ML18347A551

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Transmitting Proposed Change to Tech Spec Concerning Operability & Surveillance Requirements for Hydraulic Shock Suppressors
ML18347A551
Person / Time
Site: Palisades Entergy icon.png
Issue date: 10/08/1976
From: Bixel D
Consumers Power Co
To: Schwencer A
Office of Nuclear Reactor Regulation
References
Download: ML18347A551 (11)
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Text

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consumers

  • Power company General Offices: 212 West Michigan Avenue, Jackson, Michigan 49201
  • Area Code 517 788-0550 October 8, 1976 Director of Nuclear Reactor Regulation Att: Mr Albert Schwencer, Chief Operating Reactor Branch No 1 US Nuclear Regulatory Commission Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT - TECHNICAL SPECIFICATIONS 1* CH.ANGE - HYDRAULIC SHOCK SUPPRESSORS Attached is a revised proposed change tC? the Palisades I'ecJ:i. .'1.ica.l . Specifications concerning operability and surveillance requirements fo:r hydraulic shock sup-pressors. This change revises the previously proposed changes submitted by letter dated October 7, 1975 and is based on discussion with mem*bers of your staff and a revised 11 Model TechnicaJ_ Specific at ions" received. in May 1976.

David A. Bixel Assistant Nuclear Licensing Administrator C'"'*

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  • CONSUMERS POWER COMPANY Docket No 50-255 Request for Change to the Technical Specifications License No DPR-20 For the reason herein set forth, it is requested that the Technical Specifica-tions contained in Provisional Operating License DPR-20, Docket 50-255, issued to Consumers Power Company on October 16, 1972, be changed as described below:

I. Changes A. Add new Section 3.20 as follows:

"3.20 Hydraulic Snubbers A;pplicability Applies to the operating status of the safety-related piping hydraulic snubbers.

  • Objective To minimize the possibility of unrestrained pipe motion as might occur during an earthquake or severe transient.

Specifications_

3.20.1 During all modes of operation, except cold shutdown and refuel-ing, all hydraulic snubbers listed in Table 3.i8.l shall be operable except as noted in 'a' through 'd' below.

a. From and after the time that a hydraulic snubber is deter-mined to be inoperable, continued reactor operation is permissible only during the succeeding 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> unless the snubber is made operable prior to the end of the 72-hour period.

b, If the inoperable hydraulic snubber cannot be made oper-able within the required 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, an orderly shutdown shall be initiated and the reactor shall be in a cold shutdown condition within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.

Ii' a hydraulic snubber i-s determined to be inoperable -while

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  • the reactor is in either the cold shutdown or refueling mode, the snubber shall be made operable prior to the reactor being made critical.

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TABLE 3.20.1 Safety-Related Hydraulic Snubbers Snubber in Snubbers Snubbers Snubbers Palisades High Radiation Especially Inaccessible Accessible ID Area During Difficult During Normal During Normal Number System Location Shutdown To Remove Operation Operation 1 MSS On Main Steam Lines - EBl Upstream of MSIVs x 2 MSS On Main Steam Lines - EBl Upstream of MSIVs x 3

4 MSS MSS On Main Steam Lines - EBl Upstream of MSIVs On Main Steam Lines - EBl Upstream of MSIVs x

x e 5 MSS On Main Steam Lines - EBl Upstream of MSIVs x 6 MsS On Main Steam Lines - EBl Upstream of MSIVs x 8 MSS On Main Steam Lines - EBl Upstream of MSIVs x 9 MSS On Main Steam Lines - EBl Upstream of MSIVs x 10 MSS On Main Steam Lines - EBl Upstream of MSIVs x 11 MsS On Main Steam Lines - EBl Upstream of MSIVs x I\)

12 Mss On Main Steam Lines - EBl Upstream of' MSIVs x 15 MSS EB-1-8" Upstream of CV-0781 x 16 MSS EB-1-8" Upstream of CV-0781 x 17 rv1ss EB-1-8" Upstream of CV-0780 x 18 MES EB-1-8" Upstream of CV-0780 x 19 Mss EBD-6, E-50A, 36" Steam to Aux FW Turbine x 20 MSS EBD-6, E-50A, 36" Steam to Aux FW T:urbine x 21 ccs Component Cooling Outside Cont x 22 ccs From Component Cooling Water System to Evaporators x 23 ccs Evaporators to Component Cooling Water Sys x 24 ccs Evaporators to Component Cooling Water Sys x 25 ccs Component Cooling Water Outside Cont -

Pump Discharge x 26 ccs Component Cooling Water Outside Cont -

Pump Discharge x 27 ct:s Component Cooling Water Outside Cont -

Pump Discharge x 28 cts Component Cooling Water Outside Cont -

Pump Discharge x

Palisades

  • Snubbers Accessible ID Area During Difficult During Normal During Normal Number Sys:tem Location Shutdown To Remove Operation Operation 29 eve Primary Coolant Pump Leakoff to Volume Control Tank - 602' Pipeway x X-30 eve Letdown to Volume Control Tank - 602' Pipeway x x 31 ESS GC-8 Shutdown Cooling Lower Pressure Safety Injection Pump Suction x 32 33 34 ESS ESS ESS HC-3 Engineering Safeguards Pump Suction GC-8 Shutdown Cooling LPSI Pump Suction HC-3 Engineering Safeguards Pump Suction x

x x

e 35 ESS GC-1 LPSI Pump Discharge x 36 ESS GC-1 LPSI Pump Discharge x 37 ESS GC-1 LPSI Pump Discharge x 38 ESS GC-1 LPSI Pump Discharge x 39 ESS GC-8 Shutdown Cooling LPSI Pump Suction x w

40 ESS GC-8 Shutdown Cooling LPSI Pump Suction x 41 ESS GC-8 Shutdown Cooling LPSI Pump Suction x 42 ESS GC-1 LPSI Pump Discharge x 43 ESS HC-3 Engineering Safeguards Pump Suction x 44 ESS GC-1 LPSI Pump Discharge (After CV-3025 SDHX to LPSI Valves) x 45 ESS HC-3 Engineering Safeguards Pump Suction x 46 MSS Steam Generator A, Restraint 1-SS-l x x x 47 .MSS Steam Generator A, Restraint l-SS-2 x x x li8 MSS Steam Generator A, Restraint l-SS--3 x x x 49 MSS Steam Generator A, Restraint l-SS-4 x x x 50 MSS Steam Generator A, Restraint l-SS-5 x x x 51 MSS Steam Generator A, Restraint l-SS-6 x x x 52 MSS Steam Generator A, Restraint l-SS-7 x x x 53 MSS Steam Generator A, Restraint l-SS-8 x x x 54 MSS Steam Generator B, Restraint 2-SS-l x x x 55 MSS Steam Generator B, Restraint 2-SS-2 x x x 56 MSS Steam Generator B, Restraint 2-SS-3 x x x 57 MSS Steam Generator B, Restraint 2-SS-4 x x x 58 MSS Steam Generator B, Restraint 2-SS-5 x x x

Palisades ID

  • Inaccessible During Normal
  • Snubbers Accessible During Normal Number System Location Shutdown To Remove Operation Operation 59 MSS Steam Generator B, Restraint 2-SS-6 x x x 60 J'4SS Steam Generator B, Restraint 2-SS-7 x x x 61 MSS Steam Generator B, Restraint 2-SS-8 x x x 62 SIS On Low-Pressure Safety Injection Line Inside Cont Before Motor-Operated Valves x 63 ~IS Low-Pressure Safety Injection to T-82C x x

64 65 SIS MSS Low-Pressure Safety Injection to T-82C On EBD-7 Steam to Aux Feed Pump x e

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  • "d. Snubbers may be added to safety-related systems without prior license amendment to Table 3.20.1 provided that safety evaluations, documentation and reporting are provided in accordance with 10 CFR 50.59 and then a revision to Table 3.20.1 is included with a subsequent License Amendment Request."

B. Add new Section 4.16 as follows:

11 4.16 Inservice Inpsection Program for Hydraulic Snubbers Applicability Applies to periodic surveillance of safety-related hydraulic snubbers as listed in Table 3.20.1.

Objective To specify the frequ~ncy and type of surveillance to be applied to the hydraulic snubbers.

Specifications 4.16.1 All hydraulic snubbers listed in Table 3.20.1 shall be visually inspected. This inspection shall include inspection of the hydraulic fluid reservoir, fluid connections, and linkage con-nections to the piping and anchor to verify snubber operability in accordance with the following schedule:

Number of Snubbers Found Inoperable During Inspection or During Next Required Inspection Interval Inspection Interval 0 18 Months +/- 25%

1 12 Months +/- 25%

2 6 Months +/- 25%

3, 4 124 Days +/- 25%

5, 6, 7 62 Days +/- 25%

~8 31 Days +/- 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.

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  • "4.l6.2 The initial inspection, if not already completed, shall be performed within 6 months from the date of issuance of these specifications. For the purpose_ of entering the schedule in Specification 4.16.1, it shall be assumed that the facility had been on a 6-month inspection interval.

4.16.3 Once each refueling cycle a representative sample of at least 10% of the snubbers listed in Table 3.20.1 shall be functionally tested for operability including verification of proper piston movement, lockup and bleed. For each snubber found inoperable, an additional sample of 10% shall be tested until no more failures are found or all units have been tested. Snubbers of rated capacity greater than 50,000 pounds need not be direc-tionally tested.

Basis Snubbers are designed to prevent unrestrained pipe motion under dynamic loads (as might occur during an earthquake or severe

  • transient) but still allow normal thermal motion during start-up 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 snubbers required to protect the primary coolant system or any other safety system or component be operable during reactor operation~

Because the snubber protection is required only during relatively low probability events, a period of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> is allowed for re-pairs or replacements. In case a shutdown is required, the al-lowance of 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> to reach a cold shutdown condition will permit an orderly shutdown consistent with standard operating procedures. Since plant start-up should not commence with knowingly defective safety-related equipment, Specification 3,20,1.c prohibits start-up with inoperable snubbers.

  • All safety-related hydraulic snubbers are visually inspected for overall integrity and operability.

6 The inspection will

  • "include the fluid reservoir, fluid connections, and any linkage connections to associated piping and anchors.

The inspection frequency is based upon maintaining a constant level of snubber protection. Thus, the required inspection interval varies inversely with the observed snubber failures.

The number of inoperable 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 results of such early inspec-tions performed before the original required time interval has elapsed (nominal time less 25%) may not be used to lengthen the required inspection interval. Any inspection whose results require a shorter inspection interval will override the previous schedule .

  • Experience at operating facilities has sho"Wil that the required surveillance program should assure an acceptable level of snubber performance provided that the seal materials are com-patible with the operating environment.

Snubbers containing seal material which has not been demon-strated by operating experience, lab tests or analysis to be compatible with the operating environment should be inspected more frequently (every month) until material compatibility is confirmed or an appropriate changeout is completed.

Examination of defective snubbers at reactor facilities and material tests performed at several laboratories (Reference 1) 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 condition'S, -it also may be unsuit..;.;.

  • able for application in the higher temperature environments.

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  • "Data are not currently available to define precisely an 1J.pper 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 sat-isfactory performance under the most severe conditions expected in reactor installations.

To increase further the assurance of snubber reliability, functional tests should be performed once each refueling cycle.

Where practical, these tests will include stroking of the snub-bers to verify proper piston movement, lockup and bleed. Ten percent represents an adequate sample for such tests. Observed failures on these samples should require testing of additional units. Snubbers in. high radiation areas or those especially difficult to remove need not be selected for functional tests provided operability was previously verified .

  • Snubbers of rated capacity greater than 50,000 pounds are exempt from the functional testing requirements because of the im-practicability of testing such large units.

The snubbers associated with the steam generators are made by a different manufacturer and they have not experienced significant problems. Since these snubbers are connected into a complex system, certain tests are not considered practical. Because of the size of the steam generator snubbers and their complex sys-tem, these snubbers have been classified as especially difficult to remove. Verification of piston motion is considered adequate to demonstrate operability on a refueling cycle frequency. (l)

All applicable snubbers located inside the containment are classified as inaccessible during normal operation *

-(l)Rep6rt H-R Erickson, Bergen Paterson to K R*Goller, NRC, October{, 1974,

Subject:

'Hydraulic Shock Sway Arresters.'"

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  • C.

D.

Add to Table of Contents (Page ii):

"3.20 Hydraulic Snubbers 3-88" (page).

Add to Table of Contents (Page iii):

"4.16 Inservice Inspection Program for Hydraulic Snubbers 4-71" (page).

II. Discussion 11 This proposed change basically conforms with the model" Technical Specifica-tions and bases prepared by the NRC staff. Areas where significant differ-ences occur are discussed in the following paragraphs.

We have reviewed the seal materials in use in the hydraulic snubbers and have concluded that either operating experience, lab testing or analysis has demonstrated that the material is compatible with the operating environment.

We have, therefore, deleted the 31-day visual inspection requirement associ-ated with seal material not so demonstrated.

The snubbers on the steam generators are made by Grinnell. We have not

  • experienced any problems with these snubbers (design problems with the operating fluid supply and reservoir system have been identified and cor-rected), One snubber was completely disassembled and inspected in January 1974 with all snubber components found to be in good condition.

The snubbers on each steam generator (eight) are interconnected such that the load for any snubbing action is shared. This arrangement plus the size of the snubber and available testing equipment makes testing of these snub-bers for lockup impractical.

All safety-related snubbers located in containment are considered inaccessible during power operation. This is due to radiation, health and general safety conditions associated with their location .

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III. Conclusion Based on the foregoing, the Palisades Plant Review Committee has concluded that this change does not involve an unreviewed safety question.

CONSUMERS POWER CO.!Y1PAL'IT Sworn and subscribed to before me this 7th day of October 1976.

,Linda R Thayer, N~t1ary Public Jackson County,vMichigan My commission expires July 9, 1979.

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