ML20056A592
| ML20056A592 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 08/07/1990 |
| From: | Lainas G Office of Nuclear Reactor Regulation |
| To: | VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| Shared Package | |
| ML20056A593 | List: |
| References | |
| NUDOCS 9008080286 | |
| Download: ML20056A592 (5) | |
Text
.
t.
H 7590-01 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION t
i In the Matter of
)
VIRGINIA ELECTRIC AND POWER COMPANY Docket No. 50-280 (Surry Power Station.
Unit 1)
EXEMPTION I.
The Virginia Electric and Power Company (VEPCO, the licensee) is the holder of Operating License No. DPR-32, which authorizes operation of Surry Power Station Unit 1.
The operating license provides, among other things, that the Surry Power Station, Unit 1 is subject to all rules, regulations, and orders of the Commission now or hereafter in effect.
The facility consists of a pressurized water reactor at the licensee's e
site in Surry County, Virginia.
II.
The Code of Federal Regulations,10 CFR 50.54(o), specifies that primary reactor containments for water-cooled power reactors shall comply with Appendix J,
" Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors."
Section III.A.6(b) of Appendix J of 10 CFR Part 50 states the following:
If two consecutive periodic Type A tests fail to meet the applicable acceptance criteria in III.A.5(b), notwithstanding-the periodic retest schedule of III.D., a Type A test shall be performed at each plant shutdown for refueling or approximately every 18 months, whichever occurs first, until two consecutive Type A tests meet the acceptance criteria in III.A.5(b),
af ter which time the retest schedule specified in III.D. may be resumed, fjf0$$$bk b
$0 P
1
8 In 1983 and 1986, the licensee conducted Type A tests at Surry Unit 1.
1 These tests were considered to be failures due to leakage penalty additions from Type C (local leakage rate testing of containment isolation valves) testing.
In each case the leakage was associated with penetrations / valves in systems j
i that are normally filled with water under post-accident conditions and/or the containment sump isolation valves. The licensee indicated that the containment sump isolation valves have been replaced and they are no longer a continuing source of containment leakage, and that the last two Type A tests have demon-strated that contain:=nt integrity has not significantly degraded over the operating cycle. By letter dated April 5, 1990, the licensee requested a one-timeexemptionfromtheschedularrequirementsofparagraphIII.A.6(b)so that the normal retest schedule can be resumed in accordance with Section III.D.
III.
Surry Unit I failed the "as found" Type A tests that were conducted in 1983 and 1986, due to leakage rate additions from Type C testing.
In each case the' leakage was associated with either the normal containn.ent sump isolation valves (TV-DA-100 A&B), or with valves in systems that are normally filled with water and operating under post-accident conditions.
If these leakage additions had not been necessary, the plant would not have required an accelerated test scheduledelineatedinSectionIII.A.6(b).
In order to avoid addition of a leakage penalty and an accelerated test schedule, the licensee elected to demonstrate to the staff's satisfaction that:
1.
the corrective actions taken for the normal containment sump isolation valves for Unit I have eliminated the chronic leakage problem, and
. 2.
for Surry Units 1 and 2, the design of the water-filled penetra-tions is such that it precludes leakage of containment atmosphere through the penetrations during an accident, thus making it unnecessary to add the associated Type C leakage rates to Type A leakage rates.
The licensee addressed the normal containment sump isolation valves in its letter dated April 5, 1990. The issue of water-filled penetrations was addressed in submittals dated February 29, 1988, and August 15, 1988, pertaining to an exemption for Surry Unit 2.
Section 6.2.2.2 of the Surry Updated Final Safety Analysis Report also contains pertinent information. The staff reviewed these submittals and concluded that the subject water-filled containment penetrations H
are sealed with water to the extent that they need not be vented or drained during Type A tests, and the associated Type C leakage rates need not be added to Type A leakage rate.
The staff further concluded that the original leakage path of concern that caused the recent Type A "as found" failures (the normal containment sump isolation valves) has been corrected since these valves no longer exhibit excessive leakage. The staff's detailed evaluation of the containment sump isolation valves for Unit 1 is contained in a Safety Evaluation dated August 7, 1990 The staff's detailed evaluation of the water-filled penetration issue is provided in a Safety Evaluation dated November 21, 1988.
Therefore, on the basis of the licensee's corrective actions to reduce the "as found" containment leakage, the staff concludes that a return to the normal Type A test schedule of Section III.D. of Appendix J to 10 CFR Part 50 is justified.
By letter dated April 5,1990, the licensee also submitted information to identify the special circumstances for granting this exemption for Surry Unit 1 puret tr.l. to 10 CFR 50.12. The licensee stated that the purpose of Type A n
4 testing is to measurs and ensure that the leakage through the primary reactor containment does not exceed the maximum allowable leakage.
It also provides assurance that periodic surveillance, maintenance and repairs are made to systems or components penetrating the containment.
The licensee has replaced the valves which were a continuing source of containment leakage.
The licensee also stated that it has met the intent of the regulations in estab-lishing containment integrity, and maintaining that integrity over the operating cycle. Therefore, the licensee believes that this exemption should be granted pursuant to 10 CFR 50.12(a)(2)(ii) and (v), in that application of the regulation in this particular instance is not necessary to actieve the underlying purpose of the rule,,which is to measure and ensure that leakage through the primary containment does not exceed the allowable leakage rate at any time during the operating cycle, and, that the exemption would provide only temporary relief from the applicable requirement and the licensee has made a good faith effort to comply with the regulation. This one-time exemption will enable Surry Unit 1 to resbie the retest schedule specified in Section III.D. of 10 CFR Part 50, r
Appendix J and therefore, prevent unnecessary pressurization of the containment to design basis pressure. The staff agrees that the source of leakage which r
caused the prior failures has been corrected and an additional Type A test at this time is not required to achieve the underlying purpose of the rule.
IV.
Accordingly, the Commission has determined that, pursuant to 10 CFR 50.12(a)(1), this exemption is authorized by law, will not present an undue risk to the public health and safety, and is consistent with the common defense and security. The Commission has further determined that. special circumstances, I
y
i f
i
{
as set forth in 10 CFR 50.12(a)(2)(ii) and (v) are present, justifying the exemption; namely that application of the regulation in this particular circum-stance is not necessary to achieve the underlying purpose of the rule and the exemption is for a one-time relief only. Accordingly, th? Commission hereby l
grants an exemption to Section III.A.6(b) of Appendir ; to 10 CFR Part 50'to E
allow the licensee to resume the Type A retest schedule of Section III.D. of Appendix J for Surry Unit 1.
This exemption does not apply if the next test is f
demed i. A.:ure by the NRC acceptance criteria. Such a failure would constitute two consecutive failures 4 4 Section III.A.6(b) would again apply.
E Pursuant to 10 CFR 51.32, the staff has determined that the granting of l
this exemption will.not have a significant effect on the quality of the human environment (55 FR 31911 August 6, 1990
).
A copy of the licensee's request for exemption dated April 5,1990 is available for public inspection at the Commission's Public Document Room, 2120 L Street, N,W., Washington, D.C., and at the Swem Library, College of William and Mary, Williamsburg, Virginia 23185.
q This exemption is effective upon issuance.
FOR THE NUCLEAR REGULATORY COMMISSION V,.
(),w w
Gus C. Lainas, Acting Director Division of Reactor Projects-I/II Office of Nuclear Reactor Regulation Dated at Rockville, Maryland t
this 7th day of Aug.1990.
!