ML19308D319

RO-77-22:on 770308,main Steam Relief Valve MSV-35 Opened at 985 Psig While Operating at 40% Power.Caused by Relief Valve Lifting Due to Setpoint Drift.Main Steam Relief Valve Calibr to Correct Lift Setpoint

ML19308D319
Person / Time
Site:	Crystal River
Issue date:	03/15/1977
From:	Stewart W FLORIDA POWER CORP.
To:
Shared Package
ML19308D316	List: ML19308D315 ML19308D319
References
NUDOCS 8002270762
Download: ML19308D319 (2)

Text

~ ~ " ' " ~ ~ ~~ ~~~ ' " ~ ~

4.^.s v 4.~n7G3 C.a. L. i, 6 4 r

• I n L.8 T.J i l l l, "

CONTROL ULOCn:l l l l l l jtCAsS pntNT fLL RESUIRED INFOlis.1AT;"JJJ

, 1 , 6

• UCENSEE (CENSE EVENT NAME LCENSE NUM0 Ell TYPC TYPC 7 9 FlLlCfRlPl3l lO!0l~lO!O!O!0lnl-lO!0l l4l1 l1 l 1l 1l l0l1l

• 4 14 1b 25 26

. 30 31 32 CATEGOilf f UN OOCxET NUMUER EVENT OATE REPORT DATE ECON 41 - I -J 7 8 57 50 LL_J 59 LLJ 1015101-101310 l2 l 10I,10 la 17 l7 1 1013111s1717 i GO 61 68 69 74 75 00 EVENT DESCalPTION

$l 7 89 Miile operatinn at 40 eercent power. steadv state. Main Steam Relief Valve MSV-35 '

l UO E l opened at 985 osic. This is below Technical Snecification value of 1090 esic. Thero l 7 89 -

00 hl 7 89 were redundant systems operable and available. A sicillar occurrence of this type l 80 h!

/U9 occurred on 25 February lo77. As soon as cl ane enndf rions ne mi-end. Php 14ft spe- l 80 oin I point of 1050 psig was re-established.

(77-22) l 7 89 pnug svertu CAust

. 60 COuvumeNT couPONtNT CODE COCE COMPONENT CODE SUPREA MANUFAC1URER VOLATON O lC lC l lEl lVlAlLlVlElXl .W lD l 214 l 3 j lN l .

7 89 10 11 12 17 43 44 47 48 CAUSE DESCRIPTION ]* 5.

hl

/ 89 MSV-35 Relief Valve lif ted due to reasons that are unknown at this time as the balance l 60

@l

/ 09 of the Relief Valves did not open.

l 80 FI I FacsLify METHOO OF Status  % POWER OTHER STATUS OrSCOVEnY OCCOVEnY CESCR'PfCN

]-

/ U 9 lEl l 0l 4l 0l l N/A l @ ~ l- N/A l 10 12 13 44 45 46 CO ac w Tv CONTENT AE'.EACCD AMOUNT OF ACTMTV LOCATON OF AELEASE

'h 8 9 W OFftELEASEl l, Z) 10 11 N/A l l N/A l 44 45 80 PERSONNEL EXPOSunES NUMBER TYPE OLSCRipf0N

@89 l0l0)0l l12Zl' I N/A l 11 13 00 PERSONNEL INJURIES NUMOE88 OESCnIPTON 389l0l0l0l11 12l N/A l CD OFFSITE CONSEQUENCES hl 00 LO LOSS On OAMAGE TO FAC:UTY TYPE GECCJ1tPf0N 3dl

'N/A _. . . !

u9 to l'O PllWUCITY

]l u9 N/A

_ _ _l UU MOITIONAL FACTOn3

~

See the attached Supplementary Information. 8Q02 270 M2 ,_ l

.s, lbn .l,. / b g

NArat, ti. z P. Stewart _____ __ r u otar (813)._Hfi6 4159._

. e

(- Supplementary Information

1. Report No: 50-302/77-22

2. Facility: Crystal RLver Unit 3

3. Report Date: 8 March 1977

4. Occurrence Date: 15 March 1977

5. Identification of Occurrence: .

Main Steam Relief Valve MSV-35 lifted at a pressure of 985 psig. The required setpoint is 1050 psig i 12.

6. Conditions Prior to Occurrence:

On 8 March 1977, Crystal River Unit 3 was in Mode 1 condition at 40% power. -

7. Description of Occurrence: 5-During Mode 1, steady state, the Main Steam Relief Valve MSV-35 opened below the required setpoint. No other MSV's opened at this time. There was no safety significance as the overpower trip setpoint was set at 50%.

The balance of the MSV's were operable and redundancy was maintained.

When plant conditions permitted, the setpoint was checked and reset.

8. Designation of Apparent Cause of Occurrence:

The cause of this occurrence was determined to be a normal setpoint drift.

9. Analysis of Occurrence:

This was the second occurrence of this type of event, but the first involving MSV-35. The setpoint was calibrated as soon as conditions permitted.

10. Corrective Action:

Main Steam Relief Valve MSV-35 was calibrated to the correct lift setpoint j of 1050 psig i 1%.

11. Failure Data:

There has been one other occurrence of this event involving MSV-36 on 25 February 1977. i i

\

G i l

e *

, -w c-,--y -- -g -we , - . , - . - - - - - -

, - , - r - -