ML20205N599
| ML20205N599 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 04/14/1999 |
| From: | Raghavan L NRC (Affiliation Not Assigned) |
| To: | NRC (Affiliation Not Assigned) |
| References | |
| TAC-MA4489, TAC-MA4490, NUDOCS 9904190029 | |
| Download: ML20205N599 (3) | |
Text
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UNITED STATES s
j NUCLEAR REGULATORY COMMISSION WASHINGTON. D.C. 20565-0001 o
4*****g April 14,1999 MEMORANDUM FOR:
Docket File FROF t L. Raghavan, Senior Project Manager Mf(
Project Directorate IV Section 2 i/
Division of Licensing Project Management Office of Nuclear Reactor Regulation
SUBJECT:
SAN ONOFRE NUCLEAR GENERATING STATION, UNITS 2 AND 3 -
- FACSIMILE TRANSMISSION, ISSUES TO BE DISCUSSED IN AN UPCOMING PHONE CONVERSATION ON REClRCULATION SIGNAUEMERGENCY FEEDWATER ACTUATION SIGNAL WHILE THE CHANNEL IS IN A TRIPPED CONDITION (TAC Nos: MA4489 AND MA 4490)
The attached questions were transmitted by fax today to Mr. Jack Rainsberry of Southern California Corporation (SCE) to prepare him and others for an upcoming telephone call. This memorandum and the attachment do not convey a formal request for information or represent an NRC staff position.
I Docket Numbers 50-361 50-362
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Distribution PUBLIC S. Dembeck fg SONGS r/f 9904190029 990414 PDR ADOCK 05000361 P
PDR 1
FOLLOW-UP OUESTIONS ON SAN ONOFRE RESPONSE TO RAI DATED JANUARY 20,1999, ON TECHNICAL SPECIFICATION AMENDMFNT 1.
The scenario of spurious RAS actuation was not discussed in the updated FSAR Section 7.3.1.1.2
" Recirculation System." If the concern of " breach containmerit integrity" behinds this TS change request, then FSAR Section 7.3.1.1.2 should be revised to include this scenario.
2.
FSAR Page 7.3-29 third paragraph stated that an inadvertent RAS has been eliminated at San Onofre by providing an additional interlock to the high pressure safety injection (HPSI) pump mini-flow valves.
That was a design change by FSAR Revision 13. Now your TS change request attributes that interlock causes " breach containment integrity." It seems that your solution to fix one problem creates another problem. Have you consulted with ABB-CE what is the best way to resolve both problems?
3.
The scenarios of "a spurious SG Pressure-Low signal would block teedwater to the associate. A" and "a Main Steam Line Break could cause feeding of a ruptured SG, depleting Condensate Storage i
Tank inventory and increasing the load on the Containment Cooling System" were not discussed in the f
updated FSAR Section 7.3.1.1.7 " Auxiliary Feedwater System." FSAR Section 7.3.1.1.7 should be revised to include these scenarios. If these scenarios have not been analyzed before, is that need to be fixed generically for all CE plants?
4.
The Diverse Emergency Feedwater Actuation System (DEFAS) also has capability to initiate i
emergency feedwater system. Are the scenarios discussed in your submittal can cause a safety problem by the DEFAS?
5 In response to Question 1 under Tier 1 (Risk Impact and PRA Validity) of the Request for Additional Information (RAl) dated January 20,1999, regarding the proposed amendment to the plant Technical Specifications (TS) at San Onofre, the licensee provided in its letter dated March 22,1999, its determination of CDF, ICCDP, LERF, and ICLERP resulting from the proposed TS change. The licensee should describe its calculation and evaluation of these risk parameters in light d its intent to use the TS change to conduct ongoing continuous on-line maintenance and testing of multiple components during plant power operation.
6 In response to Question 2 under Tier 1 of the RAI, the licensee lists the valve unavailability of the valves i
with the scope of the TS change to range from 0.0024 to 0.0000024 unavailability per demand. The licensee should describe the basis for these assumed unavailabilities with respect to the operation under design-basis conditions and explain the significant range in unavailability per oemand for these valves.
7 Also in response to Question 2 under Tier 1 of the RAl, the licensee states that the Containment Spray system in the RCS cold leg injection mode can provide backup RCS injection flow in the event of failure of the High Pressure injection system. Justify Containment Spray system flow will meet accident transient conditions.
8 In response to the question under Tier 3 of the RAI, the licensee provides a list of the elements of the Configuration Risk Management Program (CRMP). The licensee should specify the qualitative and quantitative controls in place to ensure that implementation of the proposed TS change to conduct ongoing continuous on-line maintenance and testing of the multiple components during plant power operation will meet the recommendations of Regulatory Guide 1.177, the Maintenance Rule, and Part 9900 of the NRC Inspection Manual.
9.
Your response to auestien 1 discusses your updated CDF and LERF and it is commendable that the SONGS PRA model is being updated. What are the major changes that were made to your PRA that caused your baseline CDF to change? Please discuss any changes in CDF or LERF sequences that are relevant to the proposed change. Were any peer reviews performed on your updated PRA?
The response to question 2 of the RAI discussing unavailabilities does not appear to spec;fically 10 4
address what changes were made in your PRA model to reflect the proposed TS change that resulted
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in changes to CDF. Do the changes made to your PRA address the frequency and duration cf online maintenance of the D.1 and D.2 valvas?
11 Please re-address tier 2 considerations. Were all risk-significant plant equipment outage configurations identified?
Please provide reasonable assurance that risk-significant plant equipment outage configurations will not occur when a D.1 anchr D.2 valve (s) is taken out of sennee consistent with the proposed TS change.
12 In your response to question 2 of the RAI, you state that unavailability of HV-9200 will result in unavailability of the charging system is direction to establish an alternate charging path by abnormal operating instruction adequate? Is a TS change or license commitment requiring establishment of an alternate charging path also necessary?
13 In connection witn the TS change to conduct ongoing continuous on-line maintenance and testing of multiple components during plant power operation, the licensee should describe its method of taking out components from various emergency core cooling systems (ECCS) which will not impact the ECCS requ;rements for desi:,0 basis accidents.
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