05000237/LER-1976-063, Updated LER 76-063/03L-l:on 761003,stack Gas Sample Pump Flow Appeared Abnormally Low.Caused by Collection of Carbon Impeller Vane Products in Pump Cavity & Filter.Pump & Filter Replaced

Updated LER 76-063/03L-l:on 761003,stack Gas Sample Pump Flow Appeared Abnormally Low.Caused by Collection of Carbon Impeller Vane Products in Pump Cavity & Filter.Pump & Filter Replaced

ML20084A306
Person / Time
Site:	Dresden
Issue date:	03/03/1977
From:	Weidner R COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20084A309	List: 05000237/LER-1976-063, Updated LER 76-063/03L-l:on 761003,stack Gas Sample Pump Flow Appeared Abnormally Low.Caused by Collection of Carbon Impeller Vane Products in Pump Cavity & Filter.Pump & Filter Replaced
References
77-176, LER-76-063-03L, LER-76-63-3L, NUDOCS 8304050157
Download: ML20084A306 (3)

LER-2076-063, Updated LER 76-063/03L-l:on 761003,stack Gas Sample Pump Flow Appeared Abnormally Low.Caused by Collection of Carbon Impeller Vane Products in Pump Cavity & Filter.Pump & Filter Replaced

Event date:
Report date:
2372076063R00 - NRC Website

text

, .

, . coNmot s.oCx:1 l l l l l l UPDATE REPOR3T PREM(9%flMRetungagTLof-1r-7A; cpm 3 ara..;T , i t r:ceu.:na inrarim,w;<

/3 6 p, dE LICENSE NUM51A P TYpg l 01 }IlLlDlRlSl2l 14 l 0l 0l-l 0l 0l 0l 0l 0l-l0 l0 l l 4 l1 l1 l1 l1 l l0 l3 l

, 7 89 15 25 26 30 31 32

~

CATEGCAY TY C DOOMET NU* ASEA EVENT CATE REPORT DATE 4

{o@rON'T l 7 C 57 l

58 l M59

[_LJ EO l 0 l 5 l 01-l O ! 2 l 3Dj 61 60

( 1l 0l 0l 3l 7l 6) 09 74 l0 75 l3 l0 l3 l7 l ,

EVENT DESCR:PTION Q[ During normal operation, radiation protection personnel reported that' stack gas 7 89 -

@ ( sample pump flow appeared to be abnormally low. An operator confimed that 2/3 7 89

@l 7 e9 "A" pump flew was 2.6 SCDh 2/3 "B" pump flow was 0.0 SCni (flow greater than t

I

$l 2.9 SCnf is considered normal). Tech Spec section 3.8.A.1 requires continuous 7 89 ~g

-@ l chimney monitoring, but states that during plateout tests, when both pumps must 7 89 . PRvE (Continued) L SYSit*A CA'JSE CcVOCNENT CO*APONENT CODE CODE CCMDON!NT CODE SLPPLAA Mr.uFACTV{A VOLATC'J

$ l BlB l d 7 89 10 11 l 2l Z l 7) Z l Z l Zl 12 17 W43 lZl9 l 9l 9l 44 47 W

48 CAUSE DES'CR:PTiON

) @ l Normal wear products from the carbon impeller vanes collected in the sample _

t 7 89 g.

1 Ql liries, pump cavity, and filter of the 2/3 "A" pump, resulting in reduced pump

, 7 89 i 3g l efficiency and flow. The zero-flow condition on the 2/3 "B" pump was caused 7 69 (Continued) U

,, gg gg g, STATUS  % POWE A OTHER STATUS DISCOVERY DISCCVEAY DESCA.PTON j 11 y 9

l 0l 9l 7l l 'NA l y l NA j 7 8 10 12 13 44 45 46 E, j

ACT vrrY CORTENT RELEASED AMOUNT CF ACTMTV LOCA*CN OF RELEASE 3 ]@

7 8

]

9 OF [RELEASENAl 10 11 l

44 l

45 NA E

i PERSONNEL EXPOSURES 1 NUMBER TYPE DESCA# TON I E l0l0l 0l Wl NA _

l 7 89 11 ,12 13 . 8 PERSONSEL IN.JUR!ES 4

NUMBEA DESCR'PTCN 35 l 0l 0l d l NA 7 89 11 12 (1 OFFSITE CONSEQUENCES DE I "^

7 89 W LOSS OR DAMAGE TO FActLITY ,

TYPE DESCA;PTON 4

@ d 'l10 7 89 NA Sd

, PUBLCITY j

, . Og l NA '

i 7 89 El ADOITONAL FACTORS 8304050157 77030'3

• PDR S ADOCK 05000237 Ql NA PDR 7 89 ,

8' 8I 7 89 NAME: Randninh c. W fdner PHONE. Ext. 265 l

. eco ses.efq

3- ,

EVENT DESCRIPTION (Continued) be out of service, the steam jet air ejector monitors may be used to satisfy the plant chimney monitoring requirements if the reactor is operating at a ,

steady-state power level. Although a plateout test was not being performed -

when both pumps were forced out of service, the reactor had been operating in the steady-state condition for 13 hours1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br />, and both steam jet air ejector monitors were operable. During the period from 1725 to 1930 hours0.0223 days <br />0.536 hours <br />0.00319 weeks <br />7.34365e-4 months <br />, while the 2/3 "A" sample pump and suction filter were being replaced to provide rapid

! compliance with Tech Spec requirements, the steady-state operation of the unit and the static response of the SJAE monitors ensured that no unacceptable

! releases occurred. Because the cause of failure could not be readily identified on the 2/3 "B" sample pump, it was decided to first restore the operability of l

the "A" sample pump by simply replacing the pump and suction filter, Personnel ,

i errors resulting in stack gas sample pump problems have occurred occasionally l in the past. (50-237/1976-63) l CAUSE DESCRIPTION (Continued)

I by an improper valve lineup.

As stated above, the 2/3 "A" sample pump and suction filter were replaced.

The 2/3 "B" sample pump was returned to service at 1125 hours0.013 days <br />0.313 hours <br />0.00186 weeks <br />4.280625e-4 months <br /> on 10/4/76, after

~

l the valving error was discovered.

l Reevaluation of the events related to the temporary loss of stack gas sampling capability on October 3, 1976, has resulted in the following conclusions:

i

1. The proximate cause of the event was personnel error (cause code A).

This conclusion is based on the fact that, at the time of the event, l

I the operator was unable to establish flow in the standby sample train even though no equipment malfunction existed.

2. The root cause of the event was the inadequacy of the system descrip-tion in the applicable operating procedure -- DOP 1700-4.. Had a piping and valve diagram been included in the procedure, the operator would certainly have been able to readily perform the valving required to place the standby sample train in service.'

To avoid recurrence, procedure DOP 1700-4, Off-Gas Vent (Stack) Radiation Monitoring System, was revised, and a valve and piping diagram and isometric-drawing were added. Additionally, a copy of the new valve and piping diagram has been posted in the sample pump area.

• 1 a

• i .

I '

Common Ith Edison O j

3 } One First Na i Plua Chic;go. Illinois 'bl N. ~

Address R; ply to: Post Offica Box 767 Chicago. lilinois 60690 I

l l

BBS Ltr. #77-176 March 7, 1977

'\

D Mr. James G. Keppler, Regional Director Directorate of Regulatory Operations - Region III /

• o o.wc U. S. Nuclear Regulatory Commission l- 9 799 Roosevelt Road $g gI,b3[J)

                                                                                                                         ~

Glen Ellyn, Illinois 60137 \.A r. ,, E

                                                                                           \ \      .
                                                                                             ' \                       '

REFERENCES:

Docket Number 50-237 ^ Docket Number 50-249 { ' Enclosed please find an update report to Reportable Occurrence report number 50-237/1976-63. This report is being submitted to your office in accordance with the Dresden Nuclear Power Station Technical Specifications, Section 6.6.B. ,

                                                                            ...      79
                                                              " /[ [ M /'.si) $

lf. B. Stephenson Station Superintendent Dresden Nuclear Power Station , BBS:jo Enclosure cc: Director of Inspection & Enforcement Director of Mr.cagement Information & Program Control File /NRC Do )h e/30

                                                                                   .

}}