ML20028H098
| ML20028H098 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 09/25/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20028H097 | List: |
| References | |
| NUDOCS 9010090112 | |
| Download: ML20028H098 (4) | |
Text
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NUCLEAR REGULATORY COMMISSION c
o WASHINGTON. D. C. 20555 l
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION i
RELATED TO AMENDMENT NO.156 TO FACILITY OPERATING LICENSE NO. DPR-50 METROPOLITAN EDISON COMPANY JERSEY CENTRAL POWER & LIGHT CS PANY PENNSYLVANIA ELECTRIC COMPANY GPU NUCLEAR CO,RPORATION THREE MILE ISLAND NUCLEAR STATION, UNIT NO. 1 DOCKET NO. 50-289 s
INTRODUCTION GPU. Nuclear Corporation (the licensee) requested various minor changes to the Three Mile Island Unit 1 (TMI-1) Technical Specifications (TSs) in a letter dated July 26, 1989.
Two of these changes affect instrumentation surveillance frequency.
The other changes provide clarification of or correct clerical errors'in the TSs.
-EVALUATION
_ Reactor-Protection System (RPS) Testina
- I The first proposed change pertains to revision of the RPS channel testing schedule making the number of-performances per channel more equitable.
Performing tests in accordance with the present schedule accrues significantly different numbers of monthly tests per channel over time.
Since the. rotation always begins with channel A, operating cycles containing several plant j'
shutdowns and start-ups result in channel A accru %' the greatest number of test performances with 8, C and D decreasing respr ivelv.
Unnecessary degradation or wear of components having the greatest. iber of test cycles may result over the life of the plant.
This change orJj alters the order of
-test' performance previously delineated.
Specifically, the revised TSs would:
specify a continuous sequential rotation for weekly testing (even after startup-from shutdowns of less-than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />) rather than always starting the.
sequence over with channel A following a shutdown.. Revising the rotation 3
schedule of the RPS channel testing will increase confidence in the operability of those channels that had.a fewer number of tests.
At.the same I
. time, it will reduce the' wear on those components having the greatest number l;
of_ test cycles, l
L The NRC staff has evaluated this request and finds that it is justified and:
i acceptable.
This change will also make the TMI-1 TSs more consistent with the B&W; standard TSs.
' Reactor Buildina ' Sump Area Radiation Monitor Surveillance The-second. proposed change involves the calibration frequency of area gamma radiation. monitor RM-G21, which monitors radiation levels at the reactor building sump standpipe (elevation 281).
The licensee has requested exemption 9010090112 900925 PDR ADOCK,05000289 L
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.c from quarterly calibration of this monitor during periods when reactor' building purging is not permitted.
During such periods (i.e. normal power 4
operation), the monitor would be calibrated during the next scheduled reactor shutdown following the quarter in which calibration would normally be due.
This request is consistent with a similar provision for radiation monitor RM-G5 (reactor building personnel hatch) that was approved by License Amendment =NO. 103 in May 1985.
Radiation channel RM-G21 provides monitoring of activity for containment 1
isolation.
It monitors the reactor building sump and alarms and isolates the sump by closing valves WDL-V534 and WDL-V535 on detection of radioactivity above the setpoint.
The licensee's application stated that decreasing the calibration frequency will have no affect on the nuclear safety or safe plant operation since:
the safety function is required infrequently; the sump isolation valves a.
are normally closed (open only for draining the sump).
b.
changing isolation valve positions to open requires manual accion.
It is not. automatic.
Closure of WDL-V535 is automatic on low sump level,
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c.
conservatism exists in the independent alert setpoint.
d.
administrative controls' require operator action in response to excessive radiation levels indicated by sustained or unexpected alert or high-alarm from radiation monitors reading out in the control room.
i Given the above, the licensee claims. that any drift resulting from the longer calibration frequency.should not impact the ability to isolate the sump and that the benefit of the change that will result from the decrease in calibration frequency is a-reduction in personnel-exposure and this will i
offset any' decrease in reliability resulting from the increase in calibration frequency.
L In its review of this request,.the staff notes that calibration of containment.
monitors, such as-area gamma radiation monitor RM-G21, may be considered a i
special case when compared to the calibration needs of a11'other area monitors in the plant.
Calibration of these monitors requires personnel entry to the containment.
With-the reactor at power, this person would be potentially exposed to high levels of. neutron and gamma radiation, as well as airborne radioactivity levels.
In order to minimize radiation to personnel calibrating the containment areas monitors, the licensee would have to shut-down the L
reactor and purge containment prior to personnel entry..However, shutting l
down the reactor every quarter to calibrate the containment area monitors is l
not cost effective with respect to the philosphy of ALARA.
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3 Additional factors that influence our evaluation are that area monitors in containment (reactor buildi.1g) are not safety related and are not required to operate during accident or seismic events.
Only those two high-range monitors installed in accordance with NUREG-0737 need be so qualified.
Three Mile.
Island Unit 1 TSs require all area monitors to have a channel check and functional test at frequent intervals (i.e., weekly and monthly respectively)
. to verify operability of the channel, including alarm function.
. From the above, we can draw the following conclusions concerning_ area monitor RM-G21, and area. monitors in containment in general:
(1) They are not used primarily for occupational exposure purposes.
(2) They are located in high radiation areas so that an RWP and portable radiation survey equipment are required for entry into the area in accordance with TSs.
Therefore, these area monitors are not needed for radiation protection when entry into containment is made.
(3) There is no need for calibrating them every quarter if this necessitates unnecessarily exposing personnel to high levels of radiation during each calibration. 'This is not consistent with ALARA philosophy.
Channel checks and functional tests are performed frequently to assure operability of the channel in accordance with TSs.
(4) They should, however, be calibrated quarterly whenever full containment purging is permitted and not less often than once every 18 months during refueling: outages.
(5) Recalibration of these monitors should be perfors.,ed after maintenance or replacerent of any component that could affect calibration.
Based on the above criteria, we concur with the TS change that defers calibration frequency requirements for area monitor RM-G21 from quarterly to periods of shutdown when full purging is permitted.
Editorial Changes The licensee proposed changing the list of monitors in the note on page 4-Sa to exclude those monitors specifically identified, thereby resolving conflicts.
between table 4.1-1 item 28 and tables 4.21-1 and 4.21-2.
Revising-the note to, exclude the monitors identified by the specified TS sections, 3.21 (Radioactive Liquid Effluent Instrumentation) and 4.21 (Radioactive Gaseous Process Effluent Monitoring Instrumentation), eliminates possible ambiquity.in the Radiation Monitoring System channel being described.
The final proposed change is administrative in nature and has no adverse effect upon nuclear safety.
TS 4.1-1.23 has been changed to correct a clerical error since " Absolute" has been specified instead of " Relative".
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,'l 1 'i The staff concurs with the above editorial changes because they' remove ambiquity and errors from the TSs..
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In addition to the above' changes, the staff has included revised page viii to
_i the TS index to correct a clerical error on that page with the issuance of License Amendment No. 150.- Figure 3.5-2m was to remain as part of the TSs.
ENVIRONMENTAL CONSIDERATION The amendment changes a requirement with respect to installation or use of a facility component located within the restricted areas as defined in-10 CFR-Part 20 and changes surveillance requirements. We have determined that the i
amendment involves no significant increase in the amounts and no significant change in the types of any effluents that may be released off site, and that there is no significant increase in individual or cumulative occupational radiation exposure.
The staff has previously issued a proposed finding that the amendment involves no significant hazards consideration, and there has been no public comment on such finding.
Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b), no -
'ronmental impact statement or environmental i
assessment need be prepared in connection with the issuance of this amendment.
CONCLUSION' a
We have concluded, based on the considerations discussed above, that (1)'there is reasonable assurance that the. health and safety of the public will not be endangered by operation.in the proposed manner, and (2) such activities will be s
conducted in compliance with the Commission's regulations, and (3) the issuance.
of this amendment will not be inimical to the' common defense and security or to the_ health and safety of the public.
Principal Contributor:
Ronald W. Hernan Dated: September 25, 1990 l
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