ML20117M428
| ML20117M428 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 06/07/1996 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20117M420 | List: |
| References | |
| NUDOCS 9606180506 | |
| Download: ML20117M428 (3) | |
Text
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UNITED STATES 3
S NUCLEAR REGULATORY COMMISSION i
f WASHINGTON. D.C. 20555-0001
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J SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION l}
RELATED TO AMENDMENT NO. 210 TO FACILITY OPERATING LICENSE NO. DPR-32 AND AMENDMENT N0. 210 TO FACILITY OPERATING LICENSE NO. DPR-37 i'
VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION. UNIT NOS. 1 AND 2 J
DOCKET NOS. 50-280 AND 50-281 i
1.0 INTRODUCTION
By letter dated April 15, 1996, the Virginia Electric and Power Company (the licensee) proposed changes to the Technical Specifications (TS) for the Surry Power Station, (SPS) Units 1 and 2.
The changes would revise Sections
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3.12.B.5, 3.12.B.6, and 3.12.B.7 of the SPS TS to indicate that the quadrant l
power tilt ratio (QPTR) requirements are applicable only at power levels greater than 50% of rated core power.
The Section 3.12 Basis would also be l
revised to describe the basis for the changes to TS Sections 3.12.B.5, I
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3.12.B.6, and 3.12.B.7.
2.0 PROPOSED TECHNICAL SPECIFICATION CHANGES i
TS 3.12.B.5 which currently reads "The allowable QUADRANT POWER TILT is 2%" is being revised to read "The allowable QUADRANT POWER TILT is 2.0% and is only applicable while operating at THERMAL POWER > 50%."
TS 3.12.B.6 which currently reads "If, except for physics and control rod assembly surveillance testing, the QUADRANT POWER TILT exceeds 2%, then:" is being revised to read "If, except for operation at THERMAL POWER s 50% or for physics and control rod assembly surveillance testing, the QUADRANT POWER TILT exceeds 2%, then:"
TS 3.12.8.7 which currently reads "If, except for physics and control rod assembly surveillance testing, after a further period of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, the QUADRANT POWER TILT in Specification 3.12.B.5 above is not corrected to less than 2%:" is being revised to read "If, except for operation at THERMAL POWER
$ 50% or for physics and control rod assembly surveillance testing, after a further period of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, the QUADRANT POWER TILT in Specification 3.12.B.5 above is not corrected to less than 2%:"
3.0 EVALUATION Currently, TS 3.12.B.5 establishes the allowable quadrant power tilt at 2.0%
which is consistent with the Westinghouse Standard TS.
However, the current 4
W 9606180506 960607 ADOCK0500g0 DR
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2 specification does not specifically define the power levels at which the requirement is applicable.
The QPTR limit of 1.02 (i.e., a 2% quadrant power tilt) ensures that the gross radial power distribution remains consistent with the design values used in the safety analyses.
Precise radial power distribution measurements are made during startup testing, after refueling, and periodically during power operation.
The power density at any point in the core must be limited so that the fuel design criteria are maintained.
Together, the axial flux difference and control rod insertion limits provide limits on process variables that characterize and control the three dimensional power distribution of the l
reactor core. Control of these variables ensures that the core operates
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within the fuel design criteria and that the power distribution remains within the bounds used in the safety analyses, i.e.:
l a.
During a large break loss of coolant accident, the peak cladding temperature must not exceed a limit of 2200*F (10 CFR 50.46);
l b.
During a loss of forced reactor coolant flow accident, there must be at least 95% probability at the 95% confidence level (the 95/95
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departure from nucleate boiling (DNB) criterion) that the hot fuel rod in the core does not experience a DNB condition; c.
During an ejected rod accident, the energy deposition to the fuel must not exceed 280 cal /gm (Regulatory Guide 1.77); and d.
The control rods must be capable of shutting down the reactor with a minimum required shutdown margin with the highest worth control rod stuck fully withdrawn (GDC 26).
These criteria can be met by ensuring that the core peaking factor design basis is met.
QPTR is a means of ensuring that the peaking factors do not exceed the limits between surveillances.
In other words, the QPTR limits ensure that hot-channel factors, F"A and F (Z) remain below their limiting valuesbypreventinganundetectedchangefnthegrossradialpower distribution.
During power operation, the F"4 and F (Z) limits must be maintained to preclude core power distributions from, exceeding design limits assumed in the safety analyses.
Applicability 5 50% power is not required because there is either insufficient stored energy in the fuel or insufficient energy being transferred to the reactor coolant to require the implementation of a QPTR limit on the distribution of core power. At or below 50% power the additional surveillance on QPTR is not necessary.
The Section 3.12 Basis has been revised to reflect the basis for the changes to TS Sections 3.12.B.5, 3.12.8.6, and 3.12.B.7.
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SUMMARY
The staff has reviewed the licensee's proposed changes to TS Sections 3.12.6.5, 3.12.B.6, 3.12.8.7, and the attendant Basis and find them acceptable.
5.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Virginia State official was notified of the proposed issuance of the amendments.
The State official had no comment.
6.0 ENVIRONMENTAL CONSIDERATION
These amendments change a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.
The NRC staff has determined that the amendments involve 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 cumulative occupational radiation exposure.
The Commission has previously issued a proposed finding that these l
amendments involve no significant hazards consideration and there has been no public comment on such finding ( 61 FR 20860 ).
Accordingly, these amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of l
these amendments.
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7.0 CONCLUSION
The Commission has 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, (2) such i
l activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of these amendments will not be inimical to the common l
defense and security or to the health and safety of the public.
1 Principal Contributor:
Bart Buckley Date:
June 7,1996
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