05000259/LER-1990-001, :on 891213,approx 99 Snubbers Determined Not to Have Been Functionally Tested Before Installation.Caused by Inadequate Procedures Re post-mod Testing.Procedure Will Be Revised

:on 891213,approx 99 Snubbers Determined Not to Have Been Functionally Tested Before Installation.Caused by Inadequate Procedures Re post-mod Testing.Procedure Will Be Revised

ML20011E232
Person / Time
Site:	Browns Ferry
Issue date:	01/29/1990
From:	Lalor M TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML20011E231	List: 05000259/LER-1990-001, :on 891213,approx 99 Snubbers Determined Not to Have Been Functionally Tested Before Installation.Caused by Inadequate Procedures Re post-mod Testing.Procedure Will Be Revised
References
LER-90-001, LER-90-1, NUDOCS 9002120180
Download: ML20011E232 (4)

LER-1990-001, on 891213,approx 99 Snubbers Determined Not to Have Been Functionally Tested Before Installation.Caused by Inadequate Procedures Re post-mod Testing.Procedure Will Be Revised

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2) 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(viii)(B)
2591990001R00 - NRC Website

text

NRC hrm 366 U.S. NUCLEAR REGULATORY COMMISSION Approved OMB No. 3150-0104 (6-87)

Eapires 4/30/93 LICENSEE EVENT REPORT (IER)

FACILITY NAME (1) lDOCKETNUMBER(2)lJAGE(3)

_BRQWES FERRY VNIT 1

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JHil6LLATION CT NDulujhBIES WITHOUT FUNCTIONAL T111LtN_DE_ID_UNCIER_l' REC.EDURES EVENT DAY (5) l LER NU@ER_(6) l REPORT DATE (7) l OTHER FACILITIES INVOL RQJ 8)

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I 150.73(a)(2)(ill) l 150.73(aM2)(x) l Volunts.Ey_ Report LICENSEE CONTACT FOR THIS LER (12)

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TELEPHONE NUMBER lAREACODEl Jikhael Lalor. Com_p]Jance Licensino Engineer l210l5l71219l-l2[017l1 IQMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13) l l

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ABSTRACT (Limit to 1400 spaces, i.e., approximately fif teen single-space typewritten-lines) (16)

As a result of a review on December 13, 1989, approximately 99 mechanical snubbers were determined not to have been functionally tested before their installation. These snubbers were installed on units 1, 2, and 3 systems between 1982 and 1985.

i The cause of this event was procedures that did not clearly specify the post-modification testing required for new snubbers. When it was identified that a functional test was not specified as a postmodification test by the design changes for the new snubbers, there was uncertainty whether preservice test requirements were met.

l Additionally, Browns Ferry Technical Specifications do not require functional testing of new snubbers before their installation.

A voluntary report is submitted since the possibility of installing inoperable snubbers as the result of not performing functional testing at other plants could have significant consequences.

Although there are no regulatory, code, or site administrative requirements to functionally test mechanical snubbers before their installation, TVA considers it to be l

a good practice. The applicable site procedure will be revised to require functional testing of snubbers before their installation. A ten percent representative sample of i.

the 33 unit 2 new mechanical snubbers has been functionally tested and determined to l

have been capable of performing their intended function. The remaining unit 1, 2, l.

and 3 new mechanical snubbers that were not functionally tested have been placed into l.

the population of existing snubbers for ongoing functional testing in accordance with l

the Technical Specification Inservice Inspection Requirements.

NRC Form 366(6-89) 9002120180 900129 PDR ADOCK 05000259 L

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i NRC F;rm'366A U.S. NUCtEAR REGULATORY COMMIS$10N Apprsved OHD Ho. 3150-0104

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Expires 4/30/92 LICENSEE EVENT REPORT (tER)

TEXT CONTINUA 110N FACit!TY NAME (1) lDOCKETNMER(2)1 LER NUMBER (6) l l

PAGE (3) l l

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' DESCRIIIl0N OF EVEliI As a result of a review on December 13, 1989, approximately 99 mechanical snubbers in units 1, 2 and 3 were determined not to have been functionally tested before their installation. These snubbers were installed between 1982 and 1985 on systems including core spray [BG), residual heat removal (B0],

reactor core isolation cooling [BN), high-pressure coolant injection [BJ), and main steam-.[SB] systems.

The postmodification testing specified by the design changes for these snubbers was a visual inspection in accordance with American Society of Mechanical Engineers, Boiler and Pressure Vessel Code 'AGME),

Section XI.

Upon discovery of the event, a review of the regulatory, code, and site administrative documents was initiated to determine the proper postmodification testing requirements. These snubbers were considered to be new snubbers, rather than replacements, in that they'had not been previously placed in service and

- were additions to the existing systems. Postmodification testing of new snubbers is required to be consistent with the applicable industry code and does not require functional testing before placing new snubbers into service. The applicable industry code for postmodification testing of snubbers is ASME Section XI, which requires only a visual inspection of new mechanical snubbers.

Consequently, there are no code or plant administrative requirements to functionally test new mechanical snubbers before their installation.

Additionally, the Browns Ferry Technical Specifications do not require functional testing before placing new snubbers into service.

The event was reviewed for reportability determination in accordance with site procedures. A review of the event by the Shif t Technical Advisor determined that the event could be conservatively interpreted-to be reportable in accordance with 10 CFR 50.72(b)(1)(1), and an four-hour, nonemergency i

notification was made to NRC on December 29, 1989. TVA has subsequently determined that the event is not reportable in accordance with 10 CFR 50.72 or 50.73 since the technical specifications do not require functional testing of new mechanical snubbers before their installation.

A voluntary report is submitted since the possibility of installing inoperable snubbers as the result of not performing functional testing at other plants could have significant consequences.

At the time the event was discovered, units 1 and 3 were defueled, and unit 2 was in cold shutdown with fuel in the reactor vessel and the head removed.

HRC form 366(6-89)

a NRC [cre 366A U.S. NUCLEAR REGULATORY C0HHIS$10N Approved OHB N). 3150-0104 A

(6289)

Expires 4/30/92 LICENSEE EVENT REPORT (LER)

TEXT CON 11HUAT10N FACILITY NAME (1) lDOCKETNUMBER(2)l LQfMQ_(h) l l__[3GE t 3) l l

l l$EQUENTIALl l REVISION l l l l l l

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- It[MMdal 2l $! 91 91 01--l 0 1 0 1 1 l-l 0 1 0 l O! 3!nLL1! 4 TEXT (If more space is required, use additional NRC form 366A's) (17)

CAUSL.0F EVENT The cause of this event was procedures that did not clearly specify the postmodification testing required for new snubbers. When it was identified that a functional test was not specified as a postmodification test by the design h

changes for the new snubbers, there was uncertainty whether preservice test requirements were met.

ANALYS_IS OF EVENT Snubbers are designed to prevent unrestricted pipe or component motion under dynamic loads resulting from an earthquake or severe transient, but allow for normal thermal motion during startup and shutdown.

Performance of preopera-Lional testing establishes the operability of the snubber before placing it in service. Not performing adequate testing could result in the installation of an inoperable snubber. Operation with an_ inoperable snubber (s) would result in an increase'in the probability of structural damage to piping or components.

Ilowever, the new mechanical snubbers were determined to be capable of performing their intended function based on the required visual testing of each snubber performed at installation and the successful functional tests of a ten percent representative sample of the 33 unit 2 new mechanical snubbers. Therefore, this event had no potential safety significance.

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CQRRECTIVE ACTIONS _

Upon discovery of the event, a review was initiated to determine the proper postmodification testing requirements.

It was determined that there are no regulatory, code, or plant administrative requirement to functionally test new snubbers before_their installation. The current site procedure regarding postmodification testing was revised before the discovery of this event to recommend such testing. This procedure will be revised to require functional testing _of new snubbers before their installation.

A ten percent representative sample of the 33 unit 2 new mechanical snubbers has been functionally tested and determined to have been capable of performing their intende'd function. The remaining unit 1, 2, and 3 mechanical snubbers that were not functionally tested have been placed into the population of existing snubbers for ongoing functional testing in accordance with the Technical Specification Inservice Inspection Requiremente.

NRC Form 366(6-89)

• h t F;rm 366A U.S. NUCLEAR REGULATORY COMMIS$10N Appr:ved OHB No. 3150-0104 y. c. (649)

Explrss 4/30/92 LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION IACitITY NAME (1)

!DOCKETNUHDER(2)j LLlLilyMBER (6) I I

PAGE_J3)._ ___

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l l$EQUENTIALl l REVISION l l l l l l

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EREY.1.0US SIti1MILEVIliTS LER 260/87007,R1 discusses an event due to the failure to specify postmodification testing in the design change.

That event involved the inability of the drywell control air primary containment isolation valves-to close on the loss of motive air. The corrective actions for that cause included administrative programs to ensure design changes specify postmodification testing and are reviewed by cognizant personnel. Although functionally testing

[

the valves to close on the loss of motive air is currently addressed by the Browns Ferry Technical Specification Surveillance Requirements, the valves were not addressed by the technical specifications at the time of that event.

The programmatic corrective actions taken in the previous similar event were implemented after the snubber design changes associated with this event were i

issued.

COMtilIMENI The site procedure regarding postmodification testing will be revised by March 30, 1990,- to require funcitonal testing of new snubbers before their installation.

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" Energy Industry Identification System (EIIS) codes are identified in the text as [XX].

1 HRC form 366(6-89) l