ML20079P718
| ML20079P718 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 10/25/1991 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20079P716 | List: |
| References | |
| NUDOCS 9111130262 | |
| Download: ML20079P718 (5) | |
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![ps%$'g UNtYED STATES
'n NUCLEAR REGULATORY COMMISSION
.I wAssiNo ton, p. c. rosss k,,
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 80 TO FACILITY OPERATING LICENSE NO. NPF-11 AND AMENDMENT NO. 64 TO FACILITY OPERATING LICENSE NO. NPF-18 COMM0kWEALTH EDISON COMPANY LASALLE COUNTY STATION. UNITS 1 ANDJ DOCKET NOS. 50-373 AND 50-374
1.0 INTRODUCTION
Commonwealth Edison Company (Ceco, the licensee) submitted its response to the NRC Generic Letter (GL) 88-01, "NRC Position on IGSCC in BWR Austenitic I
Stainless Steel piping" for LaSalle County Station, Units 1 and 2, by letter dated July 29, 1983. Additional information was provided in respchse to an NRC Request for Additional Information (RAI) by letter dated June 30, 1989.
The staff, with assistance from its contractor Viking Systems International (VSI), reviewed the licensee's responses and issued its Safety Evaluation
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(SE) with an attached Technical Evaluation Report (TER) on Au The SE found the licensee's response acceptable with five (5) gust 22,1990.
exceptions.
CECO was requested to:
(1) Include a statement in the surveillance or administrative controls section of the Technical Specifications that includes the following:
"The inservice inspection program for piping identified in NRC Generic Letter 88-01 shall be performed in accordance with the NRC staff posi-tions on schedule, methods, personnel, and sample expansion included in Generic Letter 88-01 or in accordance with alternate measures approved by the NRC staff."
t (2)
Include an additional Limiting Condition for Operation (LCO) in the Technical Specifications that specifies reactor coolant system leakage shall be limited to a_2 gpm increase in unidentified leakage within any 24-hour period.
(3)
Include a surveillance requirement in the Technical Specifications that primary containment sump flow rate will be monitored at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
It should be noted that the position in GL 88-01 on leak rate monitoring was modified to permit leakage measurements based on sump flow instruments to be taken every 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> instead of every 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.
(4) For LaSalle County Station Unit 1, include an LCO in the Technical Specifications on operability of sump monitoring instruments. Since your plant has IGSCC weld c6tegory E weldments, Generic Letter 88-01 provides an allowed outage time of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> for repairing the drywell floor drain sump monitoring system, or an orderly shutdown should be 9111130262 911025 PDR ADOCK 05000373 P
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. initiated.
As an alternative, the staff recommends that when the drywell sump monitoring system is inoperable, the operator should use a demon-strated manual method for determining leak rate, such as measuring the time to manually pump the sump at a fixed interval (4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />).
The staff considers manual measurement a viable sump monitoring method without hardship to the operator; therefore, this method could be added to the appropriate LCO section. With the manual method operable, the outage time for the drywell sump monitoring system could be extended to 30 days.
However, if the sump pump and drywell sump monitoring systems are inoperable concurrently, then either system has to be repaired within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or an orderly shutdown should be initiated.
(5) Address the Reactor Water Cleanup system (kWCU) piping outboard of the isolation valves in the 151 program.
If the piping is within the scope of GL 88-01, the licensee will need to modify the program to include the identity of the welds as well as plans for mitigation and inspections.
A minimum of 10f of the RWCU system piping outboard of the isolation valves should be inspected at each refueling outage.
if cracks are found, the licensee should discuss sample expansion and mitigation methods with the NRC staff.
CECO submitted a response to the above deficiencies by letter dated November 5, 1990. The Technical Specification (TS) change request was submitted by letter dated April 1, 1991 and supplemental information, which was not outside the scope of the original submittal, was provided in letters dated September 13 and October 17, 1991.
2.0 DISCUSSION Ceco's response to each of the deficiencies noted in the SE proposed TS chan5?S and the staff's evaluation are presented below.
Item (1):
CECO proposed a statement be included in Technical Specification 4.0.5 stating that the inservice inspection program for piping identified in NRC Generic Letter 88-0:1 shall be performed in accordance with the NRC staff positions on schedule, metbods, personnel, and sample expansion included in generic letter 88-01 or in accordance with alternate measures approved by the NRC staff.
Since CECO proposed a statement under the inservice inspection surveillance requirements of the TS (Section 4.0.5) in its letter dated April 1, 1991, that is consistent with the guidance contained in the staff's Safety Evaluation issued on August 22, 1990, the staff finds this proposed change acceptable.
Item (2): CECO proposed on additional limiting condition for operation (LCO) be added to Technical Specification 3.4.3.2 that specifies reactor celant leakage shall be limited to a 2 gpm increase in unidentified leakage within any 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period.
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. l Since CECO proposed to add an LCO to TS Section 3.4.3.2 that is consistent with the guidance contained in the staff's Safety Evaluation issued on August 22, 1990, the staff finds this proposed change acceptable.
Item (3): This item reconnends addition of a requirement to the Technical Specifications to monitor the primary containment sump flow rate at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
Ceco stated that LaSalle County Station "shiftly" surveillance interval as defined in Table 1.1 of the Technical Specifications is "at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />." At the present time there are no Technical Specification surveillance requirements at LaSalle which require an 8-hour time interval.
As a result the station does not have any administrative controls in place to ensure that such a surveillance requirement is met. Technical Specification 4.4.3.2 currently contains a surveillance requirement to monitor the primary containment sump flow rate at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
Normally the Technical Specifi-cation "shiftly" surveillance requirements are performed three times daily (once during each shift). Therefor *,, the surveillance requirement as currently written was considered by the station to be adequate to meet the intent of the recommen-dation in Generic Letter 88-01.
The staff reevaluated the frequency of leakage monitoring after discussions with the BWR0(i and concluded that measurements taken every C hours (compared to every 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> as originally specified in GL 88-01) are adequate and necessary.
On this basis Ceco was informed that its response to monitor the containment sump flow rate at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> was unacceptable, in letters dated September 13 and October 17, 1991, CECO revised l
its April 1, 1991 TS submittal to state that monitoring of the l
primary containment sump flow rate shall be performed on average once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> not to exceed 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
Since this revision is consistent with the staff's current position, it is acceptable.
The proposed TS change also permits up to a maximum 4 additional hours to perforu this surveillance.
This provides LaSalle some flexibility in performing this surveillance which the staff also finds acceptable.
Ceco has proposed to add an action statement under TS Section 3.4.3.2 which would allow 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> to identify the leakage source if the 2 gpm increase limit is exceeded in any 24-hour period or be in hot shutdown within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in cold shutdown within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
Since this action statement is consistent with the other action statements in TS Section 3.4.3.2 related to reactor pressure coolant system leakage, the staff finds this acceptable.
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Item (4): On June 30,198" CECO provided additional information concerning l
NRC Generic Letter 88-01 as requested in an NRC letter dated May 1, 1989.
At that time it was identified that LaSalle Unit I had two Category E weldments, further In nections were performed during the third refueling outage for Jnit 1 in Spring 1990 of Weld Numbers RRd OOS.27A and RR-1001-10 using the General Electric automated " SMART" Ultrasonic Testing (UT) System. The indications which had previously been classified as Category E IGSCC were redefined to be root and internal diameter geometry. This redefinition is attributed to the additional machining of the weld crown on these two welds which resulted in a smoother scanning surface for the UT system.
The "$MAkt" UT system was able to characterize the indications more accurately on the smoother surface. As a result Weld Numbers RR-1005-27A and RR-1001-10 have been reclassified from Category E-to Category B.
The staff concurs with Ceco that LaSalle Station, Unit I no longer has any weldments classified as Category E and, therefore, the additional leak detection monitoring requirements-provided in Generic Letter 88-01 for plants with Category E weldments no longer apply.
Also, as a result of the reclassification of these welds an LCO related to the operability of the sump monitoring instruments is not required.
item (5):
An evaluation by the LaSalle Station Technical Staff InserviceInspection(ISI)/InserviceTesting(IST) Group determined that neither the Unit 1 or Unit 2 Reactor Water Cleanup System (RWCU) contains any Austenttic Stainless Steel.
Therefore, the RWCV system does not fall within the scope of NRC Generic Letter 88-01 and no further action is required.
The staff concurs with Ceco that since the RWCU systems at LaSalle Station do not contain any austinitic stainless steel, no further action is required.
In summary based on the review of CECO's responses to the staff's SE dated August 22, 1990, the staff concludus these responses are in.accordance with the rs.quirements of Generic Letter 88-01 and are, therefore, acceptable. The staff aise concludes that the proposed 15 changes contained in your April 1 September 13 and October 17, 1991, submittals are acceptable, l
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3.0 STATE CONSULTATION
In accordance with the Connission's regulations, tha Illinois State official was notified of the proposed issuance of the amendments. The State official had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
The amendments change a requirerent with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and c1ange surveillance requirenents. The NRC staff has determined I
tnat the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that;ney be released of fsite, and that there-is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that_the amendments involve no significant harards consideration, and there has been no public comment on such finding (56FR27038). Accordingly, the amendments meet the eligibility criteria-for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to i
10CFR51.22(b),noenvironmentalimpactstatementorenvironmentalassessment need be prepared in connection with the issuance of the amendments.
5.0 CONCLUSION
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i The staff has concluded, bared-on the considerations discussed above, that:
(1) there is reasnnable assurance that the health and-safety of the will not be endangered by operation in the pro >osed manner, and (2) public such activities will be conducced in compliance wit 1 the Commission's regulations, and (3) the issuance of '.hese amendments will not be inimical to the common defense and security or no the health and safety of the public.
Principal Contributor:
R. Elliott l
Dated: October 25. 1991 l.
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