ML20028H007
| ML20028H007 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 10/02/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20028H006 | List: |
| References | |
| NUDOCS 9010050147 | |
| Download: ML20028H007 (2) | |
Text
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UNITED STATES
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ENCLOSURE 2 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION AND AMENDMENT NO. 129 TO FACILITY OPERATING LICENSE NO. DPR.79 l
TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT, UNIT 2 i
DOCKET NO. 50-328 i
1.0 INTRODUCTION
r By letter dated January 12 1990,theTennesseeValleyAuthority(TVA) proposed t
to modify the Sequoyah Nuclear Plant (SQN), Unit 2. Technical Specifications (TSs). The proposed changes are to revist the trip setpoint and allowable value units for the intermediate range (IR) nuclear flux detectors and to revise the applicability requirements for the source range (SR) nuclear flux i
detectors. This is TVA's TS Change Request 88-42. This application dated January 12, 1990 superseded TVA's application dated December 2,1989 and its letter dated January 24, 1989, on the same TS change request.
In order to meet License Conditions 2.C.14 (Unit 2) and 2.C.24 (Unit 1), TVA has elected to replace the SR and IR neutron detectors. These license condi-tions were required because the present SR and IR neutron detectors did not meet the requirements of NRC Regulatory Guide 1.97. The new detectors are Class 1E equi Because of desipment, and are seismically and environmentally qualified.
- n differences between the old and new detectors, TVA has proposed changes to t1e present TS requirements on this equiprent.
The application dated January 12 1990 also proposed changes to the Sequoyah Unit 1 TSs. These changes were Issued as Amendment 136 to the Unit 1 TSs in 1
the staff's letter dated April 27, 1990.
2.0 EVALUATION l
l The new SR/IR detectors are a fission chamber design, manufactured by Gamma Metrics. The new detectors are compatible with the current system except for certain features which necessitate the following TS changes:
(a) TVA has proposed to change the footnote (symbol H) in TS Tabic 3.3-1 to state that source range outputs may be disabled above the P-6 setpoint instead of the statement that high voltage to detector may be de-energized above the P-6 setpoint. This change is required because in the new design for the SR detectors, the output signal is automatically blocked frcm the reactor trip logic for a reactor power level above the P-6 setpoint and the detector is not required to be de-energized above the P-6 setpoint.
Based on this, the staff finds the proposed change to the TS Table 3.3-1 acceptable.
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_ (b) TVA has proposed to change the units of the P-6 setpoint and allowable value listed in TS Table 2.2-1 from " amps" to " power." This change is required because the new IR detector output signals are in units of power rather than amperes. TVA has perfonned a calculation to determine the relationship between reactor power and detector current. This relation-ship was used to convert the trip setpoint and allowable value to a relative power value. The staff has reviewed the calculation and finds it acceptable. Since the actual setpoint has not been changed, it does not affect the accident analysis previously app *oved by the staff. TVA has also proposed to revise the bases in Sectio.; 2.2 of the TSs to delete the reference to IR detector current signals that are proportional to power levels.
Based on this, the staff finds the proposed c1ange to TS Table 2.2-1 and the associated bases acceptable.
Therefore, based on the above, the staff concludes that the preposed changes to the TSs in the application dated January 12, 1990 are acceptable. These changes are administrative in nature and do not invalidate any previous analysis on Sequoyah.
3.0 ENVIR0fa' ENTAL CONSIDERATION This amendment involves a change to a regt irement with respect to the installation or use of a facility componen'. located within the restricted area as defined in 10 CFR Part 20. The staff has ce urs.ined that the amendment involves no significant increase in the amounts, and no s13nificant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation expo-sure. The Comission has previously issued a proposed findinig that this amendment involves no significant hazards consideration and there has been no public coment on such finding. Accordingly, the amendment mtets the eligibil-ity criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b), no environmental impact statemen'. nor environ-mental assessment need be prepared in connection with the isstance of this amendment.
4.0 CONCLUSION
The Consnission made a proposed determination that the amendment in volves no significant hazaros c6h'ideration which was published in the Federal C.egister s
(55 FR 4278) on February 7,1990 and consulted with the State of Te:n.essee.
No public coments were received and the State of Tennessee did not have any coments.
The staff has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the will not be endangered by operation in the pro >osed manner, and (2) public such activities will be conducted in compliance wit 1 the Comission's regulations, and the issuance of the amendment will not be inimical to the common defense and security nor to the health and safety of the public.
Principal Contributor:
H. Garg Dated:- October 2,1990
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