IR 05000263/1975017
| ML20024G542 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 12/01/1975 |
| From: | Kohler J, Little W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20024G539 | List: |
| References | |
| 50-263-75-17, NUDOCS 9102120630 | |
| Download: ML20024G542 (6) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT
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REGION III
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Report of Operations Inspection
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IE Inspection Report No. 050-263/75-17
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Licensee:
Northern States Power Company.
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414 Nicollet Mall i'.inneapolis, Minnesota 55401 Monticello Nuclear Generating Plant License No. DPR-22
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Monticello, Minnesota Category:
C Type of Licensee:
BWR (GE) 575 MWe Type of Inspection:
Special, Announced.
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Dates of Inspection:
Ncrember 11-15, 1975 g
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Principal Inspector: ' p oel E.'Kohler
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Accompanying Inspectors:
None Other Accompanving Peraonnel:
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Reviewed By:
W. S. Littic. Section Leader
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Nuclear Support (Datel'
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SUMMARY OF FINDINCS
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Inspection Summary The inspection on November 11-15 (75-17):
consisted of a review and witness of the 1975 Monticello Integrated Leak Rate Test.
Enforcement Items None.
Licensee Action on Previously Identified Enforcement Items None.
_ther Significant Items O
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A.
Systems and Components 1.
Daring the ILRT, a ball valve in the TIP system was found to be leaking at approximately 500 scfh. The ball valves in the TIP penetrations are non testable and are not included in the local leak rate test program.
2.
Unresolved Item - The licensee was asked in a telephone call following the inspection to consider corrective action for penetrations identified as leaking excessively in two or e,e
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more local rate test progracs.
This will be followed up at a later inspection.
(Paragraph 3, Report Details)
B.
Facility Items (Plans and Procedures)-
1.
The contaic=ent was calculated to have an "as found" integrated leak rate of approxLmately 4 w/o/ day which is in excess of the technical specification lim 3 t of 1.2 w/o/ day.
2.
The as Icf t containment integrated leak rate at the conclusion of the test was approximately.25 w/o/ day.
l 3.
The licensee plans to run the next integrated leak rate test (ILRT) during the next refueling outage as required by their l
Technical Specification.
This time interval prior to retest l
may be as great as 24 months which exceeds the approximate 18 month minimum interval required by 10 CFR 50, Appendix J, i
Section III. A.6(b) Justification for this departure f rom Appendix J requirement will be addressed in a License Amendment Request to be submitted to the Division of Reactor Licensing prior to December 31, 1975.
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C.
!!anagerial Items
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None.
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Noncompliance Identified and Corrected by the Licensee None.
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Deviations None.
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F.
Status of Previously Reported Unresolved Items
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None.
Management Interview
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interview was conducted by Mr. liohler with Mr. Larson, A management Plant Superintendent and other members of his staff at the conclusion of the inspection. The following items were discussed.
The inspector stated that containment leakage from the ball valve A.
in the TIP system found leaking during the ILRT was a reportable The licensee stated that the valve would have to be
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examined after depressurization before a determination could be made regarding its reportability.
Examination subsequent to the
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inspectios.,resulted in,the licensee concluding that this event
%" We A w-vas reportable. ~~(Ps.ragrad 57 Report Details)
The licensee was asked whether future modifications to the TIP B.
system penetrations-would be made so that these penetrations could be classified as testable and included in the local leak rate test The licensee had not reached a conclusion at the completion program.
of the inspection.
(Paragraph 6. Report Details)
The licensee had not established acceptance criteria for leakage r
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from the reference vessel.
The licensee stated k muld d.:'.s top w ding this such crituria.
The 1.upector has no more qu s ciona r
r item.
(Paragraph 7, Report Details)
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REPORT DETAILS
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1.
Persons Contactef
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C. Larson, Plant Superintendent D. Antony, Plant Engineer, Operations M. Hasuser, Enginner B. Jenness, Engineer D. Coranson, Engineer M. Clarity, Superintendent, Plant Engineer and Radiation Protection H. Theobalt, Engineer
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H. Nimmo, Maintenance Supervisor 2.
General
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Conduct The inspector observed the integrated leak rate test.
of the test was compared with the requirements of the licenuee's test procedure, the technical specifications and 10 CFR 50, Appendix J.
3.
As Found Containment Leak Rate The results of the licensee's local leak rate test program were obtained. The containment leakage in the as found condition was estimated by the inspector to about 4 weight percent per day. The following leakage was considered significant in contributinr to 'the as f6und teontainment leakage.
wwwo<% w e g%g.m, g % %,
Penetration Leakage (scfh) at 41 psig Seismic Restraint Part D
168 AD-2561 25613 Main Steam Drain Line 306
HPCI-9 l
CRD Return Line (CRD-31)
450
KP-6 Core Spray A injection Check
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500 Hall valve in TIP system
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(1)
1652
.9 w/o/ day = 4.3 w/o/ day 344 x.
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(1)
.9 w/o/ day is equ va ent to approximately 344 sefh.
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4.
Leskina Fenetrations Identified In Previous Local Leak Rate Tests
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The inspector obtained the results of the 1973, 1974 and 1975 local leak rate test program and has identified the following penetrations as showing excessive leakage in two or more tests.
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Leakage (sefh)
Penetration 1973 1974 1975 Main Steam Drain Line (M02373)
484 306
.RPCI-9 940 65.6
CED Return Line (CRD-31)
450 IP-6 (Standby By Control)
Note 1
Core Spray Injection Check A 970 331
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Core Spray Injection Check B Noce 1 396 103 The licensee was asked in a followup telephone call whether he was considering corrective action for these penetrations.
The inspector will follow this item in a subsequent inspection
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and has no further questions at this time.
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5.
TIP Laakage The ILRT began on 0900 November 14. 1975, upon attaining a containment internal pressure of 41'psig. During the first 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> of the ILRT, the containment leakage rate was calculated t'o be about 1.6 w/o/ day, exceeding the allowable leakage rate of.9 w/o/ day. At approximately 0100 on November 15, 1975, a leak was discovered in.a ball valve E
of one"of the TIP penetrations. Upon'risolating this leake g y p,q w,.
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containment integrated leak rate dropped to about.25 w/o/ day.
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The inspector estimated that the ball valve was leaking at about 1.35 w/o/ day equivalent to about 500 scfh.
6.
Reportability of TIP Leakage At the conclusion of the inspection the inspector stated that the leakage through the ball valve in the TIP system was a reportable The basis the inspector used for this conclusion was occurrence.
that it
,ed one of the boundaries (the containment) to exceed its allowauic leak rate.
The licensee stated that reportability of this occurrence could not be determined until the valve was examined af'ter containment
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depressurization. Although the valve was.not leak tested before pressurization, preventative maintenance was performed on the valve.
The licensee took the position that the leak would not be reportable
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if it could have been attributed to the preventative maintenance
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performed on the valve.
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(1) Would not hold test pressure.
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Af ter depressurization the licensee determined that the leakage was
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a reportable occurrence.
7.
Possible Modifications to Ball Valve TIP Penetrations The licensee has classified the TIP penetratiors as non testable.
The licensee was asked whether future modification of t.iese three penetrations would be made so that they could be classified as testable and included in the local leak rate test program. At the conclusion of the inspection no decision has been made by the licensee about design modifications to the TIP system.
8.
Acceptance Criteria For Reference Vessel Leakage Before containment pressuri=ation and after containment depressur-ization the licensee is required to perform a leak test on the reference vessel used in the ILRT. The reference vessel had a leak rate of.1 w/o/ day at 50 psig before the test.
Excessive leakage of the reference vessel af ter containment depressurization would invalidate the results of the ILRT.
The licensee had not developed any acceptance criteria for allevable reference vessel leakage after containment depressurization and stated he would do so before the next ILRT. The inspector has no more questions regarding this item at this time.
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