ML20195G546
| ML20195G546 | |
| Person / Time | |
|---|---|
| Site: | Harris, 05000000 |
| Issue date: | 08/21/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20151V292 | List:
|
| References | |
| FOIA-88-497 NUDOCS 8811280036 | |
| Download: ML20195G546 (3) | |
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NUCLEAR REGULATORY COMMISSION 3
W ASHING TON, D. C. 20* SS
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SAFETY EVALUATION BY THE OFFICF OF NUCLEAR REACTUR REGUL ATICN lhCEEASED FUEL EN4!CHMEhT CAE0 LINA PCWFR & LIGHT COMPANY
$HEARON FAaRIS NUCLEAR PC'4ER PLANT DOCKET NO. 50 400 c
I l.0 INic00UCTION By letter dated by 26. 1987 Carolina Pcwer & l.ight Cerpany (CPL) applied (cr an acerdrent to operating license NPT-63 of the Shearen Farris huclear Power Plant to increase the ramirum allowed enrichment of reload fuel to 4.2 weight l
percent U 235. The scope of this request is limited to the handling and l
l storage of these rore highly enriched fuel elements. Operation with the
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increased enrichten; will be addressed in subsequent reload analyses.
2.0 E V All'AT I ON j
The Shearon Harris spent fuel storage racks censist of square stainless steel j
cans having an inside dir<nston of 8.75 inches and a 0.75 inch wall l
l thicnness. On the outer surf ace of each sice of the cans. Boraflem sheets l
l having a minimum area density of 0.02 grar.s per scuare centireter et 5cron.10 f
The i
(B.lV} are held in place by a thin. walled stainless steel wrapper plate.
I rack structure r.atntatns these cans on a 10.5 snch center to. center spectng.
j 1he spent fuel 15 nonrally stored in pool water containtev about 2000 pro of l
soluble boren which results in abcut a 301 reduction in reactivity. He ever.
l for conservatism, the spent fuel racks are calculated assuming no soluble boron in the water.
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The K(NO.ly Monte Carlo coeputer code was used to calculate the reactistty of the fuel storage array. Neutron cross sectten data f ree the CSEL.V 2D group j
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8311200036 D01100 PDR POIA i
R I C C I O 80--497 PDR
2 library was generated for,, input to XDO-!Y using the N!TAWL and X50RNEM codes. These tredels have been benchmarked against experir.cntal data and have been found to adequately reproduce the critical values.
The spent fuel pool criticality calculations were based on ro burnable poison or control' reds in the fuel assemblies, unirradiated fuel with 4.2 weight percent U-235, and. as previously rentioned, no soluble boren in the water.
In addition. a werst case calculation was r.ade to ensure that the raximum kgf for fuel asserblies in the spent fuel racks will be less than the MC acceptance criterien of 0.95.
For this calculation, the rest adverse ccebination of dimensional tolerances was assp ed as well as pure watar rnederator at a ter;erature cf CB' F and a density of 1.0 grars per cubic centireter and the minirLn poison loading of 0.02 grams 810 per square centireter in the Boraflex. The resulting 6,f, is 0.9448. including uncertainties at a 95/95 probability / confidence level, thus meeting the MC acceptance criterion for criticality, it is possible to postulate events which could lead to an increase in storage rack reactivity such as nisplaced fuel assemblics. However, for such esents.
credit nay te taken f or tre appronicately 2000 ppr. of boron in the spent Ecol water by application of the double contingency principle of ASS! N16.1 1975.
This states that one is not required to assy-e two unlikely. irdependent, concurrent events to previde for protection against a criticality accident.
The reduction in k caused by the borated water more than of f sets the gf reactivity addition caused by credible accidents.
3.0 CO'iC L U5 :2 i
Based on the above evaluation, the staf f cnrcludes thJt the spent fuel storage racks at the Shearen Harris Nuclear Power Flant can accorrodate ustinghouse 17:17 stancJrd or uptimized fuel assemblies of up to 4.2 metgnt percent U.235 less than or equal to enrictrent in every storage cell and raintain Lg 0.95.
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i E 1 05y2E 2
$hEARCh FARRIS htCLEAR PCWER PLANf ^
SYSTfPAT!C ASSESSMENT OF LICENSEE PERFORMANCE Functional Areas 1.
Management involverent in Assuring Quality.
Technical revicw of the submittal indicates that the ranagement reviews are tirely and technically apprcpriate.
Rating: Categcry ?
2.
Approach to Resolution of Technical Issues from a safety Standteint.
The licensee shewed a general understanding of the technical issue and used acceptable approaches.
Ratirg: Category 1 3.
Wesponsiveness to h2C Initiatives The licensee respended faverably to NEC initiatives.
Rating: Category 1 4
Enforcen ent History N/A 5.
Operattenal and Censtruction [ vents j
h/A C.
$tafting (ircluding Panagement) l N/A 7.
Training and Qualification Iffect ueress h/A i
Reference:
htC Fanual Ap;ench (fl6. $ystenatic Assessrent of I tcensee rer f e rranc e
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