ML20209H172
| ML20209H172 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 04/21/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20209H162 | List: |
| References | |
| NUDOCS 8705010163 | |
| Download: ML20209H172 (3) | |
Text
. _ _ _ - _ _ - _ -.
~.
o UNITED STATES 8
~g NUCLEAR REGULATORY COMMISSION o
5
-E WASHINGTON, D. C. 20555 k.....
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATTON RELATED TO AMENDMENT NO.108 TO FACILITY ODERATING LICENSE NO. DPR-66 DUQUESNE LIGHT COMPANY OHIO EDISON COMPANY PENNSYLVANIA POWER COMPANY l
l BEAVER VALLEY POWER STATION. UNIT NO. 1 l
DOCKET NO. 50-334 INTRODUCTION By letter dated July 25, 1926, (Change Request No. 125), Duquesne Light Company (the licensee) requested several changes to the Beaver Valley Power Station, Unit 1. Technical Specifications (TS) Table 3.3-3 Engineered Safety Feature i
(ESF) Actuation System Instrumentation, and TS Table 4.3-2, ESF Actuation System Instrumentation Surveillance Re.quirements. The changes would revise the applicable operational modes requirement for three Steam Line Isolation (SLI) signals (Manual, Automatic Actuation Logic, and High Steam Pressure Ratel.
These changes are proposed to be consistent with the main steam line isolation valve operability requirement which is specified in TS 3.7.1.5.
EVAltlATION The licensee's proposed changes consist of two items:
(1) delete SLI instrumen-tation and surveillance requirement in Mode 4 from TS Table 3.3-3, Items 4.a.
4.b, 4.e, and Table 4.3-2, Items 4.a 4.b. 4.e. and (2) delete the surveillance requirement in Modes I and 2 from TS Table 4.3-2. Item 4.e for the instrumentation associated with "SLI on High Steam Pressure Rate."
The SLI is designed to close the Main Steam Isolation Valves in the event of a Steam Line Break (SLB) accident to prevent uncontrolled blowdown of all steam generators. The present TS requires the Manual, Automatic Actuation Logic, and High Steam Pressure Rate signals which initiate SLI to be operable in Mode 4.
However, the Main Steam Line Isolation Valves are reouired to be operable only during Modes 1, 2, and 3 per TS 3.7.1.5.
The licensee requested that Mode 4, as specified in TS Table 3.3-3. Items 4.a. 4.b 4.e, and Table 4.3-2. Items 4.a. 4.b, 4.e. be deleted.
These chances are consistent with current guidance provided in NUREG-0452, Standard Technical Specifications (STS) for Westinghouse Pressurized Water Reactors, Revision 4 The Safety Injection System ISIS) does not reouire the SLI to be operable in Mntie 4 I
8705010163 870421 PDR ADOCK 05000334 P
~
' Although there are some differences between the licensee's Steam Line Preak (SLB) Protection Logic and the STS, Revision 4, the current licensee's SLR Protection Systems were modified from the previous systems which were similar to the STS, Revision 4, description. The ma.ior differences in the initiation of SLI are that the STS uses high steam line flow coincident with either low-low Reactor Coolant System (RCS) Tave or low steam line pressure signal, while the licensee uses low steam line pressure (above P-11) and high negative steam line pressure rate (below P-11). Here P-11 is an ESF permissive interlock which permits operators to block the pressurizer low pressure safety injection signal if below the interlock set pressure. The impact of these differences 4
has been evaluated in the previous submittal (TS Change Amendment No. 30), and the licensee's current SLB Protection System was found acceptable.
Specifically, in the previous submittal the licensee showed that if the initial RCS temperature is below 400'F, no SLI would occur due to the high steam line pressure rate in the event of a SLB accident. Although somewhat less desirable, the licensee did provide an analysis which showed that the core would always be covered and the RCS would remain subcooled following any size of SLB without high head safety injection flow for a reasonable and sufficient time before the operators take action.
In addition, the current TS 4.1.1.1.1.f specifies the RCS boron concentration be maintained to provide a shutdown margin greater than 1.77% delta k/k prior to manually blocking the safety in.iection signal (below P-11). This measure, as well as the RCS limits specified in Mode 4, assures 1
that the plant is in a safe condition. Thus, Mode 4 (RCS temperature less than 350*F) operability and surveillance requirements for the SLI on the High Steam Pressure Rate are not reouired. Therefore, these differences in the SLI signal do not warrant additional surveillance requirements in Mode 4.
As discussed above, the SLI is not required for safety during Mode 4 operation.
Also, the proposed change would not involve any hardware change. Therefore, we conclude that the licensee's proposal to delete Mode 4 from TS Table 3.3-3 items 4.a, b. and e. and Table 4.3.-2 items 4.a., b. and e, is acceptable.
The High Steam Pressure Rate SLI signal is required for the Steam Line Break i
Protection Systems only when the RCS pressure is below P-11 and safety injection actuation on low steam pressure sional is manually blocked. During Modes 1 and 2, normal plant operation, the RCS pressure is above the P-11 set point, and thus precludes initiation of this sional. Based on this, the 4
licensee has requested the surveillance requirement in Modes 1 and 2 be deleted from the TS Table 4.3-2 Item 4.e.
Although the SLB protection associated with the SLI on High Steam Pressure Rate is not required in Modes I and 2, it is required to be operable in Mode 3.
This is because the safety analysis for the SLB, as described in the Updated Final Safety Analysis Report Section 14.2.5, assumes initiation of SLI by the high steam line pressure rate signal when the RCS pressure is below P-11.
1 i
}
o In the event of a casualty condition which would require that the unit be cooled down in a short time, there may be insufficient time to perfom the required surveillance tests prior to entering Mode 3.
To ensure that this ESF is available in Mode 3, the operability surveillance tests should be perfomed in Modes 1 and 2.
The staff expressed its safety concern to the licensee that deleting the surveillance requirements for Modes 1 and 2 would increase the risk that this feature would not be available in the event of a SLB accident.
The licensee was asked to provide more,iustification with regard to this TS change request.
The licensee infomed the staff in a January 15, 1987, telephone conversation, that they were withdrawing this item from the request. This part of the licensee's application for a license amendment is therefore not approved.
ENVIRONMFNTAL CONSIDERATION This amendment involves a change in the surveillance requirements or use of a
~
facility component located within the restricted area as defined in 10 CFR Part
- 20. The staff has detemined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any affluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Comission has previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public coment on such finding. Accordingly, this amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of this amendment.
CONCLUSION We have concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and(2)suchactivitieswillbeconductedincompliancewiththe Comission'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: April 21, 1987 4
Principal Contributor:
P. Wen, reviewer J. Guillen, project engineer
-