ML20214T624
| ML20214T624 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 06/01/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20214T605 | List: |
| References | |
| NUDOCS 8706100352 | |
| Download: ML20214T624 (4) | |
Text
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,o, UNITED STATES l
[3 j', }j, NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 i
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENTS NOS.139 AND 76 TO l
FACILITY OPERATING LICENSES DPR-57 AND NPF-5 GEORGIA POWER COMPANY OGLLTHORPE POWER CORFORATION MUNICIPAL ELELIRIC AUTHORITY OF GEORGIA CITY OF DALTON, GEORGIA EDWIN I. HATCH NUCLEAR PLANT, UNITS I AND 2
_ DOCKET NOS. 50-321 AND 50-366 INTRODUCTION Sy letter dated February 13,1987 (Reference 1), supplemented by letter dated May 18,1987 (Reference 2), Georgia Power Company (the licensee) proposed changes to the Plant Hatch Units 1 and 2 Technical Specifications that would:
tl) revise the Minimum Critical Power Ratio (MCPR) scram time parameters for Lctb Units 1 ano 2; (2) replace the current method of measuring control rod
' cram times for Unit 1 by the method currently used for Unit 2; 3) revise l
the initial power assumed for certain transients for Unit 1; (4)(reduce the Option A MCPR limit for Unit 1 from 1.35 to 1.33; (5) add an Average Planar Linear Heat Generation Rate (APLHGR) limit curve to reflect the thermal-nechanical and Emergency Core Cooling System (ECCS) limits on four Lead Test Assemblies (LTAs) which are expected to be part of the Reload 10 fuel batch
"-it 1; and (6) modify the APLHGR limit curves for P8 DRB 283 and BP8 DRB 283 80-mil fuel for both Unit 1 and Unit 2 to include a previously omitted data point at 1.0 Gwd/t.
EVALUATION The proposed Technical Specification (TS) changes fall into six categories, and are discussed individually.
(1) Revise the MCPR scram time parameters.
This proposed change has to do with the Option A and Option B scram speed fonnulation. The licensee's February 13, 1987 letter (Reference 1) proposed to change the constants used in determining the ODYN Code option B scram speed l
l limit for both Unit I and Unit 2.
The change would be from the constants based on the GENESIS set of methods to those approved by the staff from a larger data base for the GEMINI methods. This is an acceptable change.
In
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C making the change the licensee proposed to remove from the TS the fomula, definitions and associated constants for the various scram times used in deter-mining MCPR limits via ODTN option A and B nethods in TS 3/4.11.C.2 for Hatch 1 and TS 3/4.2.3 in Hatch 2.
They would retain the infomation in the plant procedures. The staff found this acceptable provided the infomation removed from the TS also was included in the appropriate Bases, since it provided in-fomation relevant to scram speed and there is more than one candidate for the constants. This was discussed with the licensee and, by letter dated May 18, 1987 (Reference 2), the licensee requested that the Unit 1 Bases be modified to include the infomation that would be deleted from the TS.
Inthesameletter(Reference 2)thelicenseestatedthatthecurrentUnit2 operating cycle was calculated using the older GENESIS methodology and that it would be technically correct to leave the infomation relating to this method-ology in the Unit 2 TS for now. At a later date, a change to the Unit 2 methodology will be requested such that next operating cycle of Unit 2 can be calculated using the newer GEMINI methods. Accordingly, the licensee's May 18, 1987, letter withdraws the request to change the Unit 2 TS at this time.
This change, therefore, applies only to Unit 1 instead of to both Unit I and Unit 2 as stated in the Federal Pegister notice of this action (52 FR 9570, March 25, 1987).
Since there, thus, is no change to the Unit 2 TS and the change to the Unit 1 TS is acceptable, we conclude that the overall change to scram time parameters is acceptable.
(2) Change the method of measuring control rod scram times for Unit 1.
Scram time requirements for Unit 1 are currently specified (TS 3.3.B.2 and 3.3.C.2 and Bases 3.3.C.2) in tems of percent insertion versus time. The licensee proposes to convert the specifications from percent insertion versus time to notch position versus time. The notch position is directly related to actual control rod insertion, whereas the percent insertion requires a conversion calculation. The proposed new times specified by notch position are exactly eouivalent to the existing scram speed requirements, so there is no fundamental change in the specifications. The notch system is used on Hatch Unit 2 and is in line with the Standard TS.
It is, therefore, acceptable.
(3) Pevise the initial power assumed for certain transients for Unit 1.
The licensee proposes to change the wording in the Unit 1 TS Bases 2.1 and 2.2 and in the definitions of Design Power. The initial power level assured for some transient analyses would be changed to be consistent with the power level used in the General Electric Company (GE) GEMINI methodology (Reference 3), as approved by the staff (Reference 4).
In GEMINI, the power level uncertainty is included in adjustment factors and events are analyzed at rated rather than design power. The proposed changes reflect the differences in calculation methods and are acceptable.
(4) Reduce the Option A MCPR limit for Unit 1.
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- TS Figure 3.11-4 presents a curve of MCPR limits as a function of average measured scram speed (ODYN Code. Option A and B) for all 8 x 8 fuel types.
The licensee proposes to reduce the Option A PCPR limit from 1.35 to 1.33 (thereby changing the curve in Figure 3.11-4) as a result of a change from the GENISIS to the GEMINI methods and uncertainty analysis. The GEMINI method is approved by the staff and the proposed change in MCPR limit for Option A scram speed is reasonable and acceptable.
(5) Add an Average Planar Linear Heat Generation Rate (APLHGP) limit curve to the Unit 1 TS to reflect the thermal-mechanical and ECCS limits on four Lead Test Assemblies (LTAs) which are expected to be part of the Reload 10 fuel batch for Unit 1.
The licensee proposes to add to Unit 1 TS Figure 3.11-1 (Sheet 6) a new curve showing the maximum APLHGR (MAPLHGR) as a function of burnup for the LTA fuel type expected to be inserted (four assemblies) in the Reload 10 fuel batch.
The fuel assembly is similar to LTA fuel recently approved by the staff for insertion (in limited amounts) in other reactors, e.g., Peach Bottom 2 Cycle 8.
It is described in reports by GE, included as part of the Hatch submittal.
These reports also describe the standard GESTAR II (NEDE-24011-P-A-8, " General Electric Standard Application for Reactor Fuel") methods which will be used to analyze the transients and accidents required to demonstrate that the LTA will cperate within all design and safety limits. The LOCA analyses for the LTA in Hatch Unit 1, which provided the MAPLHGR values, were done on an assumed 14.4 Kw/ft LHGR limit, as has been approved for other reactors for this type of LTA fuel, but the operating limit in Hatch Unit I will remain at 13.4 Kw/ft; thus, 4 >
Ff no TS change for LHGR is needed for the LTA in Hatch Unit 1.
Also, unlike more complex TS provided for some previously approved similar LTA fuel, a single i
MAPLHGR curve will apply to all axial regions of the assembly. The analyses providing the LTA MAPLHGR values and the resulting proposed curve, and the des-criptions, fuel analyses, and proposed analyses for operation with the fuel in Hatch Unit I are acceptable.
(6) Modify the APLHGR limit curve for P8 DRB 283 and BP8 DR8 283 80-mil fuel for both Unit 1 and Unit 2 to include a previously onitted data point at 1.0 Gwd/t.
The licensee proposes to add a MAPLHGR data point at an exposure of 1.0 Gwd/t to the curves for two existing fuel types, P8 DRB 283 and BP8 DRB 283 with 80-mil channels, (Figure 3.11-1 (Sheet 5) for Hatch Unit 1 and Figure 3.2.1-10 for Hatch Unit 2), which had been inadvertently omitted. These are data points from the original GE analysis and their addition to the TS figures is acceptable.
We have reviewed the information submitted for proposed TS changes for Hatch 1 and 2 relating to scram speed, power level definition and MCPR and MAPLHGR limits. Based on this review we conclude that appropriate material was submitted and the changes are reasonable and acceptable.
f 1
r ENVIRONMENTAL CONSIDERATION The amendnents involve a change in use of facility components located within the restricted area as defined in 10 CFR Part 20. The staff has determined that the amendirents 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 should be no significant increase in individual or cumulative occupational radiation exposure. The Conunission has previously issued a pro-posed finding that the amendments involve no significant hazards consideration and there has been no public conment on such finding. Accordingly, the amend-ments meet the eligibility criteria for categorical exclusion set forth in 10 CFR651.22(c)(9). Pursuant to 10 CFR 651.22(b), no environnental impact state-ment or environmental assessment need be prepared in connection with the issuance of the anendments.
CONCLUSION The Connission made a proposed determination that the amendments involve no significant hazards consideration which was published in the Federal Register (52FR9570)onMarch 25, 1987, and consulted with the state of Georgia. ho public concents were received, and the state of Georgia did not have any comments.
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 en-dangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Conoission's regulations, and the issuance of the anendments will not be inimical to the common defense and security or to the health and safety of the public.
REFERENCES 1.
Letter from James P. O'Reilly, Georgia Power Company, to the NRC, dated February 13, 1987, 2.
Letter from L.T. Gucwa, Georgia Power Company, to the NRC, dated May 18, 1987 3.
Letter, J. S. Charnley (GE) to H. N. Berkow (NRC, " Revised Supplementary Information Regarding Amendtrent 11 to GE Licensing Topical Report NEDE-24011-P-A" (GESTAR II), dated January 16, 1956.
4.
Letter from G. C. Lainas (NRC) to J. S. Charnley (GE), " Acceptance for Referencing of Licensing Topical Report HEDE-24011-P-A, " General Electric Licensing Reload Report'. Supplenent to Acendment 11," dated March 22, 1986.
Principal Contributors:
L. Crocker H. Richings Dated: June 1, 1987