ML19309B078
| ML19309B078 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 09/22/1976 |
| From: | SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | |
| Shared Package | |
| ML19309B077 | List: |
| References | |
| NUDOCS 8004020685 | |
| Download: ML19309B078 (5) | |
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RANCHO SECO UNIT I TECHNICAL SPECIFICATIONS Limiting Conditions for Operation 3.12 SAFETY SYSTEMS HYDRAULlC SNUBBERS ApplicabiIIty This specification applies to the operability of safety systems hydraulic shock suppressors during power operation.
Objective To assure that safety related snubbers are cperable to protect the nuclear system during seismic transients when the reactor is operating.
Specification 1.
During power operation all safety-related snubbers listed in Table 4.12-1 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 IIsted on Table 4.12-1.
If the snubber being repaired is not restored to meet the requirements of Specification 4.12 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 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
If the requirements of Specification 4.12 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 1
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 4.12-1 provided that a revision to Table 4.12-1 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 earthquake 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 required to protect the primary coolant system or any other safety system or component be operable within a limited time interval during reactor operation.
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RANCHO SECO UNIT 1 TECHNICAL SPECIFICATIONS Surveillance Standards 4.14 SAFETY SYSTEMS HYDRAULIC SNUBBERS Applicability Tha following surveillance requirements apply as applicable to hydraulic snubbers listed in Table 4.14-1.
Objective To verify that the hydraulic snubbers will perform their design function.
Specification 1.
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 shall include, but not necessarily be limited to, inspection of the hydraulic fluid reservoir, fluid connections and linkage connec-tions to the piping and anchor to verify snubber operability in accordance with the following schedule:
Number of Snubbers Found Inoperable during inspection Next Required or during inspection Interval inspection Interval O'
18 months + 25%
1 12 months T 25%
2 6 months T 25%
3,4 4 months T 25%
5,6,7 2 months T 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 l
schedule.
2.
All hydraulic snubbers whose seal materials are other than ethylene propylene or other material that has been demonstrated to be compatible i
with the operating environment shall be visually inspected for operability monthly.
3 The initial inspection shall be performed within 6 months from the date of issuance of these specifications.
For the purpose of entering the schedule in Specification 4.14.1, it shall be assumed that the facility had been on a 6 month inspection interval.
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RANCHO SECO UNIT 1 TECHNICAL SPECIFICATIONS Surveillance Standards Eximination of defective snubbers at reactor facilities and material tests performed ct several laboratories have shown that millable gum po'lyurethane deteriorates rapidly under the temperature and moisture conditions present in many snubber lecstions. Although molded polyurethane exhibits greater resistance to these ccnditions, it also may be unsuitable for application in the higher temperature environments.
Data are not currently availabic 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 bn performed once each refueling cycle.
These tests will include stroking of the snubbers to verify proper piston movement, lock-up'and bleed.
Ten percent or ten snubbers, whichever is less, represents an adequate sample for such tests.
38 Observed failures on these samples should require testing of additional units.
Those snubbers that have a rated capacity of 50,000 lbs. or greater 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 sarve 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.
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TECHNICAL SPECIFICATIONS surveillance standards TABLE 4.14-1 snubbers Accessible During Power Operations List No.
- 1.D. No.
List No.
1.D. No.
I xx MS 20528 sw 1 30 xx ASW 20024-3A 2 xx MS 20521 SW 11 31 xx 4sw 26101-2 3 xxx Ms 20520 sw 3 32 xx 4sw 26101-6 4 xx Ms 20521 sw 13 33 xx Asw 25023-5A 5 xx Ms 20520 SW 5 34 xx Asw 26101-8A 6 xxx MS 20521 SW 14 35 xx 4sW 25023-8A 7 xx Ms 20520 SW 13A 36'xx Asw 26100-3 8
Ms 20520 sw 6 37 xx 4sw 26100-1A 9 xx Ms 20526 sw 9 38 4sw 26022-13A 10 xx 9sW 30709-3A 39 xx 4sW 26025-43 11 xx 95W 30708-4 40 45W 23620-3A 12 xx 95W 30708-5A 41 xx 4sw 53520-3 13 xx 95W 39709-4 42 xx 4sW 29101-1A 14 xx 9sW 30709-3 101 xxx Ms 20520 SW 19 15 xx SsW 20530-7A 102 xxx Ms.20521 sw 20 16 xx 5sw 20529-3A 103 xxx MS 20521 sw 22 17 SsW 53520-3 104 xx.:
MS 20520 sW 21 18 xx Ssw 32141-1A 105 xx 10 SW 20553-1A 19 SSW 32141-2 106 xx Ssw 20529-1A 20 10 SW 20530-3A 107 xx Ssw 20529-4A-21 xx 12 SW 20530-3A 108 xx Ssw 20530-8 38 22 7sw 32120-18 109 xx 7sw 30800-6 23 xx 7sw 32120-1A 110 xx 7sW 30800-8 24 xx 75W 32120-IC 111 75W 30800-12 25 xx Ms 20550 SW l 112 xx
/sW 30800-14 26 xx MS 20558 SW l 113 xx 7sW 30804-1 27 xx MS 20532 sw 1 114 xx 7sw 30805-2 28 xx Ms 20531 SW l 115 xx SsW 23803-4A 29 75W 32140-2 116 xx 45W 60014-4A a
- Numbers I to 99 designate Bergen-Patterson Units Numbers 101 to 199 designate Grinnel Units PS, P6 and P7 are on the Pressurizer surge Line SS-1 to ss-24 are on the Reactor Coolant Pumps xx -
specification 4.14.4 applies to these snubbers for lockup testing.
Exempt due to a rated capacity of 50,000 lbs. or greater.
xxx i
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/S RANCHO SECO UNIT 1 TECHNICAL SPECIFICATIONS Surveillance Standards TABLE 4.14-1 Snubbers inaccessible During Power Operations List No.
- l.D. No.
List No.
1.D. No.
P5 xx I SW 10' B&W-5 125 xx i SW 21021-3 P6 1 SW 10 BsW-6 126 xx 1 SW 23823-7A P7 1 SW 10" B&W-7 127 xx 1 SW 21025-9A 50 1 SW 20025-3 128 xx 1 SW 21005-8 51 i 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 1 SW 26020-6A 54 xx 1 SW 50060-8A 132 xx 1 SW 20082-12A 55 xx 1 SW 22000-s 133 xx 1 SW 26521-2A 56 xx 1 SW 26021-5A 134 i SW 21025-6 57 xx 1 SW 26021-7A 135 1 SW 23823-13A 58 xx 1 SW 26021-ilA 136 xx i 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 1 SW 23620-15A SS-1 xxx SS-1 62 1 SW 23626-3A SS-2 xxx SS-2 63 1 SW 29122-28A SS-3 xxx SS-3 64 xx 1 SW 29125-7A ES-4 xxx SS-4 38 65 1 SW 29125-7C SS-5 xxx SS-5 66 xx MS 20523 SW2 SS-6 xxx SS-6 67 xx MS 20521 SW17 SS-7 xxx SS-7 68 xx 1 SW 21925-9A
" or xxx SS-8 69 xx 1 SW 50050-2A
.<xx SS-9 70 xx MS 20520 SW 18 ss-lo xxx SS-10 71 xx HS 20522 SW2 SS-Il xxx SS-Il 72 xx 1 SW 50060-3A SS-12 xxx SS-12 73 xx i SW 32140-4 SS-13 xxx SS-13 74 xx 1 SW 32140-2 SS-14 xxx SS-14 75 xx 1 SW 32141-4 SS-15 xxx 55-15 76 xx 1 SW 32141-2 SS-16 xxx SS-16 77 xx 1 SW 50053-2A 55-17 xxx SS-17 117 xx 1 SW 22000-12
.55-18 xxx 55-18 118 xx CW 220uu-zA st-19 xxa 5s-19 119 xx 1 SW 12001-2 5S-20 xxx SS-20 120 1 SW 2?007-7 SS-21 xxx SS-21 121 1 SW 21022-5 55-22 xxx SS-22 122 xx I SW 21006-6A SS-23 xxx SS-23 i
123 xx 1 SW 23626-IA SS-24 xxx SS-24 124 xx 1 SW 21022-1 l
- Numbers I to 99 designate Bergen-Patterson Units Numbers 101 to 199 cesignate Grinnel Units PS, P6 and P7 are on the Pressurizer Surge Line SS-1 to SS-24 are on the Reactor Coolant Pumps xx Specificatiot 4.14.4 applies to these snubbers for lockup testing.
xxx Exempt due * > a rated capacity of 50,000 lbs or greater.
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