ML20150D606
| ML20150D606 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 03/17/1988 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20150D565 | List: |
| References | |
| NUDOCS 8803240383 | |
| Download: ML20150D606 (4) | |
Text
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UNITED STATES NUCLEAR REGULATORY COMMISSION j
WASHINGTON, D. C. 20555 e
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.15 TO FACILITY OPERATING LICENSE N0. DPR-21 NORTHEASTNUCLEARENERGYCOMPANL_ETAL.
MILLSTONE NUCLEAR POWER STATi g, E T N0. 1 DOCKET NO. 50-245 INTRODUCTION By letter dated May 15, 1987 the Northeast Nuclear Energy Company (NNECO or licensee) submitted a request for changes to the Millstone Nuclear Power Station, Unit No. 1.
The amendment would delete Technical Specification (TS) Tables 3.6.1.a and i
3.6.1.b, a listing of safety-related hydraulic and mechanical snubbert, i
respectively, and would make changes to the testing and surveillance require-ments for snubbers.
EVALUATION The licensee stated that the proposed changes are in accordance with NRC 1
Generic Letter 84-13 (May 3,1984) which concludes that the inclusion of a snubber listing within the TS is not necessary provided the snubbers are required to be operable. Other TS changes are proposed in an effort to maintain conservatism consistent with the Boiling Water Reactor Standard Technical Specifications and plant requirements. NNECO sunnarized the proposed changes as:
l'eletion of TS Tables 3.6.1.a and 3.6.1.b; Reduction of additional snubbers to be tested for each feilure from 10% to 5%;
j Addition of a surveillance requirement for the snubber life program; and, Clarification of the visual inspection acceptance criteria and functional retest requirements.
8803240383 880317 DR ADOCK OSO S
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The staff review of the proposed changes was a comparisen of the present TS and the licensee's submittal with the Standard TS (STS). Generic Letter 83-13 transmitted snubber STS to all power reactor licensees (except licensees participating in the Systematic Evaluation Program (SEP)) by letter dated May 3, 1984. Since Millstone 1 was, at that time, an SEP plant, these STS do not directly apply to Millstone 1.
Therefore, the snubber STS were used for guidance only.
1 Individual TS changes were found acceptable based on previous acceptability of STS or previcasly approved amendments at other sites.
Six significant changes /
differences were identified and discussed with the licensee.
The resolution of each change / difference issue is addressed as follows:
2.1 Inclusi_on_ _of_ All Safety-Relat_ed_ Snubb_e_r_s In the STS limiting condition for operation (LCO), all snubbers, excluding those on nonsafety-rdlated systems which have no adverse effect on any safety-related systems, are required to be operable except for cold shutdown and refueling conditions. The licensee's proposed TS requires all safety-related snubbers to be operable for the same condidtions.
It appeared possible that a nonsafety-related snubber which might effect safety in an indirect way might not be required to he operable. However, the licensee stated that their definition of safety-related snubbers includes all snubbers at Millstone 1 that could effect any safety-related system. There fore,
using their definitions, the same protection is reached as provided by the STS wording and the proposed TS is acceptable.
2.? E_ngi ne,e,rt,n3 Evaluation to Determine Operability The STS action statement for an inoperable snubber (s) requires that, within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, replace or restore this/these snuMar(s) and perform an er.gineering evaluation on the supported component, or declare the supported system inoperable and follow the appropriate action statement for that system.
In the present and proposed TS, NNEC0 is allcwed to perform an engineering evaluation instead of replacement or repair.
This makes the TS read as if an or was between the required corrective actions and the engineering evaliiation in the STS. The licensee has recently computerized the safety-related piping system supports evalu-ations and believe they are capable of performing engineering evaluations within the 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> required by TS. A plant shutdown, if required by cperability requirements, would be required if the evcluation showed the snubber was critical to pipe support.
The licensee was not willing to change to the STS wording and no technical justification could be found for insisting on the STS Nording. Therefore the current wording remains acceptable.
2.3 Insecure _ _A,t_t_achment to Suppor,t,1,n3 Structure The licensee's application adds a clarificatien staterrent that snubbers found to have insecure attachn.ents to their foundation or supporting structure shall not be included in Table 4.6.I.1 for determination of the next inspection interval. The licensee indicated that this state-ment con.es from ASME Code Section XI.
Since this rr.quirement is beyond STS requirements, it is acceptable, I
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3 2.4 Follow-up Inspectica Sarple S17e The licensee's proposed TS 4.6.I.3 would reduce the follow-up sample size from 10% (stae as the first sample size) to 5% additional snuhber j
inspection for each failure. The May 3,1984 STS, previously referenced also requires a 10% follow-up sample size for each failure. However, in more recently isr TS, such as those for Millstone 3, a 5% follow-up sorrple size has been,utnorized. Justification for this change was based on statistits showing that a 5% follow-up sample for each failure provides essertfally the same cunfidence level as the first 10% sample.
Whereas, the 10% follow-up samples, for each failure, continually improves j
the confidence level above that obtained with ti;a first sarrple. Since this charige has been approved for NNECO and other licensees, it is acceptable fur Millstone 1.
2.5 Displacerren_t Under Continuous toad The STS hydraulic and nech6ncial snubber functional test acceptance 4
criteria requires that, for snubbers specifically required to not displace under continuous load, the ability of the snubber to withstand load withcut displacement shall be verified.
The licensee's review of their systems has found that Millstone 1 does not have any snubbers that are required to not displace under continuous loads. Therefore.
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this part of the STS need not be included in their TS.
2.6 I,n c,re,a s,e,d,,Dra3 Force Limitation e
r The STS rcechanical snubber functional test acceptance criteria requires that, drag force shall not have increased more than 50% since the last functional test. The licensee states that because drag force treasure-trents, especially en small snubbers, are very hard to measure and are not usually repeatabla, this requirement is unrealistic. Again, this requirement has been eliminated from recently issued TS such as those for Mir tcne 3.
Therefore, this requirenent is not necessary for Hillstu e 1.
Based on the above, we find the proposed changes TS 3.6.I, Primary System Boundary - Snubbars, acceptable.
ENVIROWENTAL CONSIDERAi!ON This amendment changes a requirement with respect to the installation or use of a facility con.ponent located within the restricted area as defined I
in 10 CFR Part 20 and changes surveillance requirements. The '.taff has deters,ined that the amendrrent involves m s'gnificant increase in the amountr.,
and no significant change in the types, -
any effluents that may be released offsite, an+ that there is no significar,% increase in individual or cumulative occupational radiation exposure. The Corntission has previously published a proposed finding that the an,endment involves no significant hazards censidera-tion and there has been no public contrent on such finding. Accordingly, the amendntnt meets the eligibility criteria for categorical exclusion set forth in 10 CFR E51.?2(c)(9). Pursuant to 10 CFR $51.22(b), no enviror.ncntal impact staton,ent or environn<ntal assessment need be prepared in connection with the issuan.:e of the anendnent.
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4 CONCLUSION We have concluded, based on the considerations discussed above, that I
(1) there is reascrable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (2) such activities will be conducted in compliar.ce with the Commicsfon's regulctions, and the issuance of the amendrtnt will nct be inimical to the cone.on i
defense and security or to the health and safety of the public.
06ted: March 17,1988 Prircipal Contributor:
E. Conner i
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