ML20080B354
| ML20080B354 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 01/17/1984 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19264F078 | List: |
| References | |
| NUDOCS 8402070076 | |
| Download: ML20080B354 (2) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION n
O a
wAswiscrow, o. c. 2oses
'*o.....+
~ SAFETY EVALUATION AMENDMENT NO.15 TO NPF-11 LA SALLE COUNTY STATION, UNIT 1 DOCKET NO. 50-373 Introduction By letter dated Janutry 4,1984, Connonwealth Edison Company (the licensee) proposed an emergency Technical Specification change to Specifications 3.1.3.1 and 3.1.3.6 to exempt the applicability of Specification 3.0.4 when a control rod is inoperable for causcs other than being stuck.
The licensee in attempting to bring La Salle Unit I up to power discovered a control rod not being coupled; and therefore, declared the control rod inoperable. Specificatico 3.0.4 is applicable for this circumstance and this specification prohibits mode change.
Evaluation During the preparation of starting up'the La Salle County Station, Unit 1, the licensee determined that one control rod would not pass a control rod coupling check.
Repeated attempts at recoupling were not successful. The current Unit 1 Technical Specifications do not allow continuation of startup with a control rod declared taoperable.
l Previously licensed boiling water reactors have Technical Specifications (in various forms) which permit startup and continued operation with inoperable control rods.
In particular, the Brunswick and Hatch plants l
along with La Salle, Unit 2 have such a statement in corresponding Technical Specifications. However, for continued operation with a control
~
~
rod inoperable, adequate shutdown margin must still be assured as ' required by Specification 3.1.1.
The issue of common mode failures is also addressed by the Technical Specifications because if more than 8 rods are inoperable, the reactor must be in hot shutdown in 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
The licensee has determined, and the the NRC staff agrees that in accordance with 10 CFR 50.92 that operation of La Salle Unit 1, with the l
l the proposed amendment will not:
(1) involve a significant increase in the probabilityorconsequencesofanaccidentprepiouslyevaluatedbecausethe control rod shich is uncoupled during mode changes will be fully imerted into the core and will be disarmed to prevent withdrawl, ('2) create the possibility of a new or different kind of accibeht' from any accident previously evaluated because the change to the Technical Specifications is only to allow mode changes, and (3) involve a significant reduction in the
. margin of safety because the control rod will be in its most conservative position. Accordingly, the staff has made a final determination that this license amendment involves no significant hazards considerations.
l 0402070076 840117 DR ADOCK 0500037 l
1
In addition, the problem of the flux perturbation must be considered with this control rod inserted. Since the core power distribution is monitored continually by operation personnel, any effects of the inserted control red on core operating limits may be corrected by the operator by altering the control rod pattern.
In discussing this problem with the licensee, it was indicated that the power distribution flux tilt meets the tolerance allowed for the flux pattern of the core event with this control rod inserted.
Also, it was pointed out that the control rod symmetric to the inoperable rod will be partically inserted into the core to reduce the flux tilt in that region.
The licensee meets the test of prompt notification. On January 4, 1984, the need for the change was transmitted by letter (hand carried) to the NRC staff.
The NRC staff contacted the State of Illinois (Mr. G. N. Wright, Manager of Nuclear Facility Safety) by telephone at 5:15 pm on January 4,1984. The proposed amendment was described and he was informed that a no significant hazards determination had been made by the staff. fir. Wright had no comments.
Environmental Consideration We have determined that this amendment does not aut.horize a change in effluent types or total amount nor an increase in power level and will not result ir.
any significant environmental inpact. Having made this determination, we have further concluded that this amendment involves action which is insigni-ficant from the standpoint of environmental impact, and pursuant to 10 CFR Section 51.5(d)(4), that an environmental impact statement or negative declarition and enviromental impact appratsal need noi, be prepared in connection with the issuance of this amendment.
Conclusion We have concluded, based on the considerations discussed above, that:
(1) this amendment does not involve a significant increase in the probability or consequences of an accident previously evaluated. creation of a new or different accident from any previously evaluated, or a significant reduction in a safety margin, and therefore, does not involve a significant hazards consideration; (2) there is reasonable assurance that the health and safety of the public will not bc 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 this amendment will not be inimical to the comon defense and security or to the health and safety of the public.
Dated: January 4,1984
- SEE PREV 10VS CONCURRENCES DL:LB#2/Pf1 DL:LB#2/8C ABournia*:pt ASchwencer*
t ' vak 1/04/84 1/04/84 1
84
-DISTRIBUTION:
(LA SALLE AMENDMENT NO.15)
' $$$M5iiIdit7ConM57 NRC PDR L PDR NSIC PRC LBf2 Rdg.
EHylton ABournia JSaltzman, SAB CWoodhead, OELD CMil es HRDent.on JRutberg AToalston JMTaylor, DRP:IE ELJordan, DEQA:IE LHarmon DBrinkman, SSPB TBarnhart (4) 4 l
l l
1-t.
I i
3 L