ML20066J801

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Discusses Failure of Safety Relief Valves to Open.Problem Can Be Attributed to Pneumatic Actuation Sys or Main Piston Sys.Actuation of Valves May Result in Simmering Leaks or Nonclosure in Minor Binding
ML20066J801
Person / Time
Site: Hatch Southern Nuclear icon.png
Issue date: 11/03/1982
From: Nanjundeswaran
INDIA
To: Wagner M
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
References
REF-PT21-82-740-000, REF-SSINS-6835, REF-SSINS-SSINS-6 PT21-82-740, PT21-82-740-000, TAPS-DCS-T-55, NUDOCS 8211290304
Download: ML20066J801 (1)


Text

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fam: Mim TEt.EPHONE: TA R APU R 221.231 (R(TITCC) voik.ov TELEGRAM 8 ATOMPOWE R G liAII., T ARAPu R ATouiC TARAPUR (THANA) sytrialg atr4 POWER PROJECT P. O.

TELEX TAPS 0132-209. THAN A DISTRICT. 401-504 (M AH AR ASHTRA STATE) 3TTUT MTR GOVERNMENT OF INDI A R 3TI S 3ial f% 3titi DEPARTMENT OF ATOMIC ENERGY PfiU V R3fl5 fitTd R TARAPUR ATOMIC POWER STATION No."2LPS/ES/T-55 November 3, 1982 Office of the Inspection & Enforcement, US NE Washington D.C. 20555 U.S.A Attn Mr. M.R. Wegner, Division of Engg. & Quality A ance.

Sub: SSINS No.6835 IN 82-41 Failure of Safety /

Relief Valves to opsn. ,

This has reference to the above I3 document bringing out the incident of failure of reactor safety / relief valves to open at Hatch Unit 1. It appears from the IS document and the previous incident of failure of safety relief valves at Target Rock two stage safety relief valves are quite frequent. It appears from the design that the main piston and the pneumatic actuating piston system are not on the same shaft and are connected by an operating fluid system.

The problem can be either of pleumatic actuation system or on the main piston system and is difficult to isolate. It is also not certain that frequent exercising would be a satisfactory method to ensure its operability, as actuation of these valves may result in simmering leaks or non-closure in case of minor binding whi.ch might cause further problems in containment.

It would be interesting to know the results of further study on the system. Appreciate if you could keep us informed.

Thn_nHng you, Yours faithfully, f /

(K. Nanjundesvaran)

Deputy Chief Superintendent 8211290304 821103 PDR ADOCK 05000321 PDR

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