ML20049J392
| ML20049J392 | |
| Person / Time | |
|---|---|
| Issue date: | 06/30/1981 |
| From: | NRC |
| To: | |
| Shared Package | |
| ML20049J390 | List: |
| References | |
| TASK-MS-901-4, TASK-RE REGGD-, REGGD-01.XXX, NUDOCS 8203180057 | |
| Download: ML20049J392 (5) | |
Text
1 DRAFT VALUE/ IMPACT STATEMENT 2
FOR DRAFT REGULATORY GUIDE SC 901-4 3
IDENTIFICATION OF VALVES FOR INCLUSION 4
IN INSERVICE TESTING PROGRAMS 5
1.
PROPOSED ACTION 6
1.1 Description 7
This preliminary value/ impact statement contains an evaluation of the 8
basis for the proposed positions in the regulatory guide with estimates of 9
areas where value or impact may result from adherence to the positions of the 10 guide.
Since the public, including industry, has more detailed knowledge and 11 judgment of the potential costs and benefits of the proposed actions, comments 12 containing quantitative estimates of such costs and benefits are especially 13 invited to aid in comparing the technical alternatives both as to approach and 14 detailed requirements.
4 15 1.2 Summary of the Proposed Action 16 It is proposed to develop and provide guidance to licensees and their 17 agents in the following areas:
i 18 1.
Requirements for inservice testing of valves which are important to l
19 safety.
l 20 2.
Information needed by the staff to evaluate requests for relief from 21 section XI requirements.
22 3.
Conditions under which testing of valves should not be performed.
1 8203180057 810707 PDR REGGD PDR
1 1.3 Need for the Proposed Action 2
Uniform criteria to identify valves that are important to safety for 3
inclusion in an inservice testing program is not generally available to licens-4 ees. Many of the licensees in preparing their inservice testing programs in 5
compliance with the provisions of 10 CFR S 50.55a have been using ASME Sec-6 tion XI, which requires testing of certain ASME Section III code class 1, 2, 7
and 3 valves, as a guide.
However, some plants that have been issued operating 8
licenses have valves not constructed to ASME Section III requirements, and some 9
code class valves in plants built in more recent times may not be required to 10 perform a safety function. The end result has been a wide spectrum of program 11 submittals with the number of valves to be tested ranging from less than a 12 dozen to several thousand.
The need for inservice testing of valves and for 13 this regulatory guide was recognized early and has been clearly demonstrated 14 by the Three Mile Island incident and other valve malfunctions in operating 15 plants.
16 Frequently, licensees have not submitted sufficient information when 17 requesting relief from code requirements for the staff to fully evaluate the 18 impact of such relief on plant safety.
19 1.4 Value/ Impact of Proposed Action 20 1.4.1 NRC 21 The guide will provide a uniform standard for evaluating licensees' valve 22 testing programs as well as requests for relief from code requirements.
It 23 will accelerate the review process by reducing or eliminating the waiting period 24 caused by the need to request additional information from applicants and it 25 will help ensure the capability of the nuclear plant to shut down and remain 26 in the shutdown condition following a postulated accident.
27 1.4.2 Other Government Agencies 28 There should be no effect on other government agencies unless the agency 29 is an applicant such as TVA.
2
1 1.4.3 Applicant and Licensees 2
The initial impact on industry as a result of this regulatory guide will 3
be varied.
Newer plants will benefit from this guide as a result of a reduc-4 tion in the number of valves to be tested and the uniformity and accelerated 5
reviews of testing programs. Older plants with valves that have not been con-6 structed to the requirements of ASME Section III may experience some cost 7
impact due to additional staffing requirements to administer the programs and 8
may require some minor modifications in the hardware to perform the tests.
9 While this guide does not add new requirements, some licensees may include 10 additional valves in their test programs in response to this guidance with 11 some additional cost.
On the other hand, substantial cost savings should be 12 realized by providing early detection systems to identify incipient valve 13 failures that, if left uncorrected, could lead to other more costly failures 14 and subsequent repairs.
Early detection and repair could also reduce radiation 15 exposure to personnel, in the long term, by detecting leaks that, if uncorrected, 16 could result in substantial radiation release.
17 1.4.4 Workers 18 In most cases, there should be less exposure of plant personnel to irradia-19 tion from testing and maintaining valves in the 1cag term. There may be some 20 additional short-term exposure if generic problems are encountered in testing 21 of existing valves.
22 1.4.5 Public 23 A reduced potential for the failure of a system to perform its safety func-t l
24 tion because of valve failure should enhance overall plant safety as well as l
25 decrease the potential for exposure of the public to radiation due to inoper-26 able or leaky valves.
27 1.5 Decision on Proposed Action 28 Guidance is needed to identify valves that are essential to the safety of l
29 the plant or that must remain operable when called upon to shut down the plant 30 in the event of a loss of coolant accident.
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3
1 2.
PROCEDURAL APPROACH 2
2.1 Alternatives 3
Methods that have been considered for making the required guidance public 4
include NRC regulations, national standards endorsed by a regulatory guide, NUREG-5 series report, and a regulatory guide.
6 2.2 Value/ Impact of Alternatives 7
At the time of initiation of'this task, it was decided that the development 8
of a regulatory guide would be the most viable alternative.
9 3.
STATUTORY CONSIDERATION 10 3.1 NRC Authority 11 This guide would fall under the authority of the safety requirements of 12 the Atomic Energy Act through the Commissions regulations, in particular para-13 graph 20.1 of 10 CFR Part 20.
14 3.2 Need for NEPA Assessment 15 This action is not a major action as defined by 10 CFR 51.5(a)(10) and 16 does not require an environmental impact statement.
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17 4.
RELATIONSHIP TO OTHER EXISTING OR PROPOSED REGULATIONS, CODES, OR 18 NATIONAL STANDARDS 19 This guide helps fulfill a long-standing commitment to the ASME code writ-20 ing groups of Section XI to provide guidance on the selection of valves that, l
21 in the staff's view, are important to safety and should be included in a compre-22 hensive testing program. The guide generally agrees with the code and addresses l
23 only the areas that the staff feels are essential to plant safety and are in l
24 the jurisdiction of the Commission.
l 4
.o a.
1 5.
SUMMARY
AND CONCLUSIONS 2
A regulatory guide has been prepared.
3 6.
IMPLEMENTATION 4
The recommendations of this guide should be applied to all plants as this 5
is the practice that has been used in updating IST Programs.
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