ML19210A125
| ML19210A125 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 07/19/1976 |
| From: | Arnold R METROPOLITAN EDISON CO. |
| To: | |
| References | |
| NUDOCS 7910240842 | |
| Download: ML19210A125 (4) | |
Text
'
NRC FORu 195 u.s. NUCLEAR REGULATORY
'310N DOCK NU SER FILE NUM 01R NRC DISTRIBUTION FOR PART 50 DOCKET MATERIAL INCIDENT REPORT FROM: Metropolitan Edison C,.
D^TE eo CUuENT TO:,Q.P.0'Reilly 7-19-76 Reading, Pa.
R.C. Arnold DATE RECE E QLETTER O NOTO RIZ E D PROP INPUT FORM NUMBER OF COPIES RECEIVED GORIGINAL Q UNC LASSIFIE D OCOev 1
DESCRIPTION ENCLOSU RE Ltr. providing Reportable Occurrence # 76-26/3L on 6-22-76 concerning Inoperable High Radiation Actuation Mode of a Reactor Building Purge Exhaust Monitor.......
( 1 Signed Cy. Received)
~ ~ ' ~
~-
- '7
( 3 Pages)
- - " ^ - - '
PIANT NAME:
7hree Mi1e Is1and # 1 NOTE:
IF PF9SONNEL EXPOSU"3 IS INVOLVED SENDDIRECTLYTOKREGER/J.. COLLINS FOR ACTION /INFORMATION 5AB /-29-/6 A RANCH CHIEF:
Reid W/3 CYS FOR ACTION SIC.-ASST. :
Inaram W/
CYS ACRS 1 g CYS DLMi9/SENT TO LA INTERNAL DISTR BUTION
_s.3EEG-WILW NRC PDR m.4I & E (2)
.MIPC - - - -
8CHROEDER/IPPOLI'IO 4 EOUS' ION
'?!OVAK/CHECX f, RIMES w CASE MER
@ RIAUER E ESCO/MACCARY v
EISENHUT w
s ?AER 4
SHA0 4'OLIJER/H 77CH
-MREGER/J. COLLINS
~
EXTERNAL DISTRIBUTION CONTROL NUMBER vRPDR: Harrisbura. Pa.
wl4'IC:
% MSIC:
7567 1489 358 NRCFORM 195(2 76) to OTMd
Mw,3, ;p men no anosern,
~ ~, '
G %:. ? ", ;x f
/ (,
METROPOLITAN EDISON COMPANY
/ f,gg
- 3. _.... 7,.,
POGT CFIICE BOX 542 READING, PENNSYLV ANI A 19603
" TELEPHONE 215 - 200601 ta
's, g,
auly 19, 1910
/v e
, e e s/
/,N Kg s
~__
VL---
\\.
Mr. J. P. O'Reilly, Director Office of Inspection & Enforcement, Regicn I U.S. IIuclear Regulatory Cc==issicn 631 Park Avenue King of Prussia, PA 19hc6
Dear Sir:
Docket :Io. 50-289 Operating License No. DPR-50 In accordance with the Technical Specifications of our Three Mile Island Nuclear Station Unit 1 (TMI-1), we are reporting the following reiortable occurrence:
(1) Repcrt Ilumber: ER 76-26/3L (2a) Required Report Date: July 22, 1976 (2b) Date of Occurrence: June 22, 1976 (3) Facility: Three Mile Island Nuclear Station - Unit 1
(*)
Identification of Occurrence:
Title:
Inoperable High Radiation Actuation Mode of a Reactor Building Purge Exhaust Mcnitor.
Type:
A reportable occurrence as defined by Technical Specification 6.9.2.B(4) in that failure of Reactor Building purFe exhaust monitor RM-A9 to close purge exhaust valvs.s AH-VlA and AH-V1B upon receipt of a high radiation test signal showed abnormal degradation of a system designed to contain radioactive material resulting frca the fission process.
(5) Conditions Prior to Occurrence:
Pcver:
Core:
2531 MWt
." ?c: 83h !"Je (Gross) 1dQO
'6*
,U RC Flev: lh0 x 106 lbs/hr.
~
~
RC Pressure:
2155 psig RC Temp.: 579 F PRZR Level:
225 inches FRZR Temp.: 650 F (6) Description of Occurrence:
On June 22, 1976, while performing Surveillance Procedure 1303-h.15, Radiation Monitoring System (RMS) Monthly Test, Reactor Building purge exhaust monitor RM-A9 failed to close purge exhaust valves AH-V1A and AH-71B upcn receipt of a high radiation test signal. Upon recognition of this condition both valves were irmediately closed. Investigation results showed that the plug-in interlock and alarm relays for RM-A9 had been removed.
The relays were returned to their correct location and tested. The test results were satisfactory.
(7) Designation of Apparent Cause of Occurrence:
The cause of this occurrence has been determined to be personnel in that +he interlock and alarm relays, which were apparently removed during calibration to prevent spurious alarms on the RMS alarm panel, were not returncl to the RM-A9 module on completion of the maintenance.
(8) Analysis of Occurrence:
From June 11, 1976, the date on which the alarm and interlock relays were not returned to their proper location following maintenance on RM-A9, to June 22, 1976, when the relays were reinstalled, three (3) Reactor Building purges were performed.
However, it has been determined that this occurrence did not constitute a threat to the health and safety of the public in that:
a.
Review of the release data showed that no technical specification release limits were exceeded during the purges.
b.
Even though the alarm and interlock relays of RM-A9 vere missing, RM-A9 still monitored the radiation level of the purges with read out and local alarm available in the Control Rocm.
c.
The Reactor Building purge valves could have been closed
~
manually if a high radiation condition existed.
(9) Corrective Actica:
In addition to the immediate corrective action described above, the instrument maintenance personnel have been counseled regarding restoring equipment to service and assuring that adequate procedures are used.
~
(10) Failure Data: II/A Similar Occurrences: None Sincerely, I
~
R. C. Arnold Vice President RCA:JMC:cas V
1489
!;61