ML20086R742
| ML20086R742 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 07/24/1995 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20086R696 | List: |
| References | |
| NUDOCS 9507310267 | |
| Download: ML20086R742 (4) | |
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5 UNITED STATES s
j NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20666 4001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 194 TO FACILITY OPERATING LICENSE NO. DPR-50 METROPOLITAN EDISON COMPANY l
JERSEY CENTRAL POWER & LIGHT COMPANY
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PENNSYLVANIA ELECTRIC COMPANY GPU NUCLEAR CORPORATION THREE MILE ISLAND NUCLEAR STATION. UNIT NO. 1 DOCKET NO. 50-289 1.0 INTRODUCTIQff By letter dated June 1,1995, the GPU Nuclear Corporation (GPUN, the licensee) submitted a request for changes to the Three Mile Island Nuclear Station, Unit 1 (TMI-1) Technical Specifications (TSs). The requested changes would revise the THI-1 TSs to describe the use of two zirconium-based advanced fuel rod cladding materials. THI-l Technical Specification Section 5.3.1.1 currently specifies that fuel rods be clad with zircaloy or ZIRLO. The advanced fuel rod cladding materials being considered are manufactured by the Babcock & Wilcox Fuel Company (BWFC) and are designated M4 and MS. These materials have metallurgical compositions outside the zircaloy or ZIRLO specifications.
This change would allow use of the two advanced zirconium alloy fuel rod cladding materials in TMI-1 Cycle 11 and subsequent cycles.
These claddings will be initially irradiated in peripheral rod locations in two Mark B10 fuel assemblies.
Each of the two test assemblies will contain eight advanced cladding fuel rods (four M4 and four M5).
2.0 EVALUATION GPUN's June 1,1995, submittal included Topical Report BAW-2133P entitled
" MARK-BW Advanced Claddings Fuel Rod Evaluation" and a report entitled
" Evaluation of M4 and MS Cladding Alloys for THI-1," both prepared by (BWFC).
The advanced. cladding materials being considered for THI-1 are M4 and M5 type cladding.
These materials are being irradiated in the reactor core at McGuire Unit 1 and have been used in European reactors.
Post-irradiation examination results after the first and second cycles at McGuire Unit 1 indicate the materials are performing well. The licensing basis for the McGuire Unit I demonstration assemblies is documented in Topical Report BAW-2133P. The M4 alloy is identical to the F3 alloy that was evaluated in BAW-2133P.
The M5 alloy is identical in chemical composition to the F4 alloy described in BAW-2133P, but was subjected to a slightly different temperature in the final 9507310267 950724 PDR ADOCK 05000289 P
i anneal process. This slight temperature difference produces a more uniform j
homogeneous microstructure.which further enhances the corrosion properties of 3
the material. The. advanced clad materials will be irradiated at TMI-I for three cycles, beginning with the Cycle 11 reload in-September 1995. This demonstration program is being conducted to determine how various clad materials react under in-reactor conditions to support improved fuel assembly performance at higher fuel burnups and residence times.
Each of the rods to be tested is expected to perform at least as well as the current fuel design.
The non-Zircaloy-4 clad types to be utilized in the TMI-l Cycle 11 core have been tested for corrosion resistance, tensile and ourst strength, and creep i
characteristics.
Details concerning the test programs that have been performed in support of this demonstration are described in BAW-2133P.
GPUN provided nuclear, mechanical, thermal and-LOCA evaluations that demonstrate the acceptability of the advanced cladding fuel rods in TMI-1 Cycles 11, 12, and 13. The fuel rods are shown by these evaluations to meet all established design criteria and will operate safely during those cycles.
The demonstration assemblies meet the same design bases as the fuel which is i
currently in the reactor. No safety limits have been changed or setpoints altered as a. result of the use of these assemblies. The FSAR analyses are bounding for the demonstration assemblies as well as the remainder of the i
C0re.
i The demonstration assemblies will be placed in core locations which will allow them to accumulate approximately 45 to 50 GWD/MTU during three cycles of i
exposure.
Based on current cycle design projections the advanced cladding i
rods will reach burnups up to 53 GWD/MTU. The assemblies will be placed in core locations which will not experience limiting power peaking in any cycle.
Following each cycle, the demonstration assemblies will undergo a post-irradiation examination (PIE) to gauge performance. The examinations'will include visual inspections to monitor fuel performance. Direct physical i
measurements may be taken as needed.
I The licensee concluded that TMI-l can operate safely with the demonstration program in place.
The advanced zirconium-based alloys have been shown through
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testing to perform satisfactorily under conditions representative of a reactor i
environment.
In addition, the relatively small number of fuel rods involved does not represent a large inventory of radioactive material which could be released into the reactor coolant in the event of fuel failure. lhe number of fuel rods involved.is very small in comparison to the total core inventory.
failure of all the advanced cladding fuel rods from a cause related to.the demonstration would constitute significantly less than 1% fuel failure postulated in FSAR Chapter 14 safety analyses.
Failure of the fuel as a result of some unrelated phenomenon would not result in greater inventory release than non-demonstration fuel. Therefore, the licensee concluded that safety significance of this change is minimal.
The staff considers these two demonstration assemblies as lead test assemblies (LTAs).
In general, there are two criteria governing the use of LTAs:
(1) the total number of demonstration assemblies in one core should be limited, and (2) the demonstration assemblies should not be loaded in limiting
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i positions. The licensee's demonstration program conforms to these criteria.
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~ The staff, therefore, concludes that these two demonstration assemblies are acceptable for TMI-I Cycle 11 and future cycles.
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The licensee also requested an exemption to 10 CFR 50.44, 10 CFR 50.46, and 10 CFR Part 50, Appandix K in its letter of June 1,1995, since the two demonstration assemblies contain cladding material which is not zircaloy or l
ZIRLO, but has similar chemical properties. The staff considered issuance of 3
an exemption but determined that, because the clad material to be used in j
these test assemblies is neither zircaloy nor ZlRLO, these regulations do not apply and, therefore, an exemption is not required.
7' requested change would modify TS 5.3.1, " REACTOR CORE," to allow the use c4 'BWFC zirconium-based M4 or M5 alloy materials" in addition to zircaloy and i
ZlRLO as fuel rod clad material. Based on the above evaluation, the staff concludes that the change is acceptable.
The NRC staff has reviewed the licensee's TS change submittal for TMI-1, Cycle
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11 and future cycles.
Inasmuch as these two assemblies are test assemblies l
and the data from these assemblies will be used to achieve improved-performance for future fuel rod eterial, the staff conclude that the licensee has provided adequate safety assurance for these two assemblies starting in TMI-I Cycle 11.
Based on the staff's evaluation of the advanced alloy
'i requirements, the use of two demonstration assemblies and TS changes for TMI-I Cycle 11 and future cycles are approved.
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3.0 STATE CONSULTATION
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In accordance with the Cosmiission's regulations, the Pennsylvania State official was notified of the proposed issuance of the amendment.
The State official had no comments.
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4.0 ENVIRONMENTAL CONSIDERATION
i The amendment changes a requirement with respect to installation or use of a' i
facility component located within the restricted area as defined in 10 CFR
.Part 20. The NRC staff has determined that the amendment involves no i
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.
i significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration, and there has been no l
.public comment on such finding (60 FR 32366). Accordingly, the amendment-i meets 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 i
environmental assessment need be prepared in connection with the issuance of the amendment.
5.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that:. (1) there is reasonable assurance that the health and safety of the i
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public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
l Principal Contributor: Ronald W. Hernan i
Date: July 24, 1995 l
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