ML20246N072

Forwards AEOD/E906, Failure of Steam Generator Isolation Check Valve, Technical Evaluation Rept.Inservice Testing of Check Valves Should Be Conducted on Regular Basis for Both Forward & Reverse Flow Directions

ML20246N072
Person / Time
Site:	Calvert Cliffs
Issue date:	08/30/1989
From:	Rosenthal J NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD)
To:	Marsh L Office of Nuclear Reactor Regulation
Shared Package
ML20246N050	List: ML20246N045 ML20246N058 ML20246N072 ML20246N093
References
AEOD-E906, NUDOCS 8909080030
Download: ML20246N072 (2)

Text

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7 MS 3 0 1980' s ~ MEMORANDUM FOR: Lecyard B. Mcrsh AE0D/E906 Mechanical Engineering Branch A/D for Systems i Division of Engineering and Systems Technology ,

Office of: Nuclear Reactor Regulation FROM: Jack E. Rosenthal, Chief Reactor Operations Analysis Branch Division of Safety Programs Office for Analysis and Evaluation of Operational Data

SUBJECT:

FAILURE OF STEAM GENERATOR ISOLATION C iTCK VALVE Enclosed for your information is a copy of an AE0D Engineering Evalsation Report on the failure of a steam generatcr isolation check valve at each unit of.Calvert Cliffs.

The report suggests that' successful operation of the steam generator isolation check valve may be necessary to prevent a more adverse condition than the FSAR analysis for a staam line break cvent. In this manner, these check valves serve a ctitical safety application.

The report indicates. that licensees need to ensure that these check valves are capable not only of passing steam to drive the auxiliary feedwater pump turbines, but also cf preventing a simultaneous blowdown of the steam generators. As a consequence, inservice testing of these check valves should be conducted on a regular basis for both the forward and reverse flow directions. The issuance of hRC Generic Letter 89-04, " Guidance on Developing Acceptable' Inservice Testing Programs," which addresses the need for back flow testing' of check valves, would appear to be an appropriate step toward resolution'of this concern. In addition to testing, the performance of

-periodic disassembly of check valves to inspect toir interrals could provide valuable. information for the prediction of valve failures.

If you should have questions regarding this report, please do not hesitate to call either myself or Ted Cintula of my staff. Mr. Cintula can be reached at x24493.

Jack E. Rosenthal, Chief Reactor Operations Analysis Branch 3r$9080030890830 Divisi0n of Safety Programs 7 ADOCK osooo337 pdc Office for Acalysis and Evaluation of Operational Data

Enclosure:

As stated

! cc: T. Scarbrough, NRR

Distribution

i-  : Central Files VBenaroya BBrady WLanning LSpessard x0AB R/F JRosenthal MWilliams JHeltemes

i. DSP R/F GLanik HFaulkner TNovak l EJordan TCintula . PDR MTaylor See previous concurrences kdAD:DSP:AEOD *ROAB:DSP:AE0D ROAB:DSP:y0D TCintula:md GLanik JRosenth51 W

'8/A7/89 8/ /89 8/p/89 L l

_ Aut :e sw L MEMORANDUM FOR: Conrad E. McCracken, Chief. AE0D/E906 l Plant Systems Branch-A/D for Systens Division of Engineering and g Systems Technology l Office of Nuclear Reactor Regulation FROM: Jack E. Rosenthal, Chief

, Reactor Operations Analysis Branch'

.Civision of Safety Programs Office for Analysis and Evaluation of Operational Data SUBJEC7: FAILURE OF STEAM GENERATOR ISOLATION CHECK VAL 7E Enclosed for your information is a copy of an AEOD Engineering Evaluation Report on the failure of a steam generator isolation check valve at each unit of Calvert Cliffs.

The report suggests that succe uful operation of the steam generator P,olation check valve may be necessary to prevent a taore adverse condition than the FSAR analysis for a steam line break event. In this manner, these check valves serve a critical safety application.

The~ report indicates that licensees need to ensure that these check valves are capable not only of passing steam to drive the auxiliary feedwater pump turbines, but also of preventing a simultaneous blowdown of the steam generators. As a consequence, inservice testing of these check valves should be conducted en a regular basis for both the forward and. reverse flow directions. The icspante of NRC Generic Letter 89-04, " Guidance o6 Developing Acceptable Inservice Testing Programs," which addresses the need for back flow testing of check valves, would appear to be an appropriate step toward resolution of this concern. In addition to testing, the performance of periodic afsassembly of check velves to inspect their internals could provide valuable information for the prediction of valve failures.

If you should have questions regarding this report, please do not hesitate to call either myself or Ted Cintula of my staffe Mr. Cintulo can be reached at x24493.

Jack E. Rosenthal, Chief Reactor Operations Analysis Branch Division of Safety Programs Office for Analysis and Evaluation of Operational Data

Enclosure:

As stated Distribution:

Central Files VBenaroya BBrady MTaylor TNovak I ROAB R/F JRosenthal NWilliams WLanning DSP R/F- Glanik HFaulkner LSpessard EJordan TCintula PDR JHeltemes

• See previous ~concurrenences F,4ROAB:DSP:AE0D *ROAB:DSP:AE0D ROAB:DSP:AE0D TCintula:md Gl.anik JRosenthel h 8/M/89 8/ /89 8/ /89

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