ML20082N183
| ML20082N183 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 08/26/1991 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20082N170 | List: |
| References | |
| NUDOCS 9109090018 | |
| Download: ML20082N183 (3) | |
Text
-
.n
../pwa g'c;
\\
v
_,w
.!' g P ;-
UNITED STATES l
4.v g),
i-NUCLEAR REGULATORY COMMISSION f
J a
o,,
WASHINGTON, D.C. 20M6 g
e..+
l SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 83 TO FACILITY OPERATING LICENSE NO. NPF-29 l
.t ENTERGY OPERATIONS, INC., ET AL.
GRAND GULF NUCLEAR STATION, UNIT 1 I
DOCKET NO. 50-416 j
1.0 INTRODUCTION
i i
By letter dated February 22, 1991, as supplemented May 24, 1991 Entergy i
Operations,-Inc. (the licensee) submitted a request for changes to the Grand i
Gulf Nuclear. Station Unit 1, Technical Specifications (TS). The requested l
changes would increase the required minimum-usable fuel oil in the diesel generator fuel oil storage tanks from 57,200 to 62,000 gallons for each of the Division.1 and the Division 11 tanks, and from 39,000 to 41,200 gallons.for'the i
Livision III tank.
2.0 EVALUATION The TS for A.C. electrical power systems include a requirement that the fuel oil storage tanks for the emergency diesel generators (DG) shall contain a:
J certain quantity of usable fuel oil during operation (TS 3.8.1.1) and during shutdown (TS:3.8.1.2). There are three tanks, one for each of the three DGs.
i The basis for this specific 6 tion is that each of-the three tanks will contain
{
sufficient usable fuel oil to operate the associated DG for seven days follow-
=t ing a loss of_ coolant accident at maximum continuous load conditions. The presently specified minimum usable fuel oil volume is 57,200 gallons for i
Division-I and Division II diesel generators, and 39,000 gallons for Division
-t III_ diesel generator. The unusable fuel oil volume-is that below the center-line of the submersible fuel-oil transfer pump suction (8 inches above the tank i
. bottom) plus that available for the net positive suction head (NPSH) of the Jump.
For the present TS, the unusable volume ws considered to be that in the f
Jottom 2 feet of the tank which resulted in a minimum-level of 1 foot - 4 i
inches above the pump suction centerline available for NPSH.
t
\\
The minimum usable fuel oil volume was re-calculated by the licensee using
?
current diesel generator loading requirements, revised horsepower data for i
components powered by the generators, and updated fuel consumption data for the diesel engines. The calculations were made in accordance with the American National Standards Institute (ANSI) Standard N195-1976 and Regulatory Guide 1.137, " Fuel Oil Systems for Standby Diesel Generators". The results showed that the minimum usable fuel oil volume should be 62,000 gallons for r
Division -1 and Division II diesel generators and 41,000 gallons for the i
t 9109090018 910826 PDR ADOCK 05000416
[
p PDR i
?
i i
Division 111 diesel generator.
Therefore, a request for TS changes was j
submitted and administrative controls were implemented to require the larger volumes until the proposed TS are issued.
f The larger usable volumes will be obtained by reducirg the minimum fluid level above the submerged fuel oil transfer pumps from 1 foot - 4 inches to 4 inches' A minimum fluid level of 4 inches above the horizontal pump suction pipe f
centerline was specified by the manufacturer to give adequate NPSH for con-tinuous pump operation. The inlet diameter of the pump suction pipe and flange i
neh, resulting in a minimum of 3.5 inches of fluid above the suction i
The submittals indicated that the storage tank fuel oil level instrumentation can have an error of 2.25 percent of total tank depth (3.14 inches) for i
Division I and Division 11 tanks, and 3.08 percent (4.44 inches) for the
{
Division 111 tank. The minimum fuel oil storage tank levels specified for t
operability determinations in surveillance procedures include an allowance for l
these errors.
Instrumentation is presently calibrated on an 18 month interval.
If the as-found error exceeds these values, the instrumentation should be i
recalibrated on shorter intervals.
I t
The staff concludes that the required usable volumes can be obtained in the
[
manner proposed by the licensee while meeting applicable guidelines in Regulatory Guide 1.137 and ANSI Standard N195 and the pump vendor's recomended j
NPSH requirements. Accordingly, the proposed TS changes are acceptable.
3.0 STATE CONSULTATION
in accordance with the Comission's regulations, the Mississippi State official was notified of the proposed issuance of the amendment.
The State official had no coments.
4.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The NRC staff has determined that the amendment 4 ivolves no significant increase in the amounts, and no significant change in the types, l
of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation
}
t exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration, and there has been i
no public coment on such finding (56 FR 33953). Accordingly, the amendment i
meets the eligibility criteria for categorical exclusion set forth in 10 CFR i
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 i
the amendment.
l l
e
..,--.,-~~,.a cv,.
-,w
..,.-.n.,,--,,,-,-,--n.~.,n,n.-n.,,.,n,
- - ~
r
m i
f i
5.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, f
that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such l
activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the contmon defense and security or to the health and safety of the public.
Principal Contributor:
L.L. Kintner Date:
August 26, 1991 i
t f
l i
i i
i i
i
?
a b
f h
a P
. _ _. -