ML20234A970
| ML20234A970 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 09/09/1987 |
| From: | NRC OFFICE OF SPECIAL PROJECTS |
| To: | |
| Shared Package | |
| ML20234A961 | List: |
| References | |
| NUDOCS 8709180215 | |
| Download: ML20234A970 (3) | |
Text
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l SAFETY EVALUATION BY THE OFFICE OF SPECIAL PROJECTS
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i SUPPORTING AMENDMENT N0. 57 TO FACILITY OPERATING LICENSE NO. OPR-77
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AND AMENDMENT N0. 49 TO FACILITY OPERATING LICENSE NO. DPR-79 TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT, UNITS 1 AND 2 DOCKET NOS. 50-327 AND 50-328
1.0 INTRODUCTION
By letter dated Aprii 14, 1987, and clarified by letters dated July 8 and 27 I981, Tennessee Valley Auth.)rit Technical Specification (y, the licensee for Sequoyah Units 1 and 2, proposed ly) changes to TS 4.3.3.9.
The proposed changes '
involve surveillance requirements (SR) for radiation monitors in steam generhtor blowdown and condensate, demineralized effluent release lines.
2.0 EVALUATION
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The subject radiation monitors are those associated with both the steam generator blowdown liquid effluent release pathways R-90-120 and R-90-121 and the condensate demineralized liquid effluent release pathway, R;90-225. f Under the current TS, it is required that the channel functional test shall demon-strate that automatic isolation of pathways and control room alarm annuncia-tion occur if an,y of the following conditions exist:
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Instrument indicates meagred %vels above the clarm/ trip setpdint'.
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Circuit failure.
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Downscale failure.
r' The proposed TS changes refer to the deletion of the functional test SR for automatic isolation of the release pathway due to instrument downscale failure but continue to require control roon alann annunciation. The licensee stated that radiation monitors R-90-120 R-90-121 and R-90-225 were neither designed nor intended to initiate an automatic isolation of the release path-way from an instrument downscale failure. Hardware changes to the radiation j monitors would be required for the monitors to perform this function.
The proposed TS change would initiate the following actionL spon receipt of a control room alarm for these radiation monitors: The failed monitor would be declared inoperable, and the appropriate TS Limiting Conditions for Operation P
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p y- (LCO) entered. LCO 3.3.3.9.b requires ACTIONS shown in Table 3.3-12.
Action items 30 and '31 in Table 3.3-'12 call for grab sample analysis and appropriate limits'en effluent release including suspension of release of radioactive I
effluents via these pathways depending on the result of the sample analysis.
The LC0 also requires a best effort to return the instruments to operable status within 30 days and, if unsuccessful, explain in the next semi-annual Radioactive Effluent Release Report why the operability could not be corrected i
within_30 days.
In a' July 8,1987 letter, the licensee provided clarification which stated that, even if there is a downscale failure, the system is able to isolate the q
pathways in case of high radioactivity in the effluents because:
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The steam generator blowdown effluent monitors, RM-90-120 and RM-90-121, l
provide independent isolation signals to the blowdown monitor isolation valves.
Should one monitor have a downscale failure, the other monitor has the capability'of isolating the effluent release pathways in the event of an increase of radioactivity above the setpoint.
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The condensate demineralized effluent is a batch process. When a tank is ready for release, it is sampled in accordance with Regulatory Guide 1.21.
The condensate demineralized effluent radiation monitor, RM-90-225, will initiate a main control room alarm (instrument failure) and a local alarm (high radiation / instrument failure) when a downscale failure occurs. Upon receipt of the local alarm, the operator is required to terminate the release per System Operating Instruction (S01)-14.3. S01-14.3 states that, if a high radiation alarm annunciated, discharge should be stopped immediately. The local alarm (high radiation) is a multipurpose alarm that is initiated by a high radiation signal or instrument failure, i
Moreover, the licensee has clarified its commitment, by letter dated July 27, 1987, to revise currtnt Surveillance Instruction (SI-401, Steam Generator h
Blowdown Continuous Release) and System Operating Instruction (S01-55, Annunciator Response) so that downscale failure of both monitors for the steam generator blowdown pathways would require the operator to terminate the dis-charge. Together with the batch release requirements described above for the condensate demineralized discharge pathway (501-14.3), the requirements in the revised surveillance instruction, SI-401, would effectively provide the same level of assurance as the current TS would in minimizing the possibility of releasing high level radioactive material through these pathways. Therefore, the staff finds the proposed changes to the TS to be acceptable.
3.0 ENVIRONMENTAL CONSIDERATION
I These amendments involve a change to a requirement with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes to the surveillance requirements. The staff has determined that the amendments involvc no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or l
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. cumulative occupational radiation exposure. The' Commission has previously issued a proposed finding that these amendments involve no significant hazards consideration and there.has been no public comment on such finding. Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forthin10CFR51.22(c)(9).
Pursuant to 10 CFR 51.22(b), no environmental impact statement nor environmental assessment need be prepared in connection with the issuance of these amendments.
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4.0 CONCLUSION
We have concluded, based on the considerations discussed above, that:
i (1) there is reasonable assurance that the health and safety of the will not be endangered by operation in the proposed manner, and (2) public such activities will be conducted in compliance with the Commission's regulations, and the issuance of these amendments will not be inimical to the common defense and security nor to the health and safety of the public.
Principal Contributor:
Sang Bo Kim Dated: September 9,1987 1
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