05000280/LER-1988-021, :on 880728,PORV Cycled Open & Then Closed. Caused by Overly Conservative Setpoint.Setpoint Changed

:on 880728,PORV Cycled Open & Then Closed. Caused by Overly Conservative Setpoint.Setpoint Changed

ML18153B496
Person / Time
Site:	Surry
Issue date:	08/01/1988
From:	Benson D VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
88-047, 88-47, LER-88-021, LER-88-21, NUDOCS 8808110153
Download: ML18153B496 (4)

LER-1988-021, on 880728,PORV Cycled Open & Then Closed. Caused by Overly Conservative Setpoint.Setpoint Changed

Event date:
Report date:
2801988021R00 - NRC Website

text

POW 28*-06-01

• -)'l.tJ..-:----------------1 I NAC Form 366

' (9-83)

U.S. NUCLEAR REGULATORY COMMISSION APPROVED 0MB. NO. 3150-0104 EXPIRES: 8/31/88 LICENSEE EVENT REPORT (LER)

FACILITY NAME 11)

Surry Power Station, Unit 1 DOCKET NUMBER (21 I

PAGE (31 o 1s 10101012,s,o 1 loFO 13 TITLE (41 Lifting of PORV Due to Overly Conservative Setpoint EVENT DATE (51 LER NUMBER (61 REPORT DATE (71 OTHER FACILITIES INVOLVED (81 MONTH DAY YEAR YEAR ftt SE~~~~~~AL Jt ~~~~~ MONTH DAY YEAR FACILITY NAMES DOCKET NUMBER(SI ol 7 2 I s s s s js -

o 12 I 1 -

oJ o o I s o J1 sJ s OPERATING MODE (9)

THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check one or more of the folloll(ing) 1111 X

20.402(b) 20.405(cl 20.405(al(1 l(il 50.36(cl(11 50,73(*1 (2l(iv) 50.73(al(2l(v)*

73.71 (bl 73.71(cl 20.405(ol(1)(ji) 50.36(cl(2) 20,405(*) (1 l(iii) 50.73(ol(2)(il 50.73(al(2l(vii) 50.73(al(21(viiillAl X

OTHER (Specify in Abstrect bslow and in Text, NRC Form 366A) 20.405(*) (1 l(iv) 50,73(ol(2l(ii) 50,73lal(2l(viiil(B1 20.405(all1lM 50,73(ol(21(iiil 50,73(ol(2l(xl "Special Report" LICENSEE CONTACT FOR THIS LER (121 NAME TELEPHONE NUMBER AREA CODE D. L. Benson, Station Manager 8 10 I 4 3 I 5 I 7 1-I 3 I 1 18 I 4

CAUSE

SYSTEM COMPONENT I

I I

I I

I I I

COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (131 MANUFAC-TURER I

I I

I I

I

CAUSE

SYSTEM I

I COMPONENT MANUFAC-TURER

. I I

I I

I I I I

I I 1

I SUPPLEMENTAL REPORT EXPECTED (141 MONTH DAY YEAR EXPECTED SUBMISSION n YES (If yes, comp/et* EXPECTED SUBMISSION DATE/

rxi NO DATE (151 I

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

NRC Form 366 (9-83) on July 2, 1988 at 0119 hours0.00138 days <br />0.0331 hours <br />1.967593e-4 weeks <br />4.52795e-5 months <br />, with Unit 1 in cold shutdown, a Reactor Coolant System (RCS) {EIIS-AB} Power Operated Relief Valve (PORV), PCV-1456 {EIIS-PCV}, cycled open and then closed.

At the time of the event, the RCS was solid after filling and venting and a Reactor Coolant Pump (RCP)

{EIIS-P} had just been started.

The reactor operator took manual control of PCV-1145 and reduced RCS pressure below the PORV setpoint.

The cause of the event was an overly conservative PORV lift setpoint.

The setpoint was changed in April, 1988 following an analysis.

At the time this setpoint was changed, it was not recognized that instrument inaccuracies had been accounted for.

This resulted in 10 psig being subtracted from the lift setpoint.

~g~91 10153 9aoao1 S

ADOCK 05000280 PNU I

rJI$ Faro,:_;is&A (9-83)

LICENSEE EV FACILITY NAME (1)

REPORT (LERI TEXT CONTINUAT-.

POW 28-06-01 U.S. NUCLEAR REGULATORY COMMISSION APPROVED 0MB NO. 3150-0104 EXPIRES: 8/31 /88 DOCKET NUMBER (21 LER NUMBER (61 PAGE (31 Surry Power Station, Unit 1 0 I 5 IO I O I O 12 I 81 0 81 8 -

012 I 1 -

0 I O O I 2 OF O 13 Tl;XT (If more space is required, use additional NRC Form 366A 's/ (17) (9-331 1.0 Description of the Event On July 2, 1988 at 0119 hours0.00138 days <br />0.0331 hours <br />1.967593e-4 weeks <br />4.52795e-5 months <br />, with Unit 1 in cold shutdown, a Reactor Coolant System (RCS) {EIIS-AB}

Power Operated Relief Valve (PORV), PCV-1456

{EIIS-PCV}, cycled open and then closed.

At the time of the event, the RCS was solid after filling and venting and a Reactor Coolant Pump (RCP) {EIIS-P} had just been started.

The pressure transient, caused by the start of the RCP with a solid water plant condition, created a pressure rise and lifted the PORV which was set to open at 375 psig.

Manual control of RCS letdown was established and RCS pressure was reduced.

The PORV immediately closed and the RCS pressure stabilized at approximately 340 psig.

The event is reportable pursuant to Technical Specification (T.S.) 3.1.G.3 and 6.6.C.

2.0

Safety Consequences and Implications

3.0 The operability of two PORVs or the RCS vented through an opened PORV ensures that the reactor vessel will be protected from pressure transients which could exceed the limits of Appendix G of 10CFR Part 50, when the RCS temperature is less than or equal to 350 degrees Fahrenheit and the reactor vessel head is bolted.

During the event, PCV-1456 performed as required to maintain RCS pressure within T.S. limits.

Therefore, the health and safety of the public were not affected.

Cause

The cause of the event was an over*ly conservative PORV lift setpoint.

The setpoint was changed in April, 1988 following an analysis ~rom the reactor vessel material surve*illance program, which revised the heatup and cooldown curves currently in Technical Specifications.

At the time this setpoint was changed*, it was not recognized that instrument inaccuracies had been accounted *for and, as a result, 10 psig was subtracted from the lift setpoint.

• U.S. GPO: 1988-52Cl-589*ll0l)70

...I..

-~~ Fmm**366A 19-831 F).CJLITY NAME (11 LICENSEE EV

---

~--P_o_w_2_8_.:._0_6-_0_1_---~---..,-11 U.S. NUCLEAR REGULATORY COMMISSION T REPORT (LERI TEXT CONTINUATI APPROVED 0MB NO. 3150-0104 EXPIRES: 8/31/88 DOCKET NUMBER (21 LER NUMBER 161 PAGE (31 Surry Power Station, Unit 1 O

5 O

O O 2 8

0 8 8 -

0 2 1 -

0 0 0 3 OF O 3

• TEXT /If more spscs is required, uss sdditionsl NRC Form 366A's/ (171 NRC FORM 388A 19-831 4.0 Immediate Corrective Action(s)

The reactor operator took manual control of PCV-1145 and reduced RCS pressure below the PORV setpoint.

RCS pressure was stabilized at approximately 340 psig and the PORV was verified shut.

5.0 Additional Corrective Action(s)

None required.

6.0 Action(s) Taken to Prevent Recurrence The PORV lift setpoints will be raised 10 psig each, which will still ensure that the reactor vessel will be protected against pressure transients which could *exceed the limits of 10CFR Part 50 Appendix G.

The operating procedures for both units will be revised to reduce the required RCS pressure band for RCP.operation.

In addition, manual control of the RCS letdown pressure control valve during RCP starts while the RCS is solid will be required.

7.0 Similar.Events Unit 2 LER:

88-014 8.0 Manufacturer/Model Number N/A

• u.s. GPO, 1968-520-569,00070

August 1, 1988 U.S. Nuclear Regulatory Commission Document Control Desk 016 Phillips Building Washington, D.C.

20555 Gentlemen:

VIRGINIA ELECTRIC AND POWER COMPANY Surry Power Station P. 0. Box 315 Surry, Virginia 23883 Serial No.:

88-047 Docket No.:

50-280 Licensee No.:

DPR-32 Pursuant to Surry Power Station Technical Specifications, Virginia Electric and Power Company hereby submits the following Special Report for Surry Unit 1.

REPORT NUMBER 88-021-00 This report has been reviewed by the Station Nuclear Safety and Operating Committee and will be reviewed by Safety Evaluation and Control.

Very truly yours,

/

)

7

\\

/

• ~;~; ~---

i

(

-.in.

David L. Benson Station Manager Enclosure cc:

Dr. J. Nelson Grace Regional Administrator Suite 2900 101 Marietta Street, NW Atlanta, Georgia 30323