26022-13A 10 xx 9 sW 30709-3A 39 xx 4 sw 26025-43 11 xx 9 sw 30/08-4 40 x 4 sw 23620-3A 12 xx 9 SW 30708-5A 41 xx 4 sW 53520-3 13 xx 9 SV 39709-4 42 xx 4 sw 29101-1A 4
14 xx 9 sw 30709-3 101 xxx MS 20520 sw 19 15 xx 5 sw 20530-7A 102 xxx Ms 20521 SW 20 16 xx 5 SW 20529-3A 103 xxx Ms 20521 SW 22 17 x 5 SW 53520-3 104 xxx Ms 20520 SW 21 18 xx 5 sW 32141-1A 105 xx 10 SW 20553-1A l
19 x 5 sw 32141-2 106 xx 5 sW 20529-lA 20 x 10 sw 20530-3A 107 xx 5 sW 20529-4A 21 xx 12 SW 20530-3A 108 xx 5 su 20530-8 22 x 7 su 32120-1B 109 xx 7 sw 30800-6 23 xx 7 SW 32120-1A 110 xx 7 sW 30800-8 24 xx 7 SW 32120-1C 111 x 7 sW 30300-12 25 xx Ms 20550 sW l 112 xx 7 SW 30800-14 26 xx MS 20558 sW l 113 xx 7 sw 30804-1 27 xx MS 20532 SW I 114 xx 7 SW 30805-2 28 xx Ms 20531 SW l 115 xx 5 su 23803-4A 29 x 7 SW 32140-2 116 xx 4 sw 60014-4A x Designates snubbers difficult to remove or in a high radiation area
-xx specification 4.14.4 applies to these snubbers for lockup testing xxx Exempt due to a rated capacity of greater than 50,000 lbs.
Proposed Amendment No. 38
,..y
/
RANCHO SECO UNIT I TECHNICAL SPECIFICATIONS Surveillance Standards TABLE.4.14-1 i.
Snubbers inaccessible During Power Operations 4
-List No.
l.D.~No.
List No.
l.D. No.
i P5 xx I SW 10' B&W-5 125 xx 1 SW 21021-3 P6 x-
'l SW 10 B&W-6 126 xx 1 SW 23823-7A 2
.1 SW 20025-3
- 127 xx 1 SW 21025-9A 128 xx 1 SW 21005-8 51 x 1 SW 20025-1A 129 xx 1 SW 23822-7B 52 xx 1 SW 26020-5A.
130 xx 1 SW 21028-2 53 xx 1 SW 26524-4A 131 x 1 SW 26020-6A 54 xx i SW 50060-8A 132 xx 1 SW 20082-12A-55 xx 1 SW 22000-9 133 xx 1 SW 26521-2A 56 xx 1 SW 26021-5A 134 x 1 SW 21025-6 r
57 xx
-1 SW 26021-7A 135 x 1 SW 23823-13A 58 xx 1 SW 26021-llA 136 xx 1 SW 21501-20
- 59 xx
-1 SW 50063-2A 137 xx 1 SW 21501-28 60 xx 1 SW 23823-8 138 xx 1 SW 50050-6A 61 x 1 SW 23620-iSA SS-1 xxx SS-1 62 x 1 SW 23625-3A SS-2 xxx SS-2 63 x 1 SW 29122-28A SS-3 xxx SS-3 64 xx 1 SW 29125-7A SS-4 xxx SS-4 38 65 x 1 SW 29125-7C 55-5 xxx SS-5 66 xx MS 20523 SW2 55-6 xxx SS-6 67 xx MS'20521.SWl7 SS-7 xxx SS-7
'68 xx 1 SW 21925-9A SS-8 xxx SS-8 69 xx 1 SW 50050-2A SS-9 xxx SS-9 70 xx
.MS 20520 3W 18 SS-10 xxx SS-10 71 xx MS 20522 SW2 SS-11 xxx 55-11 72 xx 1 SW 50060-3A SS-12 xxx SS-12 73 xx 1 SW 32140-4 SS-13 xxx SS-13 74 xx 1 SW 32140-2 5S-14 xxx SS-14 75 xx 1 SV 32141-4 SS-15 x 55-15 76 xx 1 SW-32141-2 SS-16 xxx SS-16 77 xx 1 SW 50053-2A SS-17 x SS-17 117 xx l SW 22000-12 SS-18 xxx SS-18 118 xx 1 SW 22000-2A SS-19 xxx SS-19 119 xx 1 SW 22001-2 SS-20 xxx SS-20 120 x 1-SW 21007-7 SS-21 xxx SS-21 i
121.x l'SW 21022 SS-22 x SS-22 122'xx_
l SW 21006-6A SS-23 xxx SS-23 1231xx l'SW 23626-1A SS-24 xxx SS-24 124 xx I SW 21022-1 x Designates snubbers difficult to remove or in a high radiation area xx Specification 4.14.4 applies to these snubbers for lockup testing xxx Exempt;due to a rated' capacity of-greater than 50,000.lbs.
Proposed Amendment No. 38' 4-47d