ML20028F572
| ML20028F572 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 01/24/1983 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20028F571 | List: |
| References | |
| NUDOCS 8302020214 | |
| Download: ML20028F572 (4) | |
Text
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UNITED STATES p,
NUCLEAR REGULATORY COMMISSION
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO REQUESTS FOR RELIEF FROM INSERVICE INSPECTION REQUIREMENTS CALVERT CLIFFS NUCLEAR POWER PLANT UNIT NOS. 1 AND 2 0
DOCKET NOS. 50-317 AND 50-318 By applications dated November 6,1981 and December 21,1982, ' Baltimore Gas and Electric Company (BG&E) requested relief from inservice inspec' tion requirements of Section XI of the ASME Boiler and Pressure Vessel Code l
for Calvert Cliff.s Units 1 and 2.
The proposed relief is described herein.
i Discussion and Evaluation
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1.
Examination Reauirements for Reactor Vessel Closure Head Cladding The ASME Code Section XI,1974 Edition, with Addenda through Summer i
1975, requires a visual and surface examination or a volumetric examination of the reactor vessel closure head cladding. By appli-cation dated November.6, 1981, BG&E requested relief from this ex-amination requirement.
By adoption of the 1977 Edition of the ASME Code,Section XI, with Addenda through Summer 1978, BG&E is relieved of the requirement to 4
ins'pect the reactor vessel head cladding. The commitment, contained
. in the. November 6,1981 application, to perform a visual examination of the cladding is acceptable. Accordi.ngly relief from the required examination of the reactor vessel head cladding is. appropriate provided that visual examination is continued.
2.
Use of Code Case N-210, " Exemption to Hydrostatic Tests Af_ter Repairs" By appli, cation dated November 6,1981, BG&E requested relief from the ASME Code in that they desire to utilize Code Case N-210 in the course of performing the Inservice Inspection Program for Calvert Cliffs Units 1 and 2.
The use of Code Case N-210 is endorsed by Regulatory Guide 1.147, " Inservice Inspection Code Case Acceptability-ASME Section XI Division 1" Revision 1 of Regulatory Guide 1.147, dated February 1982, indicates that Code Case N-210 has been annulled in that it has been included in the ASME-Code by a subsequent revision.
In such instances, the continued use of the Code Case intent is sanctioned under the rules of the Code. Accordingly, we conclude that the use of Code Case N-210 for Calvert Cliffs Units 1 and 2 is acceptable, subject to the condition-l that, for repairs to piping, pumps and valves, the depth of the cavity i
not exceed 25 percent of the wall thickness.
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3.
UseofCodeCaseN-3d7,"RevisedUltrasonicExaminationVolume for Class 1 Bolting Examination Category B-G-1, Division 1, When the Examinations are Conducted from the Center-Drilled Hole" By application dated November 6,1981, BG&E requested relief from the i
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, 4 ASME Code in that they desire to use Code Case N-307 in the course of performing the Inservice Inspection Program for~ Calvert Cliffs Units 1 and 2.
Code Case N-307 allows relief from ultrasonic examination of studs in the volume that extends to within " of the threaded surface.
We have previously reviewed the use of Code Case N-307 and have found it acceptable in that, indications are most likely to occur within " of
, the threaded surface (the volume to be inspected) due to the higher stress concentrations associated with the threads.
Moreover, Code Case N-307 was subsequently approved by Regulatory Guide 1.147, Revision 1, and is therefore acceptable for use at Calvert Cliffs Units 1 and 2.
4.
Increased Inservice Leak Testinc ~in ~ Lieu of Hydrostatic Pressure Testing of Class III Component Cooling kater Systems By application dated November 6, 1981, BG&E requested relief from the ASME Code as it applies to the inservice inspection of the Class III l
component cooling water system.
Paragraph IWD-2410 requires hydrostatic Pressure Testing of Class III systems to 1.1.imes design pressure during every ten year inspection interval.
In their November 6, 1981 application, BG&E stated that "on the Component Cooling Water System main headers, where butterfly valves are installed, suffic'.ent seal to maintain pressure on isolated portions of the system cair.ot be completed. BG&E proposed'that the Inservise Leak Test reqaired every 40-month period be performed on an annual basis to substitute for hydrostatic pressure testing of this system."
In our letter and Safety Evaluation (SER) dated December 13, 1982 the NRC approved relief from the hydrostatic test requirements of IWD-2410 for inservice inspection of the Class III service water system. The service water system is similar to the component cooling wat'er. system in that both systems rely on butterfly valves for pressure boundary
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isolation.
Our approval of relief in the December 13, 1982 SER was based upon (1) the inability of these butterfly valves to sustain l
'the pressure required for a hydrostatic test (1.1 times the design pressure) and (2) the absence of a reasonable alternative other than annual leakage testing.
From the above, we conclude that the relief requested in the November 6,1981 application, for hydrostatic testing of the component cooling water system, should be granted on the same basis as described in our SER dated December 13, 1982. This relief is based upon the commitment by BG&E to perform the.40-month inservice leak test on an annual basis for the component cooling water system.
5.
Hydrostatic Testing of' Welds that Cannot be Isolated from the Steam benerator (Unit z only)
In our letter and SER dated November 19, 1982, th'e NRC provided relief from the ASME Code requirement to perform hydrostatic tests on certain welds in lines that cannot be isolated from the steam generator. These welds were associated with modifications to the auxiliary feedwater system.
This relief was based upon the desire not to perform a hydrostatic test of the steam generator to test these welds since the steam l
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- generators are limited to a total of ten (10) hydrostatic tests during the lifetime of the plant.
The next full hydrostatic test of the steam generators is scheduled during the 40-month inspection period which will begin in December 1983.
By application dated December 21, 1982, BG&E identified additional welds associated with the auxiliary feedwater system modifications, for which relief had not previously been requested.
These welds are also located such that they cannot be isolated from the steam generator in order to perform the required hydrostatic test. Accordingly, it is appropriate to provide relief from the hydrostatic test requirement for these additional welds based upon the discussion presented in our SER dated November 19, 1982.
This relief includes the following additional inspections:
1.
Surfa'ce Examination after the final weld pass.
2.
An Inservice Examination of the components at a pressure corresponding to 100% reactor power. An Inservice Examination of the components in the HOT STANDBY mode (which is approximately 50 psi greater than 100% normal operating pressure).
3.
A 100% Volumetric. Examination utilizing ultrasonic and/or radio-graphy methods.
A final issue raised by BG&E in their December 21, 1982 application relates to the surface examination of welds after removing half of the first layer by grinding. While this technique was endorsed by the NR'C in our November 19, 1982 SER, for welds for which relief from hydrostatic testing was granted, we concur with the licensee that this i
is not a requirement of the applicable repair code (USAS B 31.7).
Accordingly, the removal of weld material and subsequent surface exami-nation is not a required procedure for welds associated with the auxiliary feedwater modification as described in our SER of November 19, 1982 and the BG&E application dated December 21, 1982.
Conclusion -
The r.elief from the Code is based upon our review of the information sub-mitted by BG&E to support the determination that compliance with the ASME Code inservice inspection requirements would be impractical for the facility.
We have determined thtt the inspection from which this relief is sought is impractical and pursuapt to 10 CFR 550.55a(g)(6)(i), that the granting of this relief is authorized by law and will not endanger life or property, or the cpmmon defense and security, and is otherwise in the public interest.
In making this determination, we.have given due consideration.to the burden l
that could result if there requirements were imposed on the facility. We l
have determined that the granting of this relief does not involve a signi-l ficant increase in the prchability or consequences of an accident previously l
evaluated, does not create the possibility of an accident of a type different l
from any evaluated previously, and does not involve a significant reduction in a margin of safety; and thus, does no't involve a significant hazards l
consideration. We have concluded, based on the considerations discussed I
above, that:
(1) there is retsonable assurance that the' health ~and safety of the public will not be endargered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Comis-
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sion's regulations and the issuance of this relief will not-be inimical,
to the common defensp and. security or"to the health'and safety of the public.
Furtheremore, we have determined that the granting of this relief from ASME Code requirements does not authorize a change in effluent types or total amounts nor an increase in power level and will not result in any significant snvironmental impact. We have concluded that the granting
. of this relief is insignificant from the standpoint of environmental impact
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and pursuant to 10 CFR 51.5(d)(4) that neither an environmental impact statement nor a negative declaration and environmental impact appraisal need to be prepared in connection with this action.
JAN 2 4 N Dated:
Principal Contributors :
D. Jaffe G. Johnson Y
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