3F0186-22, Requests NRC Approval of Plans to Remove Large Bore Snubbers Associated W/Reactor Coolant Pump a & Possibly B.Request Supported by 860113 Exemption Request & Consistent W/Guidance in Generic Ltr 84-02.B&W Encl

Requests NRC Approval of Plans to Remove Large Bore Snubbers Associated W/Reactor Coolant Pump a & Possibly B.Request Supported by 860113 Exemption Request & Consistent W/Guidance in Generic Ltr 84-02.B&W Encl

ML20137L780
Person / Time
Site:	Crystal River
Issue date:	01/21/1986
From:	Eric Simpson FLORIDA POWER CORP.
To:	Harold Denton Office of Nuclear Reactor Regulation
References
3F0186-22, 3F186-22, GL-84-02, GL-84-2, NUDOCS 8601280086
Download: ML20137L780 (9)

Text

l Power C0R POR ATIO N January 21, 1986 3F0186-22 Mr. H. R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555

Subject:

Crystal River Unit 3 Docket No. 50-302 6perating License No. DPR-72 Snubber Optimization Approval Request

Dear Sir:

The purpose of this letter is to request NRC approval of Florida Power Corporation's (FPC) plans to remove the large bore snubbers associated with reactor coolant pump "A" and possibly "B". This request is technically supported by being bounded by our previous exemption request, which was supported by several submittals (see Attachment 1, " References"). It is also consistent with generic NRC guidance promulgated as Generic Letter 84-02.

FPC's original exemption request was scheduled so snubber removal could take pl ace during the next refueling outage in the Spring of 1987. This - request is being pursued because of a current forced outage. This outage was caused by a sheared pump shaft on the "A" reactor coolant pump which will necessitate disconnection or removal of all large bore snubbers. associated with this pump.

FPC's current schedule estimates restart during the later part of March 1986, therefore, expedited licensing efforts must be pursued to support this schedule. The only alternative to this effort is to reinstall the snubbers, which is inconsistent with good ALARA principles and is not justifiable from a cost and schedule viewpoint.

9601280086 860121 PDR ADOCK 05000302 P PDR

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GEN ERAL OFFICE 3201 Thirty-fourth Street South e P.O. Fox 14042. St. Petersburg, Florida 33733 e 813-866-5151

January 21, 1986 j 3F0186-22 l Page 2 i

Background

In early 1985, FPC became the lead Babcock & Wi l cox (B&W) pl ant on utilization of Leak-Before-Break (LBB) methodology by submitting a formal request for exemption from portions of GDC-4 (Reference 2). A series of meetings and submittals have provided the basis for technical acceptance of the generic B&W Owners Group work (Reference 1) and the anticipated technical acceptance of plant specific aspects. The NRC Staff has been pursuing a change to GDC-4. to obviate the need for such exemptions. Our review was being pursued in parallel to support either exemption, should the rule change not be completed in a timely fashion, or an approval under the modified rule.

NRC Actions Requested FPC is requesting NRC approval to pursue those actions concerning

our reactor coolant "A" and possibly "B" pumps per'our submittal on January 13, 1986 (see Reference 8). The following points i should be considered by the NRC in determining which course of action to pursue, i

0 Since rulemaking is proceeding as expected but is not yet

completed, FPC is not in a position to determine if approval needs to be a formal exemption or technical approval.

Therefore, Attachment 3 provides the necessary evaluations

' pursuant to 10 CFR 50.12 (as modified effective January.13, 1986).

O This request is further complicated by the snubbers being included in tabular form in the Crystal River 3 Technical l Specifications. NRC Generic Letter 84-13 informed the industry that relocating such lists was appropriate.

! Therefore, FPC submitted Technical Specification Change Request 142 to allow routine noticing of this request without awaiting technical acceptance of snubber removal.

o The scope.of this request is less than the earlier request (Reference 8) but is bounded by associated analyses (see Attachment 2). Current plans are to optimize the supports l for at least the "A" reactor coolant pump, but optimization I

of the other- pump in the same "D-ring" (reactor coolant pump "B") may be pursued to reduce the scope of Refuel VI if it

of January 21, 1986 3F0186-22 Page 3 can .be done within appropriate constraints ( sc hedul e for

forced outage, funding, ALARA, procurement, etc.). Conipl et e optimization as originally envisioned in our previous exemption will not be pursued unless the scope of work on the unaffected pumps significantly increases.

O This exemption approval need not be permanent, but may be

. interim until . approval of the broader exemption' request (scheduled in the next few weeks / months) or publication of the final rule change associated.with GDC-4_ occurs.

In summation, FPC requests' the NRC to accomplish the following actions within the schedule provided.

(a) Notice Technical . Specification Change Request Number 142 on or before February 15, 1986 (30 days prior to Mode 4).

(b) Approve our optimization program as requested for at least the "A" and "B" reactor coolant pumps and issue appropriate approval (exemption or . safety evaluation depending on rulemaking status) by March 1, 1986.

FPC appreciates that the NRC has proceeded as rapidly as it has on GDC-4 changes and that your staff has worked with FPC over the past year in parallel to this rul ema ki ng to provide both our staffs the opportunity to resolve this matter. Your efforts to bring this issue to final closure will be extremely beneficial to FPC. Should our outage schedule slip affording this effort a less restricted schedule, we will notify our project management immediately.. If FPC can facilitate your staff efforts in any way, please contact this office.

Sincerely,

// Oddn E. C. Simpson Director, Nuclear Operations Engineering and Licensing KRW/feb Attachments r

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ATTACHMENT 1 List'of References

1. B&W Report, BAW 1847, dated October 1984, subject the B&W Owners Group Leak-Before-Break Evaluation of Margins Against Full Break for RCS Primary Piping of B&W Designed NSS.

2. FPC letter to NRC, Westafer to Denton, dated. February 1, j 1985 (3F0285-02), subject Request for Exemption from a Portion of 10 CFR 50, Appendix A, General Design Criterion 4 (GDC-4).

3. Meeting on August 5, 1985 among NRC, Babcock and Wilcox', and FPC representatives to present FPC plans and define NRC staff needs for i n fo rma ti on to support the FPC request of Reference 2 above.

4. FPC letter to NRC, Westafer to Denton, dated August 30, 1985 (3F0885-24), s u bj e ct Re-evaluation of CR-3 Reactor Cooling System Loads Utilizing Leak-Before-Break Concept to Remove Reactor Coolant System Main. Loop Pipe Break Protective Devices; transmitted B&W Report prepared for FPC, subject Evaluation of Reactor Coolant System Loads and Component Support Margins Resulting from Optimized Reactor Coolant Pump Support Configuration.

5. FPC letter to NRC, Simpson to Denton dated September 27, 1985 (3F0985-26), subject Transmittal of Report Related to Request for Exemption from a Portion of 10 CFR 50, Appendix A, General Design Criterion 4 (GDC-4); transmitted B&W Report, Document ID 51-1159048-00, prepared ~ for FPC, subject Safety Balance Assessment for Elimination of-Reactor Coolant

, System Main Loop Pipe Break Protective Devices.

6. B&W Report, BAW 1847, Rev. 1, dated October 7, 1985, same subject as in Reference 1; revised-report issued to address comments and questions raised by NRC staff reviewers.

7. FPC letter to NRC, Westafer to Denton, dated October 29, 1985 (3F1085-13), subject Transmittal of Report Related to Request for Exe'mption from a Portion of 10 CFR 50, Appendix A, General Design Criterion 4; transmitted report prepared by FPC, subject Assessment of CR-3 RC Leak Detection- System, File: SP 83-133, dated October 25, 1985.

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8. FPC letter to NRC, Westafer to -Denton, dated January 13, 1986 (3F0186-12) , 'subj ect Additional Information Regarding j Request for Partial Exemption from' General Design Criterion

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• l 9.. FPC letter to NRC, Westafer to Denton, dated J a n u a ry 16, f'

1986 (3F0186-18)., subject Technical Specification- Change ,

Request No. 142; ' proposes to remove the tabular list of

snubbers from the Technical Specifications in accordance j with NRC guidance provided in Generic Letter 84-13.

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. - ATTACHMLNT 2 Babcock & Wilcox soci.., ro , oi,i. ion 1 a McDermott company 3315 Old forest Road P O Box 10935

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January 16, 1986 [jg"j[b"a 3 0o0 FPC-86-028 Mr. R.A. Webb Nuclear Project Management Engineer Florida Power Corporation P.O. Box 14042 i St. Petersburg, FL 33733 Attention: Mr. L.B. Tittle

Subject:

RC Pump Support Configurations

Reference:

1) Task 984, Rev. 1 - Alternate Support Design for RCS Pump Snubbers (Disabled Snubbers)

2) Task 918, Rev. 3 - RC Pump Snubber Removal and Installation of Alternate Supports

3) Task 020, Rev. 1 - Final Analysis of RC Pump Supports

Dear Mr. Webb:

FPC Engineering (L. Tittle) has requested B&W to confirm the acceptability of the following two interim RC pump support configurations for RC pumps A&B at Crystal River -

3 as a result of the RC pump transient of 1/1/86.

Conficuration 1 RC Pump A - 1 rigid strut and 1 400 kip snubber (Support configuration analyzed in Task 020)

RC-Pump B - 8 existing large bore snubbers Conficuration 2 RC Pump A - 1 rigid strut.and 1 400 kip snubber (Task 020 support configuration)

RC Pump B - 2 rigid struts with 6 existing large bora snubbers disabled (Task 984 analyzed pump s.upport configuration)

. B&W engineering has reviewed the CR-3 RC pump seismic modal analysis data with regard to the effects of having differing support configurations on CR-3 RC pumps A and B. The results ,

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e show that the loadings in the vicinity of each pump. are i independent of one another. The lower cold leg piping loads do not transfer through the fixed base of the steam generator. In addition, there .is negligible loadings transferred from one upper cold leg piping to the other through the reactor vessel.

With respect to all loadings in the RC piping, the loading that is most sensitive to the proposed support changes is seismic.

However, the CR-3. seismic loadings are significantly lower than the other design condition loadings. The total load is dominated by thermal expansion effects. Thus, the differing pump support configurations for RC pumps A and B would result in a negligible change in the total load on the other pump.

J Also, B&W has reviewed Task 020, Task 984 and existing stress J

analysis and B&W concludes either configuration is acceptable.

This configuration review was performed under Task 918, Level of Effort.

If you have any questions, please call.

Very truly yours,

/M . =E L.M. Lesniak Manager of Contract Engineering Nuclear Engineering Services LML/rlb l

cc: J.R. Maseda D.E. Porter E.M. Howard R.J. Finnin G.M. Olds 4

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ATTACHMENT 3 Exemption Evaluction Effective January 13, 1986 proposed exemptions to the requirements of Title 10 were required by 10 CFR 50.12 to meet more specific criteria enumerated in Subsections 50.12(a)(1) and (2). FPC's request complies with the modified rule, as demonstrated below.

"50.12 Specific exemptions.

(a) The commission may, upon application by any interested person or upon its own initiative, grant exemptions from the requirements of regulations of this part, which are (1) Authorized by law, will not present an undue risk to the public health and safety, and are consistent with the common defense and security."

The proposed action is consistent with such a standard. The rule itself is being modified to allow such approvals without necessitating an exemption. Thus, the Commission has acted on the technical concept which is the foundation of this proposal.

In fact, the Commission has encouraged such proposals in Generic Letter 84-02. Furthermore, the Commission has approved several such exemptions on several dockets over the past few months.

10 CFR 50.12 continues by adding:

"(2) The Commission will not consider granting an exemption unless special circumstances are present. Special circumstances are present whenever. . ."

4 After which six examples are listed. Florida Power Corporation (FPC) in the present request meets several of those examples.

Specifically:

"(i) Application of the regulation in the pa rti cul a r circumstances conflices "

with other rules or requirements of the Commission; or. . .

Re-installation would not be consistent with ALARA practices, which are required by several regulations and requirements.

"(11) Application of the regulation in the particular circumstances would not serve the underlying purpose of the rule or is not necessary to achieve the underlying purpose of the rule; or. . ."

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The large bore snubbers are not necessary to achieve t'he underlying purpose of General Design Change 4 (GDC-4), which is that RCS ". . . be designed to accommodate the effects. . .(of) postulated accidents, including loss of coolant accidents." By having a sufficiently accurate leakage detection system and appropriate material characteristics which form the basis of

" leaking-before-breaking", the RCS will accommodate the effects of LOCAs by timely operation action to shut the plant down prior to the catastrophic pipe break. FPC has, in fact, demonstrated the technical capability to do this by submitted evaluation and in real situations. FPC management has shut CR-3 down at least twice in recent years due to leakage anomolies. On one such occasion, a branch connection to the RCS was, in fact, degrading substantially.

"(iii) Compliance would re s ul t. in undue hardship of other costs that are significantly in excees of those c o n t empl a t ed when the regulation was adopted, or that are significantly in excess of those incurred by others similarly situated; or. . ."

Since GDC-4 is being partially exempted in like manner on several recent OL issuances, failure to grant CR-3 similar relief would be inconsistent with its application on "other similarly situated".

"(iv) The exemption would resul t in benefit to the public health and safety that compensates for any decrease in safety that may result from the grant of the exemption; or. . ."

Not applicable. There is no decrease in safety. The entire basis for the NRC's pipe break committee work is to enhance safety. This is a c compl i s h ed , in part, by increasing system flexibility, which the related modification will provide.

"(v) The exemption would provide only t em po ra ry relief from the applicable regulation and the licensee or applicant has made good failth efforts to comply with the regulation; or. . ."

FPC has acknowledged that temporary relief until GDC-4 is modified would be sufficient, although we would prefer granting the full exemption.

"(vi) There is present any other material circumstance not considered when the regulation was adopted for which it would be in the public interest to grant an exemption. If such condition is relied on exclusively for satisfying paragraph (a)(2) of this section, the exemption may not be granted until the Executive Director for Operations has consulted with the Commission."

While not being the sole basis, this situation is consistent with such a circumstance. The level of accepted technical information has grown immeasurably in recent months due to substantial NRC efforts on understanding pipe crack phenomena.

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