ML17340A650
| ML17340A650 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 12/19/1980 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17340A649 | List: |
| References | |
| NUDOCS 8101300250 | |
| Download: ML17340A650 (3) | |
Text
t UNITEDSTATES NUCLEAR REGULATORY COMMISSION WASHINGTO+ D. C. 20555 SAFETY EVALUATION AND ENVIRONMENTAL IMPACT APPRAISAL BY THE OFFICE OF NUCLEAR REACTOR REGULATIOH RELATED TO AM"=FOMENT NO. 62 TO FACILITY OPERATING LICENSE HO.
DPR-31 AHD AMENDMENT HO.
53 TO FACILITY OPERATING LICENSE NO. DPR-41 FLORIDA POWER AHD LIGHT COMPANY TURKEY POINT PLANT UNIT NOS.
3 AND 4 DOCKET NOS. 50-250 AHD 50-251 Introduction I
V
~
By letter dated January 31,
- 1979, as supplemented on September 26,
- 1980, Florida Power and Light Company (FPL) submitted an application which would delete the fuel residence time requirement from the Technical Speci-fic'ations, Appendix A to License Nos.
CPR-31 and DPR-41, of the Turkey Point Plant Unit Nos.
3 and 4.
The definitions section of the Technical Specifications now limits Unit 3 to 27,000 effective full power hours (EFPH) and Unit 4 to 30,000 EFPH.
Ou~
review is based on the batch ave~ "
discharge of 85,000 MWD/MTU for Unit Ho.
3 and 33,200 MWD/MTU for Unit I~u-Safety Evaluation We have reviewed the request of FPL to remove a Technical Specification requirement on fuel-resid= nce times from a reactor safety viewpoint.
FPL makes the argument that this deletion is acceptable from a safety consideration because the calculated times to collapse of the fuel rod cladding are in excess of any planned irradiation time.
However, this could change as the fuel design changes (such things as internal pressure and wall thickness have an important effect on cladding collapse.times).
Another reason that this deletion is acceptable is that such limitations in the Technical Specifications can be overly restric ive and would lead to a more frequent need for changes to the Technical Specificat>ons.
Such limits are not really necessary because the plant Nuclear Safety Committee is already charged with the responsibility of performing eval-uations of such changes for each reload.
If cladding is predicted to collapse during operation, FPL is reqII'd to assume a peak cladding temperature criterion of 1800'F rather than the normal value of 2200'F.
FPL is, therefore, already obligated to assure that the correct peak clad temperature limit is being used.
In addition, if a cycle length 8l Ol 30 02 5 0
should be extended over the va1ue intended at the beginning of the cycle, FPL has stated that a safety review would be done to assur>>
t.'hat the new ex.ended cycle length would not be longer than the calculated cladding col Iapse time.
A Techni cal gpeci ficat i on requirement is, there fore, not necessary.
We have also reviewed the FPL request to remove the fuel residence time limitation from the Technical Spe'cifications from the viewpoint of the accident analysis.
Historically, the residence time limit was imposed to prevent fuel rod cladding collapse.
For the situation of collapsed
- clad, a different temperature criterion is applied for peak cladding temperature in eval-uating fuel performance.
For the present situation, when clad collapse is predicted not to occur for the projected fuel lifetime, the previously approved techniques for calculating performance are still applicable.
Radiological considerations, for accidents in which f'uel failure is postu-lated to occur, stem f'rom the amount of fuel which is calculated to release fission products.
Since approved temperatures for non-collapsed clad have been
- used, removal of the resident, time restriction would not cause an inc'rease in the radiological consequences of accidents.
There is a
de facto limitation imposed on the burnup of the fuel in the Turkey Point by the resident time limit.
Since such factors is composition of the gas in th= gap, pell'et-clad ir'-teractions, internal pressure in the rod, and clad stress can influence the number of rods calculated to,ai I in accident s'.tuations, radiol'ogical consequences for high burr
~~
in the core can be larger than previously calculated.
We considered whether the de facto burnup limit should be removed, or replaced witl
- another, more appropriate, limit on MWD/MTU.
Based on our review, it was concluded that the de facto limit should be
, removed since it was imposed for a rea;on which is no longer valid.
It was further concluded that no other limit should be imposed in its place for several reasons:
(a) generally good performance of present LWR fuel to burnups in the range of 30,000 N9/HTU, (b) successful operation with a limited number of lead test assemblies to somewi ~t higher burnups and (c) current understanding of the effects of higher burnup on some fuel damage mechanisms.'
Environmental Im act A
raisal The values of environmental effects in Table'-4 will not be significantly affected by these changes for se.eral reasons.
Increasing burnup will produce changes within the spent fuel; different inventory of radionuclides, extra neutron, gamma ray, and heat fluxes.
However, the external radiation and accident resistance of the cask in which spent fuel is transported will not change.
The use of the cask may change because the regulations.
limit the radiation field outside the cask.
Generally, the field is
'limited to 200 mrem/hr at any accessible point on the surface of the closed vehicle (or cask, if the vehicle is not. closed; ) and to 10 mrem/hr at six feet from the vehicle.
The routine exposure to the public from the cask'may be considered invariant to the increases in bur nup because
~the shipper must certify to the carrier that the cask meets these regulatory limits'he conclusions in the final environmental impact statement concerning the radiological consequences of accidents remain unchanged due to removal of the Technical Specification on fuel residence time.
The limit was imposed historically to preclude clad collapse in early-design fuel rods.
Since the time to clad collapse of the present fuel rods is beyond the effective lifetime of the fuel, removal of the limit will not cause a change in the number of fuel rods predicted to fail in any accident situation and hence, no change in the radiological consequences of such accidents.
No other change in Technical Specifications is being made.
Therefore, the radiological conse uences of accidents where fuel damage is not predicted to occur will also not change.
Environmental Consideration On the basis of the foregoing analysis, it is concluded that there will be no significant environmental impact attributable to the proposed action.
Having made this conclusion, the Commission has further concluded that no environmental impact statement for the proposed action need be prepared and that a negative declaration to this effect is appropriate.
Conclusion Me have concluded, based on the considerations discussed above, that:
(1) because the amendments do not involve a signi-.i.cant increase in the probability or consequences'f accidents previously considered and do not involve a significant decrease in a safety margi n, the amendments do not involve a significant hazards consideration, (2) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed
- manner, and (3) 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 or to the health and safety of the public.
December 19, 1980