05000366/LER-1990-009-03, :on 901023,trip of Area Radiation Monitor Caused ESF Actuation

:on 901023,trip of Area Radiation Monitor Caused ESF Actuation

ML20062E914
Person / Time
Site:	Hatch
Issue date:	11/16/1990
From:	Hairston W, Tipps S GEORGIA POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
HL-1367, LER-90-009-03, LER-90-9-3, NUDOCS 9011260186
Download: ML20062E914 (7)

LER-1990-009, on 901023,trip of Area Radiation Monitor Caused ESF Actuation

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(iv), System Actuation 10 CFR 50.73(a)(2) 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(1) 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(x)
3661990009R03 - NRC Website

text

- _ -.... -. -

Georg a Pruer Company

[

.333 Ptedmont Avenue Atlanta. Georg a 30308 i

T#ephone 404 526 3195 MaAng Address 40 Inerness Center Parkway Post Ofi'ce Box 1295 Birmingham Alabama 35201 Telephone 205 668 5581 the sout*cin ekvic systern l

W. G. Hairston,111 Senior Vee President Nuclear Operations HL-1367 001395 November 16, 1990 U.S. Nuclear Regulatory Commission ATTN: Document-Control Desk Washington, D.C.

20555 PLANT HATCH -' UNIT 2 l

NRC DOCKET 50-366-OPERATING LICENSE NPF-5 LICENSEE EVENT REPORT TRIP 0F AREA RADIATION MONITOR CAUSES ENGINEERED SAFETY FEATURE ACTUATION Gentlemen:

In accordance with the requirements of 10 CFR.50.73(a)(2)(iv),. Georgia ~

4 Power Company is submitting the enclosed Licensee Event Report (LER) l concerning the unanticipated actuation of-an Engineered-Safety Feature (ESF).

This event occurred at Plant Hatch - Units 1 and 2.

Sincerely,-

k).h W

• W. G; Hairston, III JJP/ct

Enclosure:

LER 50-366/1990-009 1

c:

(See next page.)

)

h

)

O pn nwcxos*gge g4-

\\{\\

- l g

Georgia Power m.

U.S. Nuclear Regulatory Commission November 16, 1990 Page Two c: Georaia Power Comoany Mr. H. L. Sumner, Genera'l Manager - Nuclear Plant Mr. J. D. Heidt,-Manager Engineering and Licensing - Hatch NORMS U.S. Nuclear Reaulatory Commission. Washinaton. D.C.

Mr. K. Jabbour, Licensing Project Manager - Hatch-U.S. Nuclear Reaulatory Commission. Reaion II Mr. S. D. Ebneter, Regional Administrator Mr. L. D. Wert, Senior Resident Inspector - Hatch f'

i I

j

.i i

001305 t

.%6 U.5. RICLEAR NEGA.Auf wril55KM JU UN, LICENSEE EVENT REPORT (LER)

FACILITY hAME (1)

DOCKET NUMBER (2)

FIGF (3) i PIRR 11ATCH, UNIT 2 05000366 1

o, l 5 TITLE (4)

TRIP OF AREA RADIATION MON 11DR CAUSES ENGINEERED SAFE 1Y FEATURE A01UATION EVENT DATE (5)

LER NUMBER (6)

REPORT DATE (7)

OTHER FACILillES INVOLVED (8) 40NIH DAY YEAR YEAR SEO NUM REV MONTH DAY VEAR FACILlif NAMES DOCKET NUMBER (S) j PIRU llATCH, UNIT 1 05000321 l

l 10 23 90 90 009 00 11 16 90 05000 is REMRI IS MMiB NRWI M in HMMW M M M (11)

OPERATING MODE (9) 1 20.402(b) 20.405(c)

^ 50.73(a)(2)(lv) 73.71(b) 20.405(a)(1)(1) 50.36(c)(1) 50.73(a)(2)(v) 73.71(c)

POSER LEVEL 100 20.405(a)(1)(1i) 50.36(c)(2) 50.73(a)(2)(vit)

OTHER (Specify in 20.405(a)(1)(lii) 50.73(a)(2)(1) 50.73(a)(2)(vit1)(A)

Abstract below) 20.405(a)(1)(tv) 50.73(a)(2)(ll) 50.73(a)(2)(viii)(B) 20.405(a)(1)(v) 50.73(a)(2)(til) 50.73(a)(2)(x)

LICENSEE CONTACI FOR This LER (1i)

NAME TELEPHONE NUMBER AREA CODE STEVEN B. TIPPS, MANAGER NUCIIAR SAFETY AND COMPLIANCE, HATCH 912 367 7851 l

COMPLETE oNE LINE FOR EACH FAILURE DESCRIBED IN THIS REPORI (13)

CAUSE

SYSTEM COMPONENT MANUFAC-R PORT CAUSE SYSTEM COMP 0NENT MAN FAC R PORT TUR ppDS TU R T

SUPPLEMENTAL REPORI EXPECTED (14)

MONih DAY YEAR EXPECTED SUBMISSION

] YES(If yes, complete EXPECTED SUBMISSION DATE)

% NO DATE (15)

ABStaAct (16)

On 10/23/90 at approximately 0238 CDT, both Units 1 and 2 were in the Run mode at an approximate power level of 2436 CMWT (approximately 100% rated thermal power). At that time, the Main Control Room Environmental Control (MCREC, EIIS Code VI) system automatically transferred from the normal to the pressurization mode. This occurred as designed when Area Radiation Monitor (ARM, EIIS Code IL) 2D21-K60lM tripped on detected radiation greater than its setpoint of 15 mR/hr.

ARM 2D21 K601M is an input to the MCREC system-pressurization mode logic.

It tripped when a demineralized water hose, later determined to contain.a 50 mR/hr hot spot, was moved near the ARM.

The hose was being used to spray clean water on a loaded shipping cask as it was being removed from the cask storage pit near the ARM.

Shipping cask handling activities were conducted with the monitoring of llealth Physics personnel to assure radiation exposure was maintained as low as reasonably achievable; no personnel received an unexpectedly high dose from handling the contaminated hose nor did anyone become contaminated. The shipping cask was decontaminated and surveyed prior to shipment per approved plant procedures to meet Federal requirements for shipping radioactive material.

The cause of this event is less than adequate human factors.

The hose had been used to drain a cask removed earlier and had become internally contaminated.

Hoses used to drain casks were neither labeled as contaminated nor segregated from clean hoses.

Corrective actions for this event inclu& d marking and segregating contaminated hoses.

r suc ruen w a U.s.====.-------------

,aui e a w-enos W 89f

• g g'

BNPDust V30 92 :

/

FAc!LITT MAME (1)

DocKst wunnER (2)-

1.EP. NUMBER (5)-

PAGE (3) l TEAR sto aun Rev PI/#r HATCH, UNIT 2 050-00366 90 0 0 9:

00-2 0F 5 TEXT

PLANT AND SYSTEM IDENTIFICATION

General Electric - Boiling Vater Reactor Energy Industry Identification System codes are identified in the text as (EIIS Code XX).

SUMMARY OF EVENT On 10/23/90 at approximately 0238 CDT, Unit 2 was in the Run mode at an approximate power level of 2436 CMVT-(approximately 100% rated thermal pover) and Unit 1 was in the Run mode at an approximate power level of 2436 CMVT (approximately 100% rated thermal power).

At that time,.the Main Control Room ironmental Control (HCREC, EIIS Code-VI) system automatically transferred t

from the normal to the pressurization mode.

This occurred as designed when Area Radiation Monitor (ARM, EIIS Code IL) 2D21-K601H tripped on detected radiation greater than its setpoint of 15 mR/hr.

ARM 2021-K601H is an input to the HCREC system pressurization mode logic.

It tripped when a demineralized water hose, l

later determined to contain a 50 mR/hr hot spot, was moved near the ARM.

The hose was being used to spray clean water on a loaded shipping cask as it was being removed from the cask storage pit near the ARM.

Shipping cask handling activities were conducted with the monitoring of Health Physics personnel to l

assure radiation exposure was maintained as lov as reasonably achievable; no l

personnel received an unexpectedly high dose from handling the contaminated hose not did anyone become contaminated.

The shipping cask was decontaminated and surveyed prior to shipment per approved plant procedures to meet Federal requirements for shipping radioactive material.

The cause of this event is less than adequate human factors. The hose had been used to drain a cask removed earlier and had become internally contaminated.

Hoses used to drain casks were neither labeled as contaminated nor segregated from clean hoses.

Corrective actions for this event included marking and segregating contaminated hoses.

DESCRIPTION OF EVENT

on 10/22/90, activities were underway on the Refueling Floor to remove a loaded shipping cask liner from the cask storage pit located between the Unit 1 and Unit 2 Spent Fuel Pools. The liner had been loaded with spent control rod blades and local power range monitors in preparation for shipment offsite. This.

vas the fourth of a planned eleven such shipments.

The shipping cask was moved into the cask storage pit and the loaded liner was placed into it.

The shipping cask lid was then placed on the cask and the' bolts

-(

tightened. The cask lifting rigging was attached to the cask, personnel were 1

positioned on opposite sides of the cask storage pit to spray vith demineralized water the overhead crane hook,' rigging,'ari cask as they were removedLfrom the water, and the Unit 2 Shift Supervisor was notified the. shipping cask vas ready to be removed from the cask storage pit.

st r o auA u.s. wrum iuriuum.o u---

---

. <m m nw-cupe EXPnen vwt2 WM '

'g g

Facts.tri NAME (1)

DOCKET mmsEE 8 2) t.ta mmnts (5)

Pact (3) l YEAR sto mm arv Pl#ff HATCH, lNIT 2 05000366 90 009 00 3'

0F 5 rExt

~

1 On 10/23/90 at approximately 0238 CDT, personnel began lifting the shipping cask.

As the overhead crane hook came out of the vster. It was sprayed with

_i demineralized vater as part of routine decontamination operations.

At that time, ARM 2D21-K60lH tripped on high radiation (greater than 15 mR/hr) as one of the demineralized water hoses was moved near it.

This ARM is an input to.the l

[

MCREC system pressurization mode actuation logic; consequently, the HCREC system l

automatically transferred from the normal to the pressurization mode per design.

By approximately 0320 CDT, the shipping cask had been removed from the cask storage pit and placed in the cask washdown area on the Refueling Floor away from ARM 2D21-K60lH. The high radiation trip from the ARH cleared and at approximately 0320 CDT, the NCREC system pressurization mode' logic was reset and the system was returned to the normal mode.

The shipping cask vas decontaminated and surveyed prior to shipment per approved plant procedures to meet Federal requirements for shipping radioactive material.

4

CAUSE OF THE EVENT

The direct cause of this event was sensed high radiation by ARM 2D21-K60lH as a demineralized water hose was moved near it during routine decontamination operations in the cask storage pit.

Surveys of the hose performed after the ARH tripped indicated the hose was internally contaminated with contact readings as high as 50 mR/hr.

It was determined the hose had become internally contaminated when it had been used to drain another shipping cask removed a few days earlier.

The root cause of this event is less than adequate human factors, Hoses used to drain the shipping casks were neither labeled as contaminated nor segregated from clean hoses.

Consequently, personnel inadvertently chose an internally l

contaminated hose to spray demineralized water on the hook, rigging, and cask.

The internal contamination resulted in radiation levels sufficient.to trip the t

ARM vhen the hose was moved near it.

REPORTABILITY ENALYSIS AND SAFETY ASSESSMENT This report is requ uad per 10 CFR 50.73(a)(2)(iv) because'of-an unplanned l

actuation of an Engineered Safety Feature (ESP).

Specifically, the HCREC l

system, an ESF, swapped frm the normal to the pressurization mode when ARM l

2D21-K60lH tripped on sensea high radiation.

1 The ARM system provides information to plant personnel concerning radiation levels at selected locations within the plant where radioactive material may be present, stored, handled, or inadvertently introduced.

The-ARMS provide local indication as well as 'ndication in the Main Control Room.

They also alarm locally when radiation levels in that area exceed preselected setpoints, and, in the case of some of the Refueling Floor ARMS, provide a trip input to an ESF actuation logic system.

1 1

J

N roca Jus u.s. = r' = -- _- _, u -- -

. --, as e 31so-ezug W a91 '

surnani ('30M2 FAC!t.17Y NAME (1)

DOCKET WURRER (2)

LtR NUMBER ($)

PA05 (3)

TEAR sto wum REv.

3 PIMr HATCH, UNIT 2 05000365 90 009 00 4

0F 5 7t:KT The HCREC system is designed to ensure habitability of the Main Control Room following a Loss of Coolant Accident, a Fuel Hrndling Accident, a Main Steam Line Break Accident, or a Control Rod Drop Accident.

Specifically, the HCREC system enters the pre" urization mode of operation in response to a Loss of Coolant Accident sigru from Unit 1 or 2, a Refueling Floor high radiation signal from Unit 1 or 2, a Main Steam Line high flov signal from Unit 1 or 2, a Hain Steam Line high radiation signal from Unit 1 or 2, or a Main Control Room air intake high radiation signal. The pressurization mode pressurizes the Main Control Room thereby preventing inleakage of gaseous radioactive material and keeping doses to Main Control Room personnel to within 10 CFR 50, Appendix A, limits.

In the fuel handling design basis accident, a fuel bundle is dropped onto the core resulting in fuel rod damage and releases of radioactive gases into the Refueling Floor atmosphere. The results.of this design basis accident analysis indicate radiation fields sufficient to warrant the trip of selected ARHs and the resultant actuation of the HCREC system pressurization mode.

The Refueling Floor ARM trip anticipates the trip resulting from Main Control Room air intake high radiation signal.

As such, it provides additional protection over that assumed in the Unit 1 and Unit 2 Final Safety Analysis Reports from the air intake high radiation trip.

It should be noted these trips are designed to protect Main Control Room personnel from doses due to gaseous radioactive releases from accidents elsewhere in the plant.

Radiation from solid and/or liquid material which, by its physical nature, can not reach personnel in the Main Control Room is not relevant to these accident analyses.

In the event described in this report, the HCREC system entered the l

pressurization mode when Refueling Floor ARM 2021-K60lH tripped on sensed hign radiation. This occurred when an internally contaminated water hose was moved near the ARH during shipping ca'sk handling operations.

No accident or radioactive gas release had occurred to cause the high radiation signal.

The system responded as designed and would have functioned properly to protect personnel in the Main Control Room had an actual release of radioactive gas occurred on the Refueling Floor.

It shonld also be noted that shipping cask handling activities were conducted with-the monitoring of Health Physics personnel to assure radiation exposure was maintained as lov as reasonably achievable.

No personnel received an unexpectedly high dose from handling the contaminated. hose nor did anyone become contaminated, o

Based on the above, it is concluded this ever.t had no adverse impact on nuclear or personnel safety.

l l

1

^

ur su 366A U.s.--=-----m------

cum up n w-esse j

LI g g (LER)

FACILITY MARE (1)

DOCKET NUMMER (2)

LER HUptBER (5)

PAGE (3)

TEAR SEO NUR REV PIR(f HATCll, UNIT 2 05000366 90 009 00 5

OP 5 Tl;IT

CORRECTIVE ACTIONS

The MCREC system pressurization mode logic was reset and the system was returned f

to the normal mode at approximately 0320 CDT on 10/23/90.

Contaminated veter hoses were marked and segregated from clean hoses on 10/23/90.

ADDITIONAL INFORMATION

No systems other than the ARM and the.MCREC system were affected by this event.

No failed components caused or resulted from this event.

No previous similar events in which the MCREC system une<pectedly entered the pressurization mode have occurred in the last two' years as a result of shipping cask removal activities.