ML20037B791
| ML20037B791 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 11/26/1980 |
| From: | Ullrich W PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| RO-2-80-31-1P, NUDOCS 8012040429 | |
| Download: ML20037B791 (3) | |
Text
.. _
+
1 PHILADELPHIA ELECTRIC COMPANY Peach Bottom Atomic Power Station Delta, Pennsylvania 17314 November 26, 1930 Mr. Boyce H.
Grier United States Nuclear Regulatory Commission Region I Office of Inspection and Enforcement 631 Park Avenue
]
King of Prussia, PA 19406 PROMPT NOTIFICATION
SUBJECT:
REPORTABLE OCCURRENCE i
Confirming W.
T.
U11 rich's conversation with Mr. Cowgill on November 26, 1980.
~
Reference:
Docket No. 50-277 Peach Botton Unit 2 Technical Specification
Reference:
3.2.D.1(a) 3.8.C.4 Report No. 2-80-31/IP Occurrence Date:
November 23, 1980 Identification of Occurrence:
At approximately 10 PM on 11/22/80 Unit 2 power was reduced to adjust the controi rod pattern.
As a result of the power reduction, minor pressure variations occurred within the off-gas processing and sampling system.
Those variations resulted in a gradual flooding of the sample piping leading to the off-gas radiation monitors.
Over an eight to ten hour period, sample flow was reduced and radiation readings decreased to background levels.
Shift personnel identified the reduction in r_ t t' gas radiation Icvels and investigated this sampling system.
So their opinion some sample flow was selli reach-ing the radiation monitors.
Shift Supervision, cherefore, believed that the off-gas sampling system was operable during the period ofa time that steps were being taken to increase the sample flow to merama valume.
On November 24 4 25, staff investigation of these operations ~ aiong with~some special testing completed on the morning o f_ Novemb er 26, provided information which indicates that the of f-gas sampling i
p6riod of time'on the' morning of system was inoperable'during a November ~23.
This Prompt Notification is, therefore, being submitted ac this time.
94 Md O2 5
//
.=
g.
Conditions Prior to Occurrence:
unit 2 power being reduced from approximately 95 percent to 75 percent.
Power recovery was begun early on 11/23/40 and full power reached late on 11/24/80.
Apparent Cause of Occurrence:
Due to a power reduction, system dynamics in the off-gas processing and sampling system transferred water from the normal collection system into the sample system resulting in a reduction in off-gas sample flow to the radiation detectors.
Analysis of occurrence :
Although relatively minor power level changes were in progress during this period of inoperability, off-gas values were similar ~
following return of the system to service and those experienced prior to the power reduction.
Other parameters'which monitor primary coolant radiation (main steam line monitors) showed no unexpected changes.
With the present off-gas system design et Peach Bottom. the off-gas radiation monitors are for operator information only and serve no safety function.
O f f - g a ?.
from the condenser is processed through a recombiner into a five-day holdup pipe prior to release.
There was, therefore, ample opportunity to erevent release of high activity, gas had significant fuel failures occurred during the period of time that the off-gas sampling system was inoperable.
Safety significance is, therefo?e, sinimal.
Corrective Action:
On 31/24/80, a temporary off-gas radiation monitoring system was installed.
In addition, the off-gas sampling system was removed from service for a short period of time and water purged from the system.
The system was then returned to service and has been operating properly.
With the temporary radiation monitors installed, the off-gas sampling system was removed from service on 11/25 to perform tests to determine the response of the radiation detectors due to loss of off-gas s ampl e flow.
The system was placed back in service and has been operating properly since 8:30 AM, 11/26/80.
Previous Failures:
Nome similar.
Very truly yours, fV WY
_' ~ J W.
T.
Ullrich i ] k_. 73 Station Superintendent s.
hMkE e
Y
.._.>.e-,----,mn-p.we-m-m----wn-,--~e v-*w wrv'rev' ' ' ' " ' ' ' ' ' '
~~
U. S. NUCLE AO CE!ULATORY COMMISSION NRC FORM 384 mm
~
LICENSEE EVENT REPORT CONTROL BLOCK: l l
l l
1 1 Ih (PLEASE PRINT OP TYPE ALL REQUIRED INFORMATION) lo ;il l i
I I
I I
l@l I
I I
I I
I I
I I
I l@l I
I I
I l@l I
l@
7 8 9 LICENSEE CODE 14 IS LICENSE NUMSER 25 26 LICENSE TYPE JG S T C A T $8 rFTTI
=aj i i@lol 51o lo 1o1217171@l/ i /1231 il ol@l/ I /1214 I 8 to l@
CON'T f
8 60 61 DOCKET NUMBER 68 69 EVENT OATE 74 75 REPQRT DATE 80 EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h l
10121 l 10131 l bbb bd -
M2, 1
I ITTTI I I
ITTTl1 I
lo Is l l l
l o l 71 I l
i o is 1 I 80 C CE CODE Sust E COMPCNENT CODE SUSCO E S
DE Udll i
I l@ U@ l l@ l I
I I
I I 18 U@ U @
7 8
9 70 ft 12 13 18 19 20 SEOUENTIAL OCCURRENCE REPORT R E VtSION EVFNT YE AR REPORT NO.
C' iD E TYPE NO.
@.a=E A RO 1% lol 1-1 101311 l Ld i
I I
I I
l-l U
L
_ 21 22 23 24 26 27 28 29 30 31 32 TAK N AC O ONP N*
MET HOURS S8 IT FOR 9.
SU Li MA UFAC RER U@l l@
l l@
l l@
l I
I I
I U@
L_lO I
l@
l I
I I
l@
JJ 34 35 36 31 40 41 42 43 44 47 CAUSE OEWRIPTION AND CO*'r'ECTIVE ACTIONS l
lilo I {
~
li lil.
I lil2; I l
gl I
Lu AJ l 80p 7
8 9 STA S
% POWER OTHER STATUS 015 0 RY DISCOVERY DESCRIPTION li is i i l@ l i
I l@l i
I l@l I
- 5 COhNT ACTiv,Tv RELEA nr. OF RELE ASE AMOUNT OF ACTIVITY LOCATION OF RELEASE liIsl U @ U @l l
I l
7 3 9 10 11 44 4) 80 PERSONNEL EXPOSURES NUMBER TYPE DESCRIPTION li l 71 1 I
I l@U@L I
' PERSO~NEL,N,UAES oESCRIPTiO~@
NLMeeR i
b_] I l
l l@l l
90 7
4 9 11 12
'O5 ESC #4'O' ' ' ' " @
' " ^"
T E l'Isl l l@l l
80 7
1 1 10 e
ESCRIPTION ISSUE [81 1
11111111'11111 L_.
2 o 68 69 80 5 7
4 3 10 NAME.jf PREPARER PHONE:
-