ML20050A818
| ML20050A818 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 03/31/1982 |
| From: | Padovan M Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20050A808 | List: |
| References | |
| ISSUANCES-SP, NUDOCS 8204020300 | |
| Download: ML20050A818 (8) | |
Text
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Uti!TED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AN_D LICEflSING APPEAL BOARD In the Matter of l
SACRA!1EftTO MUNICIPAL UTILITY
)
Docket No. 50-312 SP DISTRICT
)
(Rancho Seco Nuclear Generating
)
Station)
)
AFFIDAVIT OF MARK L. PAD 0 VAN I fiark L. Padovan, being duly sworn, depose and State that:
1.
I an an an enployee of the U. S. Nuclear Regulatory Connission (NRC).
My present position is Project Manager of the Rancho Seco facility, Operating Reactors Branch =4, Division of Licensing within the Office of Nuclear Reactor Regulation. A copy cf my professional qualifications was previously submitted to the ASLAB in my December 11, 1981 testinony.
2.
The purpose of my affidavit is to respond to the ASLAB's Memorandun and Order dated March 8,1932, which requested information about the HPI no::les at the Rancho Seco, Crystal River-3 and Oconee plants.
The infomation in my response to Questions 1, 2 and 3 oelow, regardino Crystal River-3, Oconee and the Rancho Seco plants, was provided to me by Regional personnel, 0204020300 820331 PDR ADOCK 05000312 0
PDR l
l l
F Mark L. Padovan _uestion 1 Q
What are the differences, if any, in the nethod of manual initiation of HPl to the nakeup nozzle at Rancho Seco, Crystal River-3 and Oconee?
Fesponse The nethod of nanual initiation of HPI to the nakeup nozzles is similar at Rancho Seco, Crystal River-3 and Oconee.
For clarity, a simplified piping diagran representative of the nakeup systens in the above plants is provided in Figure 1.
Each plant has three high p-essure injection pumps (latseled A, B and C in the schenatic diagran).
Purp B nornally supplies nakeup flow fron the nakeup tani (MZ ) to the reactor coolant systen (RCS).
Punp A is nornally aligned to the MJT, but is not norrally running.
If an operational transient occurs (such as a reactor / turbine trip), pressurizer level could begin to fall.
To naintain pressurizer level, the nakeup flow to the RCS would be increased using Purp E and water from the MUT.
If a greater nakeup flow is necessary, Punp A is nanually started, drawing water f ron the MUl and injecting the water into the RCS through the nornal nakeup I
no :le.
Should 1) the water level in the MUT become low or 2) additional flow be required, Punp C can be nanually initiated with water being supplied from the borated water storage tank (BWST).
For the more frequent plant transients, only one pump, supplying water from the MUT to the RCS is necessary to maintain pressurizer level.
The only notable difference in the nakeup systens of the three plants is that makeup flow at the Oconee units is distributed to the RCS through two nornal makeup lines (rather than only one), as shown on the enclosed Figure 1 diagran.
i.
1 I
1
- I flark L. Padovan l
f Question 2 I
Are th' inservice inspection procedures relative to the nozzle tests at
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Crystal River-3, Oconee and Rancho Seco the sane? How often are the nozzles at each location surveyed? When was the last test performed at i
i j
each facility and with what results?
1
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1
Response
Crystal River-3, Oconee and Rancho Seco use the following B&W procedures for ISI inspection at the nozzles. They are:
I a.
151-120, Ultrasonic Examination of Piping and Vessel Welds Joinina i
Sinilar and Dissimilar Materials and; j
f Penetrant Exanination of Weld and Base fiaterials Including b.
151 240, j
4 i
Studs and Nuts.
l Furthermore, the following applies to these plants:
Ultrasonic and liquid penetrant procedures are ISI Procedures I
written and qualified, as required, to comply J
with ASME Section XI and V of the Code.
Applicable Code Edition 1974 with Addenda through sunner 1975.
l HPI nozzle to safe-end welds require ultrasonic Inspection Frequency t
I and liquid penetrant inspections each inspection interval (10 years).
l
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ISI inspections cover the entire circunference Area of Interest of the weld and include the base material for, l
at least, one wall thickness beyond the edge of the weld, i
i Plant specific ISI frequencies are given below:
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t
. Mark L. Padovan a.
Crystal River-3 The nozzles were originally on a 10-yeat ISI cycle. As of January 1982 only one nozzle to safe-end weld had been examined.
This examination occurred in 1970, and no deficiencies were reported. The remaining nozzle to safe-end welds were scheduled to be examined, one each outage, on the 5th, 9th and 10th outages (the plant just completed its 3rd outage).
In addition, two additional welds were scheduled to be inspected in these lines during The licensee's first 10-year ISI program did not the 8th and 9th outages.
exanine any additional welas in the HPI and nakeup lines including +5e weld that failed.
The licensee has conmitted to examine all these welds during the next outage, b.
Oconee The chronology of HPI/r.akeup line nozzle to safe-end weld I5I inspections for the three Oconee units is tabulated below:
Unit 1 1 A1 1975 1st outage 1A2 1978 4th outage Unit 2 2Al 1978 3rd outage l
2A2 1982 5th outage Unit 3 3Al 1976 1st outage 3A2 1979 4th outage 1982 Ultrasonic inspection of repair which establishes new baseline.
P
" ark L. Fadovan We will still need to verify whether the olant records indicated any deficiencies ds a result of thesa insoettions; and will subsequently subnit these results to the Board.
c.
Dancho Seco
!.o ISI work has been done on any of the four dissimilar metal welds between the sa'e-end and the cold key pioe.
Since the nozzle crackina event at Crystal As Diver-3, the NPC staff has held discussions with BM' licensees and BAW.
indicated in the enclosed "Sunnary of the Piarch 16, 1982 Meetina with BM' Licensees and ?erresentatives Concerning HPI Nozzle Crackino", all operatir a P8W plans have either 1) already shutdown to exanine all HPI and nakeuo nozzles or 2) will be cerforminq these exaninations in the inrediate future.
er.stal River-3 and Oconee-3 nozzles have been renaired, and reoairs are
%e currentl" undorway at Oconee-2. Pancho Seco has connitted to be shutdown by 1982 to inspect all HDI and nakeup nozzles for crackinu.
We under-Apr i o,
stand that D.ancho Seco now plans to shutdown on Aoril 2,1982, and will cerform these inspections during this shutdown.
Q45tico 3 As of Marc-1,1952, how nany thernal cycles have been applied to the nozzles at Crystal River-3? At Oconee? At Rancho Seco?
In each case how nany of these cycles have occurred after the initiation of the pro-cedures required ty the Connission's May 1979 Order?
Response
a.
Crystal River-3 Based on data obtained fron the licensee and B&W, the following estinate of thernal cycles has been nade:
As of January 10, 1982, 59 cycles have occurred due to reactor tr,ps and HPI actuations.
Further information is being sought on the nunber of these cycles that occurred after the Comission's May 1979 Order.
Mark L. Padovan.
b.
Oconee The following tabulation indicates the thermal cycling caused tf injecting BWST water into the HPI and makeup lines.
Total No. of Cycles Af ter May 1979 Unit i 16 0
Unit 2 11 1
Unit 3 10 2
c.
Rancho Seco The number of cycles on each no: le is as follows:
,or:le Thernal Cycles Since May 1979 A
18 7
B 33 3
C 30 4
0 30 4
We will be providing additior.al infornation on how the above number of thernal cycles were deterrined.
Qu_es ti or. 4 In view of the alleged errors in the SMUD analyses and the recent events at Oconee and Crystal River-3, does the staff still believe that the Rancho Seco facility can be safely operated "over the near term" up to the design basis linit of 40 HPl cycles? Why?
Response
As previously discussed, the staff expects the Rancho Seco facility to be shutdown by April 2,1982 to perforn non-destructive exaninations of all l
Mark L. Padovan.
HPI and makeup nozzles.
If cracking is found, the nozzle (s) experiencing the cracking will be replaced prior to the plant starting up.
Regarding the time margins available on Rancho Seco considering only the HPI thermal cycles, the testimony previously provided to the Board on January 6,1982 is unchanged.
\\h e
\\ b.\\ th r-s Mark L. Padovan
Enclosures:
1.
Ficure 1 2.
3/30/82 Mtg. Summary of 3/16/B2 Mtg.
w/ B &') licensees & representatives on HPI nor:le cracking Subs cribed and sworn to before me this J,0' day of l' arch 1982.
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, Notary Public t.dg.d<f/4 ConnissionExpirest[l$I)l9e#
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