ML20027C132
| ML20027C132 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 09/16/1982 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20027C131 | List: |
| References | |
| NUDOCS 8210130038 | |
| Download: ML20027C132 (3) | |
Text
_ _ _ _ _ _ _
j..g jo,,
UNITED STATES
],
g NUCLEAR REGULATORY COMMISSION g
j WASHINGTON, D. C 20555
%...../
SAFETY EVALUATION AMEN 0 MENT NO. 3 TO NPF-13 GRAND GULF. NUCLEAR STATION, UNIT 1 DOCKET NO. 50-416 Introduction The licensee proposed a change to the operating license and changes to the Technical Specifications for Grand Gulf Unit I which are as follows:
a)
Incorporation of additional one time Technical Specification exceptions for Phase I operations (MP&L letter dated September 13,1982).
1 b) Changes to the following Technical Specifications (MP&L letter dated September 13,1982):
(1) Table 3.6.4-1, Valve E12-F021B Stroke Time.
(2) 4.5.1.C.2.a. " Keep Filled" Pressure Alarm Surveillance.
(3) Table 3.3.8-2, Containment Spray Initiation Time.
(4) Table 3.8.4.1-1, Molded Case Circuit Breaker Response Time.
Evaluation a) One Time Technical Specification Exceptions In the license, the staff granted certain one time exceptions from the I
Technical Specifications prior to exceeding 1.0 percent of rated thermal power for the first time. Since then, the licensee has identified other i
Technical Specifications for which they need an exception for Phase I l
operation. The bases for the rcquested exceptions are consistent with the rationale and justification used in the formulation of the original license condition. The requested exceptions are related to systems which will be isolated or non-functional during Phase I operation or to systems which monitor fission product inventory. At power levels less than 1.0 percent power, there will be a sufficiently low fission product inventory so that these associated systems will not be required. The staff has reviewed the nature of the requested exceptians and the bases for the requests and finds that a one time exception for Phase I operation is acceptable.
Therefore, the additicnal exceptions from the Technical Specifications are granted.
R
., b) Technical Specification Changes (1) Table 3.6.4.1, Yalve E12-F021B Stroke Time A design change to the containment and drywell isolation valve was made during plant construction to allow for throttling flow in the RHR "C" test line to the suppression pool. The design bases, as detailed in the NSSS supplier's design specification, is that the RHR system is not required to recover from secondary modes of operation, such as testing, within the specified LPCI injection time, because the interval of time the RHR system remains in these secondary modes is so short that the effect on overall reliability is insignificant. Theref; e, the licensee has requested that the valve stroke time for valve E12-F021B be changed from 67 seconds to 101 seconds.
We have reviewed the licensee's request and the RHR system piping and instrumentation diagrams. Valve E12-F021B is the isolation valve in the RHR test return line to the suppression pool, and is normally closed.
Its safety function is to close upon receipt of an ECCS initiation signal, (should it be open during a system test) to allow realignment of the RHR system for LPCI injection. There is only a very short time period during which the safety function of this valve could be required (i.e. a LOCA occurs during the RHR system test). Also, only one loop is tested at a time and hence 2 other LPCI loops as well as the LPCS and HPCS systems would be available for injection. Based upon our review, we find the proposed change to the Technical Specification acceptable.
(2) Table 4.5.1.C.2.a, " Keep Filled" Pressure Alarm Surveillance The licensee has requested a change in the low pressure alarm setpoints f
for the " Keep Filled" system in the ECCS discharge lines. The pressure
{
alarms are indicative of voids or "not full" discharge lines. Full-discharge lines are important in preventing water hammer events. The change in setpoints has been requested to reflect plant specific conditions at Grand Gulf.
We have reviewed the revised alarm setpoints proposed by the licensee, and the elevation differences between the measurement point and the system high poi,nt for the HPCS, LPCS, and LPCI systems. We conclude that the alarm setponts are above the static head difference between the system high points and the measurement point. Based on our review, we find the proposed change to the Technical Specification acceptable.
n m m m ez u m n m -~ ~ - m:~ m - m -.~ ~ - n
~
~
~
. (3) Table 3.3.8-2, Containment Spray Initiation Time The current Technical Specification for the containment spray timers require that the setpoint and allowable value be less than or equal to ten minutes. However, in Section 6.2.1.1.5.5 of the Final Safety Analysis Report for Grand Gulf, the containment sprays are assumed to be initiated no sooner than ten minutes following a LOCA and no later than thirteen minutes. The licensee has requested that the containment spray initiation time be changed consistent with the Final Safety Analysis Report and our previous safety review. We have reviewed the licensee's justification for this change and find the proposed Technical Specification change acceptable.
(4) Table 3.8.4.1-1, Molded Case Circuit Breaker Response Time The licensee has requested an increase in the response time to 0.1 seconds for Type NZM circuit breakers. This change revises the fuse types used in the Grand Gulf design. For a worst-case condition, a limiting factor is the heating of a #1/0 penetration pigtail in 0.147 seconds to 250 C. ' Type NZM molded case circuit breakers will respond within the worst-case condition time limit. Based on NUREG-0588,
" Equipment Qualification of Safety-Related Electrical Equipment", the thermal capability of this unit with this response time is within the allowable limits. Therefore, we find the proposed change to the Technical Specification acceptable.
1 Environment &l Consideration We have determined that this amendment does not authorize a change in effluent types or total amount nor an inc aase in power level and will not result in any significant environmental impac:
sving made this determination, we have further concluded that this amer,m:lt involves action which is insignificant from the standpoint of environmental impact, and, pursuant to 10 CFR Section 51.5(d)(4), that an environmental impact statement or negative declaration and environmental impact apprndal need not be prepared in connection with the issuance of this statement.
Conclusion We have concluded, based on the considerations discussed above, that:
(1) because the amendment does not involve a significant increase in the probability or consequences of accidents previously considered ans does not involve a significant decrease in a safety margin, the amendment does 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 Coninission's regulations and the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
Dated: September 16,198?
(
t f
.