ML19261B212
| ML19261B212 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 01/02/1979 |
| From: | TOLEDO EDISON CO. |
| To: | |
| Shared Package | |
| ML19261B210 | List: |
| References | |
| NP-09-79-01, NP-9-79-1, NUDOCS 7902140174 | |
| Download: ML19261B212 (2) | |
Text
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TOLEDO EDISON COMPANY DAVIS-BESSE NUCLEAR POWER STATION UNIT ONE REPORTABLE OCCURRENCE NP-09-79-01 l
DATE OF EVENT: January 2, 1979 EACILITY: Davis-Besse Unit 1 IDENTIFICATION OF OCCURRENCE:
RE 2024 and RE 2025, Station Ventilation Radiation Moni-tors, were inoperable Conditions Prior to Occurrence:
The unit was in Mode 1, with Power (MWT) = 2541, and Load (Gross MWE) = 861.
Description of' Occurrence:
During a review of previous failures of radiation monitors, it was discovered that RE 2024 and RE 2075 were concurrently inoperable in the past, and that these were reportable occurrences.
A thorough review of Surveillance Tests ST 5032.01, " Monthly Functional Test of the Radiation Monitoring System", and ST 5032.02,
" Radiation Monitoring System Channel Calibration", was conducted, and the following dates for concurrent inoperabilities were revealed:
Date Reason For Inoperability 8/29/77 RE 2024 - actual flow out of tolerance RE 2025 - flow out of tolerance i
12/14/77 RE 2024 - low flow setpoint out of tolerance RE 2025 - no verification of operability for high and low flow lights In each case, the unit was not in compliance with Environmental Technical Specification (ETS) Table 2.4-3.
No Action Statement was applicable.
Designation of Apparent Cause of Occurrence: The apparent cause of the occurrences is attributed to component failure.
In each case, the REs were returned to operability.
The reason that previous occurrences had not been reported is due to both personnel error and difficulty.in interpreting the ETS.
I Analysis of Occurrence: Grab samples were obtained and analyzed to be within limits l
during the period that both REs were inoperable.
RE 5405A, B, and C (Auxiliary Build-I ing Radwaste Area Exhaust Monitors), as well as RE 5403A, B, and C (Auxiliary Building Puel Handling Area Exhaust Monitors) were operable during the period that RE 2024 and RE 2025 were inoperable. REs 1003A and B (Condenser Air Ej ector Monitors), however, were not operable during these periods as required by the ETS.
7902140(19
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TOLEDO EDISON COMPANY DAVIS-BESSE NUCLEAR POWER STATION UNIT ONE REPORTABLE OCCURRENCE NP-09-79-01 PAGE 2 Corrective Action: Although exact times for return to operability of RE 2024 and RE 2025 cannot in every inseance be determined, the following work was performed:
- 1) Following the inoperability of both REs on August 29, 1977, the alert setpoint on RE 2025 was reset and the setpoints on both monitors were recalibrated.
- 2) Following the inoperability of both REs on December 19, 1977, both REs were returned to operable status under Work Request 1C-1524.
A memo dated January 4,1979, has been sent to various station personnel to make them more cognizant of the fact that the inoperability of RE 2024 and RE 2025, as well as other REs in the Environmental Technical Specifications, is a reporta-ble occurrence. The Envirommental Technical Specifications are currently in the process of revision.
Modifications to Surveillance Tests ST 5032.01 and ST 5032.02 have been made to emphasize the reportability requirements of those REs in the Environmental Technical Specifications.
Failure Data: There have been no previously reported occurrences of the inopera-bility of RE 2024 and RE 2025.
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